Electrocatalytic Performance of SiO2-SWCNT Nanocomposites Prepared by Electroassisted Deposition

Abstract

Composite materials made of porous SiO 2 matrices filled with single-walled carbon nanotubes (SWCNT) were deposited on electrodes by an electro-assisted deposition method. The synthesized materials were characterized by several techniques, showing that porous silica prevents the aggregation of SWCNT on the electrodes, as could be observed by TEM microscopy and Raman spectroscopy. Different redox probes were employed to test their electrochemical sensing properties. The silica layer allows the permeation of the redox probes to the electrode surface and improves the electrochemical reversibility indicating an electrocatalytic effect by the incorporation of dispersed SWCNT onto the silica films.

Enhancement of the Electrochemical Performance of SWCNT dispersed in a Silica Sol-gel Matrix by Reactive Insertion of a Conducting Polymer

“…In particular, the electrocatalytic activity of Single-Walled Carbon Nanotubes dispersed within a SiO2 matrix was examined against several redox probes in a recent contribution [20]. It was reported in this study that the electroencapsulation of SWCNT gives rise to a well-dispersed SWCNT load within the silica film.…”

“…In our previous studies, the SWCNT@SiO2 hybrid material showed a good electrochemical performance that improved the heterogeneous rate transfer for several redox probes [20]. However, this was followed by a minor increase in the electroactive area (the electrode area transferring the charge effectively).…”

“…During the collapse of silica colloids near the electrode surface, the suspended SWCNT are trapped to form SWCNT@SiO2. Further details of the deposition method are given elsewhere [19,20]. The amount of carbon nanotubes incorporated into the electrodeposited silica matrices were determined to be around 4% by thermogravimetric analysis (see Fig.…”

“…Our research group has been recently interested in the use of electrochemistry to produce hybrid silica materials with no chemical gelification steps [19,20]. In particular, the electrocatalytic activity of Single-Walled Carbon Nanotubes dispersed within a SiO2 matrix was examined against several redox probes in a recent contribution [20].…”

“…The iron redox couple is an oxide-sensitive probe, whose electrochemical behavior allows the quantification of the electroactive area related with the graphitic edges of SWCNT i.e., the nanotube tips [20,22]. On the other hand, the dopamine organic probe reacts preferentially at the basal planes of the graphitic domains favored by π-π interactions.…”