Sol–gel synthesis and characterization of Gd-doped SnO₂ nanoparticles for water treatment and spintronic applications

The goal of the current work is to identify the structural, magnetic, and optical properties of Gd-doped SnO₂ nanoparticles and their potential use in the treatment of water contaminated with dye. These Gd-doped SnO₂ (Gd = 0%, 0.5%, 1.5%, 3%, 5%) samples were prepared by the cost-effective sol–gel approach. XRD & FTIR were used to study structural properties and to confirm that the synthesized samples have single-phase crystalline nature. Using XRD Crystallite size have been calculated and found to be in the range 12.14–9.60 nm. Particle size obtained from HRTEM lying in the range 15.94–9.86 nm which was in well agreement with XRD. Raman, PL and XPS spectroscopy were utilized to investigate defects/oxygen vacancies in the lattice. Magnetic investigations indicate that the magnetic character of synthesized samples with maximum magnetization3.95 × 10^–3 emu/g for Gd 5%. UV-DRS further showed that the band gap was reduced up to 5% Gd (E_g = 3.68 eV) in comparison to pure SnO₂ (E_g = 3.81 eV) due to the formation of vacancy defects. In comparison to pure SnO₂, Gd-doped SnO₂ (Gd 5%) was found to have a maximum photodegradation efficiency of 95.64% in 60 min under UV irradiation for Rose Bengal dye. Henceforth, it can be concluded that SnO₂ is a remarkable multifunctional material having uses in spintronic devices and as a catalyst in the degradation of organic dyes because of the improvement in the ferromagnetic character and enhancement in catalytic behavior on incorporation of rare-earth ions.