Enhanced Electrochemical Performance of Polyaniline‐Boron Doped Diamond Electrode for Supercapacitor Applications

Abstract Understanding how to tune the properties of electroactive materials is a key parameter for their applications in energy storage systems. This work presents a comprehensive study in tailoring polyaniline (PANI) suspensions by acid‐assisted polymerization method and their subsequent deposition on boron‐doped diamond (BDD) supports with low/high B concentrations. The porous or densely packed morphology of PANI is successfully controlled by varying the monomer‐to‐initiator ratio. The interaction between PANI and BDDs leads to the shift in oxidation and reduction potentials, and the high B doping resulted in the reduction of the oxidation potentials. Notably, the highest specific capacitance of 958 F g −1 , which represents 90% of the theoretical capacitance, is recorded for the support with relatively low B content. Moreover, PANI obtained by slow kinetic has a stronger interaction with the B‐doped diamond support, which is confirmed by electrochemical impedance spectroscopy. This study provides valuable insights for optimizing PANI suspension preparation methods and selecting appropriate boron doping concentrations in nanodiamond supports for composite electrodes in energy storage applications.