Metal-free BN quantum dots/graphitic C3N4 heterostructure for nitrogen reduction reaction

Exploring high-efficiency metal-free electrocatalysts towards N-2 reduction reaction (NRR) is of great interest for the development of electrocatalytic N-2 fixation technology. Herein, we combined boron nitride quantum dots (BNQDs) and graphitic carbon nitride (C3N4) to design a metal-free BNQDs/C3N4 heterostructure as an effective and durable NRR catalyst. The electronically coupled BNQDs/C3N4 presented an NH3 yield as high as 72.3 mu g h(-1) mg(-1) (-0.3 V) and a Faradaic efficiency of 19.5% (-0.2 V), far superior to isolated BNQDs and C3N4, and outperforming nearly all previously reported metal-free catalysts. Theoretical computations unveiled that the N-2 activation could be drastically enhanced at the BNQDs-C3N4 interface where interfacial BNQDs and C3N4 cooperatively adsorb N-2 and stabilize *N2H intermediate, leading to the significantly promoted NRR process with an ultra-low overpotential of 0.23 V. (C) 2021 Elsevier Inc. All rights reserved.