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

Abstract

Although semiconducting single-walled carbon nanotubes (sc-SWNTs) exhibit excellent sensing properties for various gases, commercialization is hampered by several obstacles. Among these, the difficulty in reproducibly fabricating sc-SWNT films with uniform density and thickness is the main one. Here, a facile fabrication method for sc-SWNT-based hydrogen (H 2 ) sensors with excellent reproducibility, high sensitivity, and selectivity against CO, CO 2 , and CH 4 is reported. Uniform-density and monolayer sc-SWNT films are fabricated using chemical immobilized through the click reaction between azide-functionalized polymer-wrapped sc-SWNTs and immobilized alkyne polymer on a substrate before decorating with Pd nanoparticles (0.5-3.0 nm). The optimized sc-SWNT sensor has a high room-temperature response of 285 with the response and recovery times of 10 and 3 s, respectively, under 1% H 2 gas in air. In particular, this sensor demonstrates highly selective H 2 detection at room temperature (25 °C), compared to other gases and humidity. Therefore, the chemical immobilization of the monolayer SWNT films with reproducible and uniform density has the potential for large-scale fabrication of robust room-temperature H 2 sensors.

Influence of the Pd Oxidation State in PdNi Thin Films on Surface Acoustic Wave Hydrogen Sensing Performance

“…In the context of the growing low-carbon economy (LCE), hydrogen (H 2 ) energy has gained widespread usage in various applications, such as hydrogen fuel cell vehicles and hydrogen chemical industry. − However, hydrogen exhibits notable attributes, including rapid diffusion (0.61 cm 2 /s), low ignition energy (∼0.2 mJ), and a wide flammability range in air (4–75 v/v%). − These attributes lead to safety risks in H 2 production, transportation, and utilization. To ensure the safe utilization of H 2 , there is a high demand for highly sensitive H 2 sensors with excellent long-term stability. , Depending on the underlying hydrogen sensing mechanisms, H 2 sensors can be categorized into different types, such as mechanical or electrochemical change-based, resistance-based, thermal-based, acoustically assisted, catalytic activity-based, and optically assisted sensors. − Among these, surface acoustic wave (SAW) hydrogen sensors have emerged as a promising technology due to their remarkable advantages in terms of response speed, sensitivity, and low-power consumption. , …”

Pd Decoration with Synergistic High Oxygen Mobility Boosts Hydrogen Sensing Performance at Low Working Temperature on WO3 Nanosheet

“…Energy shortages and environmental pollution have made the development of clean energy a priority. , Notably, hydrogen is an efficient and clean energy carrier with a high energy density (142 kJ·g –1 ), − and it has received remarkable attention. However, safe storage/transportation is a crucial issue for the development of hydrogen energy since H 2 is flammable and explosive as the concentration is above 4%; , hence, the scale application of hydrogen energy has been severely limited . Notably, sensing materials play a vital role in accurately detecting and monitoring the concentration of hydrogen in specific environments during transport and storage.…”