Synthesis, optical properties, and enhanced photocatalytic degradation of (Mg, Cu) co-doped TiO2 nanoparticles under ultraviolet light irradiation

Co-precipitation method was used as a quick and effective way to elaborate the Mg and Cu co-doped TiO₂ (MgCu/T) nanoparticles. The formation of a single phase (anatase) with a tetragonal structure of nano-crystallized MgCu/T was confirmed by X-ray diffraction (Card No. 89–4203). Experimental results indicate that the synthesized MgCu/T nanoparticles are nanometric, ranging from 12 to 25 nm, consistent with the findings from SEM images. Additionally, the UV–Vis reflectance spectra showed that MgCu/T nanoparticles possess strong absorption properties in the UV–visible region. Hence, the photocatalytic activities showed that the 4 mol% Mg-doped MgCu/T nanoparticles exhibited the highest activity as a photocatalyst under ultraviolet light. The maximum degradation was found to be 58% for the sample 4 mol% Mg-doped MgCu/T nanoparticles after 210 min of UV light irradiation. The increase in AC conductivity of MgCu/T nanoparticles with higher Mg concentrations can be attributed to the fact that Mg doping introduces shallow donor states in TiO₂. These states can more easily donate electrons to the conduction band, thus increasing the charge carrier concentration.