Chemical synthesis of nanocrystalline SnO2 thin films for supercapacitor application

Nanocrystalline SnO2 thin films were deposited by simple and inexpensive chemical route. The films were characterized for their structural, morphological, wettability and electrochemical properties using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy techniques (SEM), transmission electron microscopy (TEM), contact angle measurement, and cyclic voltammetry techniques. The XRD study revealed the deposited films were nanocrystalline with tetragonal rutile structure of SnO2. The FT-IR studies confirmed the formation of SnO2 with the characteristic vibrational mode of Sn–O. The SEM studies showed formation of loosely connected agglomerates with average size of 5–10 nm as observed from TEM studies. The surface wettability showed the hydrophilic nature of SnO2 thin film (water contact angle 9°). The SnO2 showed a maximum specific capacitance of 66 F g−1 in 0.5 Na2SO4 electrolyte at 10 mV s−1 scan rate.