Experimental and theoretical comparative analysis of pure WO3 and La doped WO3 for degradation of MB

This study reports the simple synthesis of pure and La-doped (1, 2, 3, 4 and 5%) WO3 nanoparticles (NPs) for the degradation of MB dye. The UV-Vis, XRD, FTIR, SEM and PL techniques have been utilized for the evaluation of prepared samples. The photo catalytic activity of these synthesized samples has been observed for the degradation of methylene blue (MB) in the presence of visible light via photo catalysts (WO3, La-WO3) NPs. Additionally, the suppression of the band gap from 2.81 to 2.23 eV along photo generated electron-hole pair has been demonstrated by UV visible and PL spectroscopy respectively. The crystalline size of 4% La-WO3, reduced from 30 to 11 nm as compared to pure WO3. FTIR spectroscopy analysis reveals the synthesized material is composed of tungsten and oxygen. However, in the presence of visible light, the optimal 4% La-doped WO3 NPs' are capable of degrade methylene blue (MB) to 94% within 180 min. To test the stability of the optimized catalyst, reusability and trapping tests have been conducted. The correlation between the theoretical model and the experiments has also been performed using the COMSOL Multiphysics module 5.3a.