Fabrication and Characterization of Pyrrole/Multi-Walled Carbon Nanotubes Composite Electrodes

Carbon based nano-materials have received a large amount of focus because of their ultra-high energy density which approaches 600 F/g. Specifically, pyrrole and graphene double layer supercapacitors have achieved the highest charge density. Their performance has been attributed to the films conductivity, surface area and low density. This study focused on fabrication of a pyrrole (Pyr)/ multi-walled carbon nanotubes (MWCNTs) composite for analysis.

Composite films were electrochemically deposited from an aqueous MWCNTs, Pyr, and sodium dodecyl sulfate (SDS) solution onto a copper substrate. After deposition the films were annealed at 230˚C for an hour, allowed to cool to room temperature, then exfoliated using tape. SEM, AFM, and ATR-FT-IR spectroscopy were performed on unexfoliated films. 4-point probe conductivity and UV-Vis transmission measurements were performed on exfoliated films.

SEM analysis (Figure 1) shows two components of the composite, MWCNTs and Pyr forming a dense mat. All three components of the precursor were present in the final film as confirmed by ATR-FT-IR spectroscopy and the films were minimally transparent in the UV-Vis region (%T<.5%). The roughness of the film from AFM was RMS = 77.1 nm. Lastly the films had low conductivity of 0.015 S/cm.

Further optimization of the precursor and deposition cycle will hopefully result in composite films with high charge density for applications in double layered capacitors.

Figure 1:SEM micrograph of the edge of the Pyr/ MWCNT composite film deposition.