Hot electron prompted highly efficient photocatalysis based on 3D graphene/non-precious metal nanoparticles

Zhang, SL (Zhang, Suling)^{[ 1 ]} ; Lu, YH (Lu, Yanhong)^{[ 1 ]} ; Wan, XC (Wan, Xingchen)^{[ 1 ]} ; Duan, YX (Duan, Yaxin)^{[ 1 ]} ; Gao, JL (Gao, Junlin)^{[ 1 ]} ; Ge, Z (Ge, Zhen)^{[ 2,3 ]} ; Wei, L (Wei, Lei)^{[ 1 ]} ; Chen, Y (Chen, Yu)^{[ 1 ]} ; Ma, YF (Ma, Yanfeng)^{[ 2,3 ]} ; Chen, YS (Chen, Yongsheng)^{[ 2,3 ]}

RSC ADVANCES, 2020, 10(69): 42054-42061

DOI: 10.1039/d0ra07146c

摘要

High dispersibility and rapid electron transfer are required for a highly efficient catalyst. In this work, such materials have been designed using a scalable hydrothermal method from graphene oxide and a metal-organic framework. A cross-linked three-dimensional graphene (3DGraphene) material loaded with mono-dispersed nitrogen-doped carbon-coated metallic Co (NC@Co) nanoparticles with uniform size of 12.2 nm (3DGraphene/NC@Co) has been obtained and exhibits excellent activity for catalytic reduction of 4-nitrophenol to 4-aminophenol. Such high catalytic activity can be assigned to the highly energetic hot/free electrons arising from 3DGraphene under light illumination and the synergistic effect between 3DGraphene and NC@Co nanoparticles. The catalytic reaction can be finished in 240 s with NaBH4 as the reducing agent, and the corresponding rate constant (k) is 1.5 x 10(-2) s(-1), comparable to that of reported noble metal catalysts. Furthermore, the magnetic 3DGraphene/NC@Co materials are beneficial for the separation from the mixture after reaction and exhibit excellent cycling stability.