Effective removal of organic pollutants using GeO2/TiO2 nanoparticle composites under direct sunlight

Abstract

TiO₂ and GeO₂/TiO₂ nanoparticle composites were synthesized from titanium tetraisopropoxide, germanium oxide, dry ethanol, and diethanolamine using a solution combustion method. The synthesized catalysts were characterized using powder X-ray diffraction, UV-Vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller surface area analysis, Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy. The photocatalytic degradation of rhodamine B (RhB) dye in aqueous solution (2.06 × 10⁻⁵ M) was achieved using synthesized pristine TiO₂ (P-T) and GeO₂/TiO₂ (GT) nanoparticle composite catalysts under direct sunlight. Among the synthesized catalysts, 1-GT afforded 100% RhB degradation in aqueous solution within 180 min. Furthermore, 85, 87, and 83% degradation was achieved using P-T, 2-GT, and 3-GT nanoparticles, respectively. RhB degradation was confirmed by chemical oxygen demand and total organic carbon analyses.