Low Surface Energy and pH Effect on SnO₂ Nanoparticles Formation for Supercapacitor Applications.

The SnO₂ nanoparticles formation by hydrothermal method at different experimental conditions such as temperature, pH, reaction time, and capping agent (cetyltrimethylammonium bromide), was studied. X-ray diffraction results confirmed regular rutile crystal structure of SnO₂. The characteristic Raman peak observed at 635 cm-1 corresponded to A1g modes of Sn-O vibrations. The study of optical property using photoluminescence confirmed the emissive spectra of SnO₂. The infrared peak observed at 618 cm-1 corresponded to E u modes of Sn-O vibrations of TO phonon because of E ⊥ to c -axis. Scanning electron microscope images clearly revealed the formation of complete SnO₂ nanoparticles. The unique SnO₂ nanoparticles stacked together to form microspheres at pH-5 showed high specific capacitance of 274.8 F/g at a current density of 0.5 A/g. The observed results confirmed the feasibility of SnO₂ nanoparticles being used as appropriate positive electrode candidate for supercapacitor applications.