School of Environment and Energy, Peking University Shenzhen Graduates School, Shenzhen, 518055, PR China.
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment of Ministry of Education, Chongqing University, Chongqing, 400044, PR China.
Colloids Surf B Biointerfaces. 2018 Jul 1;167:275-283. doi: 10.1016/j.colsurfb.2018.04.022. Epub 2018 Apr 8.
BiOBr-AgBr hybrid photocatalysts were synthesized via a facile precipitation and in-situ ion exchange method at room temperature. The as-synthesized photocatalysts were well characterized with different techniques. The disinfection activities of BiOBr-AgBr towards model bacterial strain Gram-negative Escherichia coli (E. coli) were tested under both dark and visible light irradiation conditions. 1 × 10 CFU/mL of E. coli cells could be completely inactivated by BiOBr-AgBr with the optimal silver amount (BiOBr-0.5AgBr) in 24 min under visible light irradiation, while 1.5 log CFU/mL decrease of viable cell density was achieved at the same experiment duration under dark condition. Obviously, with the visible light irradiation, the bactericidal efficiency BiOBr-0.5AgBr was significantly enhanced. The subsequent disinfection mechanism analysis showed that Ag released from BiOBr-0.5AgBr did not contribute to E. coli inactivation, while reactive oxygen species including h, surfaced bounded OH, O, and HO were found to play important roles in the disinfection process. The presence of dissolved O and the direct contact of cells with photocatalysts was found to be essential for the disinfection process. The reactive species induced the destruction of cell membrane, thus led to the death of bacteria. In addition, BiOBr-0.5AgBr exhibited good bactericidal activity within a wide pH range (5-9) and contained effective antibacterial activity even in fifth consecutive reuse cycles.
BiOBr-AgBr 杂化光催化剂通过室温下的简便沉淀和原位离子交换方法合成。通过不同的技术对合成的光催化剂进行了很好的表征。在黑暗和可见光照射条件下，测试了 BiOBr-AgBr 对革兰氏阴性大肠杆菌（E. coli）模型细菌菌株的消毒活性。在可见光照射下，含最佳银量（BiOBr-0.5AgBr）的 1×10 CFU/mL E. coli 细胞可在 24 min 内完全失活，而在相同实验持续时间下，黑暗条件下的活菌密度降低了 1.5 log CFU/mL。显然，在可见光照射下，BiOBr-0.5AgBr 的杀菌效率显著提高。随后的消毒机制分析表明，BiOBr-0.5AgBr 释放的 Ag 对 E. coli 的失活没有贡献，而包括 h、表面结合的 OH、O 和 HO 在内的活性氧在消毒过程中发挥了重要作用。发现溶解氧的存在和细胞与光催化剂的直接接触对消毒过程至关重要。反应性物质诱导了细胞膜的破坏，从而导致细菌死亡。此外，BiOBr-0.5AgBr 在较宽的 pH 值范围（5-9）内表现出良好的杀菌活性，即使在连续使用五次后，仍具有有效的抗菌活性。
