An efficient ternary photocatalyst via anchoring nickel complex and nickel oxides onto carbon nitride for visible light driven H2 evolution

Abstract

Developing earth abundant, active and stable photocatalysts for water splitting is a critical but challenging procedure for efficient conversion and storage of sustainable energy. Here, a ternary photocatalyst was rationally prepared for efficient H2 production by covalently anchoring a nickel molecule cocatalyst (NiL) onto graphitic carbon nitride nanosheets (CN) and introducing nickel oxides (NiOx) as hole-transport materials. The lower H2 overpotential by NiL and the faster separation of photoinduced carriers by NiOx nanoparticles account for the efficient H2 generation of CN without the help of noble metals. Eventually, the prepared NiL/NiOx/CN catalyst exhibited excellent performance for H2 evolution (289 μmol g−1 h−1) in TEOA solution under visible light irradiation, which is superior to 3NiL/CN (161 μmol g−1 h−1) and CN (Null). Furthermore, a possible mechanism of photocatalytic H2 production for NiL/NiOx/CN is proposed based on a series of electrochemical measurements. The noble-metal-free photocatalyst developed in this work will pave a new way to synthesize low-cost multicomponent photocatalysts for solar conversion.