EFFECT OF HEATING TEMPERATURE ON BROOKITE TIO2 SOL-GEL COATING FOR PHOTO-INDUCED HYDROPHILICITY
Brookite has been rarely used and always exits as a by-product of TiO2. Until recently, there are limited studied concerned with the preparation of brookite coating. In this paper, the main objective of producing pure brookite coating from a specially synthesized sol without using solvent for photo-induced hydrophilicity is reported. The TiO2 coatings were deposited on a glass substrate via a spin coating method at various temperatures (200 ⁰C, 300 ⁰C, and 400 ⁰C) and soaked for 3 hours. Coatings characteristic were evaluated using XRD and Raman spectroscopy. For the photocatalytic and photo-induced hydrophilicity performance, a color degradation technique of methylene blue (MB) and water contact angle measurement (CA) was utilized respectively. The test was done under UV light irradiation for 5 hours. The XRD results revealed a single peak denoted to brookite (B 111) with an orthorhombic structure was formed at 31.9° throughout all temperatures with an average crystallite size of 41 nm to 58 nm. Further analysis using Raman spectroscopy also indicated that the deposited TiO2 coatings are brookite. Results of the band gap analysis also proved that the obtained values are in agreement with the value of brookite phase. Thus, it can be confirmed that the TiO2 coatings deposited from the synthesized sol are brookite coatings. It is found that the brookite TiO2 coating deposited at 400 0C is the best to possess well-balanced properties for self-cleaning application.
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