Enhanced sensitivity towards hydrogen by a TiN interlayer in Pd-decorated SnO 2 nanowires

Clémence Badie (1) , Jae-Hyoung Lee (2) , Ali Mirzaei (3) , Hyoun Woo Kim (4) , Syreina Sayegh (5) , Mikhael Bechelany (5) , Lionel Santinacci (1) , Sang Sub Kim (6)

1 CINaM - Centre Interdisciplinaire de Nanoscience de Marseille
2 Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul.
3 Department of Materials Science and Engineering, Shiraz University of Technology
4 Division of Materials Science and Engineering, Hanyang University, Seoul
5 IEM - Institut Européen des membranes
6 Department of Materials Science and Engineering, Inha University, Incheon

IIn this study, we designed a new structure based on Pd-decorated TiN-coated SnO2 nanowires (NWs) for the selective detection of H2 gas. Initially, SnO2 NWs were prepared by a simple vapor-liquid-solid growth method. Then, atomic layer deposition (ALD) was used to grow a continuous TiN layer and, subsequently, Pd nanoparticles on the NW networks. The TiN thickness was precisely set to 0.5, 1, 2, and 5 nm, while the Pd loading was adjusted by varying the number of ALD cycles (25 to 200 cycles). Various characterization techniques revealed the amorphous nature of TiN, a homogeneous dispersion of Pd NPs and the uniform morphology and single crystallinity of the SnO2 NWs. H2 gas sensing studies revealed that the sensor with a TiN thickness of 1 nm exhibited the highest response. Pd decoration further improved the response to H2 gas. Hence, the Pd-decorated gas sensor with a 1 nm-thick TiN layer showed the highest H2 sensing performance at 250 °C among all gas sensors. Due to the unique chemical reaction between Pd and hydrogen, the fabricated sensor shows excellent performance in detecting hydrogen gas. The underlying sensing mechanism is discussed in detail. The optimized sensor has a sensitivity of 8.18 for hydrogen gas, which is four times higher than that of other gas species, showing that it is suitable for detecting hydrogen gas. We believe that this new design is a highly valuable gas sensor for the real application of H2 monitoring with high selectivity.

Mots clés: Atomic layer deposition; Chemical sensors; Crystallinity; Gas detectors; Gases; Nanowires; Palladium

Domaines: Chimie

Clémence Badie, Jae-Hyoung Lee, Ali Mirzaei, Hyoun Woo Kim, Syreina Sayegh, et al.. Enhanced sensitivity towards hydrogen by a TiN interlayer in Pd-decorated SnO 2 nanowires. Journal of Materials Chemistry A, 2023, 11 (23), pp.12202-12213. ⟨10.1039/d3ta00020f⟩. ⟨hal-04150029⟩