Co-reporter:Baojun Liu;Qidong Zhao;Yang Hou;Guohua Chen
Journal of Materials Chemistry A 2017 vol. 5(Issue 19) pp:8909-8915
Publication Date(Web):2017/05/16
DOI:10.1039/C7TA02048A
In this work, double-shelled ZnFe2O4 hollow microspheres were fabricated by a facile self-templated solvothermal method and the interiors could be precisely modulated by varying the reaction rate during the calcination process. More importantly, the formation mechanism of hollow structures with complex interior architectures could be illustrated based on the interface layer effect of the adhesion and contraction forces. When evaluated as catalytic materials for degradation of gaseous o-dichlorobenzene, the as-synthesized double-shelled ZnFe2O4 hollow structures showed significantly enhanced photocatalytic performance because of higher surface area (126.7 m2 g−1) and more effective light absorption (multiple scattering for double-shelled architectures).
Co-reporter:Fei Zhang, Xinyong Li, Qidong Zhao, and Dongke Zhang
ACS Sustainable Chemistry & Engineering 2016 Volume 4(Issue 9) pp:4554
Publication Date(Web):July 27, 2016
DOI:10.1021/acssuschemeng.6b00601
Novel ZnFe2O4/In2O3 hybrid nanoheterostructures with enhanced visible-light catalytic performance were fabricated by assembling ZnFe2O4 nanoparticles on the surface of monodispersed In2O3 nanospheres, and their photocatalytic performances were evaluated via the degradation of gaseous 1,2-dichlorobenzene (o-DCB). The catalytic activity of the resulting heterostructures for degradation of o-DCB was higher than that of either pure In2O3 or ZnFe2O4. The enhanced activity was mainly ascribed to the enhanced visible-light harvesting ability, efficient spatial separation, and prolonged lifetimes of photogenerated charges. Meanwhile, the main reaction intermediates including o-benzoquinone type species, phenolate species, formates, acetates, and maleates were verified with in situ FTIR spectroscopy. Additionally, a tentative catalytic reaction mechanism and the generation pathway of •OH over the ZnFe2O4/In2O3 nanoheterostructures were postulated. The present work provides some significative information for the eradication of harmful chlorinated volatile organic compounds and is expected to benefit the development of In2O3-based hybrid heterostructures.Keywords: 1,2-Dichlorobenzene; In situ FTIR; Nanoheterostructures; Photocatalysis; ZnFe2O4/In2O3
Co-reporter:Pancras Ndokoye, Qidong Zhao, Xinyong Li, Tingting Li, Moses O. Tade, Shaobin Wang
Journal of Colloid and Interface Science 2016 Volume 477() pp:1-7
Publication Date(Web):1 September 2016
DOI:10.1016/j.jcis.2015.11.032
In this study, we demonstrate for the first time that highly branched gold nanostars (AuNSs) and silica-coated AuNSs (AuNSs@mSiO2) could potentially serve as efficient hydrogenation catalysts. The catalytic activity could be promoted by raising the number of tipped-branches of AuNSs, which reveals that the tips play an important role as active sites. The fabricated sharply-pointed AuNSs benefit the electron transfer from BH4 anions to 4-nitrophenol. Coating AuNSs with mesoporous silica (AuNSs@mSiO2) further enhanced the reduction rate and recyclability, and also contributed to reducing the induction period. The AuNSs@mSiO2 (50–100 nm in diameter) are large enough to be catalytically inactive, but they consist of sharply-pointed tips with the radius of 2.6–3.6 nm, which are rich in coordinately unsaturated sites similar to those of nanoparticles and clusters. Such features in structure and activity would also extend their application range in heterogeneous catalysis.
Co-reporter:Pancras Ndokoye, Xinyong Li, Qidong Zhao, Tingting Li, Moses O. Tade, Shaomin Liu
Journal of Colloid and Interface Science 2016 Volume 462() pp:341-350
Publication Date(Web):15 January 2016
DOI:10.1016/j.jcis.2015.10.007
Fabrication of Au nanostars (AuNSs) can expand the application range of Au nanoparticles because of their high electron density and localized surface plasmon resonance (LSPR) on branches. Exploiting this potential requires further refinement of length of the branches and radius of their tips. To this end, we successfully synthesized AuNSs with uniform and sharply-pointed branches by combining benzyldimethylammonium chloride (BDAC) and cetyltrimethylammonium bromide (CTAB) at low BDAC/CTAB ratios. Once mixed with CTAB, BDAC lowers the critical micelle concentration (CMC) for quick formation of the micelles, which provides favorable growth templates for AuNSs formation. Besides, BDAC increases the concentration of Cl−, which favors Ag+ in adsorbing on Au facets. This feature is crucial for the yield boosting and synergic shape control of AuNSs regardless of types of Au seeds used. Use of less amounts of seeds as the center of nucleation benefited sharper and longer growth of the branches. AuNSs exhibited excellent enhancement of surface-enhanced Raman scattering (SERS) intensities as the result of high electron density localized at the tips; however, the enhancement degree varied in accordance with the size of branches. In addition, AuNSs showed high catalytic performance toward the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Efficient catalysis over AuNSs originates from their corners, stepped surfaces and high electron density at the tips.
Co-reporter:Xuejun Zou, Chunqiu Ran, Yuying Dong, Zhaobo Chen, Dapeng Dong, Dongxue Hu, Xinyong Li and Yubo Cui
RSC Advances 2016 vol. 6(Issue 25) pp:20664-20670
Publication Date(Web):06 Mar 2015
DOI:10.1039/C5RA01607J
In order to enhance the photocatalytic activity of g-C3N4 in the visible light region, BiPO4/g-C3N4 nanocomposites photocatalysts with different BiPO4 contents were prepared through a hydrothermal method including calcination. Through N2 adsorption–desorption measurements, BiPO4/g-C3N4 showed a large surface area (172.9 m2 g−1) and small pore diameter and the incorporation of BiPO4 caused a red-shift of g-C3N4 in the visible light region by UV-vis diffuse reflection spectroscopy. The photocatalytic degradation of benzene over BiPO4/g-C3N4 was investigated. Degradation of benzene could be achieved up to 73% in 2 wt% BiPO4/g-C3N4 photocatalysts under optimum reaction conditions, which was 6 times more when compared with pure g-C3N4 at the same conditions. The improved photoactivity of BiPO4/g-C3N4 could be ascribed to its effective separation of photogenerated hole–electron pairs between BiPO4 and g-C3N4. Furthermore, the BiPO4/g-C3N4 photocatalysts showed excellent stability. By using an in situ FTIR technique, ethyl acetate, carboxylic acid and aldehyde could be regarded as the intermediate products, and CO2 and H2O were produced as the final products. Through electron spin resonance (ESR), OH˙ and O2˙− were examined in the photocatalytic degradation of benzene.
Co-reporter:Fei Zhang, Xinyong Li, Qidong Zhao, and Aicheng Chen
The Journal of Physical Chemistry C 2016 Volume 120(Issue 34) pp:19113-19123
Publication Date(Web):August 2, 2016
DOI:10.1021/acs.jpcc.6b03618
Novel 3D In2S3/In2O3 heterostructures comprised of 3D In2O3 microflowers and In2S3 nanoflakes were synthesized via a facile hydrothermal process followed by an in situ anion exchange reaction. In the In2S3/In2O3 heterostructures, the In2S3 nanoflakes were in situ generated and uniformly assembled on In2O3 microflowers. The microstructures, optical properties, oxygen vacancy concentration, and photoreactivity of the heterostructures could be tuned by adjusting the amount of sulfide source. The effect of In2S3-nanoflakes modification on the oxygen vacancy concentration, optical properties, charge carrier separation, and charge carrier lifetime of In2O3 were investigated systematically. The catalytic activity of the proposed heterostructures for degradation of gaseous ortho-dichlorobenzene (o-DCB, a representative chlorinated volatile organic compounds) was higher than that of either unmodified In2O3 or TiO2 (P25). Meanwhile, oxygen vacancies, systematically explored by Raman, X-ray photoelectron spectroscopy (XPS), and low-temperature electron spin resonance (ESR) spectroscopy, were demonstrated to have a two-side effect on the photocatalytic performance. Particularly, the main reaction products including o-benzoquinone type species, phenolate species, formates, acetates, and maleates were verified with in situ FTIR spectroscopy. Additionally, ESR examination confirmed that •OH and •O2– were the predominant reactive oxygen species involved in the degradation of gaseous o-DCB. The current research provides new insight into utilizing In-based heterostructures as promising and efficient visible-spectrum-responsive catalysts for the removal of harmful chlorinated volatile organic compounds.
Co-reporter:Baojun Liu, Xinyong Li, Qidong Zhao, Jie Liu, Shaomin Liu, Shaobin Wang and Moses Tadé
Journal of Materials Chemistry A 2015 vol. 3(Issue 29) pp:15163-15170
Publication Date(Web):10 Jun 2015
DOI:10.1039/C5TA02295A
This work aims to explore the mechanism of photocatalytic degradation of gaseous 1,2-dichlorobenzene (o-DCB) over vanadium pentoxide (V2O5) hollow spheres. To this end, flower-type V2O5 hollow microspheres with diameters of about 700–800 nm were obtained with the assistance of carbon-sphere templates, and then tested in the photodegradation of o-DCB under visible light (λ > 400 nm). Due to its strong adsorption capacity and large specific surface area, the V2O5 hollow structure showed high photocatalytic activity in the degradation of gaseous o-DCB under visible light. Furthermore, the o-DCB degradation mechanism was investigated by using in situ Fourier transform infrared (FTIR) spectroscopy, and the intermediates, such as o-benzoquinone-type and organic acid species, and final products (CO2 and H2O) were also confirmed. Then, the reaction pathways over V2O5 were proposed. The outstanding performance indicated that the photocatalysts could be applied to air purification for Chlorinated Volatile Organic Compound (Cl–VOC) removal.
Co-reporter:Jingqiang Pan, Xinyong Li, Qidong Zhao, Tingting Li, Moses Tade and Shaomin Liu
Journal of Materials Chemistry A 2015 vol. 3(Issue 23) pp:6025-6034
Publication Date(Web):08 May 2015
DOI:10.1039/C5TC01008J
An ultrasound-assisted impregnation deposition technique was adopted to construct Mn0.5Zn0.5Fe2O4 nanoparticles on TiO2 nanotube arrays (NTAs) which were prepared by electrochemical anodization in a hydrofluoric acid system. The Mn0.5Zn0.5Fe2O4 nanoparticles were found to successfully deposit on the surface of the highly oriented TiO2 NTAs causing no damage to the ordered structure of the nanotubes. The as-prepared Mn0.5Zn0.5Fe2O4/TiO2 NTAs exhibited much improved photoelectrochemical capability. Compared with pure TiO2 NTAs, a more than 2.36-fold enhancement in photo-current density and a 2.17-fold enhancement in photo-conversion efficiency of the Mn0.5Zn0.5Fe2O4/TiO2 NTAs were achieved. The photoelectrocatalytic (PEC) activities of Mn0.5Zn0.5Fe2O4/TiO2 NTAs were evaluated by the degradation of toxic 2,4-dichlorophenol (2,4-DCP) in aqueous solution under simulated sun light irradiation. The experimental results indicated that the heterostructure photoelectrode showed much higher PEC activity than the pure TiO2 NTAs for the degradation of 2.4-DCP under simulated sun light irradiation. In addition, electron spin resonance examination confirmed that the photogenerated active species (˙OH and ˙O2−) were involved in the PEC degradation of 2,4-DCP. A mechanism accounting for the enhanced PEC activity of the Mn0.5Zn0.5Fe2O4/TiO2 NTAs was proposed. The enhanced PEC activity of the nanocomposite electrode could be attributed to the synergistic effects between the lowered electron–hole recombination rate by the applied bias and the wider spectral response promoted by the Mn0.5Zn0.5Fe2O4 component.
Co-reporter:Juanjuan Sun, Xinyong Li, Qidong Zhao, Moses O. Tadé and Shaomin Liu
Journal of Materials Chemistry A 2015 vol. 3(Issue 43) pp:21655-21663
Publication Date(Web):09 Sep 2015
DOI:10.1039/C5TA05659D
In an effort to develop visible-light-driven heterostructured photocatalysts with high activity, a novel quantum-sized tubelike BiVO4 sensitized TiO2 microflower catalytic system was successfully fabricated by using a facile hydrothermal and ultrasonic adhering approach. The structural and optical properties of the as-prepared samples were comparatively characterized. The staggered band structure of quantum-sized BiVO4 decorated TiO2 not only extended the photo-response range but also promoted photoexcited charges transfer and separation. Photocatalytic activities of the as-prepared samples were examined by the degradation of toluene under visible light irradiation (λ > 400 nm). Compared to the individual TiO2 microflower, BiVO4 quantum tube, BiVO4 nanoparticle and nano-BiVO4/TiO2, the quantum-BiVO4/TiO2 (Q-BiVO4/TiO2) composite exhibited higher photo activities. Electron spin resonance (ESR) examinations confirmed the generation of the photo-induced reactive oxygen species (˙OH and ˙O2−) which were involved in the photocatalytic process of Q-BiVO4/TiO2 composites. Furthermore, the enhanced photocatalytic activity of the Q-BiVO4/TiO2 composite mainly originated from the high separation efficiency of photo-induced electron–hole pairs and the efficient production of hydroxyl radicals. A detailed mechanism accounting for the superior photocatalytic activity was proposed in terms of the energy band structures of the components.
Co-reporter:Baojun Liu, Xinyong Li, Qidong Zhao, Jun Ke, Jie Liu, Shaomin Liu, Moses Tadé
Journal of Colloid and Interface Science 2015 Volume 438() pp:1-6
Publication Date(Web):15 January 2015
DOI:10.1016/j.jcis.2014.09.061
•The multiphase TixZr1−xO2 containing cubic ZrO2 has been fabricated.•The samples were used as catalysts for degradation of toluene under visible light.•The toluene conversion over Ti0.3Zr0.7O2 is ca. 15 times higher than that over P25.•Some intermediates and CO2 were verified by the in situ FTIR spectra.In the present work, the multiphase TixZr1−xO2 particles containing cubic-phase ZrO2 were fabricated via co-precipitation route. The mole ratios of Ti and Zr elements were controlled by three levels: Ti/Zr = 7/3 (maximum), Ti/Zr = 5/5 (medium), and Ti/Zr = 3/7 (minimum). The materials prepared were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), energy-dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectra (DRS) and photoluminescence (PL) spectra. For the maximum usage of solar power with fabricated catalysts, elimination of gaseous toluene was chosen as a model to evaluate the performances under visible light. The results indicated that the degradation efficiency of toluene was about 80% after 6 h reaction using Ti0.3Zr0.7O2 as the photocatalyst. On the other hand, the multiphase TixZr1−xO2 (x = 0.7 or 0.5) photocatalysts showed significant enhancement in the activity, compared with the commercial TiO2 (Degussa P25). The enhanced performances of TixZr1−xO2 might be attributed to the lower charge recombination rate of photoinduced electron–hole pairs. In addition, some intermediates (the benzaldehyde and benzoic acid) and final product (CO2) adsorbed on the surface of the particles were also detected by using in situ Fourier transform infrared (FTIR) spectroscopy.
Co-reporter:Fei Zhang, Xinyong Li, Qidong Zhao, Qianzhe Zhang, Moses Tadé, Shaomin Liu
Journal of Colloid and Interface Science 2015 Volume 457() pp:18-26
Publication Date(Web):1 November 2015
DOI:10.1016/j.jcis.2015.06.008
The α-Fe2O3/In2O3 composite hollow microspheres were first synthesized through a well-designed two-step hydrothermal approach with an aim to promote the photocatalytic activity of the pure In2O3. The morphologies, phase structures, and optical properties of the resultant samples were systematically characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, UV–vis diffuse-reflectance, and photoluminescence spectroscopy. The α-Fe2O3 nanoparticles acted as visible-light sensitizer, which were well-decorated on the surface of the In2O3 hollow microspheres. Meanwhile, the investigation of photocatalytic performance confirmed that the visible-light induced photocatalytic degradation rate of gaseous toluene was improved after the introduction of α-Fe2O3 component, which was about 1.6 times higher than that of pure In2O3 sample under identical conditions. Furthermore, some intermediates formed during the photocatalytic oxidation process were also indentified by in␣situ FTIR spectroscopy. The enhanced photocatalytic performance of the α-Fe2O3/In2O3 composites mainly stemmed from the strong visible-light-harvesting ability and the efficient spatial separation of photo-generated electron–hole pairs.
Co-reporter:Qianzhe Zhang, Xinyong Li, Qidong Zhao, Yong Shi, Fei Zhang, Baojun Liu, Jun Ke, Lianzhou Wang
Applied Surface Science 2015 Volume 337() pp:27-32
Publication Date(Web):15 May 2015
DOI:10.1016/j.apsusc.2015.02.059
Highlights
- •
The bcc-In2O3 hollow microspheres were synthesized as photocatalyst.
- •
Structural and photocatalytic properties of samples are tested.
- •
Degradation of gaseous toluene over the bcc-In2O3 hollow microspheres.
Co-reporter:Zhiguang Zhang, Xinyong Li, Qidong Zhao, Jun Ke, Yong Shi, Pancras Ndokoye, Lianzhou Wang
Journal of Colloid and Interface Science 2014 Volume 432() pp:229-235
Publication Date(Web):15 October 2014
DOI:10.1016/j.jcis.2014.07.005
•Hexagonal microprisms of Cu–ZnTPyP coordination polymer were synthesized.•The effect of CTAB concentration on the microstructure of Cu–ZnTPyP was investigated.•The growth mechanism of the Cu–ZnTPyP coordination polymers was proposed.•The hexagonal micro-prisms of Cu–ZnTPyP coordination polymer displayed enhanced photo response.Cu–ZnTPyP coordination polymer with hexagonal micro-lump and micro-prism morphologies has been successfully synthesized through a facile surfactant assisted self-assembly method based on Cu(OAc)2⋅2H2O and Zinc-5,10,15,20-tetra(4-pyridyl) porphyrin (ZnTPyP) in DMF/H2O solvent. The morphologies of three-dimensional micro-prisms and micro-lumps obtained at different concentrations of cetyltrimethylammonium bromide (CTAB) were investigated by scanning electronic microscopy. The compositions of the micro-prisms were studied by energy-dispersive spectra and inductively coupled plasma-atomic emission. X-ray diffraction analysis revealed a circular hexametric cage structure cross-linked by the main Zn–N axial coordination of the pyridyl ligands inside the micro-scale coordination polymers. The UV–Vis diffuse reflection spectroscopy revealed the formation of J-type aggregates in the both microstructures. The formation mechanism of Cu–ZnTPyP coordination polymer structure was investigated by varying CTAB concentration. Their surface photovoltage spectra indicated that the novel hexagonal micro-prism morphology of the coordination polymer displayed enhanced photo response under visible light, which is beneficial for exploiting the practical application of Cu–ZnTPyP compound.
Co-reporter:Tingting Li, Xinyong Li, Qidong Zhao, Wei Teng
Materials Research Bulletin 2014 59() pp: 227-233
Publication Date(Web):
DOI:10.1016/j.materresbull.2014.07.031
Co-reporter:Zhengru Zhu, Qidong Zhao, Xinyong Li, Hong Li, Moses Tade and Shaomin Liu
Catalysis Science & Technology 2013 vol. 3(Issue 3) pp:788-796
Publication Date(Web):12 Nov 2012
DOI:10.1039/C2CY20377D
Porous and rod-shaped nanostructures of ZnAl2O4 were successfully synthesized by a simple hydrothermal method. The Ag-doped ZnAl2O4 catalyst, based on porous ZnAl2O4, was prepared by the incipient wetness impregnation strategy and showed an excellent photoelectric property and catalytic activity. The structural properties of the samples were systematically investigated by X-ray powder diffraction (XRD), Brunauer–Emmet–Teller (BET), transmission electron microscopy (TEM), Electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) techniques. The photocatalytic degradation of toluene by the Ag-doped ZnAl2O4, ZnAl2O4 and P25 TiO2 samples was comparatively studied under UV lamp irradiation. The results indicate that the Ag-doped ZnAl2O4 sample synthesized at pH = 6 exhibited a higher capacity for the degradation of toluene. No obvious deactivation of the Ag-doped ZnAl2O4 nanorods was observed during the prolonged operation of 6 h. The Ag-doped ZnAl2O4 nanorods could be potentially applied in environmental purification in the near future.
Co-reporter:Jie Liu, Xinyong Li, Qidong Zhao, Dongke Zhang, Pancras Ndokoye
Journal of Molecular Catalysis A: Chemical 2013 Volume 378() pp:115-123
Publication Date(Web):1 November 2013
DOI:10.1016/j.molcata.2013.06.005
•Cu/Ti1−xCexO2 catalysts were found to be effective for C3H6-SCR.•Ce-doping enhanced Lewis acidity and the ratio of adsorbed oxygen and Ce3+.•Ce-doping enhanced the NO2 generation.•Ce-doping promoted the formation and reactivity of nitrates and –NCO species.A series of Cu-supported Ti–Ce mixed oxide catalysts (Cu/Ti1−xCexO2), with x = 0, 0.1, 0.2, 0.3, 0.5, 1.0, were evaluated for selective catalytic reduction (SCR) of NO with C3H6 under lean-burn conditions, and the promotional effect of ceria additive was investigated systematically. Among the tested catalysts, Cu/Ti0.9Ce0.1O2 exhibited excellent low-temperature activity, which achieved a maximum N2 yield of 50.3% and NOx conversion of 66.2% at 240 °C. The generation of Ti–O–Ce mixed bond raised the quantity of Lewis acid sites and therefore improved the distribution of the copper oxide species on the catalyst surface. The high SCR activity of the Cu/Ti0.9Ce0.1O2 was mainly attributed to the abundant Lewis acid sites and the high ratio of adsorbed oxygen on the catalyst surface, which provided more adsorption centers for NO and promoted the NO oxidation in the SCR reaction. Furthermore, the high concentration of Cu2+ was beneficial to NO adsorption. Combined with the in situ FT-IR results, it was suggested that the synergistic effect of ceria and copper promoted the formation and reactivity of nitrates, oxygenated hydrocarbons, and key intermediates isocyanate (–NCO species), and consequently, Cu/Ti0.9Ce0.1O2 catalyst exhibited the excellent SCR performance.
Co-reporter:Yang Hou, Xinyong Li, Qidong Zhao, Guohua Chen, and Colin L. Raston
Environmental Science & Technology 2012 Volume 46(Issue 7) pp:4042-4050
Publication Date(Web):March 4, 2012
DOI:10.1021/es204079d
A ternary Ag/AgBr/TiO2 nanotube array electrode with enhanced visible-light activity was synthesized by a two-step approach including electrochemical process of anodization and an in situ photoassisted deposition strategy. The dramatically enhanced photoelectrocatalytic activity of the composite electrode was evaluated via the inactivation of Escherichia coli under visible light irradiation (λ>420 nm), whose performance of complete sterilization was much superior to other reference photocatalysts. PL, ESR, and radicals trapping studies revealed hydroxyl radicals were involved as the main active oxygen species in the photoelectrocatalytic reaction. The process of the damage of the cell wall and the cell membrane was directly observed by ESEM, TEM, and FTIR, as well as further confirmed by determination of potassium ion leakage from the killed bacteria. The present results pointed to oxidative attack from the exterior to the interior of the Escherichia coli by OH•, O2•–, holes and Br0, causing the cell to die as the primary mechanism of photoelectrocatalytic inactivation.
Co-reporter:Xuejun Zou, Xinyong Li, Qidong Zhao, Shaomin Liu
Journal of Colloid and Interface Science 2012 Volume 383(Issue 1) pp:13-18
Publication Date(Web):1 October 2012
DOI:10.1016/j.jcis.2012.05.051
With the aim of improving the effective utilization of visible light, the LaVO4/TiO2 heterojunction nanotubes were fabricated by sol–gel coupled with hydrothermal method. The photocatalytic ability was demonstrated through catalytic removal of gaseous toluene species. The nanotube samples were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), surface photovoltage (SPV), Raman spectra and N2 adsorption–desorption measurements. The characterization results showed that the samples with high specific surface areas were of typical nanotubular morphology, which would lead to the high separation and transfer efficiency of photo induced electron–hole pairs. The as-prepared nanotubes exhibited high photocatalytic activity in decomposing toluene species under visible light irradiation with fine photochemical stability. The enhanced photocatalytic performance of LaVO4/TiO2 nanotubes might be attributed to the matching band potentials, the interconnected heterojunction of LaVO4 versus TiO2, and the large specific surface areas of nanotubes.Graphical abstractHighlights► LaVO4/TiO2 nanotubes were prepared by sol–gel coupled with hydrothermal method. ► Toluene removal efficiency was 75% in 6 h using the 1% LaVO4/TiO2 nanotubes. ► The LaVO4/TiO2 nanotubes showed favorable photochemical stability.
Co-reporter:Chunxia Liang, Xinyong Li, Zhenping Qu, Moses Tade, Shaomin Liu
Applied Surface Science 2012 Volume 258(Issue 8) pp:3738-3743
Publication Date(Web):1 February 2012
DOI:10.1016/j.apsusc.2011.12.017
Abstract
UV–vis spectra, XRD, H2-TPR, TEM and ESR were used to characterize a series of Cu/γ-Al2O3 catalysts, which were prepared by incipient wetness impregnation using copper nitrate, copper acetate or copper sulfate as precursors, to study the role of Cu species on Cu/γ-Al2O3 catalysts for NH3–SCO reaction. It was found that the mixture of CuO phase and CuAl2O4 phase formed on various Cu/γ-Al2O3 catalysts, and the Cu species and dispersion had significant influence on the Cu/γ-Al2O3 activity. Highly dispersed CuO phase on the support would be related with its high activity for the NH3–SCO reaction.
Co-reporter:Yu Shen, Qidong Zhao, Xinyong Li, Yang Hou, Guohua Chen
Colloids and Surfaces A: Physicochemical and Engineering Aspects 2012 Volume 403() pp:35-40
Publication Date(Web):5 June 2012
DOI:10.1016/j.colsurfa.2012.03.052
Magnesium ferrite/hematite heterostructured hollow nanospheres were successfully fabricated via a facile solvothermal method. The products were well characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, UV–vis absorption spectroscopy and surface photovoltage spectroscopy. From the absorption edge in the UV–vis absorption spectrum of MgFe2O4/α-Fe2O3 hollow nanospheres, an optical band-gap energy of about 1.986 eV was estimated. Furthermore, it was observed that the heterostructured hollow nanospheres presented a remarkable surface photovoltage response in UV and visible spectral region, which was attributed to the effective formation of chemical interface between the two crystalline phases of MgFe2O4 and α-Fe2O3.Graphical abstractHighlights► MgFe2O4/α-Fe2O3 hollow nanospheres were synthesized via a facile method. ► The formation of heterojunction between the two crystalline phases was revealed by HRTEM. ► The hollow nanospheres present remarkable surface photovoltage in UV–vis spectral region.
Co-reporter:Hong Li, Qidong Zhao, Xinyong Li, Yong Shi, Zhengru Zhu, Moses Tade, Shaomin Liu
Materials Research Bulletin 2012 47(6) pp: 1459-1466
Publication Date(Web):
DOI:10.1016/j.materresbull.2012.02.039
Co-reporter:Xuejun Zou, Xinyong Li, Zhenping Qu, Qidong Zhao, Yong Shi, Yongying Chen, Moses Tade, Shaomin Liu
Materials Research Bulletin 2012 47(2) pp: 279-284
Publication Date(Web):
DOI:10.1016/j.materresbull.2011.11.024
Co-reporter:Yang Hou, Xinyong Li, Qidong Zhao, Xie Quan and Guohua Chen
Journal of Materials Chemistry A 2011 vol. 21(Issue 44) pp:18067-18076
Publication Date(Web):13 Oct 2011
DOI:10.1039/C1JM12788H
A TiO2 nanotube/Ag–AgBr three-component nanojunction with enhanced visible-light activity was synthesized by a two-step approach including an electrochemical anodization technique followed by an in situ photo-assisted dipping and deposition approach. Ag/AgBr nanoparticles with good dispersion were effectively deposited on both the inside and outside of the TiO2 nanotubes. Surface photovoltage measurements and luminescence spectra demonstrated that the Ag/AgBr loading enhanced the visible spectral absorption of TiO2 nanotube arrays, as well as their separation efficiency of photoinduced electron–hole pairs, which may due to the nanojunction built between Ag/AgBr and TiO2 in this system. The photoelectrochemical investigations verified that the TiO2 nanotube/Ag–AgBr nanojunction showed enhanced photocurrent generation efficiency and had a more effective photoconversion efficiency of 0.71% than the aligned TiO2 nanotube arrays alone. The enhanced photoelectrochemical properties can be attributed to the extended absorption in the visible light region resulting from Ag/AgBr nanoparticles, and the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at the TiO2/Ag–AgBr nanojunction interface.
Co-reporter:Ling Zhao, Xinyong Li, Xie Quan, and Guohua Chen
Environmental Science & Technology 2011 Volume 45(Issue 12) pp:5373-5379
Publication Date(Web):May 24, 2011
DOI:10.1021/es200784e
The hydrotalcite-based NiAl mixed oxides were synthesized by coprecipitation and urea hydrolysis approaches and employed for SO2 removal. The samples were well characterized by inductively coupled plasma (ICP) elemental analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and N2 adsorption/desorption isotherm analyses. The acid–base properties were characterized by pyridine chemisorption and CO2 temperature-programmed desorption (TPD). The calcined NiAlO from the urea method showed excellent SO2 adsorption and its adsorption equilibrium showed a type I isotherm, which significantly improved the adsorption performance for low-concentration SO2. Both the physical structure and the acidic–basic sites were found to play important roles in the SO2 adsorption process. In situ Fourier transform infrared spectroscopy (FTIR) investigation revealed that adsorbed SO2 molecules formed surface bisulfite, sulfite, and bidentate binuclear sulfate. The mechanisms for SO2 adsorption and transformation are discussed in detail.
Co-reporter:Ling Zhao, Xinyong Li, Zhenping Qu, Qidong Zhao, Shaomin Liu, Xijun Hu
Separation and Purification Technology 2011 Volume 80(Issue 2) pp:345-350
Publication Date(Web):29 July 2011
DOI:10.1016/j.seppur.2011.04.035
A series of NiAl mixed oxides derived from hydrotalcite-like compounds were prepared by a urea hydrolysis method, and characterized by TGA, XRD, SEM, CO2-TPD, N2 adsorption/desorption and XPS techniques. The SO2 adsorption capacity of the materials correlated closely with their basicity and active oxygen species on the surface, as estimated by a volumetric method. The NiAl mixed oxide with the optimal Ni/Al molar ratio of 3 showed the best performance of SO2 adsorption. Moreover, its adsorption equilibrium of a type I isotherm and pore opening in the quasi-micropore region significantly improve the adsorption performance for low-concentration SO2.Graphical abstractHighlights► The use of urea method leads to smaller flower-like homogeneous aggregates. ► The more basic sites and lattice oxygen, the better adsorption performance of SO2. ► The small pore opening of 4.3 nm contributed to high adsorption of SO2 activity.
Co-reporter:Xinyong Li, Zhengru Zhu, Qidong Zhao, Shaomin Liu
Applied Surface Science 2011 Volume 257(Issue 10) pp:4709-4714
Publication Date(Web):1 March 2011
DOI:10.1016/j.apsusc.2010.12.133
Abstract
In this study, photocatalysts of TiO2 microballls were obtained via a hydrothermal treating of commercial P25 in alkaline solution, and then characterized with SEM, XRD, BET, DRS and surface photovoltage spectroscopy (SPS) techniques. The photovoltage response of the prepared TiO2 microballs on spectrum features a quantum size effect brought about by the reduced grain size with respect to the precursor. The UV-assisted photodegradation of gaseous toluene over P25 and the prepared TiO2 microballs was monitored by an in situ infrared technique. The results demonstrated that the prepared TiO2 microballs in anatase form were more active than commercial P25 in photocatalytic oxidation of gaseous toluene. The promoted activity of the hydrothermal-treated TiO2 is attributed to the increasing specific surface area and larger band gap induced by the reduced crystallite size.
Co-reporter:Wenshuang Zhang, Xinyong Li, Qidong Zhao, Yang Hou, Yu Shen, Guohua Chen
Materials Chemistry and Physics 2011 Volume 129(Issue 3) pp:683-687
Publication Date(Web):3 October 2011
DOI:10.1016/j.matchemphys.2011.05.036
Uniform α-Fe2O3 nanotubes with small aspect ratio were successfully fabricated by a hydrothermal method. In situ Fourier-transform infrared spectroscopy was used to study the mechanistic details of adsorption and photocatalytic oxidation of naphthalene over theα-Fe2O3 nanotubes. A possible degradation mechanism of naphthalene was proposed.Highlights► Uniform α-Fe2O3 nanotubes with small aspect ratio were hydrothermally fabricated. ► Photocatalytic oxidation of naphthalene over the α-Fe2O3 nanotubes could be realized. ► The naphthalene could be finally mineralized into carbon dioxide and water.
Co-reporter:Zhengru Zhu, Xinyong Li, Qidong Zhao, Shaomin Liu, Xijun Hu, Guohua Chen
Materials Letters 2011 Volume 65(Issue 2) pp:194-197
Publication Date(Web):31 January 2011
DOI:10.1016/j.matlet.2010.09.085
Porous and cubic-shaped superstructure of ZnAl2O4 was successfully synthesized by a facile wet chemical solution-phase method. The structural properties of the samples were systematically investigated by X-ray powder diffraction (XRD), Brunauer–Emmet–Teller (BET), scanning electron microscopy (SEM), energy-dispersive spectra (EDS), and Fourier transform infrared spectroscopy (FT-IR) techniques. The characterization results revealed that the structure of the cubic-shaped ZnAl2O4 was an inverse spinel structure. The sample prepared by a solution-phase chemical method has a higher surface area and monomodal pore size distributions. Furthermore, the valence states and the surface chemical compositions of ZnAl2O4 were further identified by X-ray photoelectron spectroscopy (XPS). This study provides a simple method to prepare cubic-shaped ZnAl2O4 in large scale, which broadens their practical applications.
Co-reporter:Yu Shen, Xinyong Li, Qidong Zhao, Yang Hou, Moses Tade, Shaomin Liu
Materials Research Bulletin 2011 46(12) pp: 2235-2239
Publication Date(Web):
DOI:10.1016/j.materresbull.2011.09.004
Co-reporter:Xinyong Li, Yang Hou, Qidong Zhao, and Guohua Chen
Langmuir 2011 Volume 27(Issue 6) pp:3113-3120
Publication Date(Web):February 18, 2011
DOI:10.1021/la2000975
TiO2 nanotube arrays sensitized with ZnFe2O4 nano-crystals were successfully fabricated by a two-step process of anodization and a vacuum-assistant impregnation method followed by annealing. The sample was studied by an environmental scanning electron microscope, a transmission electron microscope, energy-dispersive X-ray analysis, and X-ray diffraction to characterize its morphology and chemical composition. Ultraviolet−visible (UV−vis) absorption spectra and a photoelectrochemical measurement approved that the ZnFe2O4 sensitization enhanced the probability of photoinduced charge separation and extended the range of the photoresponse of TiO2 nanotube arrays from the UV to visible region. In addition, the behaviors of photoinduced charge transfer in a TiO2 nanotube array electrode before and after sensitization by ZnFe2O4 nanocrystals were comparatively studied. The photoluminescence of the TiO2 nanotube array electrode became suppressed, and the surface photovoltage responses on the spectrum were significantly enhanced after the introduction of ZnFe2O4 nanocrystals. The transfer dynamics of the photoinduced charges were observed directly by a transient photovoltage measurement, which revealed a fast charge separation at the interface between ZnFe2O4 nanocrystals and TiO2 nanotubes upon light excitation.
Co-reporter:Yang Hou;Xin-Yong Li;Qi-Dong Zhao;Xie Quan;Guo-Hua Chen
Advanced Functional Materials 2010 Volume 20( Issue 13) pp:2165-2174
Publication Date(Web):
DOI:10.1002/adfm.200902390
Abstract
An electrode with intimate and well-aligned ZnFe2O4/TiO2 composite nanotube arrays is prepared via electrochemical anodization of pure titanium foil in fluorine-containing ethylene glycol, followed by a novel cathodic electrodeposition method. The deposition of ZnFe2O4 is promoted in the self-aligned, vertically oriented TiO2 nanotube arrays but minimized at the tube entrances. Thus, pore clogging is prevented. Environmental scanning electron microscopy, energy-dispersive X-ray spectra, high-resolution transmission electron microscopy, X-ray diffraction patterns, and X-ray photoelectron spectroscopy indicate that the as-prepared samples are highly ordered and vertically aligned TiO2 nanotube arrays with ZnFe2O4 nanoparticles loading. The TiO2 nanotubes are anatase with the preferential orientation of <101> plane. Enhanced absorption in both UV and visible light regions is observed for the composite nanotube arrays. The current–voltage curve of ZnFe2O4-loaded TiO2 nanotube arrays reveals a rectifying behavior. The enhanced separation of photoinduced electrons and holes is demonstrated by surface photovoltage and photocurrent measurements. Meanwhile, the photoelectrochemical investigations verify that the ZnFe2O4/TiO2 composite nanotube array modified electrode has a more effective photoconversion capability than the aligned TiO2 nanotube arrays alone. In addition, the photoelectrocatalytic ability of the novel electrode is found enhanced in the degradation of 4-chlorophenol.
Co-reporter:Yang Hou, Xinyong Li, Qidong Zhao, Xie Quan and Guohua Chen
Environmental Science & Technology 2010 Volume 44(Issue 13) pp:5098-5103
Publication Date(Web):June 7, 2010
DOI:10.1021/es100004u
A well-aligned ZnFe2O4/TiO2 composite nanotube array (ZnFe2O4/TiO2−NTs) electrode with visible-light activity was successfully prepared using a two-step electrochemical process of anodization and a novel cathodic electrodeposition method followed by annealing. The ZnFe2O4 nanoparticles were highly dispersed inside the TiO2−NTs but minimized at the tube entrances. The structure and optical properties of the TiO2 nanotubes and the derived composites have been well characterized. The composites displayed a strong photo response in the visible region and low recombination rate of the electron−hole pairs. In addition, the synthesized ZnFe2O4/TiO2−NTs electrode showed much higher photocurrent density in the visible region than pure TiO2−NTs electrode. The dramatically enhanced electrochemically assisted photocatalytic activity of the composite electrode was evaluated in the decomposition of 4-chlorophenol and dichloroacetate under visible light irradiation (420 nm < λ < 600 nm). The improved photoelectrocatalytic (PEC) activity is derived from the synergetic effect between ZnFe2O4 and TiO2, which promoted the migration efficiency of photogenerated carriers at the interface of the composite and enhanced the efficiency of photon harvesting in the visible region. The degradation of 4-chlorophenol was monitored by measuring Cl− concentrations and analyzing reaction intermediates by high-performance liquid chromatography−mass spectroscopy (HPLC-MS).
Co-reporter:Wenshuang Zhang, Xinyong Li, Zhenping Qu, Qidong Zhao, Guohua Chen
Materials Letters 2010 Volume 64(Issue 1) pp:71-73
Publication Date(Web):15 January 2010
DOI:10.1016/j.matlet.2009.10.009
Urchin-shaped CaCO3 microspheres were successfully synthesized by a facile low-temperature solution-phase method. The product was characterized with X-ray diffraction (XRD), Raman spectra and high resolution transmission electron microscopy (HRTEM). The characterization results revealed that the structure of the urchin-shaped CaCO3 was grown along the (104) crystal plane with a calcite structure. Furthermore, the valence states and the surface chemical compositions of CaCO3 were further identified by X-ray photoelectron spectroscopy (XPS). This study provides a simple method to prepare urchin-shaped CaCO3 microspheres in large scale, which broads their practical applications.
Co-reporter:Jingwen Ran, Xinyong Li, Qidong Zhao, Zhenping Qu, Hong Li, Yong Shi, Guohua Chen
Inorganic Chemistry Communications 2010 Volume 13(Issue 4) pp:526-528
Publication Date(Web):April 2010
DOI:10.1016/j.inoche.2010.01.028
A mononuclear copper (II) complex with pyridine-carboxylate ligands, Cu(pc)2·2H2O (pcH = pyridine-2-carboxylic acid), and its initial ligand pyridine-2-amidoxine, have been prepared by a hydrothermal method. The structure of the complex has been characterized by X-ray crystallography. The complex was observed to be active in photo-catalyzing oxidation of Rhodamine B (RhB) and Methyl Orange (MO) in aqueous solution with hydrogen peroxide (H2O2).Highly concentrated azo dyes could be effectively degraded over a mononuclear copper complex with pyridine-carboxylato ligands under visible and UV irradiated conditions within 90 min and 10 min, respectively.
Co-reporter:Jingwen Ran, Xinyong Li, Qidong Zhao, Yang Hou, Wei Teng, Guohua Chen
Inorganic Chemistry Communications 2010 Volume 13(Issue 12) pp:1527-1529
Publication Date(Web):December 2010
DOI:10.1016/j.inoche.2010.09.003
A hetero-nuclear complex Hexakis (μ2-pyridine-2-aldoximato-N, N′, O)-iron (III) -di-nickel (II) nitrate solvate duodenaryhedrate ([FeNi2(PA)6]) has been prepared. The structure of the complex has been characterized by X-ray crystallography. The complex was observed to be active in photo-catalyzing oxidation of Rhodamine B (RhB) and Methyl Orange (MO) in an aqueous solution with hydrogen peroxide (H2O2).A hetero-nuclear complex Hexakis (μ2-pyridine-2-aldoximato-N, N′, O)-iron (III) -di-nickel (II) nitrate solvate duodenaryhedrate ([FeNi2(PA)6]) has been prepared, which was observed to be active in photo-catalyzing oxidation of Rhodamine B and Methyl Orange in an aqueous solution with hydrogen peroxide.
Co-reporter:Zhengru Zhu, Xinyong Li, Qidong Zhao, Zhenping Qu, Yang Hou, Ling Zhao, Shaomin Liu, Guohua Chen
Materials Research Bulletin 2010 45(12) pp: 1889-1893
Publication Date(Web):
DOI:10.1016/j.materresbull.2010.09.007
Co-reporter:Feifei Liu, Xinyong Li, Qidong Zhao, Yang Hou, Xie Quan, Guohua Chen
Acta Materialia 2009 Volume 57(Issue 9) pp:2684-2690
Publication Date(Web):May 2009
DOI:10.1016/j.actamat.2009.02.022
Abstract
Highly ordered ZnFe2O4 nanotube arrays were successfully prepared using porous anodic aluminum oxide (AAO) template from sol–gel solution. The ZnFe2O4 nanotubes are orderly arranged in parallel and each nanotube is composed of many agglutinating nanoparticles. The UV–vis absorption and surface photovoltage spectra of the ZnFe2O4 nanotubes and gel powders have been compared. The photovoltaic response threshold of the ZnFe2O4 nanotubes exhibited a blue-shift of about 150 nm with respect to that of the ZnFe2O4 gel powder, which implies that the photogenerated charges in the nanotubes have a higher redox activity than that of the gel powder. Both materials behave like a p-type semiconductor with photogenerated electrons accumulated at their surface.
Co-reporter:Yang Hou, Xinyong Li, Ping Liu, Xuejun Zou, Guohua Chen, Po-Lock Yue
Separation and Purification Technology 2009 Volume 67(Issue 2) pp:135-140
Publication Date(Web):2 June 2009
DOI:10.1016/j.seppur.2009.03.025
Highly oriented titania nanotube (TN) arrays with {1 0 1} crystal face were prepared on the surface of titanium substrate by liquid chemical deposition method. The obtained titania samples were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscope (SEM), BET measurements, diffuse reflectance spectroscopy (DRS), and electron paramagnetic resonance (EPR) spin trap technique. Results indicate that the nanotubes grown in this study are well-aligned and organized into high-density uniform arrays. The typical dimensions of the hollow tube are ∼90 nm in outer diameter, ∼60 nm in inner diameter, ∼15 nm in wall thickness and ∼300 nm in height. The BET surface area of the obtained titania nanotube is 275 m2/g. The EPR signals reveal that hydroxyl radical (OH) species can be produced in the nanotube system, and no OH radical EPR signals were detected under dark and/or nanotube non-existing situations. The catalytic degradation of a textile azo dye, acid orange 7 (AO7), in aqueous solution with titania nanotube arrays electrode was carried out using photo-electrocatalytic (PEC) process, comparing with electrochemical process (EP) and photocatalytic (PC) process. A significant photo-electrochemical synergetic effect was observed, which is due to the efficient charge separation and transfer at the surface-interface of titania nanotube arrays. The kinetic constant of PEC degradation of AO7 using TN electrode was 48.7%, which is higher than that using P-25 TiO2 film and TiO2 particular film electrode. The enhanced degradation rate of AO7 using titania nanotube arrays could be attributed to their larger specific surface area and nanotubular structure with preferred reactive crystal face, which would increase their absorption capacity to the targeted substrates and the rate of surface-interface charge transfers in titania nanotube semiconductor redox systems.
Co-reporter:Deling Yuan, Xinyong Li, Qidong Zhao, Jijun Zhao, Moses Tadé, Shaomin Liu
Journal of Catalysis (January 2014) Volume 309() pp:268-279
Publication Date(Web):1 January 2014
DOI:10.1016/j.jcat.2013.09.010
•CuTi-containing catalyst derived from hydrotalcite-like used for NOx removal.•Cu can be categorized into surface and bulk species of the CuTi-containing catalyst.•Surface Cu is active site, while bulk Cu possesses adsorption property.•Lewis acid sites actively contribute to the catalytic performance.•Nitrates, acetate and formate are evidenced as key intermediates for NOx removal.A series of hydrotalcite-based CuxTi1 (x = 2, 3, 4, 5)-mixed oxide catalysts have been synthesized by homogeneous precipitation and tested in the selective catalytic reduction (SCR) of NO by C3H6 in the presence of excess oxygen. Cu atoms can be categorized into surface and bulk species. The surface Cu species are the active sites while the bulk Cu species possess adsorption property for nitrogen species, and such bulk Cu species varies from CuxTiyOz to CuO with increasing Cu content. The Cu3Ti1 catalyst with the highest amount of surface copper and Lewis acid sites exhibits the best catalytic performance due to its improved electrophilicity of CuxTiyOz, which enhance the adsorption capability of nitrogen species. In situ infrared characterization revealed that nitrates in terms of bridging, bidentate and chelating species are reactive toward acetate and formate, and they are the key intermediates produced during the SCR of NO.Download high-res image (78KB)Download full-size image
Co-reporter:Zhiguang Zhang, Xinyong Li
Procedia Environmental Sciences (2013) Volume 18() pp:353-358
Publication Date(Web):1 January 2013
DOI:10.1016/j.proenv.2013.04.046
In this work, spindle-like Zn-TPyP sample was synthesized by a facile solution-phase method with CTAB as the surfactant. The Zn-TPyP particles with spindle shape showed photocatalytic activity. The structural properties of spindle-like Zn-TPyP sample were systematically investigated by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), transmission electronic microscopy (TEM), energy-dispersive X-ray spectra (EDS), X- ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflectance spectroscopy (DRS) techniques. The photocatalytic performance of the spindle-like Zn-TPyP sample was studied by degrading toluene under xenon lamp irradiation by in-situ FTIR spectroscopy. The results indicate that the spindle-like Zn-TPyP particles exhibited favorite photocatalytic degradation activity.
Co-reporter:Libin Zeng, Xinyong Li, Yueran Shi, Yefei Qi, Daqiong Huang, Moses Tadé, Shaobin Wang, Shaomin Liu
Biosensors and Bioelectronics (15 May 2017) Volume 91() pp:
Publication Date(Web):15 May 2017
DOI:10.1016/j.bios.2016.12.021
•FePO4 based single chamber air cathode MFC was constructed.•The SC-MFC exhibited high sensitivity and lasting stability for LEV online detection.•The whole detection for different concentrations of LEV can be finished in 5 min.•The excellent degradation range of LEV in this biosensor was also proposed.A bio-electrochemical strategy was developed for constructing a simple and sensitive levofloxacin (LEV) sensor based on a single chamber microbial fuel cell (SC-MFC) using FePO4 nanoparticles (NPs) as the cathode catalyst instead of traditional Pt/C. In this assembled sensor device, FePO4 NPs dramatically promoted the electrooxidation of oxygen on the cathode, which helps to accelerate the voltage output from SC-MFC and can provide a powerful guarantee for LEV detection. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to fully characterize the FePO4 NPs. Under the optimized COD condition (3 mM), the LEV with a concentration range of 0.1–1000 µg/L could be detected successfully, and exhibited the excellent linear interval in the concentration range of 0.1–100 µg/L. During this range of concentrations of LEV, a temporary effect on the anode of exoelectrogenic bacterial in less than 10 min could occur, and then came back to the normal. It exhibited a long-term stability, maintaining the stable electricity production for 14 months of continuous running. Besides, the detection mechanism was investigated by quantum chemical calculation using density functional theory (DFT).
Co-reporter:Baojun Liu, Xinyong Li, Qidong Zhao, Jun Ke, Moses Tadé, Shaomin Liu
Applied Catalysis B: Environmental (15 May 2016) Volume 185() pp:1-10
Publication Date(Web):15 May 2016
DOI:10.1016/j.apcatb.2015.12.003
Co-reporter:Jun Ke, Xinyong Li, Qidong Zhao, Baojun Liu, Shaomin Liu, Shaobin Wang
Journal of Colloid and Interface Science (15 June 2017) Volume 496() pp:
Publication Date(Web):15 June 2017
DOI:10.1016/j.jcis.2017.01.121
It finds that CQDs synthesized by hydrothermal method possess obvious upconversion properties that could transfer low energy photons to high energy photons, resulting in enhanced visible light response and utilization. Herein, carbon quantum dots (CQDs) modified TiO2 photocatylysts were successfully prepared by a facile sol-gel method. Photophysical and surficial properties of the as-prepared composite photocatalyst were investigated in details. Furthermore, photocatalytic performance was tested by degrading methylene blue (MB) under visible light irradiation. The degradation efficiency of methylene blue (MB) is as high as 90% within 120 min, which is 3.6 times higher than that of pure TiO2.
Co-reporter:Baojun Liu, Xinyong Li, Qidong Zhao, Jie Liu, Shaomin Liu, Shaobin Wang and Moses Tadé
Journal of Materials Chemistry A 2015 - vol. 3(Issue 29) pp:NaN15170-15170
Publication Date(Web):2015/06/10
DOI:10.1039/C5TA02295A
This work aims to explore the mechanism of photocatalytic degradation of gaseous 1,2-dichlorobenzene (o-DCB) over vanadium pentoxide (V2O5) hollow spheres. To this end, flower-type V2O5 hollow microspheres with diameters of about 700–800 nm were obtained with the assistance of carbon-sphere templates, and then tested in the photodegradation of o-DCB under visible light (λ > 400 nm). Due to its strong adsorption capacity and large specific surface area, the V2O5 hollow structure showed high photocatalytic activity in the degradation of gaseous o-DCB under visible light. Furthermore, the o-DCB degradation mechanism was investigated by using in situ Fourier transform infrared (FTIR) spectroscopy, and the intermediates, such as o-benzoquinone-type and organic acid species, and final products (CO2 and H2O) were also confirmed. Then, the reaction pathways over V2O5 were proposed. The outstanding performance indicated that the photocatalysts could be applied to air purification for Chlorinated Volatile Organic Compound (Cl–VOC) removal.
Co-reporter:Juanjuan Sun, Xinyong Li, Qidong Zhao, Moses O. Tadé and Shaomin Liu
Journal of Materials Chemistry A 2015 - vol. 3(Issue 43) pp:NaN21663-21663
Publication Date(Web):2015/09/09
DOI:10.1039/C5TA05659D
In an effort to develop visible-light-driven heterostructured photocatalysts with high activity, a novel quantum-sized tubelike BiVO4 sensitized TiO2 microflower catalytic system was successfully fabricated by using a facile hydrothermal and ultrasonic adhering approach. The structural and optical properties of the as-prepared samples were comparatively characterized. The staggered band structure of quantum-sized BiVO4 decorated TiO2 not only extended the photo-response range but also promoted photoexcited charges transfer and separation. Photocatalytic activities of the as-prepared samples were examined by the degradation of toluene under visible light irradiation (λ > 400 nm). Compared to the individual TiO2 microflower, BiVO4 quantum tube, BiVO4 nanoparticle and nano-BiVO4/TiO2, the quantum-BiVO4/TiO2 (Q-BiVO4/TiO2) composite exhibited higher photo activities. Electron spin resonance (ESR) examinations confirmed the generation of the photo-induced reactive oxygen species (˙OH and ˙O2−) which were involved in the photocatalytic process of Q-BiVO4/TiO2 composites. Furthermore, the enhanced photocatalytic activity of the Q-BiVO4/TiO2 composite mainly originated from the high separation efficiency of photo-induced electron–hole pairs and the efficient production of hydroxyl radicals. A detailed mechanism accounting for the superior photocatalytic activity was proposed in terms of the energy band structures of the components.
Co-reporter:Baojun Liu, Xinyong Li, Qidong Zhao, Yang Hou and Guohua Chen
Journal of Materials Chemistry A 2017 - vol. 5(Issue 19) pp:NaN8915-8915
Publication Date(Web):2017/04/17
DOI:10.1039/C7TA02048A
In this work, double-shelled ZnFe2O4 hollow microspheres were fabricated by a facile self-templated solvothermal method and the interiors could be precisely modulated by varying the reaction rate during the calcination process. More importantly, the formation mechanism of hollow structures with complex interior architectures could be illustrated based on the interface layer effect of the adhesion and contraction forces. When evaluated as catalytic materials for degradation of gaseous o-dichlorobenzene, the as-synthesized double-shelled ZnFe2O4 hollow structures showed significantly enhanced photocatalytic performance because of higher surface area (126.7 m2 g−1) and more effective light absorption (multiple scattering for double-shelled architectures).
Co-reporter:Jingqiang Pan, Xinyong Li, Qidong Zhao, Tingting Li, Moses Tade and Shaomin Liu
Journal of Materials Chemistry A 2015 - vol. 3(Issue 23) pp:NaN6034-6034
Publication Date(Web):2015/05/08
DOI:10.1039/C5TC01008J
An ultrasound-assisted impregnation deposition technique was adopted to construct Mn0.5Zn0.5Fe2O4 nanoparticles on TiO2 nanotube arrays (NTAs) which were prepared by electrochemical anodization in a hydrofluoric acid system. The Mn0.5Zn0.5Fe2O4 nanoparticles were found to successfully deposit on the surface of the highly oriented TiO2 NTAs causing no damage to the ordered structure of the nanotubes. The as-prepared Mn0.5Zn0.5Fe2O4/TiO2 NTAs exhibited much improved photoelectrochemical capability. Compared with pure TiO2 NTAs, a more than 2.36-fold enhancement in photo-current density and a 2.17-fold enhancement in photo-conversion efficiency of the Mn0.5Zn0.5Fe2O4/TiO2 NTAs were achieved. The photoelectrocatalytic (PEC) activities of Mn0.5Zn0.5Fe2O4/TiO2 NTAs were evaluated by the degradation of toxic 2,4-dichlorophenol (2,4-DCP) in aqueous solution under simulated sun light irradiation. The experimental results indicated that the heterostructure photoelectrode showed much higher PEC activity than the pure TiO2 NTAs for the degradation of 2.4-DCP under simulated sun light irradiation. In addition, electron spin resonance examination confirmed that the photogenerated active species (˙OH and ˙O2−) were involved in the PEC degradation of 2,4-DCP. A mechanism accounting for the enhanced PEC activity of the Mn0.5Zn0.5Fe2O4/TiO2 NTAs was proposed. The enhanced PEC activity of the nanocomposite electrode could be attributed to the synergistic effects between the lowered electron–hole recombination rate by the applied bias and the wider spectral response promoted by the Mn0.5Zn0.5Fe2O4 component.
Co-reporter:Zhengru Zhu, Qidong Zhao, Xinyong Li, Hong Li, Moses Tade and Shaomin Liu
Catalysis Science & Technology (2011-Present) 2013 - vol. 3(Issue 3) pp:NaN796-796
Publication Date(Web):2012/11/12
DOI:10.1039/C2CY20377D
Porous and rod-shaped nanostructures of ZnAl2O4 were successfully synthesized by a simple hydrothermal method. The Ag-doped ZnAl2O4 catalyst, based on porous ZnAl2O4, was prepared by the incipient wetness impregnation strategy and showed an excellent photoelectric property and catalytic activity. The structural properties of the samples were systematically investigated by X-ray powder diffraction (XRD), Brunauer–Emmet–Teller (BET), transmission electron microscopy (TEM), Electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) techniques. The photocatalytic degradation of toluene by the Ag-doped ZnAl2O4, ZnAl2O4 and P25 TiO2 samples was comparatively studied under UV lamp irradiation. The results indicate that the Ag-doped ZnAl2O4 sample synthesized at pH = 6 exhibited a higher capacity for the degradation of toluene. No obvious deactivation of the Ag-doped ZnAl2O4 nanorods was observed during the prolonged operation of 6 h. The Ag-doped ZnAl2O4 nanorods could be potentially applied in environmental purification in the near future.
Co-reporter:Yang Hou, Xinyong Li, Qidong Zhao, Xie Quan and Guohua Chen
Journal of Materials Chemistry A 2011 - vol. 21(Issue 44) pp:NaN18076-18076
Publication Date(Web):2011/10/13
DOI:10.1039/C1JM12788H
A TiO2 nanotube/Ag–AgBr three-component nanojunction with enhanced visible-light activity was synthesized by a two-step approach including an electrochemical anodization technique followed by an in situ photo-assisted dipping and deposition approach. Ag/AgBr nanoparticles with good dispersion were effectively deposited on both the inside and outside of the TiO2 nanotubes. Surface photovoltage measurements and luminescence spectra demonstrated that the Ag/AgBr loading enhanced the visible spectral absorption of TiO2 nanotube arrays, as well as their separation efficiency of photoinduced electron–hole pairs, which may due to the nanojunction built between Ag/AgBr and TiO2 in this system. The photoelectrochemical investigations verified that the TiO2 nanotube/Ag–AgBr nanojunction showed enhanced photocurrent generation efficiency and had a more effective photoconversion efficiency of 0.71% than the aligned TiO2 nanotube arrays alone. The enhanced photoelectrochemical properties can be attributed to the extended absorption in the visible light region resulting from Ag/AgBr nanoparticles, and the effective separation of photogenerated carriers driven by the photoinduced potential difference generated at the TiO2/Ag–AgBr nanojunction interface.
![Zinc, [5,10,15,20-tetra-4-pyridinyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/542300/31183-11-6.png)
![Zinc, [5,10,15,20-tetra-4-pyridinyl-21H,23H-porphinato(2-)-κN21,κN22,κN23,κN24]-, (SP-4-1)-](/data/chemimg/542300/31183-11-6_b.png)
