Surface Electronic Properties Of Black Phosphorus And C₃N₄ And Their Catalytic Performance For Nitrogen Reduction Reaction

Ammonia is an important chemical raw material,but the way to obtain ammonia is very limited.Haber-Bosch method is mainly used in industry.The reaction conditions are harsh and the energy consumption is huge.Electrocatalytic nitrogen reduction(NRR)is a new method for ammonia synthesis,which has the advantages of low energy input,low carbon emissions and simple reactor design.However,there are some problems in ammonia synthesis by electrocatalytic nitrogen reduction,such as poor catalyst selectivity and high price.Therefore,it is of great significance to develop an efficient and inexpensive electrocatalyst for nitrogen reduction reaction.Two-dimensional materials have many advantages,such as large specific surface area and many active sites.They are ideal materials for electrocatalysts.Electron lone pairs(ELPs)are ubiquitous in black-P but their role in creating the edge effects of black-P is poorly understood.Using the first-principle calculation,we report ELPs of black-P turn out to experience severe Coulomb repulsion and play a central role in creating the edge effects of black-P.We discover the outermost P atoms of the zigzag edges of black-PQDs are free of the Coulomb repulsion,but the P atoms of the armchair edges do experience the Coulomb repulsion.The Coulomb repulsion serves as a new chemical driving force to make electron-donor-acceptor bonds with chemical groups bearing vacant orbitals.Our results provide insights into the mechanism responsible for the peculiar edge effects of black-P and highlight the opportunity to use the ELPs of black-P for their damage-free surface functionalization.Through density functional calculations(DFT),I systematically studied the possibility of transition metal supported carbohydrate nitride as an electrocatalytic catalyst for nitrogen reduction.Our calculation results reveal that when cobalt monoatom is supported on carbon nitride as a catalyst for electrocatalytic reduction of nitrogen by alternating reaction mechanism,the overvoltage required for the reaction is only 0.61 V.This discovery opens up a new way for the production of ammonia under mild conditions with monoatomic electrocatalysts.