Assessing the photocatalytic activity of europium doped TiO₂ using liquid phase plasma process on acetylsalicylic acid

In this study, europium (Eu) was precipitated in TiO₂ powder using liquid phase plasma (LPP) process to prepare a photocatalyst with higher activity, even in the visible light range. Eu was uniformly deposited on the surface of TiO₂ by the LPP method. It was observed that the amount of Eu precipitated on the TiO₂ surface increased with increasing precursor concentration. XPS and EDS analysis showed that Eu was precipitated as europium oxide. The precipitation of Eu shifted the position of the Raman peak to a higher wavelength; with higher Eu content, the band gap energy decreased. Particularly, the photocatalytic efficiency of the Eu doped TiO₂ photocatalyst (EDTP) in the visible light source was much higher than that of bare TiO₂, and with higher Eu content, the photocatalytic activity was improved. Acetylsalicylic acid was attacked by HO∙ produced on the EDTP's surface and assumed to be finally mineralized to H₂O and CO₂ via two decomposition pathways, namely, decarboxylation and deacetylation.