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.