Noble metal-free bimetallic NiCo decorated Zn0.5Cd0.5S solid solution for enhanced photocatalytic H2 evolution under visible light

• Published in: International journal of hydrogen energy 2020-03, Vol.45 (15), p.8300-8309
• Main Authors: Li, Yunjiao, Zhang, Dianwei, Xi, Xiaoming, Shen, Yujun, Chang, Shenghong, Zhu, Jie, Chen, Yongxiang, Jiang, Liangxing, Zhang, Jian
• Format: Article
• Language: English
• Subjects: NiCo cocatalyst; Photochemical and HER; Zn0.5Cd0.5S solid solution
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2020.01.154

As we know, noble metal (Pt, Pd and Au) with appropriate adsorption free energy of H atoms and higher work function as cocatalyst has been considered to be an effective tactic to enhance photocatalytic activity. However, they are limited severely by scarcity and high-cost. Herein, Zn0.5Cd0.5S solid-solution photocatalyst decorated with noble metal-free NiCo cocatalyst has been successfully obtained through one-step photochemical route. It is found that the lifespan of charge carriers of Zn0.5Cd0.5S@NiCo can be prolonged dramatically after modification, and the photocatalytic H2 rate reach to 34.7  mmol g−1·h−1 is nearly 9 times higher than the bare Zn0.5Cd0.5S (λ ≥ 420 nm). The superior photocatalytic activity for ZCS@NiCo could be mainly ascribed to higher separation and transfer efficiency of photogenerated carriers by introduced bimetallic NiCo cocatalysts possessing the superior electron transfer property and reducing the onset over-potential of water reduction, which was proved by experiment. This study can provide a potential strategy to design a more efficient noble metal-free cocatalyst over photocatalyst. •The ZCS@NiCo composite photocatalyst is constructed via photochemical routine.•The constructed composite with excellent photocatalytic activity for H2-production.•Charge carriers have been transferred and separated efficiently via the synergistic effect of bimetallic NiCo.•A possible mechanism for photocatalytic H2-production was proposed.