School of Life Sciences , The Chinese University of Hong Kong , Shatin, NT, Hong Kong SAR , China.
Institute for Energy Research, School of Chemistry and Chemical Engineering , Jiangsu University , Zhenjiang , Jiangsu 212013 , China.
Environ Sci Technol. 2018 Apr 17;52(8):4774-4784. doi: 10.1021/acs.est.7b06537. Epub 2018 Mar 28.
Ultrathin hydrothermal carbonation carbon (HTCC)-coated cobalt ferrite (CoFeO) composites with HTCC coating thicknesses between 0.62 and 4.38 nm were fabricated as novel, efficient, and magnetically recyclable photocatalysts via a facile, green approach. The CoFeO/HTCC composites showed high magnetization and low coercivity, which favored magnetic separation for reuse. The results show that the close coating of HTCC on CoFeO nanoparticles enhanced electron transfer and charge separation, leading to a significant improvement in photocatalytic efficiency. The composites exhibited superior photocatalytic inactivation toward Escherichia coli K-12 under visible-light irradiation, with the complete inactivation of 7 log cfu·mL of bacterial cells within 60 min. The destruction of bacterial cell membranes was monitored by field-effect scanning electron microscopy analysis and fluorescence microscopic images. The bacterial inactivation mechanism was investigated in a scavenger study, and O, HO, and h were identified as the major reactive species for bacterial inactivation. Multiple cycle runs revealed that these composites had excellent stability and reusability. In addition, the composites showed good photocatalytic bacterial inactivation performance in authentic water matrices such as surface water samples and secondarily treated sewage effluents. The results of this work indicate that CoFeO/HTCC composites have great potential in large-scale photocatalytic disinfection operations.
通过简便、绿色的方法制备了厚度为 0.62nm 到 4.38nm 的超薄水热碳化碳（HTCC）包覆钴铁氧体（CoFeO）复合材料，作为新型高效、可磁回收的光催化剂。CoFeO/HTCC 复合材料具有高磁化强度和低矫顽力，有利于磁性分离再利用。结果表明，HTCC 在 CoFeO 纳米粒子上的紧密包覆促进了电子转移和电荷分离，从而显著提高了光催化效率。在可见光照射下，复合材料对大肠杆菌 K-12 具有优异的光催化灭活性能，7 个对数 cfu·mL 的细菌细胞在 60min 内完全失活。用场效应扫描电子显微镜分析和荧光显微镜图像监测细菌细胞膜的破坏。通过清除剂研究探讨了细菌失活动力学，确定 O、HO 和 h 为细菌失活动力学的主要活性物质。多循环实验表明，这些复合材料具有优异的稳定性和可重复使用性。此外，在地表水水样和二级处理污水等真实水基质中，复合材料表现出良好的光催化细菌灭活性能。这项工作的结果表明，CoFeO/HTCC 复合材料在大规模光催化消毒操作中具有巨大的潜力。
