Photocatalytic Dye Decomposition over CaMnO_3−δ and Pr_0.5Ca_0.5MnO₃: A Combined XPS and DFT Study

Abstract

In the field of environmental sustainability, the development of highly efficient photocatalytic under a wide wavelength range with band engineering is regarded as a promising strategy to enhance photocatalytic dye degradation. Here, we report on CaMnO3−δ and Pr0.5Ca0.5MnO3 perovskite materials prepared by a sol-gel combustion method. From X-ray photoelectron spectroscopy (XPS), the particle surfaces of both compounds are oxygen deficient, while the surface hydroxyl and carbonyl groups’ adsorption on the surface of Pr0.5Ca0.5MnO3 particles is more pronounced. FT-FIR spectroscopy has been used to investigate the covalent bonds and oxygen vacancy characteristics. Photocatalytic activities were investigated by the degradation of methylene blue and methyl orange under UV light. It was observed that both dye molecules are more degraded over CaMnO3−δ. The underlying mechanisms behind the photoexcitation and degradation process are established via the Spin-polarized Density Functional Theory (DFT).

Keywords

• photocatalyst
• perovskite
• dye degradation
• CaMnO₃