Synergistic effect of strontium oxide-titanium oxide nanocomposites for photocatalytic degradation of malachite green dye

The structural and optical properties of SrO and TiO2 nanoparticles (NPs), as well as SrO-TiO2 nanocomposites (ST-NCs) synthesized via the co-precipitation method, were investigated. X-ray diffraction (XRD) analysis confirmed the crystalline nature of both SrO and TiO2 NPs, as well as the nanocomposites. The crystallite sizes were determined as 49.30 nm for SrO NPs and 13.78 nm for TiO2 NPs, with sizes of 60.10, 50.20, 38.00, 37.14, and 28.84 nm observed for various compositions of TiO2 added to SrO in the ST-NCs. Morphological analysis revealed rod-shaped particles for SrO NPs and spherical agglomerated particles for TiO2 NPs. Energy-dispersive X-ray spectroscopy (EDX) confirmed the presence of strontium and oxygen in SrO NPs, titanium and oxygen in TiO2 NPs and strontium, titanium and oxygen elements in ST NCs confirms the purity of the samples. Both XRD and EDX analysis provides comprehensive confirmation of the composite nature of the samples. Optical characterization showed that the band gap energies increased with increase of TiO2 precursor content, ranging from 3.19 to 3.48 eV. Photocatalytic degradation studies under visible light demonstrated that ST- 0.4 M exhibited superior activity compared to SrO and TiO2 NPs, as well as other ST NCs compositions. Finally, the active trapping experiment reveals that the holes and hydroxide radicals are the active species in degradation process and the plausible mechanism of degradation is proposed. These findings highlight the potential of SrO-TiO2 nanocomposites for applications in photocatalysis.