Polyoxometalate Integrated with Conducting Polymer Nanocomposites for Supercapacitor and Biological Sensor Applications
Muhammed Anees Puniyanikkottil, Sib Sankar Mal
Abstract
Nanostructured redox-active composite electrode materials have been developed for energy storage applications to address conventional carbon-based supercapacitor’s limited electrochemical performance. Polyoxometalates (POMs) and conducting polymers (CP) have significantly enhanced the pseudocapacitive activity of these electrode materials. In this study, we synthesized H 4 [PVW 11 O 40 ]· x H 2 O (PVW 11 ) and combined it with polypyrrole (PPy) and polyaniline (PAni) separately to improve energy performance and conduct electrochemical analysis. The PVW 11 –PPy outperformed the PVW 11 –PAni composite, achieving an energy density of 49.07 W h kg –1 and a specific capacitance of 405.16 F g –1 . The supercapacitor cells showed a cyclic retention of 85.13% and 99.99% Coulombic efficiency after 6000 galvanostatic charge–discharge (GCD) cycles. The PVW 11 –PPy composite was fabricated into a supercapacitor device that powered a set of 10 LED bulbs for 2 min using an active mass of 76 mg. Additionally, the PVW 11 –PPy composite material was employed to sense glucose solutions with concentrations ranging from 0.04 to 0.4 mM, providing a sensitivity of 0.325 mA mM –1 cm –2, with limits of detection (LOD) and quantification (LOQ) of 0.381 mM and 1.270 mM, respectively.