Shaohui Guo

Au NPs@MoS2 Sub‐Micrometer Sphere‐ZnO Nanorod Hybrid Structures for Efficient Photocatalytic Hydrogen Evolution with Excellent Stability

MoS2 shows promising applications in photocatalytic water splitting, owing to its uniquely optical and electric properties. However, the insufficient light absorption and lack of performance stability are two crucial issues for efficient application of MoS2 nanomaterials. Here, Au nanoparticles (NPs)@MoS2 sub-micrometer sphere-ZnO nanorod (Au NPs@MoS2 -ZnO) hybrid photocatalysts have been successfully synthesized by a facile process combining the hydrothermal method and seed-growth method. Such photocatalysts exhibit high efficiency and excellent stability for hydrogen production via multiple optical-electrical effects. The introduction of Au NPs to MoS2 sub-micrometer spheres forming a core-shell structure demonstrates strong plasmonic absorption enhancement and facilitates exciton separation. The incorporation of ZnO nanorods to the Au NPs@MoS2 hybrids further extends the light absorption to a broader wavelength region and enhances the exciton dissociation. In addition, mutual contacts between Au NPs (or ZnO nanorods) and the MoS2 spheres effectively protect the MoS2 nanosheets from peeling off from the spheres. More importantly, efficiently multiple exciton separations help to restrain the MoS2 nanomaterials from photocorrosion. As a result, the Au@MoS2 -ZnO hybrid structures exhibit an excellent hydrogen gas evolution (3737.4 μmol g-1 ) with improved stability (91.9% of activity remaining) after a long-time test (32 h), which is one of the highest photocatalytic activities to date among the MoS2 based photocatalysts.

Facile preparation of a SiO2–Al2O3 aerogel using coal gangue as a raw material via an ambient pressure drying method and its application in organic solvent adsorption

Because of its outstanding properties such as a large specific area and Bronsted acidity, the SiO2–Al2O3 aerogel has been used for various applications such as adsorption, catalysis, and in synthetic chemistry. Regarding preparation of the SiO2–Al2O3 aerogel, however, expensive raw materials are always used. In addition, the traditional preparation method is supercritical drying, which is complex and has safety issues. Here, we successfully prepare a SiO2–Al2O3 aerogel utilizing coal gangue as a raw material, which is a zero-cost mining waste. More importantly, ambient pressure drying used in this work overcomes the drawbacks of supercritical drying. Characterizations show that the specific surface area of the SiO2–Al2O3 aerogel prepared from coal gangue can be comparable to that prepared from relative costly raw materials such as Al(NO3)3·9H2O or Al isopropoxide and tetraethoxysilane with supercritical drying conditions. In addition, adsorption tests show that the SiO2–Al2O3 aerogel demonstrates good adsorbability of an organic solvent. Our work provides an effective route to synthesize a SiO2–Al2O3 aerogel in mass quantities and opens a new direction for the comprehensive utilization of coal gangue.