Lower coordination Co3O4 mesoporous hierarchical microspheres for comprehensive sensitization of triethylamine vapor sensor

Sui

et al. 2022

ACS Appl. Nano Mater.

A triethylamine gas sensor with humidity resistance, high selectivity, and high response is designed. Chromium oxide particles were prepared by heating them in a water bath at 80 °C. Pt/Cr2O3 nanoparticles were obtained by sodium borohydride reduction. The structure morphology of nanoparticles was characterized by some methods. The gas response test results showed that the modification of Pt improved the response value and selectivity of Cr2O3 to triethylamine. It was found that Cr2O3–2Pt nanoparticles had the best performance, and at the optimum operating temperature of 160 °C, its response value reached 200, 68 times that of Cr2O3 (S = 2.95). In addition, the modification of Pt made Cr2O3–2Pt nanoparticles had a wide range of humidity applications. The mechanism of gas response is explained by using the Schottky barrier and hole accumulation layer model of Pt and Cr2O3 contact and energy band theory.

Section: Gas Sensing Mechanismmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Highly Selective and Humidity-Resistant Triethylamine Sensors Based on Pt and Cr₂O₃ Nanoparticles

Yang

Sui

et al. 2022

ACS Appl. Nano Mater.

“…Transition metal oxide Co 3 O 4 plays an important role in data storage, sensing, and especially catalysis due to the rich surface structures. However, the low carrier mobility and high resistivity (ρ > 1 × 10 6 Ω cm) of Co 3 O 4 severely limit the related applications. , Crystal facet and cation/anion vacancy engineering have been proven to be effective in performance improvement. − Adjusting the exposed surface dramatically promotes the electrochemical properties of Co 3 O 4 by modifying the number of active sites and the atomic oxidation state of Co species. , The catalytic activity of {111}- and {112}-enclosed Co 3 O 4 nanocrystals is better than those enclosed by {100} and {110} facets. ,, The corrosion rate of different Co 3 O 4 planes increases in the order of (001) < (111) < (011) .…”

Section: Introductionmentioning

confidence: 99%

“…Transition metal oxide Co 3 O 4 plays an important role in data storage, 1 sensing, 2 and especially catalysis 3 due to the rich surface structures. However, the low carrier mobility and high resistivity (ρ > 1 × 10 6 Ω cm) of Co 3 O 4 severely limit the related applications.…”

Section: ■ Introductionmentioning

confidence: 99%

Tuning the Semiconducting Properties in Co₃O₄/PMN–PT Heterostructures by Oxygen Vacancies and Domain Structure

ACS Appl. Electron. Mater.

Chen

et al. 2022

Epitaxial Co3O4 films with various oxygen vacancy densities were deposited on the (001)-, (011)-, and (111)-0.7Pb(Mg1/3Nb2/3)–0.3PbTiO3 (PMN–PT) substrates to modulate the electrical properties. Experiment and calculation results demonstrate that the oxygen vacancies can reduce the resistivity of Co3O4 films. Meanwhile, the resistivity of Co3O4 films decreases in the order of (111) > (011) > (001) due to the various ferroelectric domain densities of PMN–PT substrates. The Co3O4/PMN–PT (001) heterostructure exhibits the lowest resistivity of 1.7 Ω cm at room temperature under the influence of oxygen vacancies and the ferroelectric domain. The maximum relative resistance variation of Co3O4 films reaches 200% under an external electric field as the result of the ferroelectric-field effect and the migration of oxygen vacancies. This work provides a powerful way to modulate the electrical properties of Co3O4 films and further broadens the application of Co3O4.

Single‐Atom Cu Stabilized on Ultrathin WO_2.72 Nanowire for Highly Selective and Ultrasensitive ppb‐Level Toluene Detection

Guo

et al. 2023

Advanced Science

Various catalysts are developed to improve the performance of metal oxide semiconductor gas sensors, but achieving high selectivity and response intensity in chemiresistive gas sensors (CGSs) remains a significant challenge. In this study, an in situ‐annealing approach to synthesize Cu catalytic sites on ultrathin WO2.72 nanowires for detecting toluene at ultralow concentrations (Ra/Rg = 1.9 at 10 ppb) with high selectivity is developed. Experimental and molecular dynamic studies reveal that the Cu single atoms (SAs) act as active sites, promoting the oxidation of toluene and increasing the affinity of Cu single‐atom catalysts (SACs)‐containing sensing materials for toluene while weakening the association with carbon dioxide or water vapor. Density functional theory studies show that the selective binding of toluene to Cu SAs is due to the favorable binding sites provided by Cu SAs for toluene molecules over other gaseous species, which aids the adsorption of toluene on WO2.72 nanowires. This study demonstrates the successful atomic‐level interface regulation engineering of WO2.72 nanowire‐supported Cu SAs, providing a potential strategy for the development of highly active and durable CGSs.