Poly phenylenediamine and its TiO2 composite as hydrogen storage material

Poly phenylenediamine was synthesized from 1,4-phenylenediamine in presence of potassium persulphate and salicylic acid. The structure of the formed poly phenylenediamine was traced using FTIR and its morphology was examined by transmittance electron microscope (TEM). Gel permeation chromatography (GPC) was used to evaluate the polymer molecular weight which showed that the value of its molar mass is 20,000 g mol−1 and it has polydispersity index of 1.01. Different concentrations of TiO2 were incorporated in the poly phenylenediamine structure via coordination bond between the oxygen atom of TiO2 and the hydrogen atom of N–H group of polymer. The prepared composites were characterized using FTIR, TA, TEM and SEM/EDX. The TEM micrographs revealed that the composites have 2-D network structure and its morphology changed from a dendritic structure for the pure polymer to layered structure of the composite. The polymer and its composite are completely insulators. Their hydrogen storage capacity has been estimated at −193 °C and the composite reported higher hydrogen uptake values than the pure polymer. The reason is suggested to be due to the layered structure of composite which gives it the privilege to store more hydrogen in its interlayer vicinity.