Sub-ppm Hydrogen Sensing with Functionalized Carbon Nanotubes at Room Temperature

Hydrogen is a clean and efficient energy carrier with the potential to significantly reduce greenhouse gas emissions and facilitate the transition from fossil fuels. However, the environmental impact of increased hydrogen emissions in a future hydrogen economy remains poorly understood. Monitoring hydrogen levels in the atmosphere, especially at sub-ppm concentrations, is essential for evaluating its effects on safety, climate change, and the environment. In this work, we employ a novel approach to chemically functionalize single-walled carbon nanotubes with platinum nanoparticles to create ultra-sensitive chemiresistive sensors capable of detecting hydrogen concentrations as low as 100 ppb and responding to ppb-level changes at room temperature. Our results demonstrate that these sensors can reliably detect hydrogen across a wide range, from 100 ppb to 0.5%. Additionally, the sensors exhibit robust performance across varying temperatures and humidity levels and maintain high stability, showing a robust response to 100 ppm of hydrogen gas for over 90 days in ambient conditions. The low-cost of sensor fabrication, robust design and high sensitivity makes our sensors ideal for large-area hydrogen monitoring.