Vertically-oriented graphene electrodeposited with MnO2 on native SiO2/Si for high-performance supercapacitor electrodes

Supercapacitor electrodes, composed of vertically-oriented graphene (VG) and MnO2, are synthesized on native SiO2-passivated silicon wafers. The VG layers with a thickness ~3 μm deposited directly the substrates via plasma-enhanced chemical vapor deposition (PECVD). distribution levels MnO2 formed electrodepositing method investigated by using different types solutions. deeper infiltration depositions produced ethanol/water solution is observed. capacitance retention 75.22% from scan rate 20 mV/s to 100 solution, compared that 60.72% water suggests better capability. specific as high 470.80 mF/cm2 at achieved increasing loadings MnO2. original 99.29% after 5000 cycles demonstrates excellent cycling stability, which ascribed strong bonds between VG/SiO2/Si MnO2/VG. promising supercapacitor electrodes in this study provide potential for forming high-performance devices based wafer substrates.