Nickel doping as an effective strategy to promote separation of photogenerated charge carriers for efficient solar-fuel production

Abstract

Enhancing the utilization of visible light and promoting the separation of photogenerated charge carriers are critical to improve the performance of semiconductor photocatalysts. Herein, nickel, a low cost transition metal element, was doped into the crystal lattices of ZnIn₂S₄ microspheres which were composed of ultra-thin nanosheets, via a simple one-pot hydrothermal approach. As evidenced by the UV-vis diffuse reflection spectra (DRS) and photoluminescence spectra (PL), Ni doping simultaneously increases the light absorption and charge transport efficiency of ZnIn₂S₄. The modified photocatalyst achieves an excellent performance in both photocatalytic H₂ evolution and CO₂ reduction without any co-catalyst. And the doped Ni did not change the surface reaction kinetics of ZnIn₂S₄. This elemental doping strategy presents a facile pathway to enhance the photocatalytic activity of ZnIn₂S₄.