We have demonstrated an extremely facile procedure for the preparation of 3D porous manganese oxide nanostructures by pyrolysis of Mn-based coordination polymer nanowires. The highly aligned and ultralong Mn-based polymer nanowires with high chemical purities were prepared using nitrilotriacetic acid (NA) as a chelating agent by a one-step hydrothermal approach. In the synthesis, NA was slowly dissolved in water and bonded with manganese ions by carboxyl groups to form one-dimensional polymer nanowires under the protection of isopropyl alcohol, and then form highly aligned nanowire bundles. Control experiments show that the morphologies of polymer nanowires greatly depend on the precursor salts and ratios between deionized water and isopropyl alcohol. Based on the elemental analysis results, the probable molecular formula and growth mechanism have been proposed. The catalytic reaction results demonstrated that the as-prepared 3D porous manganese oxide nanostructure was a good support for aerobic oxidation of benzyl alcohol. Moreover, the catalysts can be easily separated and recycled.

A simple glucose-assisted hydrothermal process has been developed to design complex and functional ZnO/SnO2 nanostructures. In this synthesis, the abundant hydroxyl groups of glucose can ligate with Zn2+ and Sn4+, and induce nucleation. Furthermore, the glucose molecules can form stacking templates to direct the oriented attachment of nanorods and nanoplates due to the π–π electron interactions between glucose ligands. The growth mechanism is studied by changing the synthesis conditions. It is found that the morphologies of ZnO/SnO2 greatly depend on the concentrations of glucose and sodium hydroxide, as well as the molar ratios between Zn2+ and Sn4+. The as-synthesized samples are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. In particular, gas sensing tests show that these ZnO/SnO2 nanostructures exhibit enhanced sensing properties to ethanol due to the formation of nano-heterojunctions and their unique morphologies.

A new electrocatalyst, MnO2/graphene oxide hybrid nanostructure was successfully synthesized for the nonenzymatic detection of H2O2. The morphological characterization was examined by scanning electron microscopy and transmission electron microscopy. The MnO2/graphene oxide based electrodes showed high electrochemical activity for the detection of H2O2 in alkaline medium. The nonenzymatic biosensors displayed good performance along with low working potential, high sensitivity, low detection limit, and long-term stability, which could be attributed to the high surface area of graphene oxide providing for the deposition of MnO2 nanoparticles. These results demonstrate that this new nanocomposite with the high surface area and electrocatalytic activity offers great promise for new class of nanostructured electrode for nonenzymatic biosensor and energy conversion applications.

We have demonstrated an extremely facile procedure for the preparation of 3D porous manganese oxide nanostructures by pyrolysis of Mn-based coordination polymer nanowires. The highly aligned and ultralong Mn-based polymer nanowires with high chemical purities were prepared using nitrilotriacetic acid (NA) as a chelating agent by a one-step hydrothermal approach. In the synthesis, NA was slowly dissolved in water and bonded with manganese ions by carboxyl groups to form one-dimensional polymer nanowires under the protection of isopropyl alcohol, and then form highly aligned nanowire bundles. Control experiments show that the morphologies of polymer nanowires greatly depend on the precursor salts and ratios between deionized water and isopropyl alcohol. Based on the elemental analysis results, the probable molecular formula and growth mechanism have been proposed. The catalytic reaction results demonstrated that the as-prepared 3D porous manganese oxide nanostructure was a good support for aerobic oxidation of benzyl alcohol. Moreover, the catalysts can be easily separated and recycled.