Facile synthesis of TiO2-coated cotton fabric and its versatile applications in photocatalysis, pH sensor and antibacterial activities

TiO2 nanoparticles-coated cotton fabric was readily prepared by the hydrolysis of TiCl4 solution over cotton fabric and characterized various techniques in comparison with pristine cotton fabric. Initially, the photocatalytic application of the obtained fabric was carried out by using it as a catalyst for the photodegradation of rhodamine B. A higher degradation ratio for rhodamine B in the presence of TiO2-coated cotton fabric as photocatalyst was observed under visible light compared to the one performed under UVA. The reactive species trapping experiments revealed that the superoxide radicals played a major role than other radical species and two different degradation mechanisms were proposed according the trapping results. Subsequently, considering that the fabricated TiO2-coated cotton fabric is a very suitable sensor material for the development of a wearable flexible pH sensor, a potentiometric solid state pH sensor prototype was constructed and tested for pH measurements. The proposed prototype exhibited a linear potentiometric response in the pH range from 2.0 to 9.0 with a slope of −23.9 mV/decade. The pH accuracies (as relative error %) calculated for the current electrode with respect to the commercial electrode in the studied buffer solutions were ranged between −1.8% and 1.9%. The presently proposed pH electrode allowed pH measurements highly coherent with commercially available pH electrode. Finally, the antibacterial activity of the TiO2 nanoparticles was evaluated by minimum bactericidal concentration (MBC), minimum inhibitory concentration (MIC) testing and also antibacterial property of the TiO2 nanoparticles-coated cotton fabric was demonstrated by GB/T 20944.3–2008 method using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) as representative strains of Gram-positive and Gram-negative bacteria, respectively. This study would be indicative to design of nano metal oxide-coated cotton fabrics in the application of photocatalyst, pH sensor and antibacterial agent against bacteria.