Highly dispersed NiS(2) quantum dots as a promising cocatalyst bridged by acetylene black significantly improved the photocatalytic H(2) evolution performance of g-C(3)N(4) nanosheets

In this work, ternary nanocomposite (CNs–AB/NiS(2)) as a novel efficient H(2) evolution photocatalyst without the use of noble metals was successfully synthesized by depositing acetylene black (AB) and ultra-fine NiS(2) nanoparticles on the surface of CNs (g-C(3)N(4)) through ultrasonic dispersion and chemical vapor deposition methods, respectively. It was revealed that the loaded AB and NiS(2) nanoparticles have significantly improved the photocatalytic H(2) evolution efficiency of the CNs by improving the photogenerated electron–hole pair separation, visible light absorption and hydrogen evolution kinetics. Besides acting as a cocatalyst, AB served as a conductive electron bridge between CNs and NiS(2), which accelerated the effective transfer of electrons from CNs to NiS(2) and improved the H(2) evolution kinetics of the NiS(2) cocatalyst. The H(2) evolution experiments revealed that the ternary photocatalyst CNs–AB/NiS(2)10 displayed a H(2) evolution rate of up to 2434.85 μmoL g(−1) h(−1), which was a 1.41 times enhancement compared to that of the binary composite CNs–NiS(2)10 and was 12.43 times higher than that of the pure CNs. Moreover, the ternary photocatalyst CNs–AB/NiS(2)10 not only exhibited excellent photocatalytic activity and stability in the tests, but provided a novel idea for the development of high-efficiency catalysts free of noble metals as well.