Optimizing hydrogen adsorption of NixB cocatalyst by integrating P atom for enhanced photocatalytic H2-production activity of CdS

Abstract

Developing low-cost and long-lasting nickel boride (NixB) for hydrogen evolution reaction is desirable to favor the present renewable energy system. However, H atom adsorption on Ni active site is weakened by the electron transfer from B to Ni atom in NixB, causing the inhibited hydrogen-evolution process. Herein, the metalloid P is introduced into NixB to regulate the electron density of Ni active site, with the aim of enhancing its H atom adsorption to boost the photocatalytic H2-production activity of CdS. In this regard, the NixPB cocatalysts with a size of 8–10 nm are loaded on reduced graphene oxide (rGO) to produce NixPB-rGO cocatalyst, which was well coupled with CdS to prepare the NixPB-rGO/CdS photocatalyst. Photocatalytic hydrogen-evolution tests suggested that the NixPB-rGO/CdS photocatalyst displayed the highest H2-evolution rate of 5.79 mmol h−1 g−1, which is 1.8 and 9.9 times over the NixB-rGO/CdS and rGO/CdS photocatalysts, respectively. The above improved activity of NixPB-rGO/CdS photocatalyst can be attributed to the promoting hydrogen adsorption of Ni atom for efficient interfacial H2 production via the facile introduction of P heteroatom. This work provides a feasible strategy to optimize the transition metal borides cocatalysts for the photocatalytic H2 evolution.