a large amount of pollution. [2] Therefore, the increasingly acute issues of the energy dilemma and environmental pollution have spurred intensive researches to develop environmental-friendly and renewable ways to produce NH 3 . In this context, photocatalytic nitrogen (N 2 ) fixation has been viewed as a suitable alternative for the traditional Haber-Bosch process.The unique properties of N 2 , including the extreme dissociation energy of N≡N (941 kJ mol −1 ), the high ionization potential, and the passive amount of electron affinity, resulting in the fact that the process of N 2 fixation to NH 3 rarely happens under moderate conditions. [3] Nevertheless, the triple bonds of N 2 still have an opportunity to be weakened and activated when electrons in the catalysts occupied the antibonding orbitals of nitrogen atoms or the depletion of N 2 occupied p-orbital electrons through σ-bond coordination. [4] Therefore, effective adsorption of N 2 and sufficient photogenerated electrons are exactly crucial to enhance the performance of NH 3 production. To date, various conventional photocatalysts (TiO 2 , KNbO 3 , or In 2 O 3 , for instance) have been thoroughly investigated for photocatalytic N 2 reduction reaction (NRR). [5][6][7] Most of them, however, are subjected to inferior efficiency because photogenerated electrons tend to recombine with holes, lack of competent active sites for adsorbing and activating N 2 , and low solar energy utilization rate. Especially, many of them have unsatisfactory activity toward NRR owing to their poor ability for water oxidation (2H 2 O + 4h + → O 2 + 4H + ) and need the presence of hole scavengers (ethanol or methanol) that could greatly hasten the evolution of NH 3 . [8] In addition, it's well known that the NRR process in liquid phase comprises multiphase-reactions and complicated transfer mechanisms, involving 6e − /6H + . By comparison, the HER process is much faster considering that only two electrons and two protons are involved, [9] finally contributing to the fact that plentiful active sites and photogenerated electrons are expended by the HER and then poor selectivity is exhibited. [10] From the above point of view, it is of grand significance to exploit efficient and stable photocatalysts for NRR.Covalent organic frameworks (COFs), a class of appearing crystalline photocatalysts with periodic framework structure, have attracted researchers' attention. The favorable Seeking highly-efficient, non-pollutant, and chemically robust photocatalysts for visible-light-driven ammonia production still remained challenging, especially in pure water. The key bottle-necks closely correlate to the nitrogen activation, water oxidization, and hydrogen evolution reaction (HER) processes. In this study, a novel Bi decorated imine-linked COF-TaTp (Bi/COF-TaTp) through N-Bi-O coordination is reasonably designed to achieve a boosting solar-to-ammonia conversion of 61 µmol −1 g −1 h −1 in the sacrificial-free system. On basis of serial characterizations and DFT calculations, the incorporated Bi ...

Exploiting cost‐effective, high‐efficiency, and contamination‐free semiconductors for photocatalytic nitrogen reduction reaction (N2RR) 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‐C3N4 (BxCvN) is herein developed through precise dopant and defect engineering. The optimized B15CvN 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‐C3N4), 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 BxCvN, which is distinctly revealed through the charge density difference calculations. The current study provides an alternative groundbreaking perspective for advancing photocatalytic N2RR through the targeted configuration of the defect and dopant sites.