Synthesis of SnO2, Zn-doped SnO2 and Zn2SnO4 nanostructure-based hierarchical architectures by using deep eutectic precursors and their photocatalytic application

Different hierarchical structures of pure tin dioxide (SnO2), zinc doped SnO2 and zinc tin oxide (ZTO; Zn2SnO4) with zero, one and two-dimensional (0D, 1D and 2D) nano-building blocks were synthesized with deep eutectic precursors choline chloride:SnCl2 and choline chloride:ZnCl2. The synthesis was performed by the hydrothermal method. The effects of some synthesis parameters such as pH, temperature, type of solvent, type of Sn precursor, and the amount and type of Zn precursor were studied on the size, morphology and structure of the synthesized products. The products were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), energy dispersive X-ray (EDX) and UV-vis spectroscopy, zeta potential and Brunauer-Emmett-Teller (BET) surface area analysis techniques. In the next step, the performance of the synthesized metal oxides was investigated for the photocatalytic application. The as-prepared metal oxides were used as photocatalysts for the removal of methyl orange (MO) dye. The experiments showed that Zn doped SnO2 with a flower-like hierarchical morphology consisting of 2D petals with nanoscale thickness can remove MO from an aqueous environment with a degradation efficiency of 99.5% in 15 min.