Inorganic mineral doped polypyrrole for hydrogen storage in alkaline medium

Cupric chloride is used as oxidant to synthesize polypyrrole doped with inorganic mineral (ImDPpy). The formation of ImDPpy was confirmed by 1HNMR, BET, SEM, HRTEM, DSC, FTIR, Raman, XRD, UV–vis and XPS studies. The surface area calculated for ImDPpy is 36.671 m2/g. Surface area of IMDPpy is 4.671 m2/g higher than the reported value of Ppy in the literature. In DSC, ImDPpy display a peak at 88.07 °C (endothermic glass transition temperature, Tg), Tg of ImDPpy is almost identical to that of Ppy-MWCNT composite and is higher than Tg of undoped Ppy. Electrochemical analysis of ImDPpy in 0.01 M NaOH indicated the maximum charge stored in ImDPpy in the form of protons as 8090 mF/g. The maximum hydrogen storage capacity of ImDPpy is found to be 18mAh/g at an applied current density of 1 mA/cm2. The mineral doped in Ppy during polymerization is identified as [Cu2(OH)3Cl] from XPS and Raman analysis.