Novel plasmonic p-n heterojunction Ag-Ag2CO3/Bi2Sn2O7 photocatalyst for Cr(VI) reduction

A novel Ag-Ag2CO3/Bi2Sn2O7 p-n heterojunction photocatalysts with different ratios of Ag/Bi2Sn2O7 were successfully prepared by in-situ precipitation method, which possessed surface plasmon resonance(SPR)-enhanced performances. The structure, morphology, optical and photoelectric properties of the as-synthesized photocatalysts were characterized using various techniques, and their photocatalytic activities was evaluated by reducing Cr (VI) in visible light. Among the Ag-Ag2CO3/Bi2Sn2O7 photocatalysts, the 15% Ag-Ag2CO3/Bi2Sn2O7 prepared at the Ag/Bi2Sn2O7 mass ratio of 15% possess the best photocatalytic activity, which was 7.88 and 3.24 times higher than that of Bi2Sn2O7 and 15% Ag2CO3/Bi2Sn2O7, respectively. And the Cr(VI) removal was still above 87.5% after 5 cycles. It was explained that the formation of Ag2CO3/Bi2Sn2O7 p-n heterojunction and the SPR effect of metal Ago on Ag2CO3 nanoparticles were the reasons for the enhanced photocatalytic activity of Ag-Ag2CO3/Bi2Sn2O7. The present study can provide an new insight into the design of highly efficient Bi2Sn2O7-based photocatalysts for the green and sustainable treatment of Cr(VI)-containing wastewater. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

A novel Ag-Ag2CO3/Bi2Sn2O7 p-n heterojunction photocatalyst was successfully prepared by the in-situ precipitation method with different Ag/Bi2Sn2O7 ratios, showing enhanced photocatalytic performance. The 15% Ag-Ag2CO3/Bi2Sn2O7 exhibited the best photocatalytic activity among the photocatalysts, with 7.88 and 3.24 times higher activity compared to Bi2Sn2O7 and 15% Ag2CO3/Bi2Sn2O7, respectively.