Transition metal atoms implanted into MXenes (M2CO2) for enhanced electrocatalytic hydrogen evolution reaction

Transition metal (TM) modification is an effective method to improve the catalytic properties of MXenes for hydrogen evolution reaction (HER). We implanted TM atoms into MXenes to avoid the atomic aggregation of traditional TM modification. The HER catalytic properties of M2CO2 (M = Ti, V, Hf, Zr and Ta) after implanting TM atoms are studied by density functional theory (DFT) calculations. The results showed that the implantation of TM atoms could change the conductivities of MXenes and the differential Gibbs free energies of HER. Good HER catalytic activity and metallic conductivity could be simultaneously achieved for some MXenes with TM atoms implantation. The change law of Gibbs free energies showed a periodic law when MXenes were implanted different TM elements, which is related with the periodic change of the electronegativity of TM elements. A number of M2CO2 (M = Ti, Hf, Zr and Ta) were proved to be good HER catalysts after implanting TM atoms.