Photocatalytic and Antimicrobial Properties of [AgTiO 2 ]:[Clay] Nanocomposite Prepared with Clay Different Ratios

Abstract

This work aimed to synthesis a novel material that would be able to efficiently remove both organic and microbiological pollutants from wastewater. Through the hydrothermal process, we first doped titanium dioxide, a semi-conductor possessing excellent photocatalytic properties with silver nanopar-ticles having good antibacterial properties. The obtained material was then associated with clay known for its good adsorbent properties to form [Ag-TiO2]:[clay] type nanocomposites. The different mass composition of [Ag-TiO2]:[clay] considered in this work were 1:1; 1:0.5; 1:0.1; 1:0.05 and 1:0.01. The prepared nanocomposites were characterized by means of XRD, FTIR and SEM techniques. Results revealed the presence of TiO2 anatase and Ag on the surface of the clay mainly composed of kaolinite and quartz. The photo-catalytic activities of the nanocomposites were tested in the presence of syn-thetic Orange II (25 mg/L) wastewater under visible light irradiation. The ex-periments demonstrated that organic pollutants were effectively photode-graded when the proportion of clay in the mixture (AgTiO2)-(Clay) was infe-rior or equaled to 50%. The use of commercial TiO2, for comparison purpose, showed a lower degradation efficiency of the Orange II solution (η < 30%). The antibacterial properties of the nanocomposites [AgTiO2]:[clay] were also assessed in the presence of two types of bacteria E. coli (Gram negative) and S. aureus (Gram positive). The antibacterial activities of the nanocomposites were characterized with and without UV irradiation. In dark conditions, the antibacterial activities of nanocomposites (AgTiO2)-(Clay) against S. aureus gradually increased with increasing the clay amount. Under visible light ir-radiation, the nanocomposites showed a significant antimicrobial activity against E. coli and S. aureus