Influence of anionic precursors on electrochemical properties of tin oxide nanoparticles: a comparative analysis

A cost-effective chemical precipitation method has been adopted to synthesis tin oxide (SnO₂) nanomaterials with the help of two different anionic sources (NH₃OH and NaOH). Initially, the X-ray diffraction (XRD) studies confirm the formation of regular rutile tetragonal crystal structure of SnO_2. The functional group analysis by Fourier transform infra-red (FTIR) spectroscopy identifies the presence of Sn-OH stretching mode of vibration. The morphological with elemental confirmation by HRSEM with EDAX analysis observes the formation of SnO₂ agglomeration in appropriate ratio (Sn and O) without showing any other impurities. The particle size analysis (PSA) reveals that the synthesized SnO₂ nanomaterials are in a nano-sized range of 10 nm to 33 nm. The optical analysis using UV–Visible (UV) and photoluminescence (PL) spectroscopy reveals that the bandgap energy of synthesized materials is found to be 4.12 eV and 4.14 eV, blue-shifted from bulk materials. The electrochemical behavior of synthesized tin oxide nanomaterials as working electrodes are examined by a conventional three-electrode system with analyzed parameters such as cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS). This study exposes the highest specific capacitance C_sp value of 405.15 F g⁻¹ at a scan rate of 1 mV s⁻¹ and 403.72 F g⁻¹ at a current density of 0.5 Ag⁻¹. The highest energy density and power density value of 27.48 Wh kg⁻¹ at 0.5 Ag⁻¹ and 145.83 W kg⁻¹ at 1 Ag⁻¹, respectively, presents a promising positive working electrode material for supercapacitor applications.