Air bubbles induced piezophotocatalytic degradation of organic pollutants using nanofibrous poly(vinylidene fluoride)-titanium dioxide hybrid

Abstract

Flexible and porous poly (vinylidene fluoride)-titanium dioxide (PVDF-TiO2) hybrid prepared by sequential electrospinning and electrospraying was investigated for piezoelectric-driven semiconductor photocatalysis (PDSP) application. FT-IR and XRD results confirmed the direct preparation of nanofibrous PVDF layer with piezo-responsive β- and γ-crystalline phases by electrospinning. FE-SEM and FTIR spectra discerned that the fibrous structure of PVDF support and its piezo crystalline forms were preserved even after the process of TiO2 NPs deposition. In complementary to the visual observation by FE-SEM, XPS, and EDS, spectroscopical results confirmed the deposition of TiO2 NPs on the piezo responsive PVDF support. XPS studies confirmed that 53% of the hybrid surface was covered by TiO2 NPs. Under UV irradiated conditions, water bubble induced piezo activity enhanced the degradation of methylene blue (MB) by 99%. The PDSP efficacy of the hybrid was proportional to the extent of air bubble supply. The % of total organic carbon removal was 66, which indicate the mineralization of MB. The non-selective OH mediated photooxidation by this hybrid was found to be also suitable for degrading non-dye pollutants such as 4-aminophenol. Overall, PVDF-TiO2hybrid was found to be a potential PDSP useful for water remediation and detoxification.