Air-condition process for scalable fabrication of CdS/ZnS 1D/2D heterojunctions toward efficient and stable photocatalytic hydrogen production

We report the scalable fabrication of CdS/ZnS 1D/2D heterojunctions under ambient air conditions (i.e., room temperature and atmospheric pressure) in which ZnS nanoparticles are anchored on the surface of CdS nanosheets. The as-formed heterojunctions exhibit a significantly enhanced photocatalytic H-2 evolution rate of 14.02 mmol h(-1) g(-1) when irradiated with visible light, which is similar to 10 and 85 times higher than those of pristine CdS nanosheets and CdS nanoparticles, respectively, and superior to most of the CdS-based photocatalysts reported to date. Furthermore, they provide robust photocatalytic performance with demonstratable stability over 58 h, indicating their potential for practical applications. The formation of 1D/2D heterojunctions not only provides improved exposed active sites that respond to illumination but also provides a rapid pathway to generate photogenerated carriers for efficient separation and transfer through the matrix of single-crystalline CdS nanosheets. In addition, first-principles simulations demonstrate that the existence of rich Zn vacancies increases the energy level of the ZnS valence band maximum to construct type-II and Z-scheme mixed heterojunctions, which plays a critical role in suppressing the recombination of carriers with limited photocorrosion of CdS to enhance photocatalytic behavior.