J. Mater. Sci. Technol. ›› 2025, Vol. 233: 201-209.DOI: 10.1016/j.jmst.2025.03.005

• Research article • Previous Articles     Next Articles

Enhanced charge carrier transport in TiO2/COF S-scheme heterojunction for efficient photocatalytic H2O2 production

Yang Liua, Meng Lia,b,*, Tao Liua, Zhen Wuc, Liuyang Zhanga,*   

  1. aLaboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan 430078, China;
    bGuangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning 530001, China;
    cDepartment of Chemical Engineering, Ordos Institute of Technology, Ordos 017000, China
  • Received:2025-02-21 Revised:2025-03-17 Accepted:2025-03-17 Published:2025-10-20 Online:2025-11-05
  • Contact: *E-mail addresses: limeng_2016@126.com (M. Li), zhangliuyang@cug.edu.cn (L. Zhang).

Abstract: Hydrogen peroxide (H2O2) is a crucial oxidant with diverse industrial applications, yet its conventional synthesis suffers from high energy consumption and hazardous byproducts. Photocatalysis offers a sustainable alternative, but its efficiency is often compromised by rapid charge recombination. Herein, we reported the rational design of a TiO2/TD-COF S-scheme heterojunction, which achieved a remarkable H2O2 production rate of 2162.3 µmol g-1 h-1, representing almost 14-fold enhancement compared to pristine TiO2. Through in-situ irradiated X-ray photoelectron spectroscopy (ISI-XPS) and femtosecond transient absorption spectroscopy (fs-TAS), we demonstrate an ultrafast charge transfer driven by internal electric field (IEF) that efficiently separates photogenerated carriers while preserving their redox potentials. Furthermore, in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and electron paramagnetic resonance (EPR) spectroscopy provide direct experimental evidence for the dual-pathway mechanism, involving both the oxygen reduction reaction (ORR) and water oxidation reaction (WOR). This work demonstrates the potential of S-scheme heterojunction in overcoming the limitations of traditional photocatalytic systems, offering a scalable and sustainable approach for solar-driven H2O2 production.

Key words: TiO2 nanofiber, COF, S-scheme heterojunction, H2O2, Femtosecond transient absorption spectroscopy