Multi-dimensional nanocarbons hybridized with silicon oxides and their application for electrochemical capacitors

Abstract

We report a facile and versatile strategy to prepare multi-dimensional nanocarbons hybridized with mesoporous SiO2. Carbon nanoplatelets (CNPs, two-dimensional structure of nanocarbons) were combined with carbon nanotubes (CNTs, one-dimensional nanocarbons) to form multi-dimensional carbons (2D-1D, CNP-CNTs). The CNP-CNTs were synthesized by directly growing CNTs on CNPs. A simple solution-based process using TEOS (tetraethyl orthosilicate) resulted in coating or hybridizing CNP-CNTs with mesoporous silica to produce CNP-CNTs@SiO2. The nanocarbons' surface area significantly increased as the amount of TEOS increased. Electrochemical characterizations of CNP-CNTs@SiO2 as supercapactior electrodes including cyclic voltammetry and galvanostatic charge-discharge in 3 M KOH (aq) reveal excellent-specific capacitance of 23.84 mF cm(-2) at 20 mV s(-1), stable charge-discharge operation, and low internal resistance. Our work demonstrates mesoporous SiO2 on nanocarbons have great potential in electrochemical energy storage.