Construction of a Zn0.65Cd0.35S/SnO2 S-scheme heterojunction for efficient photocatalytic CO2 reduction

Abstract

Promoting the migration rates of the photogenerated charge carriers to improve the efficiency of photocatalytic CO₂ reduction reactions remains a challenge for efficient and sustainable energy conversion. To address the very poor migration rates of photo-generated charge carriers in Zn_xCd_1−xS (ZCS), we integrated SnO₂ with rapid electron transport onto ZCS to create an S-scheme heterojunction with ZCS. This as-formed S-scheme heterostructure performs well in electron separation and transport, demonstrating impressive activity and selectivity for CO in reactions without the need for additional sacrificial agents or sensitizers. The inclusion of SnO₂, characterized by its swift electron transport, inherent stability, and potent oxidation ability, effectively mitigates the accumulation of photogenerated holes in the catalyst. Moreover, the ZCS/SnO₂ S-scheme heterojunction exhibits superior stability over pure ZCS for repeated reaction for 5 cycles.