Utilizing TiO₂ photocatalysis and natural SiO₂ superhydrophilicity synergy to improve self-cleaning activity in cotton fabric

This study aims to explore the function of hydrophilic features of natural SiO₂ in supporting the TiO₂ photocatalysis process for developing cotton fabric with high self-cleaning performance. SiO₂ was produced by extracting natural materials such as Bengkulu beach sand with a high SiO₂ content. The method used is dip-coating in its sol form with the help of ultrasonic waves to maximize the composite loading on the fabric. TiO₂/SiO₂ composite sols were synthesized at three distinct molar ratios, 2:1, 1:1, and 1:2. The self-cleaning activity was observed against methylene blue using the digital image colorimetry technique. SEM images reveal agglomerated TiO₂ and SiO₂ particles attached to the cotton fabric fibers with an average size of 14 nm. The FTIR investigations also demonstrate the existence of Ti \(-\) $-$ O \(-\) $-$ C and Si \(-\) $-$ O \(-\) $-$ C bonds, indicating TiO₂ and SiO₂ particles’ interaction with cotton fabric fibers. Contact angle measurements show that cotton fabric with TiO₂ increases hydrophilicity to 17.8 \(^\circ\) ${}^{\circ }$ , whereas cotton fabric with SiO₂ has a superhydrophilic surface (0 \(^\circ\) ${}^{\circ }$ ). This observation is consistent with the FTIR data, in which the O \(-\) $-$ H stretching band develops following the addition of TiO₂ sol and is more obvious in samples containing SiO₂. The O–H stretching band appears after adding TiO2 sol and is more pronounced in samples containing SiO2 The characterization results showed that TiO₂/SiO₂ composites were successfully added to cotton fabrics. Cotton fabrics with a ratio of TiO₂/SiO₂ (1:1) showed the best self-cleaning activity against methylene blue, reaching 95.25%. Modified cotton fabrics also showed particle adhesion stability with a slight decrease in self-cleaning activity.