Novel photocatalyst incorporating Ni-Co layered double hydroxides with P-doped CdS for enhancing photocatalytic activity towards hydrogen evolution

Abstract

Abstract Designing durable and highly active photocatalysts for hydrogen evolution via water splitting is still very challenging. Novel NiCo-LDH/P-CdS hybrid photocatalysts are fabricated by combining strategies of P-doping and in-situ loading of NiCo-LDH. P-doping creates a mid-gap at the bottom of the conduction band of CdS, which facilitates to prolong the life-time of the photo-induced electrons. Subsequently, the in-situ loading of NiCo-LDH is able to form heterojunctions between NiCo-LDH and P-CdS that not only promote the separation efficiency of carriers, but also effectively reduce the light corrosion phenomenon commonly observed in CdS. The as-prepared 2 mol% NiCo-LDH/40 wt% P-CdS sample shows a high visible-light catalytic H2 production rate of 8.665 mmol·h−1 g−1, which is 45 times higher than pure CdS. The apparent quantum yield is determined to be 14.0% at 420 nm monochromatic light. Based on the calculation of density function theory (DFT), the rational photocatalytic mechanism has been proposed and is well consistent with the experimental results. Our study not only demonstrates a facile, eco-friendly and scalable strategy to synthesize highly efficient photocatalysts, but also provides a new viewpoint of the rational design and synthesis of advanced photocatalysts by harnessing the strong synergistic effects through simultaneously tuning and optimizing the electronic structure and surface.