CdxZn1-xS with bulk-twinned homojunctions and rich sulfur vacancies for efficient photocatalytic hydrogen production

Utilizing photocatalysts devoid of noble metals for solar hydrogen production is a viable option in resolving the rising energy crisis. However, the current photocatalytic performance is inadequate due to the insufficient conversion of solar energy into storable chemical energy. Photocatalysts with bulk-twinned homojunction for enhanced photocatalytic performance have received attention in recent years. In addition, it has been demonstrated that introducing sulfur vacancies is an effective approach to improving the photocatalytic performance of metal sulphides. A key factor in increasing photocatalyzed solar hydrogen production is the charge separation and limiting their recombination using stacking fault. Herein, we synthesized novel nanocrystal solid solutions of twinned wurtzite/zinc blende, CdxZn1-xS (x = 0.1, 0.3, 0.5, 0.7 and 0.9), having rich sulfur vacancies. The solid solutions were prepared via a facile alkaline-assisted hydrothermal pathway, and then the activity, morphology, and surface properties were correlated using extensive characterization techniques. It was found that the Cd0·5Zn0·5S solid solution with twinned homojunction and rich sulfur vacancies exhibited a higher solar hydrogen production activity and stability than the bare Cd0·5Zn0·5S solid solution.