Interlayer Charge Transfer Over Graphitized Carbon Nitride Enabling Highly-Efficient Photocatalytic Nitrogen Fixation.

Exploiting cost-effective, high-efficiency, and contamination-free semiconductors for photocatalytic nitrogen reduction reaction (N 2 RR) is still a great challenge, especially in sacrificial-free system. On basis of the electron "acceptance-donation" concept, a boron-doped and carbon-deficient g-C 3 N 4 (B x CvN) is herein developed through precise dopant and defect engineering. The optimized B 15 CvN exhibisted an NH 3 production rate of 135.3 µmol h -1  g -1 in pure water with nine-fold enhancement to the pristine graphitic carbon nitride (g-C 3 N 4 ), on account of the markedly elevated visible-light harvesting, N 2 activation, and multi-directional photoinduced carriers transfer. The decorated B atoms with coexistent occupied and empty sp 3 hybridized orbitals are theoretically proved to be in charge of the increase of N 2 adsorption energy from -0.08 to -0.26 eV and the change in N 2 adsorption model from one-way to two-way end-on pattern. Noticeably, the elaborate coordination of doped B atoms and carbon vacancies greatly facilitated the interlayer interaction and vertical charge migration of B x CvN, which is distinctly revealed through the charge density difference calculations. The current study provides an alternative groundbreaking perspective for advancing photocatalytic N 2 RR through the targeted configuration of the defect and dopant sites.