Graphene with SiN3 ligand for superior CO2 electrochemical reduction

Carbon dioxide (CO2) emissions exacerbate the greenhouse effect, and electrocatalytic reduction CO2 into value-added chemicals is regarded as a promising and effective method to cope with the issue. Silicon (Si) as a kind of metalloid element presents the features of non-metal and metal, potentially showing the advantages of metallic and non-metallic electrocatalysts simultaneously. By density functional theory (DFT), the screened SiN3 anchored graphene is selected to study the electrocatalytic CO2 reduction reaction (CRR) due to its good CO2 capture ability, high stability and feature of the conductor. Along the reaction coordinate, the HCHO can be formed owing to the minimum energy barrier. Moreover, the SiN3 anchored graphene presents high catalytic selectivity toward CRR rather than the complete H2 evolution reaction (HER). During the CRR procedures, the SiN3 ligand and C framework act as the electron translocator and electron reservoir respectively, which facilitate the CRR. This work provides a pathway to design highly effective metal-free CRR electrocatalysts and to achieve highly effective CRR.