Effective Electron–Hole Separation Over Controllable Construction of CdS/Co-Ni-P Core/Shell Nanophotocatalyst for Improved Photocatalytic Hydrogen Evolution Under Visible-Light-Driven

Abstract

In artificial photocatalysis, the slow kinetics of electron–hole transfer and high charge recombination rate have been the Achilles heel of photocatalytic conversion efficiency. Therefore, methods for promoting exciton splitting and charge separation have received sustained attention. Here, Co-Ni-P is used as a molecular cocatalyst, which is designed onto the surface of cadmium sulfide nanorods. CdS-Co-Ni-P constitutes a unique CdS/Co-Ni-P core/shell structure, which is a new type of efficient heterostructure photocatalysts used for photocatalytic decomposition of water to produce hydrogen. The modification strategy maximizes the contact area between the cocatalyst and the reactant, which effectively increases the light absorption capacity of the composite catalyst, reduces the overpotential of generating hydrogen, and accelerates the interface transfer rate of electron–hole pairs, thus achieving better photocatalytic decomposition of water. The reaction kinetics of the reduction is enhanced. Compared with pure CdS of the same quality, the optimal photocatalyst CdS-Co-Ni-P has a hydrogen evolution rate of 9.67 mmol g−1 h−1, which is about 5.3 times that of pure CdS. This work demonstrates that the new and efficient CdS/Co-Ni-P core/shell photocatalyst has great potential for photocatalytic production of H2.