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

Exploring high-efficiency metal-free electrocatalysts towards N2 reduction reaction (NRR) is of great interest for the development of electrocatalytic N2 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 μg 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 N2 activation could be drastically enhanced at the BNQDs-C3N4 interface where interfacial BNQDs and C3N4 cooperatively adsorb N2 and stabilize *N2H intermediate, leading to the significantly promoted NRR process with an ultra-low overpotential of 0.23 V.