Dual active sites of single-atom copper and oxygen vacancies formed in situ on ultrathin TiO2(B) nanosheets boost the photocatalytic dehalogenative C–C coupling synthesis of bibenzyl

• Published in: Catalysis science & technology 2024-03, Vol.14 (6), p.1568-1578
• Main Authors: Chen, Qifeng, Zheng, Peng, Liu, Haodi, Zhang, Yuanrong, Li, Shuaitao, Guo, Hongpian, Fang, Yanfen, Hu, Xun, Duan, Ran
• Format: Article
• Language: English
• Subjects: Adsorption; Benzyl bromide; Charge efficiency; Charge transfer; Copper; Electromagnetic absorption; Nanosheets; Oxygen; Photocatalysis; Synergistic effect; Synthesis; Titanium dioxide
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/d3cy01611k

The combination of photocatalytic dehalogenation of halogenated aromatics and C–C coupling synthesis of valuable organics is an interesting method for the elimination of pollutants and synthesis of valuable chemicals. Herein, we present a green method for the photocatalytic dehalogenation of benzyl bromide and selective coupling synthesis of bibenzyl achieved on the dual active sites of single-atom Cu and surface oxygen vacancies (VOS) generated in situ on ultrathin 2D-TiO2(B) nanosheets. The experimental results show that single-atom Cu sites on ultrathin TiO2(B) nanosheets can improve charge transfer and separation efficiency and stabilize VOS formed in situ; the presence of VOS not only improves light absorption capacity but also favors the adsorption of reactant benzyl bromide molecules. More importantly, the dual sites of single-atom Cu and adjacent VOS form a solid frustrated Lewis pair, favor the adsorption of benzyl bromide molecules, activate the C–Br bond, and boost the C–C coupling synthesis of bibenzyl. This work provides a novel insight into photocatalytic C–C coupling through the synergistic effect of single-atom Cu and VOS on ultrathin nanosheet photocatalysts.