Characterization of <scp> Ca/TiO ₂ </scp> and <scp> Ba/TiO ₂ </scp> na

Abstract

Cresols are increasingly used in the production of various industrial products, and their release into the environment has become a major source of water pollution because they biodegrade slowly and inefficiently. Consequently, photocatalysis has emerged as a promising approach for degrading these contaminants. In this study, the structural modifications of TiO 2 induced by Ca and Ba doping are analyzed, together with their influence on photocatalytic activity under UV irradiation. XRD analysis showed the coexistence of anatase, rutile, and TiO 2 (B) phases in the Ca/ TiO 2 and Ba/TiO 2 photocatalysts. Rietveld refinement enabled quantification of the crystalline phase composition and estimation of crystal sizes (<59 nm). Raman spectroscopy was used to determine the relative concentration of oxygen vacancies, which play a crucial role in photocatalytic degradation. Morphological analyses by SEM and TEM confirmed the correspondence between the crystallite sizes obtained from Rietveld refinement and the irregular particle morphology. XPS and EDS analyses confirmed the presence and homogeneous dispersion of Ca and Ba dopants within the TiO 2 matrix. Nitrogen adsorption–desorption isotherms revealed mesoporous materials with pore sizes below 8 nm and specific surface areas of up to 80 m 2 /g. All doped photocatalysts exhibited enhanced photocatalytic activity towards p ‐cresol degradation under UV irradiation, achieving nearly 100% removal efficiency and outperforming commercial TiO 2 . Doping TiO₂ with Ca and Ba was successfully achieved, leading to enhanced structural and photocatalytic properties. Both series of samples exhibited excellent photocatalytic performance, attributable to the synergistic effects of phase coexistence (anatase and TiO 2 (B)), the presence of oxygen vacancies (up to 18%), and high specific surface areas (up to 80 m 2 /g). These results are particularly encouraging, as they demonstrate that the photocatalytic activity of TiO 2 can be effectively enhanced by doping with abundant, low‐cost alkaline earth metals such as Ca and Ba. © 2026 Society of Chemical Industry (SCI).