Carrier transport and shielding properties of rod-like mesoporous TiO2-SiO2 nanocomposite

Synthesizing material candidates having both high ultraviolet (UV) absorbing capacity and low photoactivity is a paramount challenge. The present study reports the sonosynthesis of titanium oxide (TiO2) - silicon dioxide (SiO2) nanocomposite that possesses good UV screening efficacy but reduced photoactivity. It was observed that the synthesized TiO2-SiO2 & nbsp;(TS11) composite with a 1:1 M ratio of TiO2 and SiO2 precursors showed lower photoactivity (25.91% pollutant degradation in 300 min) while maintaining its UV shielding properties (20% UV transmittance in 200-400 nm region). The surface area and average pore diameter of TS11 nanocomposite was found to be 2 m(2)g(-1) and 18.8 nm as per Barrett- Joyner-Halenda (BJH) analysis. Low photoactivity could be accounted to the reduced surface area and unique rod-like morphology of the TS11 composite that probably trapped the photoactive TiO2 particles within the SiO2 rods. The TS11 nanocomposite showed tunable band gap in comparison to that of bare TiO2 and SiO2 which is desirable for optoelectronic applications. The carrier transport properties were evaluated by fabricating an ITO/TS11/Al based Schottky diode. Lower carrier mobility, diffusion length and higher transit time under illumination in comparison to other TiO2 composites appears consistent with reduced photoactivity.