Boron doped C3N5 for photocatalytic nitrogen fixation to ammonia: The key role of boron in nitrogen activation and mechanism

Compared to g-C3N4, g-C3N5 can harvest more visible light and prolong the lifetime of photogenerated carriers, and exhibited a more excellent NH3 yield under visible light. A new catalyst boron doping g-C3N5 (B-C3N5) was prepared by a simple one-step calcination for photocatalytic nitrogen fixation. B-C3N5 achieved the NH3 yield up to 421.18 mu mol h(-1) g(-1). Raman and ESR analysis reveal that the B tend to occupy the C vacancies in C3N5, which effectively improve the charge transfer capability and optimize band structure of B-C3N5. The B sites display perfect performance for N-2 adsorption and activation to generate NH3. The intermediates of NRR process are identified by in-situ DRIFTS and a reaction mechanism is proposed to reveal the role of the B -O -H during the N-2 adsorption, activation, and reduction process.

Automated summary

Compared to g-C3N4, g-C3N5 can efficiently utilize visible light and extend the lifetime of photogenerated carriers, leading to enhanced NH3 production. A boron-doped g-C3N5 catalyst (B-C3N5) was synthesized via a simple one-step calcination method for photocatalytic nitrogen fixation. B-C3N5 demonstrated significantly improved NH3 yield with a rate of 421.18 mu mol h(-1) g(-1). Raman and ESR analysis indicated that B tended to occupy the C vacancies in C3N5, thereby enhancing the charge transfer capability and optimizing the band structure of B-C3N5. The B sites exhibited excellent performance in N-2 adsorption and activation, leading to NH3 generation. In-situ DRIFTS was used to identify the intermediates of the NRR process, and a reaction mechanism was proposed to elucidate the role of B -O -H during N-2 adsorption, activation, and reduction.