Photocatalysis of nanocomposite titania–natural silica as antibacterial against Staphylococcus aureus and Pseudomonas aeruginosa

Abstract

The entries of pathogenic bacteria into the human body remain a severe problem to health that can be prevented using antibacterial agents. Meanwhile, the photocatalytic technique using semiconductor nanocomposite TiO₂–SiO₂ has great potential as an antibacterial method. In order to utilize natural resources, SiO₂ supporting materials are obtained from the extraction of beach sand due to the high silica content. Therefore, this study aims to synthesize a nanocomposite of TiO₂ with SiO₂ extracted from beach sand as an antibacterial agent against Staphylococcus aureus and Pseudomonas aeruginosa. The antibacterial activity test used the dilution and optical density method. Based on XRD analysis, the crystals of TiO₂ in the synthesized composites showed a more dominant anatase structure. Furthermore, Ti–O–Si bonds were identified from the IR spectrum, which showed the interaction between TiO₂ and SiO₂. In addition, SEM-EDX results showed agglomerated spherical particles with a TiO₂–SiO₂ nanocomposite particle size of 40–107 nm. The best antibacterial activity was demonstrated by the 1 : 0.5 TiO₂–SiO₂ nanocomposite, with inactivation percentages of S. aureus and P. aeruginosa of 98.69% and 97.44%, respectively.