Electrospun TiO₂/Cu@NH₂-MIL-125-loaded PVDF/PAN nanofibers for multifunctional applications

Population growth and environmental degradation are raising concerns, particularly regarding water safety. Furthermore, existing water treatment methods are often inadequate for effectively purifying water to meet acceptable drinking standards. As a result, there is a growing need to develop efficient, environmentally friendly and cost-effective water treatment systems. This study investigates the effective use of electrospun TiO₂/Cu@NH₂-MIL-125/PVDF/PAN nanofiber for environmental remediation applications, which have emerged as a viable solution for water purification. The nanofibers were fabricated using the electrospinning technique under optimal parameters (applied voltage = 15 kV, flow rate = 0.02 mL/h). Characterization techniques such as X-Ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Fourier-Transform infrared spectroscopy (FTIR) confirmed successful incorporation of TiO₂/Cu@NH₂-MIL-125 composite into the nanofiber matrix. The antibacterial activity against Bacillus subtilis and Escherichia coli was evaluated using the minimum inhibitory concentration (MIC) assay via disk diffusion method. The results revealed insignificant antibacterial activity, with no inhibition zones observed for the TiO₂/Cu@NH₂-MIL-125/PVDF/PAN nanofibers against either bacterial strain. Additionally, the adsorption capacity for heavy metal like lead and cadmium was evaluated using batch adsorption techniques. Optimal conditions at pH 6 resulted in 100 % removal of cadmium and 40 % removal of lead. The Langmuir isotherm model and pseudo-second-order kinetic model were identified as the most suitable for describing cadmium adsorption, indicating a uniform adsorbent surface and chemisorption as the rate limiting step, driven by physiochemical interaction. On the other hand, lead absorption followed the Freundlich isotherm and pseudo-second-order kinetic model, suggesting a chemisorption process with heterogeneous surface energies and varying binding affinities at different sites. This study presents novel multifunctional nanofibers composed of unique integration of TiO₂, Cu and NH₂-MIL-125. This has not been previously reported for water remediation applications. Overall, the findings contribute to the development of cost-effective and environmentally friendly nanomaterials for point-of-use water treatment.