Acta Phys. -Chim. Sin. ›› 2025, Vol. 41 ›› Issue (6): 100068.doi: 10.1016/j.actphy.2025.100068

Special Issue: S-scheme heterojunction in photocatalysis

• ARTICLE • Previous Articles    

Waste plastics promoted photocatalytic H2 evolution over S-scheme NiCr2O4/twinned-Cd0.5Zn0.5S homo-heterojunction

Jingzhuo Tian1,2, Chaohong Guan3, Haobin Hu4, Enzhou Liu1,2,*(), Dongyuan Yang5,*()   

  1. 1 School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials, Northwest University, Xi'an 710127, Shaanxi Province, China
    2 Shaanxi Key Laboratory for Carbon Neutral Technology, Xi'an 710069, Shaanxi Province, China
    3 University of Michigan?Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China
    4 Gansu Key Laboratory of Efficient Utilization of Oil and Gas Resources in Longdong, Longdong University, Qingyang 745000, Gansu Province, China
    5 School of Chemistry and Chemical Engineering, Xi'an University of Science and Technology, Xi'an 710054, Shaanxi Province, China
  • Received:2025-01-15 Revised:2025-02-16 Accepted:2025-02-18 Published:2025-04-19
  • Contact: Email: liuenzhou@nwu.edu.cn (Enzhou Liu)yangdongyuan885@163.com (Dongyuan Yang)
  • Supported by:
    the Local Science and Development Fund Project Guided by the Central Government(24ZYQM001); the National Natural Science Foundation of China(22378326); the National Natural Science Foundation of China(11974276); the National Natural Science Foundation of China(22078261); the Natural Science Basic Research Program of Shaanxi Province(2023-JC-YB-115); the Shaanxi Key Science and Technology Innovation Team Project(2022TD-33); the Excellent Doctoral Dissertation Cultivation Program at Northwestern University(YB2024012); the Program of China Scholarship Council(202406970056)

Abstract:

The simultaneous enhancement of separation and utilization of bulk and surface charges is crucial for achieving efficient photocatalytic H2 evolution reactions. In this study, NiCr2O4/T-CZS composites were fabricated by incorporating NiCr2O4 nanosheets onto the surface of twinned Cd0.5Zn0.5S (T-CZS) nanoparticles using a solvent evaporation strategy. After optimization, the 6% NiCr2O4/T-CZS exhibited an impressive hydrogen (H2) evolution rate (rH2) of 81.4 mmol∙h−1∙g−1 when employing polylactic acid (PLA) plastic as a sacrificial agent in NaOH solution. The reason behind this can be mainly attributed to the fact that T-CZS consists of wurtzite Cd0.5Zn0.5S (WZ-CZS) and zinc blende Cd0.5Zn0.5S (ZB-CZS) with slight band structure differences, thereby facilitating rapid bulk phase and interface charge separation due to the S-scheme charge transfer routes between WZ-CZS and ZB-CZS, as well as T-CZS and NiCr2O4. Moreover, this system can effectively retain electrons with strong reducing ability for efficient H2 evolution reaction (HER) and generate hot electrons through the localized surface plasmon resonance (LSPR) effect of NiCr2O4, which enhances the absorption of UV-Vis-NIR light energy, thereby facilitating the HER process. What's more, NaOH solution can indirectly promote the HER kinetics by enhancing the oxidative driving force of holes. Additionally, other metal chromates (MCrxOy), such as CoCr2O4, AgCrO2, Bi6CrO12, BaCrO4, ZnCr2O4, CdCr2O4, CuCr2O4 etc., were employed to enhance the activity of T-CZS too. The results show that above homo-heterojunction composites can integrate waste plastic degradation and photocatalytic H2 evolution effectively based on their S-scheme bulk phase and interface charge separation mechanisms. This work provides new insights into energy and environmental challenges.

Key words: Photocatalyst, Twinned Cd0.5Zn0.5S, NiCr2O4, Double S-scheme, Homo-heterojunctions, Waste plastic