Manganese Cadmium Sulfide Nanoparticles Solid Solution on Cobalt Acid Nickel Nanoflakes: A Robust Photocatalyst for Hydrogen Evolution

Graphical Close to the edge : A Mn 0.25 Cd 0.75 S/NiCo 2 O 4 p–n heterostructure is synthesized through a hydrothermal method and shows a high photocatalytic H 2 evolution rate of 61159 μmol g −1 h −1 . The band edge position is estimated by the core level alignment method, which affords a deeper understanding of the p–n heterostructure. Photocatalytic water splitting for hydrogen evolution is one of the most promising methods to mitigate environmental and energy-related issues. In this study, manganese cadmium sulfide (Mn x Cd 1- x S) solid solution is used to construct a p–n heterostructure with NiCo 2 O 4 through a hydrothermal method. The Mn 0.25 Cd 0.75 S/NiCo 2 O 4 composites are used for photocatalytic hydrogen evolution reaction, and the optimal hydrogen rate with 40 mg of Mn 0.25 Cd 0.75 S/NiCo 2 O 4 40 mg (MCS/NCO 40) is 61159 μmol g −1 h −1 , which is about 16.3 times than that of pure Mn 0.25 Cd 0.75 S. After combining with NiCo 2 O 4 , the light absorption scale, the separation efficiency of photogenerated carriers, and the reaction kinetics are enhanced. Moreover, the band offset of MCS/NCO composites is calculated by the core level alignment method, demonstrating the formation of a p–n heterostructure. The built-in electric field from the p–n heterostructure drives charge transfer and enhances separation efficiency, which results in improved photocatalytic performance.