Enhanced photocatalysis of VCrO4-doped TiO2 for dye degradation under UV light

Abstract

VCrO₄-doped TiO₂ nanocomposites were synthesized using a dilute precipitation method and characterized by HR-SEM, EDS, HR-TEM, XRD, UV–Vis-DRS, and PL spectroscopy. HR-SEM and HR-TEM analyses confirmed the formation of a nanoflower-like morphology, enhancing surface area and active sites for photocatalysis. XRD analysis indicated lattice distortions due to VCrO₄ incorporation, while UV–Vis-DRS revealed a narrowed band gap from 3.2 eV (TiO₂) to 2.8 eV (VCrO₄–TiO₂), improving visible light absorption. PL spectra showed reduced electron–hole recombination, enhancing charge carrier lifetime. The photocatalytic activity was evaluated by degrading Naphthol Blue Black (NBB) dye under UV light, where VCrO₄–TiO₂ achieved 90% degradation in 45 min, significantly outperforming pure TiO₂ (63% degradation). The apparent rate constant (k_app) for VCrO₄–TiO₂ was 0.067 min⁻¹, higher than TiO₂ (0.051 min⁻¹), confirming superior photocatalytic efficiency. The catalyst demonstrated excellent stability and reusability over multiple cycles without significant performance loss. These results highlight VCrO₄–TiO₂ as a promising photocatalyst for wastewater treatment and environmental remediation.