Morphology Dependent Charge Storage in Electropolymerised Porphyrin Films on Gold Nanostructures

The effect of morphology of the underlying gold nanostructure on the charge storage behavior of electropolymerized 5,10,15,20‐tetrathien‐2‐ylporphyrin is systematically examined in the present study. Electropolymerisation of thien‐2‐yl‐substituted porphyrins occurs through oxidative coupling of the thiophene moieties, leading to the formation of extended π‐conjugated polymeric networks. The fabricated electrodes were characterized using UV visible spectroscopy, Raman spectroscopy, XPS, SEM, HR TEM and AFM. A comprehensive electrochemical investigation involving cyclic voltammetry, galvanostatic charge–discharge experiments, electrochemical impedance spectral measurements and kinetic analysis reveals that the morphology of the gold substrate plays a decisive role in deciding the charge storage kinetics of the hybrid polymeric materials. The results demonstrate that spherical gold nanostructures predominantly promote surface controlled capacitive charge storage whereas dendritic nanostructures introduce diffusion related limitations. These findings underscore the importance of nanostructure morphology in tailoring charge transport and optimizing the electrochemical performance of polymer based energy storage materials.