Development of novel Co3+ doped LaMnO3 perovskite electrodes for supercapacitors and sensors: Mechanism of electrochemical energy storage and oxygen intercalation

LaMnO3 and La1-xCoxMnO3 (x = 0, 0.05, 0.2, 0.4) nanomaterials were prepared by the sol-gel method, and their structural and morphological properties were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. XRD results were validated using computational XRD pattern generated using density functional theory (DFT) calculations and found that they are in good agreement with each other. The estimated crystallite size from XRD and TEM is ∼23 nm for all synthesized undoped and doped materials. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanometric charge-discharge (GCD) properties of prepared electrodes were analyzed to study their capacitive performance and stability. An electrochemical sensor was developed for the detection of the paracetamol drug and analyzed using CV responses. These analyses showed La1-xCoxMnO3 are potential electrode materials with a high specific capacitance of 651.54 Fg−1 for x = 0.2 at the scan rate of 5 mVs−1 in 1 M KCl aqueous electrolyte for electrochemical supercapacitors and x = 0.05 for the development of an electrochemical sensor for paracetamol detection.