Electrochemical reduction of CO2 on S-triazine-based g-C3N4 surface modified with metal and nonmetal atoms: A DFT study

The electrochemical CO 2 reduction reaction (CO 2 RR) is one of the most effective methods for converting greenhouse gases into valuable products. This study explores the surface modification of s-triazine g-C 3 N 4 to enhance its performance in CO 2 RR through density functional theory calculations. Surface modification techniques, including doping, decorating, and co-decorating with metal and nonmetal atoms (Li, Be, B, C, N, O, F, Al, Si, P, S, and Cl) were used. The designed surfaces were screened according to their energetic and geometric parameters, as well as their ability to activate the adsorbed CO 2 molecule. The adsorption energy of CO 2 on the screened surfaces was found to be between − 0.70 and − 2.53 eV. The selectivity of the catalysts for CO 2 RR was demonstrated by comparing the free energy changes for HER and the first step of CO 2 hydrogenation on their surfaces. Among the modified surfaces, 2B2C-C 3 N 4 (limiting potential: − 0.33 eV) and 4B-C 3 N 4 (limiting potential: − 0.83 eV) exhibited better performance and selectivity in producing CH 3 OH and CH 4 , respectively. These results demonstrate the significant impact of decorating the surface of g-C 3 N 4 with carbon and boron atoms, which makes it an effective catalyst for converting CO 2 into useful fuels. • The electrocatalysis performance of modified s-triazine-based g-C 3 N 4 was studied by DFT. • Doping, decorating, and co-decorating with metal and non-metal atoms are surface modification techniques. • Decorated g-C 3 N 4 with carbon and boron atoms are effective catalyst for CO 2 RR. • 4B-C 3 N 4 and B-C 3 N 4 shows active and selective for CH 3 OH. • 2B2C-C 3 N 4 with limiting potential − 0.33 eV exhibited better selectivity in producing CH 4 .