Stabilizing CuGaS2 by CdS crystalline through interfacial Z-scheme charge transfer for enhanced photocatalytic CO2 reduction under visible light
CuGaS2 is one of the most excellent visible-light-active photocatalysts for CO2 reduction and water splitting. However, CuGaS2 suffers from serious deactivation in photocatalytic reactions, which is mainly due to the photo-oxidation induced self-corrosion (Cu+ to Cu2+). Here, we construct a CuGaS2/CdS hybrid photocatalyst dominated by Z-scheme charge transfer mechanism. The transfer of photo-generated electron from excited CdS nanocrystaline to CuGaS2 across the coherent interface reduces Cu2+ formation and favors Cu+ regeneration. This process suppresses the deactivation of CuGaS2 and maintains high performance. Both the activity and stability of photocatalytic CO2 reduction to produce CO over CuGaS2/CdS hybrid are remarkably improved, which shows approximately 4 folds as high as CuGaS2 and 3 folds as high as CdS in converting CO2 into CO. Our study demonstrates that, even using the semiconductors prone to be photo-corrode d, it is possible to obtain satisfied catalytic activity and stability by designing efficient Z-scheme charge transfer type photocatalysts.