Influence of Ethanolic Plant Extracts on Morphology and Size Distribution of Sol-Gel Prepared TiO2 Nanoparticles

Abstract

The influence of ethanolic extracts of three common plants (Equisetum arvense, Syzygium aromaticum and Camellia sinensis) on the morphology and size distribution of TiO2 nanoparticles prepared using the sol-gel method is presented. The phytochemicals extracted from the plants acted as surfactants, modifying the growth mechanism and stabilizing high-quality small, quasi-spherical, non-aggregated TiO2 nanoparticles with sizes in the range from 20–50 nm. The most satisfactory result was achieved using extracts of E. arvense. The structural, morphological, and optical properties of TiO2 nanoparticles prepared using E. arvense ethanolic extracts are discussed. After thermal treatment at 550 °C, the TiO2 nanoparticles were present only in the anatase crystalline phase, with a bandgap of 3.27 eV, as confirmed by X-ray diffraction and UV-vis analyses, respectively. These small morphologically homogeneous TiO2 nanoparticles stabilized by low-cost, abundant and eco-friendly capping agents may be useful as components in photovoltaic cells, pharmaceutical and cosmetic products, as well as for photocatalytic uses.