The distinguished hydrogen sensibility by selecting diameters of single-walled carbon nanotubes and adding sensitive materials

Hydrogen sensors based on palladium (Pd)/semiconducting single-walled carbon nanotube(s-SWNTs) have showed great performance in sensitivity, limit of detection (LOD), and response time. With the development of research, it is proved that diameters and chirality of s-SWNTs strongly influence the detection. In this paper, we fabricated two kinds of sensors with different diameters, and that results showed response of sensor with 0.7-1.2 nm s-SWNTs was almost 6 times higher than that of the one with 1.2-1.6 nm sSWNTs. The former could achieve the response of change =6.09 for 1 ppm H2 in N2, and the latter was =1.07. Furthermore, with Pd/HKUST-1 as functionalization for capturing more hydrogen (H2), the system formed a synergistic effect to enhance the change of resistance. The fabricated Pd/HKUST-1/s-SWNTs film (0.7-1.2 nm) H2 sensor presents a very fast recovery time of 8 s at 10 ppm anda detection limit of 1 ppm H2 in nitrogen(N2). In addition, in the air the sensor can also work. Its response time of the sensor to 0.05% H2 in air are 0.183 s. By choosing the diameter of s-SWNTs and adding H2-sensitive materials, the sensors are expected to achieve the fast response and recovery with high sensitivity and low LOD. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.