Ternary noble-metal-free heterostructured NiS-CuS-C3N4 with near-infrared response for enhanced photocatalytic hydrogen evolution

Fast charge recombination and limited visible-light absorption often hinder the practical applications of graphitic carbon nitride (g-C3N4) for photocatalytic hydrogen evolution. In this work, we report the synthesis of ternary heterostructured noble-metal-free NiS-CuS-C3N4 with near-infrared (NIR) response for enhanced solar light hydrogen evolution from water. At an optimal 7% NiS-3% CuS-C3N4 composition, a H-2-evolution rate of 1602 mu mol g(-1) h(-1) can be achieved. The apparent quantum efficiency at 400 nm and 940 nm was measured to be 9.7% and 0.44%, respectively. Based on detailed analysis, the reasonable mechanism is proposed and the significantly enhanced photocatalytic performance should be attributed to dramatically improved charge transfer through type-II hetero-junction and NiS cocatalyst. Additionally, the computational study is employed to help explain the promotion of NiS. In this case, this work might provide a platform for the construction of efficient noble-metal-free C3N4-based ternary heterostructured photo catalysts in the future. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.