Pt/Graphene Catalyst and Tellurium Nanowire-Based Thermochemical Hydrogen (TCH) Sensor Operating at Room Temperature in Wet Air

Abstract

We present a thermochemical hydrogen (TCH) gas sensor fabricated with Pt-decorated exfoliated graphene sheets and a tellurium nanowire-based thermoelectric (TNTE) layer operating at room temperature in wet air. The sensor device was able to detect 50 ppm to 3% of hydrogen gas within several seconds (response/recovery times of 6/5.1 s at 4000 ppm of hydrogen gas) at room temperature due to the relatively high surface area of homogeneously dispersed Pt nanocrystals (∼8 nm) decorated on graphene sheets and the excellent Seebeck coefficient (428 μV/K) of the TNTE layer. Furthermore, it was observed that the effect of the relative humidity on sensing properties was greatly minimized by incorporating Pt-decorated graphene sheets. These results indicate that our device has great potential as a low power consumption gas sensor for IoTs.

Wearable Thermoelectric Materials and Devices for Self‐Powered Electronic Systems

“…Various TE sensors based on Te nanomaterials have been developed for sensing physical and chemical parameters. [203,204] Adv. Mater.…”

Sensors Based Upon Nanowires, Nanotubes, and Nanoribbons: 2016–2020

“…Thermochemical mechanisms have been another innovative mechanism for nanostructured gas sensors. While film-based sensors were first described in 2001 for hydrogen detection, they have only recently adapted to metal NW-based sensing elements . Usually, these devices consist of two components: a catalyst to react with the analyte gas and produce/absorb heat and a thermoelectric NW to convert a temperature difference into a voltage signal.…”

“…Usually, these devices consist of two components: a catalyst to react with the analyte gas and produce/absorb heat and a thermoelectric NW to convert a temperature difference into a voltage signal. The temperature change generated by the catalyst can be related to the Seebeck coefficient of the thermoelectric NW by eq : where Δ V is the voltage difference across the nanowire, α is the Seebeck coefficient of the nanowire, and Δ T is the temperature change. Since the signal Δ V is dependent on a temperature change (Δ T ), thermochemical devices are only functional for analyte gases that can undergo a large enthalpy change.…”

Highly Water-Dispersible Graphene Nanosheets From Electrochemical Exfoliation of Graphite

“…Graphene, atomically thin carbon layers exfoliated from graphite in which multiple layers of sp 2 -bonded carbon atoms are arranged in a hexagonal lattice, has been standing at the center of materials due to its great potential applications in next-generation electronic devices ( Kwon et al, 2020 ; Alonso et al, 2018 ), energy conversion and storage devices ( Jang et al, 2021 ; Tanguy et al, 2020 ), catalysis ( Hwang et al, 2019 ; Lu et al, 2016 ), and other functional composites ( Ryu et al, 2020 ; Wu et al, 2017 ) owing to its unique electrical, mechanical, optical, and chemical properties ( Kwon et al, 2017 ; Dong et al, 2017 ; Kim et al, 2019 ). While the preparation methods of graphene such as Scotch Tape exfoliation ( Novoselov et al, 2004 ), epitaxial growth ( Yang et al, 2013 ), and chemical vapor deposition using gaseous precursors ( Plutnar et al, 2018 ) could yield high-quality graphene, its commercialization has been hindered owing to the lack of cost-effective industrial-scale production methods.…”