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Nitrogen-doped titanium dioxide (N-TiO2) nanoparticles were prepared using a modified sol-gel method. The as-prepared nanoparticles were characterized by state-of-the-art techniques for their optical, structural and morphological properties. The crystallite size, surface area and bandgap energy of reference TiO2and N-TiO2nanoparticles were found to be 16.1 and 10.9 nm, 83.6 and 131.8 m2g−1and 3.23 and 2.89 eV, respectively. The photocatalytic activities, in terms of 2,4-dichlorophenol (2,4-DCP) degradation, of reference TiO2and N-TiO2were found to be 46.9% and 65.4% at 120 min of treatments under UV light irradiation and 21.5% and 77.6% at 240 min of treatment under visible light irradiation, employing 153.4 µM 2,4-DCP, 1 g/L photocatalyst dosage, and pH 5.6. Interestingly, considerable H2production rate (i.e., 386 μmol h−1g−1) was observed for visible/N-TiO2system in presence of 0.2 wt% Pt. The study revealed that visible/N-TiO2photocatalytic system can be used as an economically viable technology for environmental sustainability.

This study demonstrates the synthesis of highly hydrophilic poly(vinylidene fluoride) composite membranes incorporated with Titania (TiO2) nanotubes (PVDF/TNT) and then its photocatalytic applications were explored for effective degradation of brilliant green (BG) dye. The membranes were fabricated through phase inversion method using poly(vinylidene fluoride) (PVDF) as matrix, Titania nanotubes (TNT) with different concentrations (0–2 wt%) as filler and poly(vinylpyrrolidone) as pore former. Successful fabrication of composite membranes (PVDF/TNT) was confirmed by using X-ray diffraction analysis, Fourier transform infra-red spectroscopy, differential scanning calorimetry (DSC), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Membrane properties were studied using contact angle, tensile strength, solvent content, pure water flux, bovine serum albumin (BSA) rejection, antifouling properties, porosity and shrinkage ratio. The degradation results suggested that the fabricated membrane can effectively be applied as a heterogenous photocatalyst for the degradation of BG. The results confirm that the dispersion of TNTs increases the antifouling properties of membranes to a maximum value. A minimum pore volume 0.34 cc g−1, pore size 28.4 nm and maximum surface area 142 m2 g−1were obtained with loading 1.5 wt% TNTs in PVDF membranes, which can degrade BG up to 42% compared to 13% in the absence of fabricated membrane after 90 min of reaction time. The photocatalytic degradation mechanism of BG by PVDF/TNT ultrafiltration membranes showed that OH is mainly involved in the degradation process. The degradation byproducts of BG were determined using LC–MS/MS and accordingly degradation pathways were proposed.