Fabrication of Pt-MWNT/Nafion Electrodes by Low-Temperature Decal Transfer Technique for Amperometric Hydrogen Detection

Abstract

A Pt nanoparticle-decorated multiwall carbon nanotube (Pt-MWNT) electrode wasprepared on Nafion by a hot-pressing at relatively low temperature. This electrode exhibitedan intricate entangled, nanoporous structure as a result of gathering highly anisotropic Pt-MWNTs. Individual Pt nanoparticles were confirmed to have a polycrystalline face-centeredcubic structure with an average crystal size of around 3.5 nm. From the cyclic voltammogramsfor hydrogen redox reactions, the Pt-MWNT electrode was found to have a similar electrochemicalbehavior to polycrystalline Pt, and a specific electrochemical surface area of2170 cm2mg−1. Upon exposure to hydrogen analyte, the Pt-MWNT/Nafion electrode demonstrateda very high sensitivity of 3.60 μA ppm−1 and an excellent linear response over the concentrationrange of 100-1000 ppm. Moreover, this electrode was also evaluated in terms ofresponse and recovery times, reproducibility, and long-term stability. Obtained results revealedgood sensing performance in hydrogen detection.