Identification\nof Active Sites on Boron-Doped Graphitic\nCarbon Nitride as a Metal-Free Single-Atom Photoelectrocatalyst for\nthe Nitrogen Reduction Reaction

While being considered a promising metal-free single-atom\nphotoelectrocatalyst\nfor the nitrogen reduction reaction (NRR), the active sites of boron\n(B) atom-doped graphitic carbon nitride (B-g-C<sub>3</sub>N<sub>4</sub>) are still elusive. Herein, we comparatively investigate three well-established\nB-doped sites theoretically and identify a substitutional doping structure,\nnamely, BC<sub>3</sub>, as the active site for the photoelectrocatalytic\nNRR on B-g-C<sub>3</sub>N<sub>4</sub>. Our research offers not only\na new understanding of B-g-C<sub>3</sub>N<sub>4</sub> but also useful\natomic-level information for the rational design of better catalysts.