Chinese Journal of Catalysis ›› 2027, Vol. 92: 1-36.DOI: 10.1016/S1872-2067(26)65276-X

• Reviews •     Next Articles

S-scheme heterojunctions for coupled redox photocatalysis: Orchestrating electron-hole synergy to unlock dual half-reactions

Banghu Wei, Wei Ren, Jinhe Li, Weikang Wang, Qinqin Liu*()   

  1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, Jiangsu, China
  • Received:2026-06-11 Accepted:2026-07-21 Online:2027-01-02 Published:2026-10-30
  • Contact: *E-mail: qqliu@ujs.edu.cn (Q. Liu).
  • About author:Qinqin Liu, (Professor and Ph.D. Supervisor at the School of Materials Science and Engineering, Jiangsu University, is a young academic leader of Jiangsu University. Her research interests mainly focus on the design and synthesis of nanomaterials and photo(electro)catalytic materials, as well as their applications in energy conversion and environmental remediation. She currently serves as a member of the Photocatalysis Professional Committee of the Chinese Society of Imaging Science and Technology, a young council member of the Chinese Society of Imaging Science and Technology, a member of the Chinese Chemical Society, a member of the Jiangsu Materials Society, and a young editorial board member of Chinese Journal of Catalysis, Acta Physico-Chimica Sinica, and Chinese Journal of Structural Chemistry. She also serves as a reviewer for several international academic journals. She has led more than 10 research projects, including projects supported by the National Natural Science Foundation of China. In recent years, she has published more than 200 SCI-indexed papers in internationally renowned journals, including Angewandte Chemie International Edition, Nano Letters, and National Science Review, with over 6000 citations and an H-index of 54. She has received the Second Prize of the Science and Technology Invention Award of the Ministry of Education, and has been granted 10 Chinese invention patents and 1 PCT international patent.)
  • Supported by:
    National Natural Science Foundation of China(22102064);National Natural Science Foundation of China(22472069)

Abstract:

Against the backdrop of the global "dual-carbon" strategy, solar-driven photocatalysis emerges as a promising avenue for clean energy conversion and carbon neutralization. However, conventional single photocatalysts suffer from rapid carrier recombination and mismatched redox reaction kinetics, severely limiting their catalytic performance. Different from conventional heterojunctions that compromise redox potential for enhanced charge separation, S-scheme heterojunctions feature a unique band alignment that selectively eliminates useless low-energy carriers via interfacial recombination. This configuration preserves high-energy electrons and holes with robust redox capabilities, fundamentally resolving the intrinsic trade-off between charge separation efficiency and thermodynamic redox driving force in photocatalysis. Based on this working principle, this review systematically elucidates the efficient utilization mechanism of electron-hole pairs in S-scheme heterojunctions, with a specific focus on the synergistic promotion mechanism between paired reduction and oxidation half-reactions in photocatalytic redox coupling systems. We highlight three major categories of reduction reactions—hydrogen production, CO2 reduction, and H2O2—coupled with diversified value-added oxidation processes (e.g., organic molecule oxidation, biomass upgrading, and pollutant oxidative degradation). Through the rational regulation of active site construction, band structure engineering, and interfacial charge modulation in S-scheme heterojunctions, the reaction kinetics, conversion efficiency, and catalytic pathways of both reduction and oxidation half-reactions can be synchronously optimized, which substantially improves the atom utilization efficiency and overall economic value of solar energy photocatalytic conversion. This review systematically clarifies the intrinsic correlation and synergistic mechanism between S-scheme heterojunction design and dual-reaction coupling catalysis, aiming to provide feasible theoretical guidance and technical roadmaps for the rational construction of high-efficiency, low-cost, and multifunctional solar-driven photocatalytic systems.

Key words: S-scheme heterojunction, Dual reactions, Charge separation, Electron-hole synergy, Redox photocatalysis