Graphene-Based TiO2 Cement Composites to Enhance the Antibacterial Effect of Self-Disinfecting Surfaces

Abstract

This paper studies the photocatalytic performance of graphene-based titanium dioxide (TiO2) on cementitious composites for the decomposition of Escherichia coli (E. coli) under visible light. Graphene-based TiO2 was first synthesized through a hydrothermal process. The composites were then evaluated in terms of adsorption capability and degradation of methylene blue dyes. The adsorption test shows a remarkable increase in the amount of dye adsorbed into the composite surface. GO-P25 could adsorb around 60% of the initial dye, while less than 10% of the initial dye was adsorbed by pristine TiO2-P25. The synthesized graphene-based TiO2 significantly enhanced the dye degradation activity (94%) compared to pristine P25 (36%) and Krono (52%), even with the longer irradiation time for P25 and Krono. This led to an increase in reaction rate that was almost 20 times that of P25. Considering the good adsorption capabilities and high photodegradation of dye under visible light for GO-P25, cement-based surfaces containing GO-P25 are expected to be improved for the decomposition of Escherichia coli (E. coli) under visible light. Graphene-based TiO2 on a cement-based surface showed high antibacterial activity with a 77% reduction in number of bacteria compared to a cement-based surface containing pristine TiO2. This study confirms the effectiveness of the composites for disinfection of E. coli under visible light.