Enhanced removal of hazardous organic contaminants with advanced visible light-active F-doped TiO2/rGO/PVDF photocatalytic membranes

Abstract

Polyvinylidene fluoride (PVDF) membranes and composite variants with x% FGT/PVDF photocatalytic membranes were prepared at different concentrations (x = 1 %, 5 %, and 10 %) using the phase inversion technique. The synthesized photocatalysts and the membrane materials were thoroughly characterized using different analytical methods. The focus was on determining the photocatalytic efficiency of these materials in degrading two important harmful dyes, namely methylene blue (MB) and crystal violet (CV), under visible light irradiation. High degradation percentages of MB (96 %) and CV (92 %) at 90 minutes were observed with 5 % F-TiO2/rGO (named as 5 %FGT). Similarly, the 5 % F-TiO2/rGO/PVDF (5 %FGT/PVDF) photocatalytic membranes showed 98 % and 93 % degradation of MB and CV, respectively. Kinetic studies revealed that the photocatalytic degradation reaction followed a pseudo-first-order mechanism. The total organic carbon (TOC) analysis of the treated MB and CV dyes showed a degradation of 78 % and 71 %, respectively. Recycling of the most active 5 % FGT/PVDF composite membrane exhibited very high stability of 800 min. The composite material utilizes the photocatalytic properties of TiO2 and the stimulating transport properties of rGO. Additionally, fluorine doping enhances charge carrier separation, tunes the bandgap for visible light response, and increases surface activity, thereby improving the overall degradation of organic pollutants. These properties make the composite material promising for various applications in environmental remediation and wastewater treatment.