The applications of sulfide in photocatalytic hydrogen production are limited due to the rapid recombination of the electron-hole pairs. In this paper, a kind of novel flower-like ternary Ni/NiS/Zn_0.2Cd_0.8S composite catalyst with twin crystals and heterojunction structure is synthesized by a multi-step method. Compared with pure Zn_0.2Cd_0.8S, the ternary Ni/NiS/Zn_0.2Cd_0.8S catalyst shows significantly a highly visible light absorption, photoelectric performance and hydrogen production, i.e., both transient photocurrent and hydrogen production rate are increased by 18 times and 83 times, respectively. Combining the theoretical calculations and experimental results, a possible photocatalytic reaction mechanism is proposed. In this catalyst, it is known that the twin crystal Zn_0.2Cd_0.8S belongs to the homojunction structure, Zn0.2Cd0.8S combines with NiS to form a heterojunction and simultaneously supports the excellent conductivity of Ni, Which therefore, the synergy of the nano-scaled NiS and Ni co-catalysts show a great improvement in separation efficiency of the photo-generated electron-hole pairs, and allows the Ni/NiS/Zn_0.2Cd_0.8S catalyst to have excellent hydrogen production performance in photocatalytic decomposition of water.

由于电子-空穴对的快速复合，硫化物在光催化制氢中的应用受到限制。本文通过多步法合成了一种新型的具有双晶结构和异质结结构的花状三元Ni / NiS / Zn _0.2 Cd _0.8 S复合催化剂。与纯Zn _0.2 Cd _0.8 S相比，三元Ni / NiS / Zn _0.2 Cd _0.8S催化剂具有明显的可见光吸收，光电性能和制氢性能，即瞬态光电流和制氢速率分别提高了18倍和83倍。结合理论计算和实验结果，提出了可能的光催化反应机理。在该催化剂中，已知双晶Zn _0.2 Cd _0.8 S属于同质结结构，Zn0.2Cd0.8S与NiS结合形成异质结并同时具有优异的Ni电导率，因此，纳米尺度的NiS和Ni助催化剂在光生电子-空穴对的分离效率上有很大提高，并且允许Ni / NiS / Zn _0.2Cd _0.8 S催化剂在水的光催化分解中具有优异的制氢性能。