Enhanced photocatalytic activity of cubic ZnSn(OH)6 by in-situ partial phase transformation via rapid thermal annealing

In this study, a mixed phase ZnSn(OH)6/ZnSnO3 photocatalyst was synthesized by calcining ZHS nanostructures via rapid thermal annealing (RTA) process. The composition ratio of ZnSn(OH)6/ZnSnO3 was controlled by changing the duration of the RTA process. The obtained mixed-phase photocatalyst was characterized by X-ray diffraction, field emission scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray photo-electron spectroscopy, UV-vis diffuse reflectance spectroscopy, ultraviolet photoelectron spectroscopy, photo-luminescence, and physisorption analysis. Results showed that ZnSn(OH)6/ZnSnO3 photocatalyst obtained by calcining ZHS at 300 degrees C for 20 sec displayed the best photocatalytic performance under UVC light illumination. Under optimized reaction conditions, ZHS-20 (0.125 g) demonstrated nearly complete removal (>99%) of MO dye in 150 min. Scavenger study revealed the predominant role of OH center dot in photocatalysis. The enhanced pho-tocatalytic activity of the ZnSn(OH)6/ZnSnO3 composites was mainly ascribed to the photosensitization of ZHS by ZTO and effective electron-hole separation at the ZnSn(OH)6/ZnSnO3 heterojunction interface. It is expected that this study will provide new research input for the development of photocatalyst through thermal annealing -induced partial phase transformation.

Automated summary

A mixed phase ZnSn(OH)6/ZnSnO3 photocatalyst was synthesized by calcining ZHS nanostructures via rapid thermal annealing process. The composition ratio of ZnSn(OH)6/ZnSnO3 was controlled by changing the duration of the RTA process. The obtained mixed-phase photocatalyst displayed the best photocatalytic performance under UVC light illumination, with nearly complete removal (>99%) of MO dye in 150 min.