Acta Phys. -Chim. Sin. ›› 2025, Vol. 41 ›› Issue (8): 100084.doi: 10.1016/j.actphy.2025.100084

Special Issue: S-scheme heterojunction in photocatalysis

• ARTICLE • Previous Articles     Next Articles

CdS/DBTSO-BDTO S-scheme photocatalyst for H2 production and its charge transfer dynamics

Jiajie Cai1, Chang Cheng2, Bowen Liu1, Jianjun Zhang2,*(), Chuanjia Jiang3,*(), Bei Cheng1,*()   

  1. 1 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, Hubei Province, China
    2 Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430078, Hubei Province, China
    3 College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
  • Received:2025-02-20 Revised:2025-03-10 Accepted:2025-03-24 Published:2025-06-07
  • Contact: Email: zhangjianjun@cug.edu.cn (Jianjun Zhang)jiangcj@nankai.edu.cn (Chuanjia Jiang)chengbei2013@whut.edu.cn (Bei Cheng)
  • Supported by:
    the National Key Research and Development Program of China(2022YFB3803600); the National Natural Science Foundation of China(22238009); the National Natural Science Foundation of China(22361142704); the National Natural Science Foundation of China(22261142666); the National Natural Science Foundation of China(22278324); the National Natural Science Foundation of China(52073223); the Natural Science Foundation of Hubei Province of China(2022CFA001); the Fundamental Research Funds for the Central Universities(63241632)

Abstract:

Photocatalytic hydrogen (H2) production is a clean energy technology, with great potential for addressing the global energy crisis and related environmental problems. However, single-component photocatalysts often suffer from low efficiency primarily due to fast charge carrier recombination and the tradeoff between light-absorbing capacity and redox capabilities. Constructing heterojunctions provides a promising strategy to overcome these drawbacks, and S-scheme heterojunctions have recently stood out, demonstrating the capability to efficiently facilitate electron/hole separation, while maximizing the redox capability. Among them, polymer-based S-scheme photocatalysts are emerging, though the charge carrier dynamics in inorganic-organic S-scheme heterojunctions remain to be elucidated. Herein, we fabricated an S-scheme heterojunction comprised of the conjugated polymer dibenzothiophene-S, S-dioxide-alt-benzodithiophene (DBTSO-BDTO) and cadmium sulfide (CdS) for photocatalytic H2 production. The S-scheme mechanism was verified using in situ irradiated X-ray photoelectron spectroscopy, and the charge carrier transfer dynamics were analyzed in depth using femtosecond transient absorption spectroscopy, which revealed that a considerable fraction of electrons undergo interfacial charge transfer in the CdS/DBTSO-BDTO composite. Owing to the improved charge separation efficiency and redox capability, the performance of the composite surpassed that of DBTSO-BDTO and CdS, and the H2 evolution rate of the optimized CdS/DBTSO-BDTO material reached 3313 μmol·h−1·g−1, three times that of pure CdS. The findings provide new insights into the electron transfer mechanisms of S-scheme heterojunctions, and can guide the design of polymer-based photocatalysts for solar fuel production.

Key words: Photocatalysis, Cadmium sulfide, S-scheme heterojunction, H2 production, Femtosecond transient absorption spectroscopy