Synthesis of sol gel based titanium dioxide photocatalyst investigations on their modification interaction with metal ions and antimicrobial activity

Abstract

The impact of nanotechnology has become increasingly evident in different areas of newlinescience and technology, including the field of environmental remediation and newlinedisinfection. A number of environmentally beneficial technologies such as heterogeneous newlinephotocatalysis (HP) and Solar Disinfection (SODIS) using nanosized TiO2 as newlinephotocatalysts have been developed and applied extensively for air purification, water newlinetreatment and environmental remediation. TiO2 is a promising photocatalyst in terms of newlinecatalytic performance and stability in aqueous media and has gained considerable newlineattention due to its chemical stability, insolubility in water, non-toxicity, low cost, and newlineother advantageous properties. newlineIn this research work we have synthesized mesoporous TiO2 nanoparticles by a simple newlinesol-gel method using titanium tetrachloride as a precursor. The characterization of TiO2 newlinenanoparticles by XRD, TEM, TG-DTA, and N2 adsorption-desorption analysis indicate newlineformation of pure anatase phase, polycrystalline TiO2 showing good physicochemical newlineproperties with a particle size of ~13 nm and surface area of 72.80 m2/g. The synthesized newlineTiO2 nanoparticles exhibited good photocatalytic activity under both UV light and newlinesunlight for the degradation of toxic dyes Malachite green and Methylene blue. The TiO2 newlinealso showed promising bactericidal activity against pure bacterial cultures of E. coli, P. newlineaeruginosa, S. aureus and K. pneumoniae as well as microorganisms from the discharge newlinewater from a sewage treatment plant which had a high microbial load. newlinevi newlineAlthough TiO2 is considered an ideal photocatalyst because of its photocatalytic newlineproperties, it has a wide band gap of 3.2 eV that limits its photocatalytic activity to the newlineultraviolet (UV) region of the light spectrum, which is ~4 % of the total solar energy newlineavailable, far too small for practical applications. Hence, to lower the band gap of TiO2 newlineand to improve its absorption in the visible light region the TiO2 was doped with newlinetransition metals, non-metal anions, and surface modified.