Ni-modified CdS/TiO2 heterostructures for efficient noble-metal-free visible-light hydrogen production

Visible-light-driven photocatalytic hydrogen production is a promising route for sustainable fuel generation; however, its efficiency is limited by rapid charge recombination and the frequent use of noble-metal cocatalysts. Herein, Ni-modified CdS/TiO 2 heterostructures are synthesized through sequential CdS incorporation and light-assisted alkaline deposition of Ni-containing species. Structural, optical, surface, and photoelectrochemical analyses indicate intimate CdS/TiO 2 interfacial contact, reduced radiative recombination, and favorable interfacial charge-transfer behavior. The best-performing TiCdNi0.7 photocatalyst achieves a hydrogen evolution rate of 4352 μmol-H 2 /g cat ·h, corresponding to a 12.7-fold increase relative to Ni-free TiCd. After 20 h of cycling, TiCdNi0.7 retains 75.2% of its initial activity, while the main crystalline phases remain largely preserved despite surface chemical changes. These results demonstrate an effective noble-metal-free strategy for visible-light-driven H 2 evolution through controlled semiconductor-interface and Ni-surface engineering.