The Addition of TiO2 Ratios in SiO2–TiO2 Nanocomposite by Sonochemical Process for the Enhancement in Self-cleaning Property

Abstract

This research aims to study self-cleaning property for removing atmosphere pollutants on the substrate surface. Thus, the modification of nanocomposite material for self-cleaning property is an important challenge to solving the organic pollutants on various surfaces. Nanocomposite material in this work is focused on SiO2-TiO2 based metal oxide materials that synthesized by sonochemical process with the precursors of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TTIP). The crucial parameter of different amount of titanium ratios in SiO2 matrix is related to the improvement on structural and self-cleaning properties. The ratios of Si:Ti precursor were varied at 1:0.1, 1:0.5, 1:1 and 0:1 (pure TiO2). The structural phase of SiO2-TiO2 nanocomposite powder was detected by X-ray diffraction technique (XRD). Chemical bonding structure in SiO2-TiO2 nanocomposite was analysed by Fourier transform infrared spectrophotometer (FTIR). Surface morphology of SiO2-TiO2 nanocomposite was monitored by field emission scanning electron microscope (FE-SEM). SiO2-TiO2 nanocomposites synthesized by sonochemical process were in form of composite powder with the spherical SiO2 particles and decorated TiO2 on its surface. After that, the products of SiO2-TiO2 nanocomposite with different TiO2 ratios were mixed with TES 40 WN solution and deposited on glass slides substrate by spray coating to study its hydrophilic property by contact angle method. The contact angle of SiO2-TiO2 nanocomposite film was reduced with the increase of Ti ratio in SiO2 matrix resulting to the development of hydrophilic surface on substrate. The influence of TiO2 in SiO2 matrix on self-cleaning and property would be improved by hydroxyl groups on the composite surface corresponding to Ti–O–Si linkages. For self-cleaning property, Si:Ti ratio at 1:1 in SiO2-TiO2 nanocomposite showed the optimized condition with decreasing contact angle at 28.97 degree in 60 min after UVA irradiation.