Facile electrosynthesis of silicon carbide nanowires from silica/carbon precursors in molten salt

Abstract

Silicon carbide nanowires (SiC NWs) have attracted intensive attention in recent years due to their outstanding performances in many applications. A large-scale and facile production of SiC NWs is critical to its successful application. Here, we report a simple method for the production of SiC NWs from inexpensive and abundantly available silica/carbon (SiO2/C) precursors in molten calcium chloride. The solid-to-solid electroreduction and dissolution-electrodeposition mechanisms can easily lead to the formation of homogenous SiC NWs. This template/catalyst-free approach greatly simplifies the synthesis procedure compared to conventional methods. This general strategy opens a direct electrochemical route for the conversion of SiO2/C into SiC NWs, and may also have implications for the electrosynthesis of other micro/nanostructured metal carbides/composites from metal oxides/carbon precursors.

A Natural Transporter of Silicon and Carbon: Conversion of Rice Husks to Silicon Carbide or Carbon‐Silicon Hybrid for Lithium‐Ion Battery Anodes via a Molten Salt Electrolysis Approach

“…The selected‐area electron diffraction (SAED) (the inset picture of Figure f) also verifies that the crystalline structure of SiC contains the lattice plane spacing of (111), (220) and (311) lattice, which agrees well with the XRD patterns. Notably, Si is not observed in all three electrolytic products prepared at 2.4, 2.6 and 2.8 V. It has been reported that SiC was prepared by the electrochemical reduction of the mixture of SiO 2 and C, and the electrolytic products were determined by the configuration of C and SiO 2 . All electrolytic products are C−SiC composites, indicating that the SiO 2 and C are sufficiently contacted in the C−RHs.…”

Controllable conversion of rice husks to Si/C and SiC/C composites in molten salts

“…In addition, anodic evolution of corrosive Cl 2 can be avoided, replaced by releasing CO 2 on a graphite anode or O 2 on an inert anode [27]. However, formation of unpleasant SiC in CaCl 2 -based molten salt largely restricts the conversion of RHs to Si/C composites [8,22,23,[32][33][34].…”

Catalytic synthesis of SiC nanowires in an open system

“…These properties make SiC NWs a promising candidate material for many applications, such as reinforcement material for ceramics/metals, field‐emission devices, hydrogen sensor, and photoelectrocatalysts etc. Until now, SiC NWs have been synthesized in the high vacuum closed system by various techniques, for instance, carbon nanotube template, chemical vapor deposition, sol‐gel process, thermal evaporation, carbothermal reduction and molten salt method etc. Liu et al reported the high flexible SiC NWs synthesized by a catalyst‐assisted fluidized bed chemical vapor deposition method.…”

“…Tony et al reported a novel synthesis of SiC nanotubes by microwave heating of blended silicon dioxide and multi‐walled carbon nanotubes. Zou et al reported a simple method for the production of SiC NWs from silica/carbon (SiO 2 /C) precursors in molten calcium chloride.…”