Broken holey graphene oxide for electrocatalytic N2-to-NH3 fixation at ambient condition

Abstract

Electrocatalysts is critical for nitrogen reduction reaction (NRR) under ambient conditions. Defect engineering is generally employed to prepared high-performance electrocatalysts. Herein, we report a broken holey graphene oxide (BHGO) prepared by a facile high-temperature etching method. Compared with the holey graphene oxide (HGO) and graphene oxide (GO), the BHGO exhibits higher electron transfer capability and richer active sites (coordination of one-dimensional edges and zero-dimensional oxygen-doping defects). The BHGO catalyst reaches excellent NRR performance (NH3 yield of 22.27 μg h−1 mg−1 and Faraday efficiency (FE) of 11.01 % in 0.1 M Na2SO4 solution at the ambient condition. Illustrated by the density functional theory (DFT) calculations, the introduction of coordinated multi-dimensional defects redistributes the charge, enhancing adsorption of nitrogen (N2) and reducing energy barrier at rate-determining step (N*→NH*). Moreover, catalytic performance can be well preserved in an aqueous solution. The proposed multi-dimensional defect engineering strategy and established DFT simulations may pave an exciting avenue toward the design and development of high-performance catalysts.