BN cluster-doped graphdiyne as visible-light assisted metal-free catalysts for conversion CO₂ to hydrocarbon fuels

Carbon dioxide electrochemical reduction reaction (CO₂RR) under ambient conditions provides an intriguing picture for conversion of CO₂ to useful fuels and chemicals. Here by means of density functional theory (DFT) computations, the formation configuration and CO₂RR catalytic activity of boron nitrogen cluster-doped graphdiyne (BN-doped GDY) were systematically investigated. The band structure and optical adsorption spectra reveal that BN-doped GDY exhibits semiconductor with the band gap of 0.902 eV and shows photothermal effect under visible and even infrared light irradiation. The BN-doped GDY could act as a hot spot to enhance CO₂RR. The adsorption configurations of various reaction intermediates indicate that boron atoms are active sites, which can be further confirmed by charge analysis. Based on thermodynamic analysis, the reaction pathways and onset potentials were studied as compared with Cu(111) surface. For the production of CO, the onset potential for BN-doped GDY (-1.06 V) is higher than that for Cu(111) surface. While for the reduction of CO₂ to HCOOH, CH₄, CH₃OH, and C₂H₄ on BN-doped GDY, the onset potentials are lower than that on Cu(111) surface, which are -0.57 V, -0.62 V, -0.57 V, and -0.82 V, respectively. Moreover, the onset potential of competitive hydrogen evolution reaction on BN-doped GDY is high to -0.82 V, which shows us a good selectivity towards to CO₂RR rather than HER. Our results may pave a new avenue for the conversion of CO₂ into high-value fuels and chemicals.