TiO2-MWCNTs/ PVDF: Photophysical properties, photocatalytic activity, and recycling in industrial effluent wastewater treatment by different photocatalytic sources

This paper presents a comprehensive study on the fabrication, characterization, and photocatalytic performance of TiO2-MWCNTs/PVDF nanocomposite membranes for the treatment of industrial dye wastewater. The TiO2MWCNTs nanocomposites with varying TiO2 weight percentages (4 %, 7 %, 10 %) were synthesized using a solgel method. These were incorporated into PVDF membranes via solvent casting to obtain (TiO2-MWCNTs)x%/ PVDF nanocomposites. The nanocomposites were characterized by techniques like XRD, SEM, FTIR, UV-vis DRS, PL, and BET analysis. The results showed that increasing TiO2 content led to higher crystallinity, surface area, and porosity of the nanocomposites, which enhanced their photocatalytic activity. The TiO2-MWCNTs nanocomposites displayed efficient photodegradation of Indigo carmine dye under Xenon lamp irradiation, with 10 % TiO2 sample showing the highest rate constant of 17.88 x 10-3 s- 1. Similarly, (TiO2-MWCNTs)x%/PVDF nanocomposites exhibited superior dye degradation compared to pure PVDF. The photocatalytic treatment of actual industrial wastewater containing textile dyes was also demonstrated under sunlight using (TiO2MWCNTs)x%/PVDF membranes. The COD values of samples treated with 8 % nanocomposite were within the permissible limits of 1000 ppm specified by Saudi Arabian regulations. The recycling experiments proved the reusability of the nanocomposite membrane for up to 7 treatment cycles without significant loss of efficiency. Overall, this work provides valuable insights into the synergistic effects of TiO2-MWCNTs nanocomposites supported on PVDF membranes for efficient solar photocatalytic treatment of dye-containing industrial wastewaters. The recyclable nanocomposite system offers a sustainable and eco-friendly solution to this environmental problem.