In situ one-pot fabrication of g-C3N4 nanosheets/NiS cocatalyst heterojunction with intimate interfaces for efficient visible light photocatalytic H2 generation

Abstract Constructing high-quality earth-abundant semionconductor/cocatalyst heterojunction remains a grand challenge in the promising fields of photocatalytic solar fuel H 2 production. Herein, an intimate g-C 3 N 4 nanosheet/NiS cocatalyst heterojunction is fabricated by in situ one-step calcination of urea, thiourea and nickel acetate. Interestingly, thiourea could act as both the precursor of g-C 3 N 4 and the sulfur source of NiS. The H 2 -evolution activity of as-obtained photocatalysts was tested in a triethanolamine (TEOA) scavenger solution under visible light irradiation. Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) mapping analysis clearly demonstrated that the NiS catalyst nanoparticles could be in situ fabricated and homogeneously distributed on the surface of g-C 3 N 4 nanosheets without an obvious aggregation. The maximum H 2 -production rate of 29.68 μmol h −1 could be achieved, which is nearly comparable to that of 0.5 wt% Pt loaded sample. It is believed that the intimate heterojunction interfaces between NiS nanoparticles and g-C 3 N 4 nanosheets could be in situ constructed by high temperature calcination, which achieved the improved charge separation, the enhanced oxidation ability of TEOA and the accelerated the sluggish H 2 -evolution kinetics, thus resulting in the remarkably enhanced hydrogen evolution. Therefore, our study provides insights into constructing high-quality robust g-C 3 N 4 -based heterojunction material for photocatalytic applications by using a simple one-step in-situ calcination technique.