Sain Manisha, Chowdhury Shamik
School of Environmental Science and Engineering, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India.
School of Environmental Science and Engineering, Indian Institute of Technology, Kharagpur, West Bengal, 721302, India.
Environ Res. 2025 Oct 1;282:122004. doi: 10.1016/j.envres.2025.122004. Epub 2025 May 29.
Bisphenol A, a widespread and potent endocrine disruptor in aquatic environments, poses significant health risks, emphasizing the need for advanced photocatalysts to effectively remove this contaminant from water while enabling easy and cost-effective recovery for repeated use. Accordingly, this study presents the development of such a material by combining titanium dioxide (TiO) nanoparticles, graphitic carbon nitride nanoflakes (g-CN), and reduced graphene oxide (rGO) nanosheets. Subsequent dip-coating of the ternary composite with a rationally designed diblock polymer enables its surface wettability to switch from hydrophilic to hydrophobic depending on the pH of the reaction medium. Due to the synergistic effects of TiO (strong oxidative potential), g-CN (moderate bandgap for visible light absorption), and rGO (high electron mobility), the TiO/g-CN/rGO composite exhibits superior textural, optical, and electrochemical properties, thereby promoting efficient photocatalytic activity. Additionally, the pH-responsive wettability improves interaction with bisphenol A in acidic conditions and facilitates composite recovery by inducing aggregation under alkaline conditions. Notably, under optimal conditions, the ternary composite with the appropriate TiO content achieved 95.6 % degradation of bisphenol A within 180 min under visible light. Mechanistic studies indicated that superoxide anions and hydroxyl radicals were primarily responsible for the dissociation of bisphenol A. The composite also demonstrated excellent reusability, maintaining its remarkable photocatalytic capabilities over multiple cycles. Furthermore, TiO/g-CN/rGO showed promising performance in degrading bisphenol A across various real water matrices, with degradation efficiency ranked as follows: tap water > river water > municipal wastewater. This work highlights the importance of developing photocatalysts with switchable surface characteristics to realize their practical applications in wastewater treatment and related fields.
双酚A是一种在水生环境中广泛存在且具有强大内分泌干扰作用的物质，会带来重大健康风险，这凸显了需要先进的光催化剂来有效从水中去除这种污染物，同时实现简便且经济高效的回收以重复使用。因此，本研究通过将二氧化钛（TiO）纳米颗粒、石墨相氮化碳纳米片（g-CN）和还原氧化石墨烯（rGO）纳米片相结合，展示了这种材料的开发过程。随后用合理设计的二嵌段聚合物对三元复合材料进行浸涂，可使其表面润湿性根据反应介质的pH值从亲水性转变为疏水性。由于TiO（强氧化电位）、g-CN（对可见光吸收具有适中带隙）和rGO（高电子迁移率）的协同作用，TiO/g-CN/rGO复合材料展现出优异的结构、光学和电化学性能，从而促进了高效的光催化活性。此外，pH响应性润湿性在酸性条件下改善了与双酚A的相互作用，并在碱性条件下通过诱导聚集促进了复合材料的回收。值得注意的是，在最佳条件下，具有适当TiO含量的三元复合材料在可见光下180分钟内实现了双酚A 95.6%的降解。机理研究表明，超氧阴离子和羟基自由基是双酚A解离的主要原因。该复合材料还表现出优异的可重复使用性，在多个循环中保持其显著的光催化能力。此外，TiO/g-CN/rGO在降解各种实际水基质中的双酚A方面表现出良好的性能，降解效率排序如下：自来水>河水>城市污水。这项工作突出了开发具有可切换表面特性的光催化剂以实现其在废水处理及相关领域实际应用的重要性。
