Stabilizing CuGaS by crystalline CdS through an interfacial Z-scheme charge transfer for enhanced photocatalytic CO reduction under visible light

• Published in: Nanoscale 2020-04, Vol.12 (16), p.8693-87
• Main Authors: Wu, Shimiao, Pang, Hong, Zhou, Wei, Yang, Baopeng, Meng, Xianguang, Qiu, Xiaoqing, Chen, Gen, Zhang, Ligang, Wang, Shengyao, Liu, Xiaohe, Ma, Renzhi, Ye, Jinhua, Zhang, Ning
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d0nr00483a

CuGaS 2 is one of the most excellent visible-light-active photocatalysts for CO 2 reduction and water splitting. However, CuGaS 2 suffers from serious deactivation in photocatalytic reactions, which is mainly due to the photo-oxidation induced self-corrosion (Cu + to Cu 2+ ). Here, we constructed a CuGaS 2 /CdS hybrid photocatalyst dominated by a Z-scheme charge transfer mechanism. The transfer of photo-generated electrons from excited nanocrystalline CdS to CuGaS 2 across the coherent interface reduces Cu 2+ formation and favors Cu + regeneration. This process suppresses the deactivation of CuGaS 2 and maintains high performance. Both the activity and stability of photocatalytic CO 2 reduction to produce CO over the CuGaS 2 /CdS hybrid were remarkably improved, which was approximately 4-fold higher than CuGaS 2 and 3-fold higher than CdS in converting CO 2 into CO. Our study demonstrates that even using the semiconductors prone to photo-corrosion, it is possible to obtain satisfactory catalytic activity and stability by designing efficient Z-scheme-charge-transfer-type photocatalysts. A Z-scheme type CuGaS 2 /CdS hybrid has played a key role in the suppression of CuGaS 2 photocorrsion and maintained exceptional activity.