Green synthesis of tin oxide nanoparticles by using leaves extract of Chromolaena Odorata: The effect of different thermal calcination temperature to the energy band gap

Abstract Tin oxide nanoparticles (SnO2 Nps) are critical conducting oxides that are used in numerous applications, inclusive of solar cells, electrodes, gas sensors, optoelectronic devices, and catalysts. The green production of SnO2 Nps utilising leaves extract of Chromalaena Odorata is described in this research. SnO2 Nps were synthesised at ambient temperature and then calcined at five different calcination temperatures, which were 500, 600, 700, 800, and 900 °C, with slow and in-situ thermal calcination modes. The X-Ray Diffraction (XRD), Fourier-Transform Infrared (FTIR), Field-Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDX), and UV–Vis Diffuse Reflectance Spectrometer were utilised to analyse all the resulting outcomes. The Kubelka-Munk (KM) function calculated the SnO2 Nps energy characteristic. From this study, the main findings can be divided into 2 parts. First, at slow thermal calcination mode, SnO2 Nps exhibit the highest energy band gap value (3.2 eV) at 900 °C with a reflectance of 53%. Second, at in-situ thermal calcination mode, SnO2 Nps exhibit the highest energy band gap value (3.3 eV) at 800 °C with a reflectance of 49%. Overall, the results suggest that the green synthesised SnO2 Nps can hold as a promising candidate for optical application.