Synergy of monoatomic copper and oxygen vacancy formed in-situ on ultrathin TiO2(B) nanosheet for efficient photocatalytic dehalogenative C−C coupling synthesis of bibenzyl

Abstract

Abstract Photocatalytic C − C coupling reaction plays an important role in the synthesis of organics that are widely used as fine chemicals, medicine and pesticides. However, the development of high-performance, low-cost photocatalysts to drive the C − C coupling reaction under mild conditions remains a severe challenge. Herein, we present a green photocatalytic method for the selective coupling synthesis of bibenzyl over an ultrathin TiO2(B) nanosheet photocatalyst with single-atom Cu anchored and rich in oxygen vacancy (VO), which were generated in-situ in the reaction system. The method requires no tedious pre-functionalization steps, which allows the use of cheap copper compounds as starting materials. The experimental results show that the introduction of single-atom Cu sites on the ultrathin TiO2(B) nanosheet can improve the charge transfer and separation efficiency, and the presence of surface VO not only improves the light absorption capacity but also favors the adsorption and activation of reactant benzyl bromide. More importantly, the synergy of single-atom Cu sites and surface oxygen vacancy of TiO2(B) endows the high efficiency in the C − C coupling synthesis of bibenzyl. This work provides a novel insight into the photocatalytic C − C coupling reaction through the collaborative strategy of single-atom Cu species and oxygen vacancy on ultrathin nanosheet photocatalysts.