Visible light active Ni-doped SnS₂/g-C₃N₄ type-II heterojunction for enhanced photoelectrochemical performance

Abstract This study presents an effective strategy to enhance the PEC performance of bare SnS 2 by incorporating Ni into SnS 2 nanosheets and then forming type-II heterojunction with g-C 3 N 4 nanosheets. The Ni-SnS 2 /g-C 3 N 4 photoanode shows a significantly enhanced photocurrent density of around 3.5 mA cm −2 , which is about 1.4 times higher than Ni-SnS 2 and ∼11.6 times greater than SnS 2 at 1.0 V with respect to Ag/AgCl. The Ni-SnS 2 /g-C 3 N 4 photoanode achieves an incident photon-to-current conversion efficiency (IPCE) of approximately 16.1%, whereas Ni-SnS 2 and SnS 2 exhibit IPCE values of ∼13.0% and ∼0.6%, respectively. The enhanced PEC performance of Ni-SnS 2 /g-C 3 N 4 is attributed to the extended optical absorption spectrum and enhanced photocatalytic activity. The synergistic effect of Ni-doping and type-II heterojunction of Ni-SnS 2 with g-C 3 N 4 facilitates efficient electron migration from g-C 3 N 4 to Ni-SnS 2 , which minimizes recombination losses.