Preparation of boron-doped diamond foam film for supercapacitor applications

A boron-doped diamond (BDD) electrode with surface nanostructure is fabricated by introducing SiO2 microspheres as a template on a Ta substrate via hot filament chemical vapor deposition (HFCVD). The improved specific active surface area and active materials enhance the availability of the electrochemically active sites, and improve the capacitive performance. Consequently, the fabricated BDD electrode with concentration ratio 2 of SiO2 and diamond powder (BDD-SD2) possesses smaller R-s, a maximum specific capacitance of 6.44 mF cm(-2) at a current density of 0.10 mA cm(-2), and good cycling stability with 83.1% retention over 3000 cycles. The influence mechanism of the fabricated BDD foam electrode on the capacitive performance is then revealed.