In past decade, inorganic semiconductors have been successfully demonstrated as light absorbers in efficient solar water splitting to generate chemical fuels. Pseudo-binary semiconductor Zn1-xCdxS have exhibited a superior photocatalytic activity of H2 evolution from water splitting under artificial solar irradiation without any noble metal. However, most studies revealed that the extremely high efficiency with an optimal content of Zn1-xCdxS solid solution was determined as a result of elevating the conduction band minimum and the width of bandgap. However, in addition to corresponding band structure and bandgap, the local crystal structure should be remarkably considered to determine its’ photocatalytic performance. Herein, we demonstrated that the correlations between the photocatalytic activity and structural properties were first studied through synchrotron X-ray absorption and X-ray diffraction spectroscopy. The crystal structure transformed from Zinc blende to a coexisted phase of Blende and minor Wurtzite phase at a critical point, and the heterojunction formed by co-existence of Blende and Wurtzite phase in the Zn1-xCdxS solid solution can significantly improve the separation and migration of photo-induced electron-hole pairs. These results provided a significant progress toward the realization of the photoelectrochemical mechanism in heterojunction between Blende and Wurtzite phases, which can effectively separate the charge-carries and further suppress their recombination to enhance the photocatalytic activity.

Heterojunction of zinc Blende/Wurtzite in Zn1-xCdxS solid solution for efficient solar hydrogen generation: X-ray absorption/diffraction spectroscopy approach

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.