Cd-ZnGeON solid solution: the effect of local electronic environment on the photocatalytic water cleavage ability

Abstract

The efficiency of hydrogen generation through photocatalytic water cleavage was elucidated for calcinated Cd-ZnGeON host systems. The electronic structures of the Cd-ZnGeON solid solution were explored via synchronized X-ray diffraction, X-ray absorption spectroscopy at the K-edge for elements O, N, Zn and Ge, X-ray photoelectron spectroscopy, diffuse reflection spectroscopy, and high-resolution transmission electron microscopy, etc., which were used as sensitive analytical probes. A good correlation was observed between the ability of Cd-ZnGeON for photocatalytic water splitting and the local atomic arrangement in its lattice. Based on advanced structural information about the solid solution, a concise lattice-model was proposed for hydrogen generation through water splitting. The electron-transfer route for hydrogen generation via photocatalytic water cleavage was also traced. The results reveal that the wurtzite Cd-ZnGeON calcinated at 600 °C generates a large amount of hydrogen (3647.25 μmol H2 h−1 g−1).