LAUSR

Abstract The biosynthesis of ZnSnO3 nanoparticles via Aspalathus Linearis natural extracts is reported in this contribution. Crystallinity of orthorhombic perovskite ZnSnO3 nanoparticles at room temperature and annealed at 300 and 500 °C was investigated by X-ray diffraction. High resolution transmission electron microscope (HRTEM) and high resolution scanning electron microscope (HRSEM) were used for determination of morphology, confirmed the nanoclusters of ZnSnO3 annealed at 500 °C were polycrystalline with an average particle size of 18.5 nm. UV–vis diffused reflectance showed absorption edge at 354 nm and a band gap of 3.50 eV for ZnSnO3 nanoparticles. Raman modes at 482 and 636 cm−1 are distinctive Raman shifts of ZnSnO3 nanoparticles. The other complementary investigations by infrared, thermogravimetry and differential scanning calorimetry were done. Cyclic voltammetry of ZnSnO3 nanoparticles on glassy carbon electron (GCE) showed two redox peaks, oxidation peak at 3.8 V and reduction peak 2.7 V. The reaction was diffusion controlled with a diffusion coefficient of 1.93 × 10−7 cm2 s−1. Electrochemical impedance spectroscopy showed charge transfer resistance of 3.325 × 10−5 and 3.154 × 10−5 Ω showing slight improvements in ionic conductivity with the addition of K3Fe(CN)6 to the KOH electrolyte.