posted on 2021-03-16, 20:04authored byHien Duy Mai, Sangmin Jeong, Tri Khoa Nguyen, Jong-Sang Youn, Seungbae Ahn, Cheol-Min Park, Ki-Joon Jeon
Developing
sensing approaches that can exploit visible light for
the detection of low-concentration hydrogen at room temperatures has
become increasingly important for the safe use of hydrogen in many
applications. In this study, heterostructures composed of monolayer
MoS2 and Pd nanoclusters (Pd/MoS2) acting as
photo- and hydrogen-sensitizers are successfully fabricated in a facile
and scalable manner. The uniform deposition of morphologically isotropic
Pd nanoclusters (11.5 ± 2.2 nm) on monolayer MoS2 produces
a plethora of active heterojunctions, effectively suppressing charge
carrier recombination under light illumination. The dual photo- and
hydrogen-sensitizing functionality of Pd/MoS2 can enable
its use as an active sensing layer in optoelectronic hydrogen sensors.
Gas-sensing examinations reveal that the sensing performance of Pd/MoS2 is enhanced three-fold under visible light illumination (17%
for 140 ppm of H2) in comparison with dark light (5% for
140 ppm of H2). Photoactivation is also found to enable
excellent sensing reversibility and reproducibility in the obtained
sensor. As a proof-of-concept, the integration of Pd nanoclusters
and monolayer MoS2 can open a new avenue for light-induced
hydrogen gas sensing at room temperature.