Interfacial Heterojunction Formation Modulating the Charge Carrier’s Pathway of CdS@CoSe₂/WS₂ Nanocomposites for Enhanced Photocatalytic Hydrogen Evolution

Hydrogen fuel production via solar-assisted water splitting offers a promising route toward carbon neutrality by addressing energy and environmental problems. Producing hydrogen on a large scale and at an affordable price requires the development of extremely efficient photocatalysts. Therefore, we designed a noble-metal-free ternary heterojunction comprising 1D CdS nanorods, 2D WS2 nanosheets, and metal–organic framework (ZIF-67)-derived CoSe2 nanostructures. The fabricated CdS@CoSe2/WS2 nanocomposite exhibits good photostability and a high hydrogen yield of 246.98 mmol g–1 h–1 owing to its strong visible light harvesting capabilities and optimum band edge levels. Moreover, the as-obtained nanocomposites offer numerous active sites to trigger strong light reflection, which boosts their absorption capacity and plays a major role in alleviating the charge carrier transport rate to permit their separation. We believe that the present work opens up new possibilities for the development of a CdS-based photocatalyst for enhanced photocatalytic hydrogen production in the visible-light region.