A DFT study of two-dimensional P2Si monolayer modified by single transition metal (Sc-Cu) atoms for efficient electrocatalytic CO2 reduction

Abstract

In the present work, a stable two-dimensional (2D) P2Si monolayer was predicted. The monolayer is semimetallic/metallic under the PBE/HSE06 functional and is mechanically isotropic. The stability of the P2Si monolayer has been proved via cohesive energy, mechanical criteria, molecular dynamics simulation, and phonon dispersion respectively, and the monolayer possesses high carrier mobility which is three times that of MoS2. On the other hand, the catalytic performance of the P2Si monolayer modified with a single transition metals (M = Sc-Cu) atom for the electrochemical reduction of CO2 was investigated, and the monolayer can catalyze CO2 with three constraints: stable molecular dynamics, high migration potential of metal atoms, and suitable band gap for electrocatalyst after metal doping exhibiting excellent catalytic stabilization activity and CRR selectivity. In addition, the reduction product of V@P2Si is HCOOH with an overpotential as low as 0.75 V, and the most suitable reaction path is *CO2 → *CHOO → O*CHOH → * + HCOOH with the final reduction product HCOOH obtained. As a whole, the above results endow the P2Si monolayer to be a good 2D material holding great promises for applications in nanoelectronics and CO2 reduction catalysts.