Molybdenum-doped ZnS sheets with dominant {111} facets for enhanced visible light photocatalytic activities.

ZnS is widely used as a semiconductor photocatalyst in photo-electrochemical water splitting and photodegradation under ultraviolet (UV)-light irradiation. In this work, Molybdenum (Mo)-doped ZnS sheets with dominant {111} facets are developed using a hydrothermal method with Mo ions as precursors to realize non-visible-light photocatalytic activity and reduce the recombination rate of photoexcited carriers in ZnS. Mo ions are found to play a key role in the growth process of the sheet-like structure. Mo-dopants in the ZnS sheets introduce the acceptor energy levels among the bandgaps. The light absorption range of Mo-doped ZnS sheets covers the entire visible light and even extends to the near-infrared light region. The p-type Mo-doped ZnS sheets exhibit enhanced photocatalytic activities under visible light irradiation, which is promising for the photo-electrochemistry and photo-oxidation applications.

Facet-selective photodeposition of gold nanoparticles on faceted ZnO crystals for visible light photocatalysis.

Hexagonal prism-like ZnO crystals dominated with polar facets were synthesized using a hydrothermal method. The Gold (Au) nanoparticles were selectively photodeposited on the polar surfaces of faceted ZnO crystals as a result of anisotropic photocatalytic activities of the polar and nonpolar facets. The size of Au nanoparticles uniformly dispersed on the polar facets increased with increasing Au-loading amount. These Au-loaded ZnO crystals showed an additional visible light absorption band from 400nm to 800nm. The 0.1wt% Au-loaded ZnO crystals with visible light absorption peak at approximately 690nm exhibited the highest photocatalytic activity under visible light irradiation.