Graphene quantum dots modified flower like Bi₂WO₆ for enhanced photocatalytic nitrogen fixation

Graphene quantum dots modified Bi₂WO₆ (GQD/Bi₂WO₆) composites is applied to photocatalytic N₂ fixation. The as-prepared GQD/Bi₂WO₆ samples showed considerable increase in photocatalytic nitrogen fixation compared to the pure Bi₂WO₆ and GQD. The results revealed that GQD uniformly placed on the surface of Bi₂WO₆ and tight junction between the two samples helped to boost the photocatalytic activity. The PL, photocurrent and EIS analyses further demonstrated that the composite had the low recombination rate of photo-generated charges. Photocatalytic nitrogen fixation test indicated that GQD/Bi₂WO₆ with 10 wt% GQDs exhibited the highest ammonia synthesis rate in the presence of visible light, which is 8.88-fold and 33.8-fold higher than pure Bi₂WO₆ and GQD. Simultaneously, the GQD/Bi₂WO₆ sample has high stability.