Coatings based on hybrid carbon-Platinum nano-ink for multifunctional applications

Abstract

In this study, carbon nanotubes (CNT) decorated with 30 wt% concentration of platinum nanoparticles (4 nm) were synthesized to form a stable nano-ink intended for coating applications. Morphological analyses revealed the multi-walled structure of CNT and the efficient attachment of Pt nanoparticles on their surfaces. The obtained I_D/I_G ratio of the Raman spectrum, which represents the defect density in graphitic structures, is 0.40, indicating good crystallinity of CNT. XRD and XPS revealed a dominant (111) crystallographic orientation for Pt nanoparticles and its metallic phase. The electrical properties of the 100 μm thickness CNT/Pt coatings were measured under both direct current and alternating current to study the complex internal electrical components, associated with capacitances and inductances. The thermoelectric characteristics, induced by the Joule effect, showed that electrical conductance increases with temperature (in the temperature range from 305 to 420 K), and was modeled using a heat transfer balance. Furthermore, when the coating was subjected to an alternating magnetic field, it exhibited behavior consistent with Faraday's law of induction, demonstrating fast-switching capabilities. Moreover, the nanohybrid coating did not exhibit induction heating effects when exposed to an alternating magnetic field. This behavior can be associated with the metallic nature of the hybrid film given by the Pt nanoparticles, characterized by their low magnetic permeability. Our results highlight the potential of CNT/Pt as a nanomaterial for controlling thermoelectric applications, with a dual facet of measuring oscillating magnetic fields without being affected by thermomagnetic effects.