This study investigates the photocatalytic degradation of crystal violet (CV) dye using various metal oxide (MOₓ) catalysts, including TiO₂, ZnO, ZrO₂, Fe₂O₃, CuO, Cu₂O, and Nb₂O₅. The research focuses on evaluating the effectiveness of these catalysts under UV irradiation conditions. The study employs techniques such as BET and Raman spectroscopy to characterize the catalysts, revealing that TiO₂ and ZnO have surface areas of 5 m²/g and 12.1 m²/g, respectively. Activity tests show that TiO₂ and ZnO can decompose up to 98% of the dye within 2 hours under UV light. The decomposition of CV is influenced by factors such as the type of MOₓ, band gap energy, and the recombination rate of electron-hole pairs. The study highlights that TiO₂ and ZnO are the most effective catalysts for CV degradation, with TiO₂ showing a 95% conversion and ZnO a 98% conversion. The results indicate that the band gap energy of the catalysts plays a crucial role in the degradation process, with TiO₂ and ZnO having band gaps that align with the energy required for the reaction. Additionally, the specific surface area of ZnO contributes to its higher catalytic activity. The study also explores the reaction kinetics and proposed mechanisms for CV degradation, emphasizing the importance of charge separation and the formation of reactive oxygen species. The findings suggest that TiO₂ and ZnO are effective heterogeneous photocatalysts for the degradation of CV, with their performance influenced by factors such as band gap, water splitting, and surface area. The study concludes that these catalysts are promising for environmental applications due to their efficiency and reusability.This study investigates the photocatalytic degradation of crystal violet (CV) dye using various metal oxide (MOₓ) catalysts, including TiO₂, ZnO, ZrO₂, Fe₂O₃, CuO, Cu₂O, and Nb₂O₅. The research focuses on evaluating the effectiveness of these catalysts under UV irradiation conditions. The study employs techniques such as BET and Raman spectroscopy to characterize the catalysts, revealing that TiO₂ and ZnO have surface areas of 5 m²/g and 12.1 m²/g, respectively. Activity tests show that TiO₂ and ZnO can decompose up to 98% of the dye within 2 hours under UV light. The decomposition of CV is influenced by factors such as the type of MOₓ, band gap energy, and the recombination rate of electron-hole pairs. The study highlights that TiO₂ and ZnO are the most effective catalysts for CV degradation, with TiO₂ showing a 95% conversion and ZnO a 98% conversion. The results indicate that the band gap energy of the catalysts plays a crucial role in the degradation process, with TiO₂ and ZnO having band gaps that align with the energy required for the reaction. Additionally, the specific surface area of ZnO contributes to its higher catalytic activity. The study also explores the reaction kinetics and proposed mechanisms for CV degradation, emphasizing the importance of charge separation and the formation of reactive oxygen species. The findings suggest that TiO₂ and ZnO are effective heterogeneous photocatalysts for the degradation of CV, with their performance influenced by factors such as band gap, water splitting, and surface area. The study concludes that these catalysts are promising for environmental applications due to their efficiency and reusability.