J. Mater. Sci. Technol. ›› 2025, Vol. 231: 308-321.DOI: 10.1016/j.jmst.2024.12.102

• Research article • Previous Articles    

Photocatalytic H2 evolution over Ni3(PO4)2/twinned-Cd0.5Zn0.5S S-scheme homo-heterojunction using degradable plastics as electron donors

Jingzhuo Tiana,b,1, Chaohong Guanc,1, Qiqi Zhanga, Tao Suna, Haobin Hud,*, Enzhou Liua,b,*   

  1. aSchool of Chemical Engineering, Northwest University, Xi'an 710069, China;
    bShaanxi Key Laboratory for Carbon Neutral Technology, Xi'an 710069, China;
    cUniversity of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China;
    dGansu Key Laboratory of Efficient Utilization of Oil and Gas Resources in Longdong, Longdong University, Qingyang 745000, China
  • Received:2024-11-01 Revised:2024-12-12 Accepted:2024-12-14 Published:2025-10-01 Online:2025-03-24
  • Contact: *E-mail addresses: hhb-88@126.com (H. Hu), liuenzhou@nwu.edu.cn (E. Liu).
  • About author:1 These authors contributed equally to this work.

Abstract: The development of catalysts that can efficiently separate both bulk and interface charges is crucial for conversion and utilization of solar energy. In this study, a homo-heterojunction was fabricated by combining twinned-Cd0.5Zn0.5S (T-CZS) and Ni3(PO4)2 with crystalline water (NiPO) using a solvent evaporation strategy for efficient photocatalytic H2 evolution in water containing degradable plastics. The bulk phase of T-CZS consists of wurtzite Cd0.5Zn0.5S (WZ-CZS) and zinc blende Cd0.5Zn0.5S (ZB-CZS), they exhibit a slight difference in energy range and can form S-scheme homojunction, while NiPO and T-CZS constitute the S-scheme heterojunction, they work together to promote the separation of bulk and interface charges. This double S-scheme homo-heterojunction achieves a hydrogen evolution rate (rH2) of 73.2 mmol h-1 g-1 over 8 % NiPO/T-CZS in a solution mainly composed of polylactic acid (PLA), which exhibits an increase by factors of 243.0 and 4.5 compared to NiPO and T-CZS individually. Meanwhile, PLA plastics are degraded into organic chemicals including formic acid, acetic acid, and pyruvic acid. Moreover, NiPO exhibits (localized surface plasmon resonance) LSPR effect, which can broaden the light absorption range of the system, reduce the H2 evolution overpotential, and enhance electron utilization efficiency. Based on electron capture experiments and band theory analysis, the introducing of plastic as an electron donor further accelerates the evolution process of H2, while alkaline sodium hydroxide (NaOH) solution promotes the PLA dissociation and enhances oxidation driving force, indirectly promoting the H2 evolution kinetics of this system. The present research offers prospective solutions for engineering solar-powered H2 evolution to tackle energy challenges.

Key words: Photocatalyst, Waste plastic, Twinned Cd0.5Zn0.5S, Ni3(PO4)2, Double S-scheme, Homo-heterojunction