Preparation of Mn5O8and Mn3O4nano-rods through cathodic electrochemical deposition-heat treatment (CED-HT)

A novel cathodic electrochemical deposition (CED) procedure followed by a heat treatment (HT) step was developed for the preparation of Mn 5 O 8 nano-rods. The CED was performed on a 0.005 M MnCl 2 under a galvanostatic condition and a current density of 10 mA cm −2 . The products were characterized through x-ray diffraction, FT-IR and SEM analyses, which proved the formation of Mn 3 O 4 nano-rods as intermediates. The probable reactions leading to the CED formation and growth of nano-rods on the cathode surface were evaluated and discussed. To finalize the reaction and convert the Mn 3 O 4 to the end product, the nano-rods were next subjected to the HT stage in an oxygen containing atmosphere to form Mn 5 O 8 nano-rods. The end product of this step was also evaluated by the same analytical techniques as the intermediate product. SEM results indicated that the HT step does not influence the morphology of the intermediate nano-particles, while the DSC-TG analysis of the thermal behavior Mn 3 O 4 nano-rods under the HT step revealed the possibility of physicochemical changes leading to the formation of Mn 5 O 8 and hence the CED-HT method was considered as a novel method for the preparation of both Mn 3 O 4 and Mn 5 O 8 nano-rods with uniform size distribution.