Novel CdLa2S4/Ni2P photocatalyst with boosting H2 evolution: Heterostructures promote photogenic carrier interface separation

Abstract

Metal sulfides, often exhibited excellent photocatalytic H2 evolution ability, has attracted more and more attention, whereas their industry applications were limited due to the photocorrosion. Therefore, the inhibition of photocorrosion is the key issue to promote the industrialization of metal sulfide catalysts. In this work, CdLa2S4 /Ni2P catalysts with satisfactory H2 evolution property were designed and synthesized. Catalyst with 15 % Ni2P dosage exhibited maximum photocatalytic H2 evolution rate as 1.143 mmolh-1g−1, which was 10 times higher than that of pure CdLa2S4. Such high catalytic efficiency maintained after 5 photocatalytic cycles. According to the results of transient photocurrent and photoluminescence, the heterojunction structure formed by Ni2P and CdLa2S4 improved the separation efficiency of photogenerated electron-hole pairs, thus prompted the H2 evolution ability and the catalyst stability. Further EPR results confirmed the existence of heterojunctions in the catalyst and proposed a possible reaction mechanism. The results show that the CdLa2S4/Ni2P composite photocatalyst has good visible light response and photochemical stability, and has broad application prospects in solar driven photocatalytic decomposition of water to hydrogen production.