Poly(vinylidene fluoride-hexafluoropropylene)/ mesoporous graphitic carbon nitride composite membranes for photocatalytic methylene blue degradation and sensing applications

In this work, poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)/mesoporous graphitic carbon nitride (mpg-C3N4) composite fiber web have been prepared and characterized for photocatalytic methylene blue (MB) degradation and sensing applications. The electrospinning technique, operating at a flow rate of 1 mL/h and a voltage of 15 kV, was utilized to prepare the composite membranes of PVDF-HFP with the uniform distribution of the mpg-C3N4. The composite web demonstrated outstanding photocatalytic activity for the degradation of MB, reaching a quick 68% drop in MB concentration in just 45 min. The composite web furthermore worked as a sensor for MB detection. After MB exposure, the film resistance was increased, suggesting its potential as a chemiresistive sensor. The maximum resistivity of PVDF-HFP/mpg-C3N4 composites was found to be 90 Omega.m at 2% concentration of MB. The MB molecules' adsorption on the surface of the composite web and the existence of photocatalytic byproducts on the surface may be responsible for this shift in resistance. This dual functionality highlights the adaptability and potential of the PVDF-HFP/mpg-C3N4 composite web as a versatile material for environmental sensing and cleanup. This research presents a comprehensive approach to the synthesis, characterization, and evaluation of such flexible membranes for potential applications as self-cleaning devices and chemiresistive sensor.