Noble metal-free metal-organic framework-derived onion slice-type hollow cobalt sulfide nanostructures: Enhanced activity of CdS for improving photocatalytic hydrogen production

The hollow materials have played a significant role in cutting-edge innovations for energy conversion due to their peculiar properties and their wide range of potential applications. These materials show great promise for the development of cleaner power sources to address growing environmental concerns at a time of increasing global demand for energy. Noble metal-free MOF-derived onion slice-type hollow structured Co₄S₃ was developed and embedded with CdS nanoparticles for photocatalytic hydrogen production. The incorporation of Co₄S₃ with the CdS particles effectively accelerated charge separation and transfer in photocatalytic reactions due to the low density, hollow interior, and shell permeability of the onion-type composite. The optimized Co₄S₃/CdS photocatalyst led to an enhanced rate of H₂ production of 12,360 μmol h⁻¹ g⁻¹ under simulated solar light irradiation; this value is 26-fold greater than that of the pristine CdS nanoparticles. The Co₄S₃/CdS composite exhibited remarkably stable photocatalytic performance for up to 65 h and could be reused in five successive cycles. Furthermore, to the best of our knowledge, this is the highest H₂ production rate achieved with cobalt sulfide-based CdS nanoparticle photocatalysts in the photocatalysis of water under simulated solar light irradiation. Owing to its low cost and high efficiency, this photocatalytic system should hold great potential for the development of highly efficient photocatalytic materials for use in various fields.