Electrochemical evaluation of doped polyaniline films: Influence of ADS and pTSA dopants

Ammonium dodecyl sulfate (ADS)-doped polyaniline (ADS-PANI) and p-toluenesulfonic acid (pTSA)-doped polyaniline (pTSA-PANI) were synthesized via chemical oxidative polymerization. Morphological and surface analyses using SEM and BET revealed that ADS-PANI exhibits a nanofibrous texture, along with higher specific surface area (SSA) and pore volume compared to pTSA-PANI. XRD and FTIR characterizations indicated that ADS-PANI has sharper diffraction peaks and enhanced structural order, suggesting improved crystallinity and thermal stability. Furthermore, XPS analysis confirmed the effective incorporation of dopants into the PANI matrix. Their electrochemical behaviors were evaluated through cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) techniques, with the objective of assessing their potential in supercapacitors (SCs). The ADS-PANI electrode exhibited superior specific capacitance values of 413.80 and 363.35 F g −1 at current densities of 1 and 10 A g −1 , respectively, in contrast to 372.35 and 302.75 F g −1 for pTSA-PANI. Variable scan rate CV indicated a surface-confined electron transfer mechanism for both electrodes. Electrochemical impedance spectroscopy (EIS) was employed to determine the series resistance (R s ) and charge transfer resistance (R ct ), with the ADS-PANI electrode demonstrating lower R s and R ct values, indicative of improved electrolyte interaction and charge transport characteristics. • Doped PANI (ADS-PANI and pTSA-PANI) synthesized via simple emulsion polymerization at ambient temperature. • ADS-PANI shows nanofibrous morphology with higher surface area (42.3 m 2 g -1 ) and pore volume (0.039 cm 3 g -1 ). • XRD and FTIR confirm enhanced crystallinity and stronger dopant-polymer interaction in ADS-PANI. • ADS-PANI delivers 413.8 F g -1 at 1 A g -1 and retains 87.8 % capacitance at 10 A g -1 , outperforming pTSA-PANI. • Good cycling stability with 80.04 % capacitance retention after 2000 GCD cycles at 10 A g -1 .