ABSTRACT

Titania (TiO₂) powder is the most extensively employed photocatalyst for the purification of water. Nonetheless, the usage of conventional powder catalysts in water treatment has the limitation of settling of the catalyst during the reaction and the additional step of separation of the powders from the liquid. To overcome this limitation and extend the application of TiO₂ for practical applications, coatings are promising. In the present study, a comparison of the photocatalytic property of titania coatings deposited by suspension plasma spray (SPS) and solution precursor plasma spray (SPPS) methods using similar plasma spray parameters is presented. The coatings are characterized by field emission scanning electron microscopy, profilometry, X-ray diffractometry, and Raman spectroscopy. The photocatalytic performance and efficiency of photodecomposition of the developed coatings are studied using methylene blue as the organic pollutant. The study demonstrates a higher photocatalytic activity and photodecomposition efficiency for the SPPS titania coating compared to SPS titania coatings. The improved performance is attributed to the presence of oxygen vacancies and is corroborated with X-ray photoelectron spectroscopy. The SPPS titania coatings hold promise for industrial-scale applications as it is economical, simple and does not involve multiple steps.

摘要

二氧化钛（TiO ₂）粉末是用于净化水的最广泛使用的光催化剂。然而，在水处理中使用常规粉末催化剂具有在反应过程中催化剂沉降的限制以及从液体中分离粉末的额外步骤。克服这一限制并扩展TiO ₂的应用对于实际应用，涂料是有前途的。在本研究中，提出了使用相似的等离子喷涂参数，通过悬浮等离子喷涂（SPS）和溶液前体等离子喷涂（SPPS）方法沉积的二氧化钛涂层的光催化性能的比较。该涂层的特征在于场发射扫描电子显微镜，轮廓测定法，X射线衍射法和拉曼光谱法。以亚甲基蓝为有机污染物，研究了已开发涂层的光催化性能和光解效率。研究表明，与SPS二氧化钛涂层相比，SPPS二氧化钛涂层具有更高的光催化活性和光分解效率。性能的提高归因于氧空位的存在，并通过X射线光电子能谱得到了证实。SPPS二氧化钛涂料经济，简单且不涉及多个步骤，因此有望用于工业规模的应用。