Iron oxide loaded biochar/polyaniline nanocomposite: Synthesis, characterization and electrochemical analysis

The value-added application of biochar in electrochemical energy storage had been explored in the present work. The biochar was derived from the local agriculture residue, banana stem (BS). BSwas pyrolyzed at 500 degrees C under nitrogen atmosphere for 12 h. It was transformed into magnetic biochar (MB) and magnetic biochar-polyaniline (PANI) composite. The electronic transitions around 325 and 410 nm characterized the composite formation. The distribution of the crystalline magnetite phase throughout the PANI matrix was evident from the 20 values in and around 17.8% 20.4 degrees, 25.1 degrees, 33.4 degrees and 43.6 degrees in the composite. The heterogeneous porosity (mesopores and micropores) of the biochar was revealed from SEM images. PANI insertion into these sites was confirmed from the disappearance of these sites after compositing. TEM images indicated the uniform distribution of magnetite nanoparticles in the composite with average grain size of 6.25 nm, which is in agreement with the data obtained from XRD (8.08 nm). The charge transfer resistance offered by MB (11.0 Omega) is greater than that of the composite (9.6 Omega), highlighting that the composite could serve as a better electrode material over MB. The MB and the composite showed specific capacitance values (Cs-MB = 234.8 Fg(-1), Cs-composite = 315.7 Fg(-1)) higher than those reported in the literature with other biochars.