Synthesis and Evaluation of Novel TiO2-based Self-cleaning Coating Layer for Buildings

Abstract

Abstract This research was carried out in order to analyse the potential of novel nitrogen-doped TiO2/SWCNT (N-doped TiO2/SWCNT) photocatalyst nanocomposites for pollutant removal that deposits on surfaces of buildings. In the present work, the procedure to fabricate this nanocomposite follows a simple method which is sol-gel synthesis method using titanium tetraisopropoxide (TTIP) and ammonia as the precursor. Different composition of TiO2 and SWCNT were used to achieve the optimum composition suitable for building surfaces as a self-cleaning coating. The fabricated dried sols were characterized by XRD to ensure TiO2’s anatase nanocrystalline structure was maintained even after doping. The morphology of these novel coatings was observed by FESEM. FESEM showed that uniform dispersion between TiO2 and SWCNT is present which exhibited a vine-like structure. Methylene blue degradation test was conducted to measure the photocatalytic efficiency of each coating. The highest degradation efficiency achieved was 72.43 %. Spin-coating method was used to deposit a thin layer of this coating on the glass substrate to inspect the water contact angle (WCA) of the as-prepared coatings. The coatings displayed a contact angle of 21.3 °proving that the wetting characteristic falls under hydrophilic category in which any sprinkled water is able to remove the dirt that deposits on the surface. Self-cleaning testing was carried out on glass substrates to further evaluate the coating layers. The coated substrates cleaned about 99 % of the dirt that deposited on its surface. These coatings could be utilized in various applications be it indoors or outdoors, for water remediation, energy saving panels and many potential fields.