Constructing the separation pathway for photo-generated carriers by diatomic sites decorated on MIL-53-NH2(Al) for enhanced photocatalytic performance
Gang Wang, Yan Liu, Ning Zhao, Huimei Chen, Wenjie Wu, Yueyue Li, Xiangwen Liu, Ang Li, Wenxing Chen, Junjie Mao
Abstract
High yield production of phenol from hydroxylation of benzene with low energy consumption is of paramount importance, but still challenging. Herein, a new strategy, consisting of using diatomic synergistic modulation (DSM) to effectively control the separation of photo-generated carriers for an enhanced production of phenol is reported. The atomic level dispersion of Fe and Cr respectively decorated on Al based MIL-53-NH2 photocatalyst (Fe1/Cr:MIL-53-NH2) is designed, in which Cr single atoms are substituted for Al3+ while Fe single atoms are coordinated by N. Notably, the Fe1/Cr:MIL-53-NH2 significantly boosts the photo-oxidation of benzene to phenol under visible light irradiation, which is much higher than those of MIL-53-NH2, Cr:MIL-53-NH2, Fe1/MIL-53-NH2, and Fe nanoparticles/Cr:MIL-53-NH2 catalysts. Theoretical and experimental results reveal that the Cr single atoms and Fe single atoms can act as electron acceptor and electron donor, respectively, during photocatalytic reaction, exhibiting a synergistic effect on the separation of the photo-generated carriers and thereby causing great enhancement on the benzene oxidation. This strategy provides new insights for rational design of advanced photocatalysts at the atomic level.