One-step Hydrothermal Synthesis of Sn-doped OMS-2 and Their Electrochemical Performance

Different amount of Sn doped manganese oxide octahedral molecular sieve (OMS-2) were synthesized by one-step hydrothermal method using SnCl4, MnSO4 and KMnO4 as raw materials. The Sn-OMS-2 materials were characterized by X-ray diffraction (XRD), Raman spectra, Uv-vis spectra, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM) and surface area analysis. The XRD, Raman and UV-Vis analysis confirm the cryptomelane-Q type of MnO2 crystal structure and no extra peaks related to tin metal or impurities were observed. SEM and TEM images show the nanorod morphology of the materials. EDX result proves that Sn has been successfully doped into the OMS-2 structure. The supercapacitive performances of Sn-OMS-2 materials were tested using cyclic voltammetry (CV) and galvanostatica charge-discharge techniques in 1M Na2SO4 electrolyte under different scan rate. Improvement in capacitance of the OMS-2 materials is observed after doping with Sn, and increased with the Sn dopant rise, of which 15%Sn-OMS-2 sample exhibited the best supercapacitive property (187 F/g).