Abstract: Obtaining a high-performance hydrogen (H2)
gas sensor based on carbon nanotube (CNT) remains challenging.
In this view, two CNT samples such as untreated
(R-CNT) and nitric acid (HNO3)-treated (called functionalized
or F-CNT in short) were deposited on the SiO2/Si substrate
using an electrophoretic deposition technique. The structure,
morphology, and electrical characteristics of these samples
were evaluated.Fourier transforminfrared (FTIR) spectra confirmed
the presence of OH groups at the walls of nanotubes
after acid treatment. Moreover, it found the current increased
from 35 μA for R-CNT to 11 mA for F-CNT. In addition, both
R-CNT and F-CNT were used to fabricate H2 gas sensors.
The sensing capacity of the obtained sensors was measured
under the H2 gas exposure range of 20 to 300 ppm operated at
room temperature (RT), 50 C, and 75 C. The H2 gas sensor
made of F-CNT showed a much higher response (368%) and
shorter response time (15 s) as well as recovery time (72 s)
than the one made using R-CNT. It was asserted that the
H2 gas sensing performance of the proposed sensor can
significantly be improved via the acid treatment or functionalization of CNT.