Evaluation of curcumin assistance in the antimicrobial and photocatalytic activity of a carbon based TiO2 nanocomposite

Abstract

The present study focuses on the synthesis of visible light active curcumin supported TiO₂/AC (curcumin–TiO₂/AC) through sol–gel and wet impregnation methods for the decolourization of Reactive Blue 160. The characterization technique SEM with EDAX confirms the doping of curcumin and accumulation of TiO₂ nanoparticles into the pores of activated carbon. Further, the crystalline structure and band gap energy were studied by the X-ray diffraction technique and UV-visible diffuse reflectance spectroscopy, respectively. The inhibition of electron–hole recombination was evidenced by photoluminescence spectroscopy. The photocatalytic activity of the nanocomposites was monitored under visible light irradiation through various optimized conditions, such as pH – 3, catalyst concentration – 0.1 g, irradiation time – 3 h. Improved degradation was observed for curcumin–TiO₂/AC due to the narrow band gap and effective charge separation by the surface modifiers compared to TiO₂/AC. Additionally, the antimicrobial activity of curcumin–TiO₂/AC was tested against Staphylococcus aureus, Escherichia coli and Candida species. These results indicated that doping of curcumin on TiO₂/AC inhibits the recombination of electron–hole pairs to improve the photocatalytic performance in the visible region.