Room-Temperature Hydrogen Sensor with High Sensitivity and Selectivity using Chemically Immobilized Monolayer Single-Walled Carbon Nanotubes

摘要

Although semiconducting single-walled carbon nanotubes (sc-SWNTs)exhibit excellent sensing properties for various gases, commercialization ishampered by several obstacles. Among these, the difficulty in reproduciblyfabricating sc-SWNT films with uniform density and thickness is the mainone. Here, a facile fabrication method for sc-SWNT-based hydrogen (H_2) sensorswith excellent reproducibility, high sensitivity, and selectivity against CO,CO_2, and CH_4 is reported. Uniform-density and monolayer sc-SWNT films arefabricated using chemical immobilized through the click reaction betweenazide-functionalized polymer-wrapped sc-SWNTs and immobilized alkynepolymer on a substrate before decorating with Pd nanoparticles (0.5–3.0 nm).The optimized sc-SWNT sensor has a high room-temperature response of285 with the response and recovery times of 10 and 3 s, respectively, under1% H_2 gas in air. In particular, this sensor demonstrates highly selectiveH_2 detection at room temperature (25 ℃), compared to other gases andhumidity. Therefore, the chemical immobilization of the monolayer SWNTfilms with reproducible and uniform density has the potential for large-scalefabrication of robust room-temperature H_2 sensors.