Ultrathin Ni(OH)2 nanosheets decorated with Zn0.5Cd0.5S nanoparticles as 2D/0D heterojunctions for highly enhanced visible light-driven photocatalytic hydrogen evolution

Abstract

Designing and fabricating highly efficient photocatalysts for water splitting is a promising strategy to address energy and environmental issues. Cadmium sulfide (CdS) has received significant interest as a photocatalyst for visible-light-induced hydrogen (H2) generation. However, the severe photocorrosion, high overpotential, rapid charge recombination, and sluggish surface reaction kinetics drastically hinder its practical application in water splitting. Herein, uniform zinc cadmium sulfide (Zn0.5Cd0.5S) nanoparticles were anchored on ultrathin Ni(OH)2 nanosheets via a facile solution-phase approach to form an intimate two-dimensional (2D)/zero-dimensional (0D) heterojunction. Under visible light irradiation, the 7%Ni(OH)2/Zn0.5Cd0.5S composite exhibited the highest H2 production rate of 6.87 mmol·h−1·g−1 with an apparent quantum yield of 16.8% at 420 nm, which is almost 43 times higher than that of pristine Zn0.5Cd0.5S and considerably higher than that of the Pt/Zn0.5Cd0.5S photocatalyst. The high photoactivity of the 2D/0D Ni(OH)2/Zn0.5Cd0.5S heterojunction can be ascribed to its unique and robust structure, wherein the ultrathin Ni(OH)2 nanosheets not only provide an excellent platform for the incorporation of Zn0.5Cd0.5S nanoparticles but also serve as an effective cocatalyst to promote photoinduced electron transfer and offer more active sites for photocatalytic H2 generation. This work paves the way toward the development of versatile, low-cost, and highly efficient 2D/0D heterojunction photocatalysts for solar energy conversion.