The polyaniline/manganese dioxide composites (PANI/MnO_2) containing different amounts of manganese dioxide were prepared by chemical polymerisation of aniline using ammonium peroxodisulfate (APS) and MnO_2 as the oxidizing agent.The inclusion of PANI in the composite was confirmed by FTIR, UV-VIS, XRD and SEM analysis. It shows that PANI in the composite is amorphous and the crystal structure of MnO_2 is unchanged compared with the initial MnO_2. The PANI formed in the reaction is deposited preferentially ...