Enhanced Photocatalytic N2 Fixation and Water Purification Using Bi/ZnSnO3 Composite: Mechanistic Insights and Novel Applications

A composite of cheap metallic Bi-decorated ZnSnO3 was synthesized via a solvothermal method and applied for photocatalytic N2 fixation for the first time. The results demonstrated that the Bi/ZnSnO3 composite with 1.5% Bi exhibited superior photocatalytic performance. with the optimal sample producing NH3 at a rate of 988 μmol L-1 g-1 h-1 under simulated sunlight. This is 5 times faster than that of pure ZnSnO3. Additionally, the Bi/ZnSnO3 composite showed significantly better photocatalytic performance than pure ZnSnO3 in RhB degradation. Structural analyses confirmed successful loading of Bi nanoparticles on the surface of ZnSnO3. Furthermore, diffuse reflectance spectroscopy analysis revealed that the surface plasmon resonance effect of metal Bi effectively improved the optical absorption performance. However, the sensitization of metal Bi had a limited contribution to the high photocatalytic activity of the Bi/ZnSnO3. Electrochemical analyses indicated that the Schottky barrier formed between Bi and ZnSnO3 captured photo-generated electrons and promoted the charge separation, which was considered responsible for the increased photoactivity of Bi/ZnSnO3.This work provides a new application of Bi/ZnSnO3 and may offer new ideas for the application of ZnSnO3 materials in the field of photocatalysis, which are crucial for addressing environmental pollution and energy conversion challenges.