Design single nonmetal atom doped 2D Ti2CO2 electrocatalyst for hydrogen evolution reaction by coupling electronic descriptor

2D MXenes, with large surface area, good conductivity, adjustable hydrophilic and varies surface functional groups, are potential catalyst for hydrogen evolution reaction (HER). In this work, 14 kinds of nonmetal (NM) single atom doped 2D Ti2CO2 catalysts were screened by DFT method. It was found that the surface doping of nonmetal single atom can effectively promote the HER activity of Ti2CO2. Among them, Ti2CO2 with rich fluorine termination groups realizing efficient electrocatalytic HER has been successfully verified by recent experiments. Through the analysis of electronic structure, it is found that nonmetal single atom valence electron number and bader electron transfer coupled electron descriptor is suitable to accurately predict the trend of 2D NM-Ti2CO2 catalytic activity for HER. The large-scale screening of this work and the mechanism analysis of nonmetal single atom surface doping enhanced of 2D Ti2CO2 HER activity not only provide a database reference for the experimental synthesis of NM-MXenes HER catalyst, but also provide a electronical mechanism guidance for the extensive design of new NM- MXenes materials.