Improvement of photocatalytic degradation of organic dyes by vanadium doped titanium oxide nanoparticles using solar simulator

The removal of complex organic contaminants and pollutants from water, the heterogeneous photocatalytic degradation of methylene blue (MB), Eosin, Fluorescein and Rhodamine 6G (Rh 6G) dyes were studied using vanadium-doped titanium oxide nanoparticles (V-TiO₂ NP_s) as a derived catalyst, incorporated in a Polyvinyl Alcohol (PVA) solution as a host to form thin films doped from dyes and V-TiO₂ NP_s. Solar simulator light was tested for the photodegradation process. Vanadium-doped titanium oxide nanoparticles (V-TiO₂ NP_s) was successfully synthesized by a sol-gel technique and the solid-state thin films of PVA/dye/V-TiO₂ were prepared by a casting method. The chemical synthesis of V-TiO₂ NP_s was confirmed by X-ray diffractograms, Energy Dispersive X-ray (EDX), High Resolution Transmission Electron [HRTEM] and Fourier transform infrared spectroscopy [FTIR]. We had studied the effect of V-TiO₂ NP_s as a catalyst to enhance the photocatalytic activity of different organic dyes and we found that the vanadium doped TiO₂ nanoparticle behave as the best catalyst for successfully photodegraded of Methylene Blue (MB), Eosin and Fluorescein dyes but effect of V-TiO₂ NP_s as a catalyst on the photodegradation of Rh 6G dye take a more time to degraded under solar simulator. The V-TiO₂ nanoparticles displayed eminent realization for achieving nearly 99% degradation of MB, 97% of Fluorescein, 99% of Eosin after 120 min. So, the V-TiO₂ NPs can be used as a pollutant removal in the wastewater application. But from the results of photocatalytic performance of Rh 6G, we noticed that the photodegradation of Rh 6G dye in the presence of V-TiO₂ NPs is weak as 50% photodegraded after 300 min and this is due to the strong reaction between the catalyst and Rh 6G dye. In this case, V-TiO₂ NPs behave as a photostabilizer for Rh 6G dye under solar simulator and this structure (Rh 6G/V-TiO₂) can be apply as a photoanode in a dye sensitized solar cell application. The optical band gap energy of V-TiO₂ NP_s with a MB, Eosin and Fluorescein dyes were calculated at zero minute and at 120 min but the band gap energy for Rh 6G dye with a catalyst was calculated at 300 min and we found that the band gap energy was increased by increasing exposure time. From the observation to measure the pseudo-first-order rate constants of four dyes were computed. The photodegradation percentage was determined and found that the photodegradation percentage of MB, Eosin and Fluorescein in the presence of the of V-TiO₂ NP_s as a catalyst is higher than the photodegradation percentage of pure dyes.