Abstract The present work reports a convenient way to evaluate the photocatalytic activity of anatase TiO2 films by monitoring the degradation of methylene blue (MB) directly on the TiO2 coated tiles under simulated solar light (1 sun condition; AM 1.5G simulator) using Raman spectroscopy. For this purpose, nanocrystalline TiO2 films of aesthetic quality (thickness ∼80±5 nm) were deposited by the sol-gel method on the glazed tiles. XRD and Raman studies of the calcined coatings (500°C/2 h in air) confirmed the formation of anatase phase of TiO2. The water contact angle (θ) value of the coated tiles was found to be 20±1° (hydrophilic) and no significant change of θ was noticed after storing in ambient condition for 3 months. The MB decomposition on the TiO2 coating under 1 sun condition was monitored by recording the Raman spectra with respect to time. Using this technique, the apparent rate constant (kapp) value of MB degradation was found to be 0.2554 min−1. The total photo-decomposition of dye and its repeatability studies through direct Raman monitoring of the coating surface ensured the self-cleaning ability of the TiO2 coatings. GRAPHICAL ABSTRACT

中文翻译：

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拉曼光谱法对瓷砖上锐钛矿TiO2涂层的光催化评价

摘要 目前的工作报告了一种评估锐钛矿 TiO2 薄膜光催化活性的便捷方法，通过使用拉曼光谱直接监测 TiO2 涂层瓷砖上亚甲蓝 (MB) 在模拟太阳光（1 日光条件；AM 1.5G 模拟器）下的降解. 为此，通过溶胶-凝胶法在釉面砖上沉积了具有美学品质（厚度约 80±5 nm）的纳米晶 TiO2 薄膜。煅烧涂层（空气中 500°C/2 小时）的 XRD 和拉曼研究证实了 TiO2 锐钛矿相的形成。发现涂层瓷砖的水接触角（θ）值为 20±1°（亲水），在环境条件下储存 3 个月后，θ 没有明显变化。通过记录相对于时间的拉曼光谱来监测在 1 个太阳条件下 TiO2 涂层上的 MB 分解。使用这种技术，发现 MB 降解的表观速率常数 (kapp) 值为 0.2554 min-1。通过对涂层表面的直接拉曼监测，染料的总光分解及其可重复性研究确保了 TiO2 涂层的自清洁能力。图形概要