Composite Nanoshells for Enhanced Solar-to-Fuel Photocatalytic Conversion.

摘要

This is the report of a study to further investigate the fabrication of thin films of the compound semiconductor Ag-In-Zn-S. The researchers also measured the photoelectrochemical activities of these compounds. By using electrophoretic deposition, the annealed powders of this quaternary solid solution were deposited on the ITO substrate. A larger photo-current density was measured by illuminating on the glass side when the film is thick. At 0 V v.s. SCE, the photo-current density is 0.137 mA/square cm. SEM images show that the structure of the film is porous. The exposed area on ITO is expected to be the reactive sites when bias voltage is applied, with or without light irradiation. In a separate experiment, the metal oxide (SiO2 or SnO2) -coated nanoshells were synthesized. SnO2-coated nanoshells provided enhanced stability at high pH. The effect of temperature and localized surface plasmon resonance, typically with addition of Ag at Au NPs (nanoparticles) was evaluated. Layered structure composed of nanoshell/SiO2/ZnO was also studied. With/without silica layer, nanoshells (NSs) show totally different absorption peaks appeared in UV- vis spectrum. With the presence of nanoshells at SiO2, the IR range in the solar spectrum can be fully utilized. The incorporation of nanoshell at SiO2, as well as the nanostructure of photocatalyst will be further investigated.