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

In the present work, a stable two-dimensional (2D) P 2 Si monolayer was predicted. The monolayer is semimetallic/metallic under the PBE/HSE06 functional and is mechanically isotropic. The stability of the P 2 Si 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 MoS 2 . On the other hand, the catalytic performance of the P 2 Si monolayer modified with a single transition metals (M=Sc-Cu) atom for the electrochemical reduction of CO 2 was investigated, and the monolayer can catalyze CO 2 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@P 2 Si is HCOOH with an overpotential as low as 0.75 V, and the most suitable reaction path is *CO 2 → *CHOO → O*CHOH → * + HCOOH with the final reduction product HCOOH obtained. As a whole, the above results endow the P 2 Si monolayer to be a good 2D material holding great promises for applications in nanoelectronics and CO 2 reduction catalysts. Within the range of transition metal atom-loaded P 2 Si electrocatalysts, V@P 2 Si showed the best CRR catalytic performance compared to HER, with HCOOH being the most likely product among the possible products CO, CH 4 , HCOOH, HCHO, CH 3 OH.