Synthesis and Electrochemical Characterization of APS/FeCl3-PANI@NiO Nanocomposites for Supercapacitors

Abstract

Specific capacitance (C_s) optimization of NiO nanomaterials, particularly with conductive polymers such as polyaniline (PANI), which is synthesized using ammonium persulfate (APS) and ferric chloride (FeCl₃), has been a material of great interest for their use in electrochemical devices. The facile formation of NiO nanomaterials enhanced the electrical properties with a high density of Ni²⁺ vacancies via co-precipitation synthesis. It was found that the resulting PANI@NiO nanocomposites had considerably better thermal stability and electrical conductivity than pure NiO nanomaterials. Structural and morphological properties of the nanocomposites were analyzed through characterization techniques like UV-Vis, FTIR, BET, XRD, and FE-SEM-EDX. XRD studies demonstrated the crystallinity of NiO nanomaterials and PANI, and FE-SEM was used to investigate the uniform dispersion of NiO in polymer matrices. Cyclic voltammetry (CV) reveals that the PANI@NiO nanocomposites exhibit a highly improved specific capacitance compared to NiO nanomaterials. The composites FeCl₃-PANI@NiO show the maximum value of C_s very interestingly. The maximum C_s attained was 971.9 F/g at a scan rate of 1 mV/s. Conversely, the PANI@NiO (APS) nanocomposite exhibited a different pattern, with C_s rising at scan rates of up to 10 mV/s, reaching a peak of 817.24 F/g. This suggests outstanding charge transfer efficiency at moderate scan rates. Such exceptional performance likely arises from the synergistic benefits of PANI, which enhance surface area, boost electrical conductivity, and facilitate effective charge transport within the composite. This study shows that the PANI@NiO nanocomposites could be significant materials for high-performance supercapacitors, and the PANI synthesis route significantly influences their electrochemical characteristics.

Graphical Abstract