Thermoelectric (TE)-based gas sensors have attracted
significant
attention due to their high selectivity, low power consumption, and
minimum maintenance requirements. However, it is challenging to find
low-cost, environmentally friendly materials and simple device fabrication
processes for large-scale applications. Herein, we report self-powered
thermoelectric hydrogen (TEH) sensors based on bismuth sulfide (Bi2S3) fabricated from a low-cost Bi2S3 TE layer and platinum (Pt) catalyst. When working at room
temperature, the monomorphic-type TEH sensor obtained an output response
signal of 42.2 μV with a response time of 17 s at a 3% hydrogen
atmosphere. To further improve device performance, we connected the
patterned Bi2S3 films in series to increase
the Seebeck coefficient to −897 μV K–1. For comparison, the resulting N tandem-type TEH sensor yielded
a distinguished output voltage of 101.4 μV, which was greater
than the monomorphic type by a factor of 2.4. Significantly, the response
and recovery time of the N-tandem-type TEH sensor to 3% hydrogen were
shortened to 14 and 15 s, respectively. This work provides a simple,
environmentally friendly, and low-cost strategy for fabricating high-performance
TEH sensors by applying low-cost Bi2S3 TE materials.