Regulating Electronic Properties of Bi 2 MoO 6 via Atomic‐Scale Sn Engineering to Construct Multiple Active Sites for Solar Nitrogen Fixation Under
Sameer Rai, Tanu Bagaria, Antra Mohini, Anustup Sadhu, Nilmadhab Mukherjee, Ripan K. Biswas, Uttam Kumar Ghorai, Soma Sharma, Amreen Bano, Bharati DebnathABSTRACT
Photocatalytic ammonia (NH 3 ) production provides a green alternative to the energy‐intensive Haber–Bosch process; however, low efficiency and limited understanding of N 2 activation hinder progress. Experimental results, supported by density functional theory (DFT), demonstrate that Sn‐doped Bi 2 MoO 6 significantly enhances photocatalytic nitrogen reduction reaction (PNRR) by tuning electronic structure and enriched active sites. This work reports at the optimal Sn incorporation, 10% Sn‐BMO with a preferentially exposed (131) facet accompanied by a substantial concentration of oxygen vacancies delivers an NH 3 production rate of 2.07 mmol g −1 , which is 10.9 times greater than that of pristine Bi 2 MoO 6 under simulated solar irradiation (Xenon lamp). The presence of high amount of oxygen vacancies in the 10% Sn‐BMO promotes N 2 adsorption and activation, facilitating N≡N bond dissociation through proton coupling. The N 2 fixation pathway was elucidated by tracking reaction dynamics through infrared spectroscopy. A solar‐to‐NH 3 efficiency of ∼1.04% in pure water positions this breakthrough as a viable pathway toward decentralized NH 3 production with improved accessibility and sustainability. Moreover, under natural sunlight in the designed prototype system, 10% Sn‐BMO exhibits an NH 3 production rate of ∼450 µmol g −1 . These findings validate efficient laboratory and outdoor solar‐driven NH 3 production through rational catalyst design for sustainable ammonia synthesis.