Kappa-carrageenan for benign preparation of CdSeNPs enhancing the electrochemical measurement of AC symmetric supercapacitor device based on neutral aqueous electrolyte

Abstract

This study presents the development of an electrochemical supercapacitor with a cadmium selenide nanoparticles (CdSeNPs) electrode utilizing a straightforward and economical method based on kappa-carrageenan (κ-CGN). The structural, morphological, and optical characteristics of CdSeNPs were assessed. Activated carbon (AC) and green-prepared CdSeNPs were easily mixed to achieve excellent electrochemical properties. The nanoelectrode (AC@CdSe) was tested in an aqueous electrolyte of sodium sulfate (Na2SO4) with a concentration of 1 Molar. Specific capacitance (Csp) for the AC electrode and the AC@CdSe electrode at 1 A g−1 was calculated to be 103 and 480 F g−1, respectively. Besides, the symmetric supercapacitor AC@CdSe/AC@CdSe device has a high specific energy of 52 Wh kg−1 and a maximum specific power of 2880 W kg−1, with a specific capacitance of 115.5 F g−1. With a coulombic efficiency of between 82 % and 100 %, the device continues to maintain excellent capacitance after 10.000 cycles.