High performance supercapacitor and non-enzymatic hydrogen peroxide sensor based on tellurium nanoparticles

•A wet chemical approach for the preparation of tellurium nanoparticles•Excellent cycle life with 100% Coulombic efficiency•High energy density (116 Wh kg− 1) and power density (1186 W kg− 1)•High sensitivity and selectivity towards H2O2

Tellurium nanoparticles (Te Nps) were synthesized by wet chemical method and characterized by XRD, Raman, FESEM, TEM, XPS, UV-Vis and FL. The Nps were coated on graphite foil and Glassy carbon electrode to prepare the electrodes for supercapacitor and biosensor applications. The supercapacitor performance is evaluated in 2 M KOH electrolyte by both Cyclic Voltammetry (CV) and galvanostatic charge-discharge method. From charge-discharge method, Te Nps show a specific capacitance of 586 F/g at 2 mA/cm2 and 100 F/g at 30 mA/cm2 as well as an excellent cycle life (100% after 1000 cycles). In addition, the H2O2 sensor performance of Te Nps modified glassy carbon electrode is checked by CV and Chronoamperometry (CA) in phosphate buffer solution (PBS). In the linear range of 0.67 to 8.04 μM of hydrogen peroxide (H2O2), Te NPs show a high sensitivity of 0.83 mA mM− 1 cm− 2 with a correlation coefficient of 0.995. The detection limit is 0.3 μM with a response time less than 5 s.