Comprehensive analysis of structural, optical, and photocatalytic properties of single-phase calcium vanadates: Insights into CaV2O6 and Ca2V2O7

The primary issue related to industrialization is that environmental pollution contributes to human health hazards. One significant cause of environmental contamination is the usage of various dyes in industries. In this context, photocatalysis plays a significant role due to its inherent nature. The cost-effective gel matrix method synthesized two distinct phases of calcium vanadate. The prepared vanadates' phase formation, crystallinity, optical properties and elemental composition were investigated using X-ray Diffraction (XRD), Raman spectroscopy, UV–visible spectroscopy and X-ray Photoelectron Spectroscopy (XPS). The band gap calculation was done from the Tauc plot using the UV absorbance studies. The morphology of the synthesized vanadates was examined using Scanning Electron Microscopy (SEM). Employing methylene blue (MB) as a model dye, the dye degradation illustrated the photocatalytic activity of synthesized semiconductor photocatalyst by irradiating visible light. The degradation efficiency of Ca₂V₂O₇ is 97 % within 4 h, which can be used for removing the dyes from the waste waters.