Zhu Li, Wang Wei, Zhao Pei, Wang Shulin, Yang Kun, Shi Hebin, Xu Man, Dong Yingchao
Engineering Research Center of Environmental Materials and Membrane Technology of Hubei Province, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430073, Hubei, China; Foshan (Southern China) Institute for New Materials, Foshan, 528200, Guangdong, China.
Engineering Research Center of Environmental Materials and Membrane Technology of Hubei Province, School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan, 430073, Hubei, China.
Water Res. 2022 Nov 1;226:119209. doi: 10.1016/j.watres.2022.119209. Epub 2022 Oct 6.
Membrane fouling is a critical challenge for current ceramic membranes, which suffer from low flux and insufficient removal. Development of self-cleaning catalytic ceramic membranes is promising to address this challenge. Herein, we design heterogeneous silicon carbide ceramic membranes featuring a novel structure of g-CN-decorated β-SiC nano-wire catalytic functional layer, which enables enhanced anti-fouling self-cleaning performance. At chemical harsh (alkaline or especially acidic) conditions, the nano-wire membrane exhibits catalysis-enhanced removal performance for organic contaminants. Unlike conventional particle-packing membrane structure, such a nano-wire network membrane structure has not only high porosity (56.1%), but exceptional water permeance (110 L·m·h·bar) and removal (100%) of organic substance under simulated sunlight, outperforming state-of-the-art organic membranes and ceramic membranes. Superoxide radical (∙O) was experimentally confirmed to be major reactive species responsible for self-cleaning function. We also propose a catalytic mechanism model with radical formation pathway, enabled by the as-formed g-CN@β-SiC heterojunction structure with reduced electron-hole recombination. This work would provide new insights into not only rational design of next-generation ceramic membranes with self-cleaning function but also more applications of efficient treatment of refractory wastewaters containing degradable organic substances by using such membranes.
膜污染是当前陶瓷膜面临的一项严峻挑战，这类陶瓷膜通量低且去除效果不佳。开发具有自清洁功能的催化陶瓷膜有望解决这一难题。在此，我们设计了一种非均相碳化硅陶瓷膜，其具有由g-CN修饰的β-SiC纳米线催化功能层的新颖结构，能够增强抗污染自清洁性能。在化学苛刻（碱性或特别是酸性）条件下，纳米线膜对有机污染物表现出催化增强的去除性能。与传统的颗粒填充膜结构不同，这种纳米线网络膜结构不仅具有高孔隙率（56.1%），而且在模拟阳光下具有出色的透水率（110 L·m·h·bar）和有机物去除率（100%），优于现有技术的有机膜和陶瓷膜。实验证实超氧自由基（∙O）是负责自清洁功能的主要活性物种。我们还提出了一种具有自由基形成途径的催化机制模型，该模型由形成的具有减少电子-空穴复合的g-CN@β-SiC异质结结构实现。这项工作不仅将为具有自清洁功能的下一代陶瓷膜的合理设计提供新的见解，还将为使用此类膜高效处理含有可降解有机物质的难处理废水提供更多应用。
