Enhanced light-responsive supercapacitor utilizing BiVO4 and date leaves-derived carbon: A leap towards sustainable energy harvesting and storage

This study explores light-responsive supercapacitors, aiming to transform energy systems by enabling the simultaneous conversion and storage of light into electricity. The study introduces an innovative light-responsive supercapacitor, employing bismuth vanadate (BiVO4) as the photoactive material and date leaf-derived carbon (DLC) as the conductive electrode material. The device also incorporates fluorine-doped tin oxide (FTO) as the transparent current collector and Na2SO4 as the electrolyte. The constructed FTO/BiVO4/DLC//DLC/FTO asymmetric light-responsive supercapacitor showcased remarkable electrochemical performance, achieving a capacitance of ∼150 F/g at a current density of 0.5 A/g, thereby validating its effective charge transfer capacity during electrical activities. Further experimentation with varying photo-charging times resulted in a peak specific capacitance of ∼290 F/g. The device demonstrated an energy density of around ∼13 Wh/kg and a power density of ∼200 W/kg in the absence of light, with the energy density notably doubling to 26 Wh/kg upon extended photo-charging. Remarkably, the supercapacitor maintained ∼90% of its initial specific capacitance and ∼86% of its Coulombic efficiency following 12000 GCD cycles, underscoring its electrochemical stability and durability. The development of such a proficient and resilient light-responsive supercapacitor holds significant promise for the advancement of the energy-storage sector and offers valuable insights for renewable energy researchers. [Display omitted] •Light-responsive supercapacitor as combined energy harvesting and storage system.•FTO/BiVO4/DLC//DLC/FTO asymmetric capacitor yielded excellent specific capacitance.•The light-responsive supercapacitor showed high energy and power densities in the dark.•Upon increasing the photocharging time, the energy density increased.•The asymmetric light-responsive supercapacitor exhibited excellent electrochemical stability.