Single-step grown boron doped nanocrystalline diamond-carbon nanograss hybrid as an efficient supercapacitor electrode

Abstract

Direct synthesis of a nano-structured carbon hybrid consisting of vertically aligned carbon nanograsses on top of boron-doped nanocrystalline diamond is demonstrated and the carbon hybrid is further applied as an electrode material for the fabrication of supercapacitors. The hybrid film combines the dual advantages of sp² (carbon nanograss) and sp³ (nanocrystalline diamond) bonded carbon, possessing not only the excellent electrical characteristics of sp² carbon but also the exceptional electrochemical stability of sp³ carbon. As a result, the specific capacitance of the as-prepared hybrid material reaches up to 0.4 F cm⁻², one of the highest reported in diamond-based supercapacitors. The entire electrochemical results exhibit enhanced electron transfer efficiency with remarkable stability of 95% of capacitance retention even after 10 000 cycles.