In-situ synthesis of Bi0 on 3D-3D-shaped (BiO)2CO3 surface for photocatalytic inactivation: Metal self-doping mechanism

Studies have shown that Bi-based semiconductor photocatalysts have been favorably applied in environmental protection. The present study creates Bi-based photocatalysts using the glycol-assisted solvothermal method and examines their efficacy in killing bacteria and purifying ship's ballast water. This synthesis method encourages the flower-ball-like (BiO)2CO3 packaged within nanosheets to generate Bi nanospherical particles in situ, resulting in the preparation of 3D–3D Bi/(BiO)2CO3 heterojunctions. At the same time, the combined surface plasmon resonance (SPR) effects of semimetallic Bi and (BiO)2CO3 promote the system's photocatalytic killing of bacteria in ship's ballast water. The combined characterization shows that the 3BBOC composite sample has the highest photocatalytic sterilization efficiency in pure seawater. The photocatalytic activity is 3 times that of only (BiO)2CO3. The SPR effect of the Bi nanoparticles generated in situ improves the heterojunction's absorption and utilization of visible light. After periodic stability tests, Bi/(BiO)2CO3 heterojunctions are shown to have excellent environmental adaptability and stability. The experiment of capturing free radicals shows that hydroxyl free radicals are most effective in killing bacteria.