Hollow dodecahedral Zn0.3Cd0.7S@NiCo-mixed metal oxide p-n heterojunction with high-efficiency photocatalytic hydrogen production activity

The growing demand for clean and sustainable energy has driven extensive research into efficient photocatalysts for hydrogen production. However, many semiconductor photocatalysts in this field still face the challenges such as wide band gap, limited visible light absorption, and inefficient separation and transport of photoinduced charges. In this study, nickel–cobalt layered double hydroxide (NiCo-LDH) was synthesized using an “etch-and-grow” method with zeolitic imidazolate framework-67 (ZIF-67) as a sacrificial template, followed by high-temperature calcination to produce nickel–cobalt mixed metal oxide (NiCo-MMO). Zn 0.3 Cd 0.7 S quantum dots were used to modify NiCo-MMO resulting in a hollow dodecahedral Zn 0.3 Cd 0.7 S@NiCo-MMO composite photocatalyst. In hydrogen production performance test, the optimized Zn 0.3 Cd 0.7 S@NiCo-MMO exhibited excellent performance (8177.5 μmol·g −1 ·h −1 ) and demonstrated good cycling stability. The hollow dodecahedral structure of the Zn 0.3 Cd 0.7 S@NiCo-MMO enhanced the light trapping ability and provided large surface area. The p-n heterojunction formed within Zn 0.3 Cd 0.7 S@NiCo-MMO accelerated carrier separation and transfer, effectively inhibited the recombination of photogenerated electrons and holes, and significantly improved the hydrogen production activity.