Exploiting cost-effective, high-efficiency, and contamination-free semiconductors for photocatalytic nitrogen reduction reaction (N2 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-C3 N4 (Bx CvN) is herein developed through precise dopant and defect engineering. The optimized B15 CvN exhibisted an NH3 production rate of 135.3 µmol h-1 g-1 in pure water with nine-fold enhancement to the pristine graphitic carbon nitride (g-C3 N4 ), on account of the markedly elevated visible-light harvesting, N2 activation, and multi-directional photoinduced carriers transfer. The decorated B atoms with coexistent occupied and empty sp3 hybridized orbitals are theoretically proved to be in charge of the increase of N2 adsorption energy from -0.08 to -0.26 eV and the change in N2 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 Bx CvN, which is distinctly revealed through the charge density difference calculations. The current study provides an alternative groundbreaking perspective for advancing photocatalytic N2 RR through the targeted configuration of the defect and dopant sites.
Keywords: boron doping; carbon defect; graphitic carbon nitride; nitrogen activation; photocatalytic NH 3 production.
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