Superior electro-catalytic performance achieved by the negatively charged boron atom on BC3/TM/graphene sandwich heterostructures

Abstract

The sandwich heterostructures (SHSs) are novel two-dimensional materials that hold great potential as efficient electro-catalysts. In this work, we computationally designed the BC3/TM/Gr SHSs by intercalating transition metal atoms into the BC3/graphene heterostructure. After the computational screening, only BC3/Sc/Gr, BC3/Ti/Gr, BC3/Y/Gr and BC3/Zr/Gr are validated as stable SHSs. The electron donation from the intercalated TM atom results in the formation of the negatively charged boron atom (Bδ−) and activation of the BC3 surface, making the BC3/TM/Gr SHSs highly promising as single-atom catalysts (SACs). The BC3/Sc/Gr and BC3/Y/Gr SHSs exhibit potential in carbon dioxide reduction reaction (CO2RR) and carbon monoxide reduction reaction (CORR) electro-catalysis. Particularly, when BC3/Y/Gr SHS serves as CORR electro-catalyst, the step (*CHO→*CHOH) is a potential determining step, with an extremely low limiting potential (UL = −0.10 V). The BC3/Ti/Gr and BC3/Zr/Gr SHSs are suitable as hydrogen evolution reaction (HER) electro-catalysts. Specially, the BC3/Ti/Gr SHS serves as an ideal HER electro-catalyst in acid condition, with close-to-zero adsorption free energy (ΔGH = 0.006 eV) and fairly low overall activation barrier (0.20 eV). By analyzing the electronic properties, the unique adsorption activity of the Bδ− on H atom and unsaturated CO2RR intermediates is elucidated as the origin of excellent catalytic activity of BC3/TM/Gr SHSs, which is modulated by the intercalated TM atom. Our work is instructive to rational design of SACs towards energy conversion based on non-metal elements.