Oxygen-Vacancy-Enriched Porous α-MoO₃ Nanosheets for Trimethylamine Sensing

Abstract

Two-dimensional ultrathin porous α-MoO3 nanosheets with oxygen vacancies were synthesized by a simple solvothermal method. The thickness of the precursor reaches 14 nm and is accumulated by sheets of 2–6 nm. The pore size is 2–10 nm on the surface. A gas sensor was assembled with the α-MoO3 nanosheets annealed at 400 °C (α-MoO3-400). The sensor based on α-MoO3-400 achieves the fastest response to trimethylamine (TMA) gas at relatively low operating temperature (133 °C). The response of the sensor is 198–50 ppm TMA and the detection limit is 20 ppb. In addition, the sensing mechanism is verified by experiment that the gas molecules adsorb on the surface of MoO3 and participate in the electron transfer of the semiconductor. DFT calculations suggest that MoO3 containing oxygen vacancy can increase charge transfer after TMA adsorbed.

Rational Design of Semiconductor‐Based Chemiresistors and their Libraries for Next‐Generation Artificial Olfaction

“…For instance, acidic oxides such as MoO 3 and WO 3 exhibit high responses and selectivity to basic gases such as NH 3 , dimethylamine, and trimethylamine. [365][366][367][368][369][370][371][372] Thus, the combining acidic and basic oxides can provide other opportunities to tune the gas selectivity.…”

Two-dimensional β-MoO3@C nanosheets as high-performance negative materials for supercapacitors with excellent cycling stability

“…38 Sun et al reported the synthesis of a MoO 3Àx nanosheet, involving the reux of the bulk a-MoO 3 precursor in water at 80 C for 7 days. 39 The b-MoO 3 phase is believed to be superior to a-MoO 3 and h-MoO 3 in its catalysis and electrochemical applications, [40][41][42] but there are only a few reports on the preparation of the metastable b-MoO 3 phase. 43 In this regard, it is highly desirable to explore b-MoO 3 nanomaterials with a simple and efficient method to meet the demand of high catalytic performance energy storage devices in further commercial applications.…”

MoO2 Nanospheres Synthesized by Microwave-Assisted Solvothermal Method for the Detection of H2S in Wide Concentration Range at Low Temperature

“…The optimal working temperature is 100 • C, which is much lower than that of other metal oxide gas sensors and beneficial for energy saving (Guo W. et al, 2016;Wang et al, 2019;Nguyen et al, 2020). The low working temperature may come from the abundant chemisorbed oxygen and oxygen vacancy in MMO (Shen et al, 2019). Therefore, further tests of sensing properties are all completed at 100 • C. Figure 3B presents the response of MMO to H 2 S at different concentrations (1-240 ppm).…”