Data underlying the publication: Advanced ceramics in radical filtration: TiO2 layer thickness effect on the photocatalytic membrane performance

Membranes with advanced oxidation processes (AOPs) are a promising combination to separate and degrade organic pollutants in a single system. In this work, we describe the fabrication and characteristics of nine membranes with different TiO2 top layer thicknesses (from 0.26 to 21.9 μm), giving attention to the critical catalyst thickness and the formation of defects. We also report the optimum photocatalyst thickness for our single-layer membranes (∼2.74 μm), after which more titanium dioxide does not improve the degradation. However, an increase in degradation for membranes with multiple TiO2 layers was still possible. These results and the comparisons with the literature suggested that the optimal catalyst thickness is closely related to the material morphology. We obtained a maximum degradation at the lower filtration rate (1.6 L m−2 h−1) of 72% with a single layer membrane of 3.4 μm and 82% with a membrane with six layers of 21.9 μm. Furthermore, a 1D mass transport and reaction model that describes the coating thickness effect was developed and fitted with the experimental data. Other parameters are also discussed, such as light penetration limitations, surface area, and surface reaction rate constant. These results and analysis provide a better understanding of the fabrication and optimization of photocatalytic membranes.

耦合高级氧化工艺（Advanced Oxidation Processes, AOPs）的膜材料，是一种可在单一体系中同步实现有机污染物分离与降解的极具应用前景的组合方案。本研究针对9种顶层二氧化钛（TiO₂）厚度区间为0.26~21.9 μm的膜材料，系统阐述了其制备方法与性能特征，并重点关注了关键催化剂厚度与缺陷形成机制。本研究同时明确了单层膜的最优光催化剂厚度约为2.74 μm，当厚度超过该临界值后，二氧化钛负载量的提升无法进一步改善降解性能；但对于多层二氧化钛膜结构而言，仍可通过优化工艺实现降解性能的提升。结合实验结果与文献对比分析可知，最优催化剂厚度与材料形貌密切相关。在较低过滤速率（1.6 L·m⁻²·h⁻¹）条件下，3.4 μm厚单层膜的最高降解率可达72%，而21.9 μm厚六层膜的最高降解率可达82%。此外，本研究构建了可描述涂层厚度影响的一维传质反应模型，并通过实验数据完成了模型拟合。本研究还讨论了其他相关参数，包括光穿透限制效应、比表面积与表面反应速率常数。上述研究结果与分析可为光催化膜的制备与优化提供更为深入的理论支撑与参考依据。