Synthesis, characterization, and photocatalytic application of novel TiO2 nanoparticles

Novel TiO2 nanoparticles (TNP) having a high specific surface area were successfully synthesized in a vortex reactor by sol–gel process with optimized operating parameters. These 10–20 nm TNP were characterized and compared with TiO2 synthesized by solution combustion (TSC) method and commercially available TiO2 (degussa P25 and anatase by Aldrich). Characterization was performed by X-ray diffraction spectroscopy (XRD), specific surface area analysis, energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), diffuse reflectance ultraviolet–visible spectroscopy (DR/UV–vis), and Fourier transformed-infrared spectroscopy (FT-IR). TNP showed comparatively smaller size with little porosity between them, good crystalline anatase with small rutile phase, higher BET surface area, confined band gap energy, and higher OH groups. Photocatalytic oxidation of ethylene (a naturally occurring gas produced by plant tissues, engine exhausts, and plant and fungi metabolism) has been investigated at ambient temperature in an ad hoc designed pyrex glass photocatalytic reactor, by using these TNP and compared with TSC, and commercial TiO2. Higher photocatalytic conversion of ethylene was observed for TNP compared to TSC and commercial TiO2. Mixed phase of TN with high surface area might induce the adsorption of ethylene pollutant and water with generation of OH groups (oxidizing agent) on the surface of TNP leading to higher photocatalytic activity.