Electrochemical behavior of nanostructured SnO2 thin films in aqueous electrolyte solutions

Novel nanostructures of tin oxide (SnO2) nanopyramids and nanoplates were grown on anodized Cu substrates using an electrodeposition method by altering deposition voltage. The chemical bonding, structure and morphology of nanostructures were examined using Fourier transform infrared spectra (FT-IR), Raman spectroscopy, X-ray diffraction (XRD) and Field emission scanning electron microscope (FE-SEM). The orthorhombic crystal structure of electrodeposited SnO2 nanostructures has been confirmed by XRD. Microstructure from FE-SEM evidenced the existence of nanopyramids with edge length between 200 and 250 nm and nanoplates of thickness 800 nm. Cyclic voltammetric (CV) studies elaborate the electrochemical performance of prepared electrodes in aqueous LiOH·H2O, Li2CO3 and Li2SO4 electrolytes. Lithium ion alloying/de-alloying took place in all the above electrolytes for SnO2 electrodes confirmed by the appearance of pair of redox peaks at −0.35/−0.53 V and 0.01/−0.45 V (versus Ag/AgCl). CV curves of SnO2 electrodes in these aqueous solutions suggested battery characteristics of the material.