Searching for highly efficient multifunctional electrocatalysts based on the single metal doped graphitic carbon nitride

Multifunctional catalysts with highly efficient oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) are in great demand for energy conversion and storage devices. In this study, based on a series of single transition metal atom anchored graphitic carbon nitride (g-CN) monolayer (TM@g-CN, TM = Fe-Cu, Ru-Ag), possible multifunctional electrocatalysts are screened out by using the density functional method. Our results demonstrated that Pd@g-CN is an excellent trifunctional catalyst with small overpotentials of 0.41/0.19/−0.28 V for ORR/OER/HER. For Cu@g-CN and Rh@g-CN, they show bifunctional activity toward OER and HER. For Cu@g-CN, the overpotentials are 0.38/−0.25 V for OER/HER, while they are 0.34/−0.22 V for Rh@g-CN. The adsorption strength of the intermediate *OH is a good descriptor for ORR and OER. These results suggest that the single transition metal atom anchored g-CN would be promising multifunctional catalysts and could provide useful guidance for their practical applications. Pd@g-CN exhibits promising catalytic performance toward ORR/OER/HER with the overpotentials of 0.41/0.19/-0.28 V