Key Factors in Enhancing Pseudocapacitive Properties of PANI-InO(x) Hybrid Thin Films Prepared by Sequential Infiltration Synthesis

Sequential infiltration synthesis (SIS) is an emerging vapor-phase synthetic route for the preparation of organic–inorganic composites. Previously, we investigated the potential of polyaniline (PANI)-InO(x) composite thin films prepared using SIS for application in electrochemical energy storage. In this study, we investigated the effects of the number of InO(x) SIS cycles on the chemical and electrochemical properties of PANI-InO(x) thin films via combined characterization using X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and cyclic voltammetry. The area-specific capacitance values of PANI-InO(x) samples prepared with 10, 20, 50, and 100 SIS cycles were 1.1, 0.8, 1.4, and 0.96 mF/cm², respectively. Our result shows that the formation of an enlarged PANI-InO(x) mixed region directly exposed to the electrolyte is key to enhancing the pseudocapacitive properties of the composite films.