J. Mater. Sci. Technol. ›› 2025, Vol. 214: 255-265.DOI: 10.1016/j.jmst.2024.07.015

• Research Article • Previous Articles     Next Articles

Carbon quantum dots and interfacial chemical bond synergistically modulated S-scheme Mn0.5Cd0.5S/BiOBr photocatalyst for efficient water purification

Shijie Lia, Changjun Youa, Qingquan Xueb,*, Yiqian Zhaoa, Fang Yangc, Yanping Liua, Lina Baid, Mingyi Zhangd,*, Chunqiang Zhuange,*   

  1. aKey Laboratory of Health Risk Factors for Seafood of Zhejiang Province, National Engineering Research Center for Marine Aquaculture, Zhejiang Ocean University, Zhoushan 316022, China;
    bKey Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China;
    cSchool of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China;
    dKey Laboratory for Photonic and Electronic Bandgap Materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin 150025, China;
    eInstitute of Microstructure and Property of Advanced Materials, Beijing University of Technology, Beijing 100124, China
  • Received:2024-06-10 Revised:2024-07-03 Accepted:2024-07-13 Published:2025-04-10 Online:2025-04-05
  • Contact: *E-mail addresses: qingquanxue@zjsru.edu.cn (Q. Xue), zhangmingyi@hrbnu.edu.cn (M. Zhang), chunqiang.zhuang@bjut.edu.cn (C. Zhuang)

Abstract: Devising robust S-scheme photocatalysts is of central importance for achieving high-efficient micropollutant decontamination. However, the conscious optimization of S-scheme system with high performance remains a prime challenge. Herein, carbon quantum dots (CDs) and Mn0.5Cd0.5S (MCS) are mounted on BiOBr (BOB) microspheres, establishing an advanced S-scheme heterojunction with interfacial Bi-S bond. The interfacial Bi-S bonds function as superb channels at atomic-scale to abate the energy barrier for S-scheme charge transportation. Meanwhile, CDs serve as electron collectors to preserve highly reductive electrons from MCS, further augmenting the spatial separation of photo-carriers. Therefore, the optimized CDs/MCS/BOB (MBC) heterojunction manifests significantly strengthened tetracycline hydrochloride (TC) destruction activity and its reaction rate constant is approximately 3.1, 2.2, 2.1, and 1.5 folds that than that of MCS, BOB, BOB/CDs and MCS/BOB. In addition, MBC exhibits high stability and significant resistance to environmental interferences. The toxicology evaluation confirms the effective abatement of toxicity of TC after treatment. This achievement demonstrates the benefits of CDs-optimized S-scheme photosystems with chemical bonds for photocatalytic water decontamination.

Key words: Interfacial chemical bond, Carbon quantum dots, S-scheme heterojunction, Internal electric field, Synergistic effect, Photocatalysis