Synthesis and characterization of TiO2 quantum dots by sol gel reflux condensation method

Abstract Owing to their high specific surface area, titanium dioxide (TiO2) quantum dots (QDs) offer superior properties for UV radiation harvesting from solar spectrum for applications such as self-cleaning surfaces and removal of organic contaminants. In this work, a novel sol-gel reflux condensation route developed to produce TiO2 QDs is reported. The process involved using titanium tetra-isopropoxide (TTIP) as the precursor that was hydrolyzed and then subjected to reflux condensation for 24 h. Subsequent drying and annealing treatments produced QDs with a relatively high yield of 33%. TEM examination revealed spherical QD morphology with an average crystallite size of 5–7 nm. This was also confirmed from QD size calculation involving Scherrer equation for the most intense peak in the x-ray diffraction (XRD) pattern. Both XRD and Raman spectroscopy studies cofirmed the crystalline anatase phase formation. From UV/Vis data and the Tauc plot, the energy band gap value (Eg) was computed to be ~3.76 eV.