Platinum nanoparticle-supported polymer-grafted carbon nanotubes via noncovalent interactions and their application to hydrogen sensors

Abstract

In this study, a platinum (Pt) nanoparticle-loaded multiwalled carbon nanotube material was fabricated. Polyethylene glycol was grafted onto the nanotube surface via noncovalent bonding to achieve high dispersibility without damaging the nanotube morphology, followed by the deposition of Pt nanoparticles via a polyol reduction method. Successful polymer grafting and Pt loading were confirmed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction. The resulting material was developed as an electrode for a hydrogen electromotive force (EMF) sensor to detect hydrogen gas below the H2 explosion limit. The sensor electrode device responded rapidly to hydrogen, with a potential difference of approximately 100 mV and reproducible cycling stability. In addition, the electrochemically active surface area was qualitatively evaluated using cyclic voltammetry, which demonstrated the potential of the material as an electrocatalyst. Hydrophilic polyethylene glycol (PEG) was grafted onto multiwalled carbon nanotubes (mwCNTs) via noncovalent bonding to improve water stability without damaging the nanotube morphology. Platinum (Pt) nanoparticles were subsequently deposited on the grafted nanotubes to fabricate a Pt-supported mwCNT, owing to the π–π interactions between the terminal pyrene moieties on the modified PEG chains and the CNT surface, the grafted material maintained stable dispersion. And the resulting material was developed as an electrode for a hydrogen electromotive force (EMF) sensor to investigate its hydrogen gas response behavior.