Scalable synthesis of anatase titania quantum dots: Precursor influence, formation mechanism, and multifunctional applications

This study demonstrates a straightforward and scalable approach for synthesizing anatase titania (TiO 2 ) quantum dots (QDs) using various titanium precursors. The synthesis employed a simple sol-gel method combined with reflux condensation in an aqueous solution, eliminating the need for templates or organic solvents. A subsequent annealing process resulted in QDs with a high yield exceeding 43%. The primary objective was to investigate the effects of different precursors on the properties of the QDs and the mechanisms governing their formation. X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses confirmed that the crystallite size was consistently below 10 nm, with variations influenced by the choice of precursor. The crystalline anatase phase was successfully identified through XRD and Raman spectroscopy. The optical properties of the QDs were studied using UV-Vis-NIR spectroscopy, and the energy bandgap (Eg) was determined to range from 4.04 to 4.08 eV, based on Tauc plot analysis. This value exceeds the typical bandgap of bulk TiO 2 , a phenomenon attributed to quantum size effects. The findings highlight the potential of this method for producing high-yield TiO 2 QDs with tunable properties, paving the way for advancements in applications such as photocatalysis, optoelectronics, and energy storage.