Co-reporter:Yi Feng, Haiqiang Lu, Xiaoli Gu, Jianhao Qiu, Mingmin Jia, Chaobo Huang, Jianfeng Yao
Journal of Physics and Chemistry of Solids 2017 Volume 102() pp:110-114
Publication Date(Web):March 2017
DOI:10.1016/j.jpcs.2016.11.022
•N-doped porous ZnO was synthesized via a simple calcination method.•N-doped ZnO show better photocatalytic activity.•N-doping enhances visible-light harvesting ability of ZnO.A facile and simple method was offered to synthesize porous N-doped ZnO via direct calcination of urea and ZIF-8 mixture. From XRD and XPS analysis, nitrogen has been successfully incorporated into ZnO lattices without introducing other N-containing or Zn-containing phases. Such nitrogen doping can enhance the visible-light harvesting ability and inhibit the recombination rate of electron-hole pairs; as a result, improved visible-light driven photocatalytic activity was achieved in N-doped porous ZnO and the photocatalytic activity of N-doped ZnO is 2.58 times higher than that of ZIF-derived pure ZnO.
Co-reporter:Yi Feng, Shichang Liu, Guozhen Liu, Jianfeng Yao
Chemosphere 2017 Volume 170(Volume 170) pp:
Publication Date(Web):1 March 2017
DOI:10.1016/j.chemosphere.2016.11.166
•Porous carbon spheres were synthesized via direct carbonization of fruit of Liquidambar formosana.•Fast oil absorption was achieved by using natural centimeter-sized biochar.•Excellent recycling ability and high mechanical properties of the carbon spheres.Porous carbon spheres with a diameter of 1–2 cm were prepared via a simple carbonization of the fruit of Liquidambar formosana. After carbonization, the spherical structure and inner finger-like pores were maintained with high resistance to impact. Due to the porous structure and the hydrophobic nature, the carbonized fruit of Liquidambar formosana can float on the water surface and show a super-fast oil or organic solvent sorption ability (sorption saturation can be achieved within 1–2 min). Moreover, about 99% of adsorbed oil can be easily removed from spheres via organic solvent such as ethanol or hexane, which shows good recyclability of samples. In general, considering the low-cost and abundance of raw material collected from nature and the facile synthetic process (only by carbonization), the centimeter-sized porous spheres via the carbonization of fruit of Liquidambar formosana are very promising to be used for the application of oil or organic solvent spill cleanup.
Co-reporter:Xiong-Fei Zhang;Yi Feng;Chaobo Huang;Yichang Pan
Cellulose 2017 Volume 24( Issue 12) pp:5649-5656
Publication Date(Web):24 October 2017
DOI:10.1007/s10570-017-1529-x
Free-standing cellulose nanofiber (CNF) films were prepared by a specially designed oven-drying approach. For the first time, the evaporation rate was carefully controlled to enhance the gas separation performance of the CNF film with the highest H2/N2 and H2/O2 selectivities of 159.4 and 218.2, respectively. The dense structure formed by the CNFs and the intra- and inter-fibrillar hydrogen bonds are believed to contribute to the separation property. Particularly, the specific role of floating-shape film precursor formed at the rapid evaporation stage (stage I) and the mechanism for film formation were investigated. This study demonstrated that the evaporation rate controlled by the heating temperature exhibited significant influence on surface, uniformity and gas separation of the CNF films.
Co-reporter:Mingmin Jia, Yi Feng, Shichang Liu, Jianhao Qiu, Jianfeng Yao
Journal of Membrane Science 2017 Volume 539(Volume 539) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.memsci.2017.06.005
•UiO-66-NH2 and graphene oxide composite membrane were designed and fabricated.•Amine functionalization improves the crystals dispersibility in composite membrane.•The intrinsic large pore of UiO-66-NH2 greatly increases the gas permeation.•The functional groups in UiO-66-NH2 adjust non-selective defects of GO membranes.UiO-66-NH2 were either intercalated into graphene oxide (GO) layers (GOU@S) or covered by GO layers (GO/U@S) to form UiO-66-NH2/GO composite membrane. Results show that different synthesis methods would lead to different membrane morphology, thickness and gas separation performance. For GOU@S membrane, UiO-66-NH2 was well-dispersed and intercalated into GO layer, whereas two continuous layers (GO and UiO-66 layer) with an obvious boundary were observed for GO/U@S. Due to the morphology and structure difference, better hydrogen separation performance was achieved for GOU@S membrane compared to GO/U@S membrane and pristine membrane due to the close interfacial contact between UiO-66-NH2 and GO, which arises from the hydrogen bonding formed between -NH2 group in UiO-66-NH2 and -OH group in GO and the electrostatic force between UiO-66-NH2 and GO layers. The ideal selectivities of H2/N2 and H2/CO2 were increased to 9.75 and 6.35, respectively, for the GOU@S membrane with a H2 permeance of 3.9 × 10−8 mol m−2 s−1 Pa−1.Download high-res image (305KB)Download full-size image
Co-reporter:Xiong-Fei Zhang, Jianfeng Yao, Xiaoxia Yang
Microporous and Mesoporous Materials 2017 Volume 247(Volume 247) pp:
Publication Date(Web):15 July 2017
DOI:10.1016/j.micromeso.2017.03.047
•Nano size TS-1 shows higher selectivity and stability compared to the micro size TS-1.•Catalyst lifetimes are markedly extended due to the well-developed hierarchical pore systems.•The mesopores facilitate mass transfer and change the distribution of acid sites.•Trimerization of phenyl acetaldehyde occurs at the external acid sites of TS-1-N.•The micropore structures are irreversibly destroyed upon NaOH treatment.In this study, isomerization of styrene oxide to phenyl acetaldehyde was investigated over a series of TS-1 catalysts with different crystal sizes and post-treatment methods under a gas-phase atmosphere free of solvents. The physicochemical properties of the samples were characterized by a combination of N2 adsorption, XRD, NH3-TPD, UV–vis, FT-IR and SEM. By the characterization of catalysts and investigation of their catalytic performances, results indicated that nano size TS-1 exhibited better anti-coking ability and phenyl acetaldehyde selectivity than micro size TS-1. Additionally, TPAOH treatment led to the development of considerable mesoporosity without significant destruction of its intrinsic zeolite properties. The results highlighted that the existence of well-developed hierarchical pore systems in TS-1-O could reduce diffusion path length and enhance transport of phenyl acetaldehyde out of the zeolite crystals, thus markedly improving catalytic stability and selectivity. However, upon NaOH treatment, the micropore structures were irreversibly destroyed accompaning with the amorphization of the zeolite crystals.Download high-res image (303KB)Download full-size image
Co-reporter:Jianhao Qiu;Yi Feng;Xiongfei Zhang;Xingguang Zhang;Mingmin Jia
RSC Advances (2011-Present) 2017 vol. 7(Issue 18) pp:10668-10674
Publication Date(Web):2017/02/07
DOI:10.1039/C7RA00050B
g-C3N4/TiO2 composites with homogeneous well-combined structures were prepared by a simple stir-dried method, using dicyandiamide (DICY) and tetrabutyl orthotitanate (TBOT) as the precursors, followed by high-temperature calcination. Various characterization techniques including XRD, FTIR, nitrogen adsorption–desorption, SEM and XPS confirm the formation of an interconnected structure between g-C3N4 and TiO2 in the composites. g-C3N4/TiO2 composites exhibit much higher photocatalytic activity than that of pure g-C3N4 and TiO2 in the degradation of methylene blue under visible light. In particular, the CT-5 composite prepared with DICY/TBOT at a mass ratio of 5 : 1, exhibited a photodegradation activity that is about 3.8 times that of TiO2 and 2.9 times that of pure g-C3N4. The homogeneous g-C3N4/TiO2 composite CT-5 can be repetitively used without significant loss of activity. The strong synergistic effect between g-C3N4 and TiO2 achieved by this preparation method greatly improves the separation efficiency of photo-generated electrons and holes, thus offering enhanced photocatalytic performances.
Co-reporter:Jianhao Qiu, Yi Feng, Xiongfei Zhang, Mingmin Jia, Jianfeng Yao
Journal of Colloid and Interface Science 2017 Volume 499(Volume 499) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.jcis.2017.03.101
UiO-66 was modulated by addition of acetic acid or HCl in the precursor solution. The resulting acetic acid-promoted UiO-66 has more regular octahedral structures and high surface areas of 892–1090 m2/g. Anionic dyes (methyl orange (MO) and Congo red (CR)) and cationic dyes (methylene blue (MB) and rhodamine B (RhB)) were examined for the selective dye adsorption on various UiO-66. The acid-promoted UiO-66 exhibits an excellent selective adsorption to anionic dyes, where the adsorption capacities of MO and MB are 84.8 and 13.2 mg/g, respectively. However, UiO-66 prepared without acid shows similar adsorption to both anionic dye MO (70.4 mg/g) and cationic dye MB (67.5 mg/g). Mixed dyes (MO/MB and MO/RhB) adsorption on acid-promoted UiO-66 further proves the selective adsorption to anionic dyes. The adsorption mechanism was studied by testing the Zeta potential of acid-promoted UiO-66, and more positive Zeta potential (hydrogen ions) of UiO-66 is beneficial to the anionic dye adsorption.Download high-res image (95KB)Download full-size image
Co-reporter:Yi Feng, Yaquan Wang, Yayan Wang, Shichang Liu, Jinlong Jiang, Chongjiang Cao, Jianfeng Yao
Journal of Colloid and Interface Science 2017 Volume 502(Volume 502) pp:
Publication Date(Web):15 September 2017
DOI:10.1016/j.jcis.2017.04.086
A simple method was offered to synthesize porous attapulgite (ATP)/polymer beads. The polymeric network acts as both holder to support ATP inside the inner pore structure and as the obstacle to avoid the agglomeration of ATP during the adsorption process. Moreover, such beads are millimeter-size and can float on water surface, making such beads easy-to-handle and facile-to-recover without weight loss. The maximum adsorption capacity of such beads for Cu(II) and Cd(II) were 25.3 and 32.7 mg/g, respectively, and pH value plays a key role in determining the adsorption capacities. The ATP/polymer beads also show good recycling ability and chemical stability. All these properties make such beads promising candidates as adsorbents for heavy metal removal.Download high-res image (93KB)Download full-size image
Co-reporter:Xiong-Fei Zhang;Xiaoxia Yang
Catalysis Letters 2017 Volume 147( Issue 6) pp:1523-1532
Publication Date(Web):06 April 2017
DOI:10.1007/s10562-017-2004-x
The catalytic performance of the isomerization of styrene oxide to phenyl acetaldehyde was investigated over different modified beta catalysts under gas-phase atmosphere free of solvents. The physicochemical properties were characterized by a combination of X-ray diffraction (XRD), N2 adsorption, Fourier transform infrared spectroscopy (FT-IR), Magic Angle Spinning Nuclear Magnetic Resonance (MAS-NMR), NH3-Temperature programmed desorption (NH3-TPD) and thermo gravimetric analysis (TGA), etc. Acid sites with stronger strength are responsible for the formation of condensation products and fast deactivation of catalysts. The obtained results also demonstrate that the introduction of boron atoms can create suitable acid strength and acid distribution without significantly destroying its microporous structures. Therefore, BAl-BEA sample is highly active and selective for the rearrangement of styrene oxide as well as very stable to deactivation.
Co-reporter:Yi Feng;Yayan Wang;Yaquan Wang
Journal of Materials Chemistry A 2017 vol. 5(Issue 41) pp:21893-21897
Publication Date(Web):2017/10/24
DOI:10.1039/C7TA06966A
Hydrophobic foam-like materials are attracting significant interest as promising absorbents for oil spill clean-up and recovery from water bodies. Many hydrophobic modification methods for sponges have been reported so far. In this work, we reported a relatively simple, low-cost and environmentally friendly method of hydrophobic modification of commercial melamine sponge (MS) via simply soaking MS in furfuryl alcohol solution, followed by polymerization in acid solution. The results indicate that furfuryl alcohol not only reacts with MS but also polymerizes onto the surface of MS, leading to the hydrophobic nature of the modified MS. The modified MS shows excellent sorption capacities for various oils and organic solvents (75–160 g g−1) and can be utilized as an excellent oil absorbent or as an oil-collecting device with the assistance of a pump.
Co-reporter:Xianbiao Wang, Jin Liu, Sookwan Leong, Xiaocheng Lin, Jing Wei, Biao Kong, Yongfei Xu, Ze-Xian Low, Jianfeng Yao, and Huanting Wang
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 14) pp:9080
Publication Date(Web):March 21, 2016
DOI:10.1021/acsami.6b00028
To selectively remove heavy metal from dye solution, inspired by the unique pore structure of ZIF-8, we developed a synthetic strategy for rapid construction of ZnO@ZIF-8 heterostructure photocatalyst for selective reduction of Cr(VI) between Cr(VI) and methylene blue (MB). In particular, ZnO@ZIF-8 core–shell heterostructures were prepared by in situ ZIF-8 crystal growth using ZnO colloidal spheres as template and zinc source within 8–60 min. The shell of the resulting ZnO@ZIF-8 core–shell heterostructure with a uniform thickness of around 30 nm is composed of ZIF-8 crystal polyhedrons. The concentration of organic ligand 2-methylimidazole (Hmim) was found to be crucial for the formation of ZnO@ZIF-8 core–shell heterostructures. Different structures, ZnO@ZIF-8 core–shell spheres and separate ZIF-8 polyhedrons could be formed by altering Hmim concentration, which significantly influences the balance between rate of Zn2+ release from ZnO and coordinate rate. Importantly, such ZnO@ZIF-8 core–shell heterostructures exhibit size-selective photocatalysis properties due to selective adsorption and permeation effect of ZIF-8 shell. The as-synthesized ZnO@ZIF-8 heterostructures exhibited enhanced selective reduction of Cr(VI) between Cr(VI) and MB, which may find application in the dye industry. This work not only provides a general route for rapid fabrication of such core–shell heterostructures but also illustrates a strategy for selectively enhanced photocatalysis performance by utilizing adsorption and size selectivity of ZIF-8 shell.Keywords: heterostructure; photocatalysis; rapid construction; size-selective; ZnO@ZIF-8;
Co-reporter:Yu Li, Kang Zhou, Ming He, Jianfeng Yao
Microporous and Mesoporous Materials 2016 Volume 234() pp:287-292
Publication Date(Web):1 November 2016
DOI:10.1016/j.micromeso.2016.07.039
•ZIF-8 and ZIF-67 with modified textural structure are prepared using mixed bases.•Enhanced rhodamine B adsorption is found for ZIF-8 and ZIF-67 prepared with triethylamine.•ZIF-67 prepared with triethylamine has better methyl orange adsorption than ZIF-8.ZIF-8 and ZIF-67 were prepared by using mixed-base ammonium hydroxide and triethylamine (TEA). These two bases could promote the ZIF synthesis, and the yields are significantly improved. The texture structure and morphologies of ZIF prepared with mixed-base also have obvious changes. Three typical dyes, neutral rhodamine B (RB), anionic methyl orange (MO) and cationic methylene blue (MB), were examined for the dye adsorption by using various ZIFs. ZIF-8 and ZIF-67 prepared with TEA have enhanced RB adsorptions that are 2.3–3.8 times of those prepared without TEA, and ZIF-8 exhibited better adsorption performance than ZIF-67. For MO adsorption, ZIF-67 crystals have better adsorption performance than ZIF-8, and ZIF-67 prepared with TEA has a decreased MO adsorption. For MB adsorption, the addition of TEA does not change the MB adsorption for both ZIF-8 and ZIF-67.
Co-reporter:Ying Wang, Haiqiang Lu, Yuanyang Wang, Jianhao Qiu, Jing Wen, Kang Zhou, Li Chen, Guanglei Song and Jianfeng Yao
RSC Advances 2016 vol. 6(Issue 3) pp:1860-1864
Publication Date(Web):21 Dec 2015
DOI:10.1039/C5RA23087J
N-doped TaOxNy is prepared using ethylenediamine as the nitrogen source by a sol–gel method. The obtained samples are subsequently calcined at 500–900 °C. XRD analysis and XPS survey indicate the presence of immature TaO2 (Ta4+) in the N-doped TaOxNy sample sintered at 550 °C (TaOxNy-550), and the UV results show TaOxNy-550 has a rather strong absorption in the visible light region. The photocatalytic activities of TaOxNy are evaluated in hydrogen generation by water splitting and photodegradation of methyl orange. The N-doped TaOxNy sample sintered at 550 °C shows the highest H2 generation rate of 3.12 mmol g−1 h−1, and only 3.1% methyl orange is left after 90 min irradiation. Such photocatalytic activities are comparable to the conventional nitrogen-doped titania.
Co-reporter:Xiaoli Gu, Kang Zhou, Yu Li and Jianfeng Yao
RSC Advances 2016 vol. 6(Issue 20) pp:16314-16318
Publication Date(Web):26 Jan 2016
DOI:10.1039/C5RA28058C
Millimeter-sized composite polyethersulfone/TiO2 beads were fabricated with different amounts of TiO2 and the surfactant F127 by a modified phase inversion method and the resulting composite carbon beads were obtained after calcination. The composite carbon/TiO2 beads were tested for oil adsorption and rhodamine B (RB) adsorption. For the adsorption of corn oil, the volume gains for composite carbon/TiO2 beads prepared with 2–4 g TiO2 and 0–1 g surfactant F127 were in the range of 46–77%. In the adsorption of linear paraffin oil and silicone oil, composite carbon/TiO2 beads (CB-4 and CB-4-1F) prepared with 4 g TiO2 exhibited volume gains of oil of 74–77%. CB-4 and CB-4-1F also exhibited enhanced adsorption of RB, and only 22% and 16% of RB remained in solution after 24 h of adsorption, respectively. This study provides an easy and low-cost method for preparing millimeter-sized carbon/TiO2 sorbents for oil and dye adsorption.
Co-reporter:Jianjun Zhou;Jin Chen;Ming He
Journal of Applied Polymer Science 2016 Volume 133( Issue 39) pp:
Publication Date(Web):
DOI:10.1002/app.43946
ABSTRACT
Cellulose nanocrystals (CNCs) were used as a sustainable additive to improve the hydrophilicity, permeability, antifouling, and mechanical properties of blend membranes. Different CNC loadings (0–1.2 wt %) in cellulose acetate (CA) membranes were studied. The blend membranes were prepared by a phase-inversion process, and their chemical structure and morphological properties were characterized by attenuated total reflectance–Fourier transform infrared spectroscopy, scanning electron microscopy, porosity, and mean pore size and contact angle measurement. The blend membranes became more porous and more interconnected after the addition of CNCs. The thickness of the top layer decreased and a few large holes in the porous substrate appeared with increasing CNC loading. In comparison with the pure CA membranes, the pure water flux of the blend membranes increased with increasing CNC loading. It reaches a maximum value of 76 L m−2 h−1 when the CNC loading was 0.5 wt %. The antifouling properties of the CA membrane were significantly improved after the addition of CNCs, and the flux recovery ratio value increased to 68% with the addition of 0.5 wt % CNCs. In comparison with that of the pure CA membranes, the tensile strength of the composite membranes increased by 47%. This study demonstrated the importance of using sustainable CNCs to achieve great improvements in the physical and chemical performance of CA ultrafiltration membranes and provided an efficient method for preparing high-performance membranes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43946.
Co-reporter:Haiqiang Lu, Ying Wang, Yuanyang Wang, Wensheng Liang and Jianfeng Yao
RSC Advances 2015 vol. 5(Issue 109) pp:89777-89782
Publication Date(Web):15 Oct 2015
DOI:10.1039/C5RA17692A
Titania-based nanotubes are prepared via hydrothermal and post treatment of titania with different anatase/rutile ratios. Commerical TiO2 P25 with an anatase/rutile ratio of 80/20 changes to sodium titanate, hydrogen titanate and anatase after hydrothermal treatment at 130 °C over 2 h, ion exchange by washing with water and calcination at 400 °C for 5 h. The final tubular structure has a lot of defects owing to a great quantity of dehydration. Pure rutile is more stable than P25. Lamellars exfoliate from (110) facets of rutile at 130 °C hydrothermal treatment to roll up into nanotubes. Only a small amount of rutile transfers to amorphous sodium titanate within 24 h, and it recrystallizes on the surface of nanotubes and results in a perfect tubular structure with a small amount of dehydration. The dissolution–recrystallization mechanism plays an important role in the composition and crystal structure of titania-based nanotubes.
Co-reporter:Hui Li, Yubao Hao, Haiqiang Lu, Liping Liang, Yuanyang Wang, Jianhao Qiu, Xianchao Shi, Ying Wang, Jianfeng Yao
Applied Surface Science 2015 Volume 344() pp:112-118
Publication Date(Web):30 July 2015
DOI:10.1016/j.apsusc.2015.03.071
Highlights
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N-doped titania with a higher N-doping level is prepared by a sol–gel method.
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Doping mechanism is explained by XRD, FT-IR and UV–visible absorption spectroscopy.
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Photocatalytic performance is evaluated by dye degradation and H2 evolution.
Co-reporter:Ming He;Jianjun Zhou;Huan Zhang;Zhenyang Luo
Journal of Applied Polymer Science 2015 Volume 132( Issue 36) pp:
Publication Date(Web):
DOI:10.1002/app.42488
ABSTRACT
Microcrystalline cellulose (MCC) and its oxidized product dialdehyde cellulose (DAC) were introduced as the reinforcing filler in epoxidized soybean oil (ESO) thermosetting polymer. The composites comprising up to 25 wt % cellulose fillers were obtained via a solution casting. The reinforcing effects of the cellulose were evaluated by microstructure analysis, dynamic mechanical analysis, and tensile and thermal stability tests. The results showed that at the same filler concentration, DAC led to higher stretching strength, modulus, and break elongation than MCC. The 5 wt % DAC loading in ESO polymer exhibits the highest toughness and thermal stability due to the good dispersion and interfacial interaction between DAC and ESO polymer matrix. The increased storage modulus and glass transition temperature also indicate the cellulose fillers impart stiffness to the composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42488.
Co-reporter:Xiaoli Gu, Haiqiang Lu, Chun Kan, Jianfeng Yao
Materials Research Bulletin 2015 68() pp: 185-188
Publication Date(Web):
DOI:10.1016/j.materresbull.2015.03.046
Co-reporter:Xiong-Fei Zhang, Yanzhan Chen, Yi Feng, Xingguang Zhang, Jianhao Qiu, Mingmin Jia, Jianfeng Yao
Journal of Alloys and Compounds (25 May 2017) Volume 705() pp:392-398
Publication Date(Web):25 May 2017
DOI:10.1016/j.jallcom.2017.02.207
Co-reporter:Jie Wang, Ran Ran, Jaka Sunarso, Chao Yin, Honggang Zou, Yi Feng, Xiaobao Li, Xu Zheng, Jianfeng Yao
Journal of Power Sources (15 April 2017) Volume 347() pp:259-269
Publication Date(Web):15 April 2017
DOI:10.1016/j.jpowsour.2017.02.072
