B-active-center-driven photocatalytic coupling of CO₂ and N₂ toward urea synthesis on penta-B₂C

Photocatalytic direct synthesis of urea from CO₂ and N₂ is an important way to achieve carbon neutrality and value-added nitrogen fixation, but the lack of efficient catalysts limits the further development of this reaction. Here, we systematically studied the structural properties of the new two-dimensional material penta-B₂C and its performance in photocatalytic synthesis of urea through the DFT system. The results show that the band gap of penta-B₂C is 2.44 eV and it has strong absorption in the visible light region; the free energy of the rate-determining step of the photocatalytic reduction of CO₂ to produce the *CO intermediate is only 0.26 eV, and the generation of the by-product *HCOOH can be significantly inhibited; *CO is preferentially strongly adsorbed on the surface and activates N₂ through π-backbonding, promoting the formation of *N₂-CO intermediates in urea synthesis; the final study found that the free energy of the rate-determining step of the optimal path for urea synthesis is only 0.72 eV. The results show that penta-B₂C exhibits high selectivity and activity in the direct synthesis of urea from CO₂ and N₂via photocatalysis. This study broadens the application potential of penta-B₂C in photochemical urea synthesis and provides new theoretical insights into the mechanism of direct synthesis of urea from CO₂ and N₂.