Improving Photocatalytic Nitrogen Fixation Performance of Surface-Modified Bi₂MoO₆ by Tuning Surface Work Functions

Efficient photocatalytic nitrogen fixation critically depends on rapid charge carrier transport and effective surface reactions. In this study, a Bi 2 MoO 6 -based photocatalyst was successfully developed through surface modification with varying concentrations of ascorbic acid. After modification by ascorbic acid, defects were introduced on the surface of Bi 2 MoO 6 catalyst, which changed the octahedral coordination environment of MoO 6 , resulting in structural adjustment, reduced band gap, increased conduction potential, and reduced surface work function. These changes facilitated accelerated photo-induced charge migration and separation of Bi 2 MoO 6 . Consequently, the efficiency of photogenerated charge carrier separation was significantly enhanced, resulting in improved photocatalytic performance. Notably, the optimized BMO-1 catalyst exhibited a maximum NH 3 production rate of 240.5 μmol·g −1 ·h −1 without the use of sacrificial agents under visible light irradiation, which is 4.5 times higher than that of pristine Bi 2 MoO 6 . This work demonstrates a simple, effective, and controllable strategy for catalyst modification to boost photocatalytic nitrogen fixation performance.