Green synthesis of Ag-TiO2 nanoparticles using turmeric extract and its enhanced photocatalytic activity under visible light

Abstract

Green chemistry is considered a feasible alternative to traditional chemistry and can be applied to the synthesizing of nanomaterials. The current work employed a reducing agent derived from turmeric extract to design an environmentally friendly and cost-effective plant-mediated method for producing silver-doped titanium dioxide (Ag-TiO2) for the photodegradation of methylene blue (MB). The green synthesis of Ag-TiO2 was carried out utilizing a dry and wet ball milling sol-gel method with turmeric extract. The effect of varying Ag concentrations in Ag-TiO2 on MB degradation was investigated. According to our findings, the optimal amount of Ag on TiO2 modification resulted in an increase in surface area, an improvement in visible light absorption, and a decrease in the TiO2 bandgap. X-ray absorption spectroscopy results showed the presence of Ag+ in the TiO2 structure, indicating Ag substitution and oxygen vacancy formation in TiO2. Ag NPs could considerably increase the electron–hole separation and enhance the photocatalytic efficiency of the Ag-TiO2. The 3 %Ag-TiO2 provided the highest photocatalytic activity for 80 % MB degradation under visible light for 9 h. The method presented here leads to a straightforward and environmentally benign route to make visible-light-active Ag-TiO2 nanoparticles and can be used for treatment of wastewater.