Electrodeposition route to synthesize nanocrystalline MnPO4.H2O thin films

Abstract This work reports on the low temperature synthesis of MnPO4.H2O thin films using electrodeposition method. The electrochemical oxidation of manganous (manganese II ions) in phosphoric acid on platinum (Pt) electrode was investigated by applying cyclic voltammetry (CV). The results indicate that the electrodeposition of MnPO4.H2O thin film requires simultaneous oxidation of manganous Mn2+ ions and water on the surface of the electrode. The influence of certain electrodeposition parameters such as the electrolysis potential and the concentration of manganous ions has been carried out in order to determine the optimal conditions of electrodeposition. The synthesized samples were characterized by Fourier Transform Infra-Red (FTIR) spectroscopy, Thermogravimetry (TG), X-ray diffraction spectroscopy (XRD), and Scanning Electronic Microscopy (SEM). FTIR spectrum of the sample shows lattice vibrations associated with the presence of the PO43− ions and water molecules, typical of MnPO4.H2O phase. The Thermal analysis TG demonstrates that the synthesized compound is stable up to 500°C. The analysis of XRD spectra confirms the MnPO4.H2O phase and the obtained thin films are composed of fine particles crystallizinge in the monoclinic space group, C2/c (Z = 4), with lattice parameters a = 6.916 A, b =7.467 A, c = 7.368 A and β = 112.35°. The SEM micrographs of the synthesized optimal film show homogeneous and nano-sized particles with an average particles size of 35 nm. The results demonstrate that the electrodepoition method for the synthesis of MnPO4.H2O thin films is an efficient way to produce high purity nanosized particle formed thin films at low temperature of 60°C.