Precise design and construction of NiO-Ni heterostructures for active hydrogen evolution photocatalysis

The design of metal-oxide-metal heterostructure photocatalysts is an effective and widely used approach to solve global environmental problems. In this work, we designed and prepared a NiO-rich NiO-Ni heterostructure in an N-doped carbon matrix as a photocatalyst using a simple chemical method for hydrogen evolution reactions. It has an optimal photocatalytic hydrogen production rate of 1395 μmol. g−1. h−1, which is ∼8 times higher than that of Ni rich NiO-Ni (178 μmol. g−1. h−1). Combined experimental results demonstrate that such a good performance benefits from the specific NiO-Ni interface, which could improve the utilization of sunlight and charge separation efficiency. Moreover, this interface contributes to improved structural stability during the photocatalytic reactions, ensuring superior catalytic performance. This work provides a new strategy for the design and synthesis of efficient precious-metal-free heterostructure catalysts for photocatalytic hydrogen evolution reactions.