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Increasing environmental concerns and depletion of fossil fuels have created great interest in developing more efficient energy storage devices.The supercapacitors have become an attractive solution for energy storage because of its greater energy density than those of conventional capacitors and greater power density than that of batteries.1 MnO2 has been widely used in supercapacitor applications due to its specific capacitance,environmental compatibility,and cost effectiveness.2 However,because of its poor electrical conductivity and cyclic stability,the full potential of MnO2 has not been realized.We have developed a method for coating δ-MnO2 shells on Au nanocrystals to fabricate multifunctional core-shell nanostructures.With proper light irradiation,the Au core can elevate the localized temperature of MnO2,which would speed up charge-discharge and increase capacitance.The Au core can also improve electrical conductivity of the material.Monodisperse Au/MnO2 nanostructures with tunable MnO2 shell thickness and plasmon wavelength from green light to red light are obtained.Two times increase of capacitance is observed by irradiating Au/MnO2 nanostructures with laser(671nm).This work confirms the effectiveness of utilizing localized surface plasmon resonance to increase the capacitance of MnO2-based supercapacitors.