Ni₂O₃ Decoration of WO₃ Thin Film for High Sensitivity NH₃ Gas Sensor

Abstract

A facile method for fabricating thin films of granular tungsten oxide (WO 3 ) particles decorated with nickel oxide (Ni 2 O 3 ) nanoparticles was developed for high response NH 3 gas sensor. The WO 3 granular film was fabricated by sputter deposition of tungsten, followed by oxidation. Ni 2 O 3 nanoparticles were deposited onto the WO 3 film by arc-discharge deposition of single-wall carbon nanotubes (SWCNTs) with Ni catalyst nanowires, followed by burning the carbon nanotubes. The Ni nanoparticle catalysts deposited on the SWCNTs were then oxidized to Ni 2 O 3 . The Ni 2 O 3 nanoparticles on the surface exhibited a catalytic role in ammonia gas reactions. A maximum response of 13.5 at operating temperature of 250°C to 200 ppm NH 3 gas concentration was found. In addition, the gas sensing mechanism of Ni 2 O 3 decorated WO 3 film was also discussed in this study.

Hybrid Nanostructures Obtained by Transport and Condensation of Tungsten Oxide Vapours onto CNW Templates

“…The described method leads to hybrid nanostructures that can certainly find application in photoelectrochemical decomposition of water as a renewable energy source [13,14], respectively in gas sensor applications [12,43]. Moreover, the oxidation, vapor transport and condensation processes, evidenced in this paper, may contribute to the understanding of erosion and redeposition phenomena occurring in the fusion machines equipped with tungsten walls [15].…”

“…Promising functional hybrid nanostructures, characterized by novel properties, may be formed based on the decoration of tungsten (W) oxide on CNW templates. An important aspect, about combing these two materials, is highlighted by tungsten oxide unique properties, which makes it, nowadays, an important candidate for applications such as gas sensors [12] and, more recently, for photoelectrochemical water splitting [13,14]. On the other hand, tungsten oxides were studied with respect to their incidence in fusion technology, where they can form, sublimate, redeposit and affect the properties of the tungsten walls used in the fusion reactors [15].…”

Self-Healing, Laminated, and Low Resistance NH3 Sensor Based on 6,6′,6″-(Nitrilotris(benzene-4,1-diyl))tris(5-phenylpyrazine-2,3-dicarbonitrile) Sensing Material Operating at Room Temperature

“…However, the self-healing of the overall device still faces challenges, which are the limits of the substrates and self-healing gas sensing materials. , There is reported a covalent adaptable networks (CANs)-based polyurethane (PU) polymer which had excellent flexible and self-healing properties, and it could be applied as a substrate . Meanwhile, as a key component, the sensing materials of the NH 3 sensors most select semiconductor metal oxides, solid electrolytes, and carbon and metal–organic frameworks, but the lack of flexibility and self-healing ability restricts their application in self-healing NH 3 sensors. − Specifically, organic small molecules have the characteristics of working at room temperature, flexibility, and self-healing ability with the drive of the PU substrate, which shows great application potential in the field of self-healing NH 3 sensors. − As in our previously reported work, the NH 3 sensors based on pyrazino phenanthrene derivatives were developed with rapid response time and excellent stability, and the sensing mechanism was attributed to the adsorption of NH 3 to organic groups. , Based on the above, the 6,6′,6″-(nitrilotris­(benzene-4,1-diyl))­tris­(5-phenylpyrazine-2,3-dicarbonitrile) (TPA-3DCNPZ) molecule was designed; it has abundant organic groups, such as the pyrazine and cyano groups, which could adsorb NH 3 . The spin-coating process was used to fabricate a planar NH 3 sensor based on the Al 2 O 3 substrate with gold interdigitated electrodes (S1), to verify the feasibility of the molecular design strategy.…”