Chinese Journal of Catalysis ›› 2027, Vol. 92: 219-236.DOI: 10.1016/S1872-2067(26)65232-1

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WO3/PHI S-scheme heterojunction with photoinduced dual defects for highly selective photocatalytic CO2-to-CO conversion

Mengxuan Liua, Rongxin Zhangb, Xin Zhangb,*(), Yanfeng Zhanga,*()   

  1. a National Demonstration Center for Experimental Chemistry Education, Hebei Key Laboratory of Inorganic Nano-materials, College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang 050024, Hebei, China
    b Hubei Key Laboratory of Low Dimensional Optoelectronic Materials and Devices, Hubei University of Arts and Science, Xiangyang 441053, Hubei, China
  • Received:2026-06-22 Accepted:2026-08-11 Online:2027-01-02 Published:2026-10-30
  • Contact: *E-mail: zhangyanfeng@hebtu.edu.cn (Y. Zhang),
    xinzhang@hbuas.edu.cn (X. Zhang).
  • Supported by:
    Hebei Provincial Natural Science Foundation(B2022205008);Innovation Capability Improvement Plan Project of Hebei Province(22567604H);Joint Foundation for Innovation and Development of Hubei Natural Science Foundation(JCZRLH202600137)

Abstract:

Photocatalytic CO2 reduction, which converts solar energy into chemical energy, represents a highly promising strategy. However, conversion efficiency is often constrained by the poor adsorption and activation of CO2 and H2O molecules. Here, we report an oxygen and nitrogen-vacancy-enriched WO3/poly(heptazine imide) (PHI) S-scheme heterojunction for efficient and selective CO2 photoreduction. The optimized WO3/PHI heterojunction delivers a CO evolution rate of 129.2 μmol g-1 h-1 with 96.1% selectivity, corresponding to 7.9- and 6.5-fold enhancements over pristine WO3 and PHI, respectively. Experiments and theoretical calculations demonstrate that the in-situ formed and photoinduced dual vacancies facilitate adsorption of CO2 and H2O, thereby improving the efficiency of photocatalytic CO2 reduction. The interfacial W-N bonds serve as critical channels to accelerate interfacial charge transfer across the WO3/PHI heterojunction. The S-scheme charge-transfer pathway, in concert with a dual-defect interfacial architecture, promotes charge transport, substantially boosting CO2 reduction performance. This work provides mechanistic insight into defect-assisted S-scheme photocatalysis and offers a rational strategy for designing efficient photocatalysts for solar fuel production.

Key words: S-scheme heterojunction, WO3/poly(heptazine imide), Dual defect, Synergistic effect, Photocatalytic mechanism