Platinum-Nanoparticle-Modified Single-Walled Carbon Nanotube-Laden Paper Electrodes for Electrocatalytic Oxidation of Methanol

Platinum nanostructures have been used as electrocatalysts on various electrode subtrates for applications such as molecular sensing and fuel storage. Lightweight and flexible paper-based devices embedded with micro- or nanoscale metallic electrodes could prove highly useful for wearable devices and other portable applications. We here demonstrate that nanometer-thickness single-walled carbon nanotube (SWCNT)-laden paper prepared via ambient vacuum filtration offers an excellent conducting electrode substrate for the deposition of platinum through either electrodeposition or vacuum filtration. Characterization of the resulting paper electrodes reveals the formation of crystalline, interspersed, discrete spiky platinum nanoclusters (PtNCs) on the SWCNT film fabricated through electrodeposition, while those made via vacuum filtration feature interconnected spherical platinum nanoparticles (PtNPs). Using methanol as a benchmark molecule, we demonstrate that PtNP-SWCNT paper electrodes prepared via vacuum filtration have higher electrocatalytic efficiency compared to electrodes made via electrodeposition, and this is most likely due to the greater electroactive surface area of the PtNP-SWCNT paper electrode. This combination of the superior catalytic properties of platinum nanostructures with the flexible, thin, and conductive SWCNT paper substrate could prove highly valuable for the low-cost manufacturing of high-quality, disposable electrodes for a variety of applications.