Tailoring the electronic structure by transition-metal single atom on Ti3C2O2 for improving hydrogen evolution activity

Abstract The development of high efficient and low-cost electrocatalysts for hydrogen evolution reaction (HER) is crucial for boosting the water splitting technology. Based on the density functional theory, we investigate the HER catalytic activity of a serials of transition metal atoms (TM = V, Cr, Mn, Fe, Co, Ni) implanted into or anchored on Ti 3 C 2 O 2 as a low-cost 2D electrocatalyst with high thermodynamic stability. The results show that compared with the host Ti, the dopant TM donates less electrons to its adjacent oxygen atoms, leading to a stronger H and O bonding, while the anchored TM atom donates excess electrons to its adjacent oxygen atoms, leading to the extremely weak H and O bonding. For TM-anchored Ti 3 C 2 O 2 , those oxygen sites far away from TM exhibit the optimal hydrogen adsorption free energy because of their moderate electrons, indicating that the active sites and catalytic performance of Ti 3 C 2 O 2 are both modulated by TM atoms.