Enhancement of titanium dioxide microspheres doped with transition metals: Characterization and photocatalytic evaluation

The objective of this study is to improve the photocatalytic activity of pristine TiO2 doped with transition metals such as Cu, Fe, and Ag, proving the improvement through the degradation of Eriochrome black T (EBT) under illumination (100 W xenon lamp). The synthesis of these catalysts was achieved via the sol-gel/solvothermal method and their characterization by X-ray diffraction, scanning electron microscope, and diffuse reflectance. A spherical morphology and anatase phase were found in the prepared catalysts. With 0.5 at.% dopant in TiO2, Fe was found to have the lowest band-gap energy, while Cu and Ag had values similar to that of pristine TiO2. Different concentrations of dopants like 0.25, 0.5, and 1.0 at.% were tested, of which 0.5 at.% dopant content produced better photocatalytic degradation than pristine TiO2. The metal inclusion in the TiO2 structure enhanced the photocatalytic activity; thus, the TiO2:0.25Cu material produced 90% color removal and 87% reduction in chemical oxygen demand at 180 min of photocatalysis.