Graphene shell on silica nanowires toward a nanostructured electrode with controlled morphology

Abstract

We report a direct growth of highly conductive nanocrystalline graphene on dielectric SiO2 nanowires. Graphene structure on the nanowire surface is easily controlled by adjusting the growth conditions. In addition, highly dense ZnO nanorods are electrochemically grown on graphene/dielectric nanowire, which demonstrates potential for the nanostructured electrode with controlled morphology.

Unraveling the Factors Affecting the Electrochemical Performance of MoS2–Carbon Composite Catalysts for Hydrogen Evolution Reaction: Surface Defect and Electrical Resistance of Carbon Supports

“…To realize three-dimensional (3D) nanostructured electrodes, SiO 2 NWs were grown on a conductive Ti substrate and GCSs were then coated on the SiO 2 NWs through CVD techniques. The formation mechanism of the GCSs can be explained by the noncatalytic thermal pyrolysis of carbon sources (e.g., CH 4 ) and their self-nucleation on the SiO 2 surface. − As shown in Figure a, these carbon atoms randomly nucleate on the SiO 2 NW surfaces and start to form graphene domains (step 1). As the domains rapidly grow further, graphene edges are generally produced on the surface due to the misalignments between adjacent graphene domains (step 2).…”

“…Silicon NWs (Si NWs) were grown on Ti foil (2 cm × 2 cm) using the vapor–liquid–solid method, as described in our previous articles reported elsewhere. − Gold (Au, 5 nm) was deposited on the Ti foil by thermal evaporation and loaded into a low-pressure chemical vapor deposition (LPCVD) system. Au-catalyzed Si NWs were grown by silane (SiH 4 , 10% in helium) gas at 500 °C and 40 Torr for 20 min.…”

Thermoelectric Properties of Nanowires with a Graphitic Shell

“…[20,21] Large Dbands in the spectra result from the nanocrystalline nature of the graphitic shell layer on Si and SiO 2 . [22,23] To estimate the average number of graphitic shell layers on the SiO 2 nanowires, we synthesized ag raphitic shell on aq uartz plate under the same growth conditions as those used to prepare the SiO 2 NWs with the FLG shell and measured its transmittance ( Figure 3b). The absorbance of an individual graphene layer is approximately 2.3 %, [24] and so we estimate that the average number of FLG and MLG shells on the SiO 2 nanowirei sa pproximately 2a nd 9, respectively.…”