CeO2 quantum dots/LZU1 Z-scheme heterojunction for photocatalytic selective oxidative coupling of benzylamines
Yezi Hu, Rusong Sang, Feng Chu, Zewen Shen, Guixia Zhao, Junrong Yue, Xiubing Huang
Abstract
Imines play a pivotal role as multifunctional intermediates in pharmaceutical and biological applications , and their selective synthesis under mild conditions has attracted increasing interest. In this study, a covalent-organic frameworks (COFs) modified with CeO 2 quantum dots (QDs) were prepared through a simple chemical reaction using LZU1 COFs and Ce(NO 3 ) 3 ·6H 2 O serving as precursors. The optimized 5CeO 2 QDs@LZU1 decorated with about 3.9 wt% CeO 2 QDs demonstrates excellent performance in the photocatalytic selective oxidative of amines in visible light conditions, achieving nearly 100% benzylamine conversion and over 99% imine selectivity within 6 h, which is significantly superior to that of pure LZU1 and CeO 2 . The remarkable enhancement in activity is mainly attributed to the fact that the interaction between CeO 2 QDs and LZU1 COF in 5CeO 2 QDs@LZU1 improves the visible light response and concurrently promotes the separation efficiency of photogenerated e ‒ and h + pairs. Broad substrate scope also provides a prospect for the industrial synthesis of various imines. Our findings not only expand the application range of COFs by incorporating QDs but also lay the groundwork for their further rational design and optimization.