【Research Background】

The sensing performance of the metal oxide semiconductor gas sensor is greatly affected by the operating temperature, which is a parameter that controls the conductivity, surface reactivity, and electron transfer rate. Most semiconductor-based gas sensors can achieve high performance when the operating temperature exceeds 300 °C, because at low temperatures, it is not enough to overcome the thermal energy barrier and initiate a gas sensing reaction. Considering the adverse effects brought by high operating temperature, such as inaccurate experimental data, liquefied petroleum gas (LPG) explosion, etc., surface modification, precious metal or inorganic doping of conductive polymers are used to form composite materials with carbon nanotubes, Lower the operating temperature.

Due to the synthesis method of MXene, interlayer water molecules or surface functional groups make MXene have different gas sensing characteristics from traditional 2D materials, which may be due to the interaction between the adsorbed gas molecules and the sensing material than the typical charge transfer model It‘s more complicated. Therefore, it is very important to study the factors that may affect the low temperature selectivity. Iron molybdate (Fe 2 (MoO 4 ) 3 ) materials have been widely researched and applied in the fields of magnetic devices, methanol oxidation catalysis, energy storage, and gas sensor detection. Compared with traditional simple metal oxides, Fe 2 (MoO 4 ) 3 with multiple metal elements has abundant oxygen vacancies, which is beneficial to selective sensing performance. Studies have shown that iron molybdate materials have a better gas response to acetone at relatively high temperatures. In order to reduce the operating temperature and improve the gas sensing performance, the relevant gas sensing performance was studied using Fe 2 (MoO 4 ) 3 /MXene composite material.

【Achievement Introduction】

Recently, Professor Lin Zhidong of Wuhan University of Technology published a research paper titled: Enhanced gas sensing properties at low working temperature of iron molybdate/MXene composite in the internationally renowned academic journal Journal of Alloys and Compounds . Fe 2 was prepared by hydrothermal method (MoO 4 ) 3 /MXene nanocomposites. A resistive gas sensor was prepared using the composite material, and its low-temperature gas sensing performance of n-butanol was studied. Composite materials have better electrical conductivity and higher gas response than Fe 2 (MoO 4 ) 3 alone at lower operating temperatures . The enhanced gas-sensitive performance depends on the composition and structure of the composite material, which can be easily controlled by adjusting the mass ratio of the MXene/Fe 2 (MoO 4 ) 3 composite material. These results reveal its potential application in low-temperature gas sensing.

【Graphic introduction】

Figure 1. XRD characterization of  Fe 2 (MoO 4 ) 3 and composite materials.

Figure 2.  SEM characterization of Fe 2 (MoO 4 ) 3 and composite materials .

Figure 3.  TEM characterization of Fe 2 (MoO 4 ) 3 and composite materials.

Figure 4. Nitrogen adsorption-desorption isotherms ofFe 2 (MoO 4 ) 3 and composites and BJH pore size distribution (internal).

Figure 5. The relationship between the gas response performance of Fe 2 (MoO 4 ) 3 and composite sensors and temperature.

Figure 6. The gas-sensing performance ofFe 2 (MoO 4 ) 3 and composite sensors to n-butanol.

【Summary of this article】

      In this paper, Fe 2 (MoO 4 ) 3 /MXene composite was prepared by a single hydrothermal method . The synthesized composite material exhibits a layered structure, in which Fe 2 (MoO 4 ) 3 microspheres are assembled from nanosheets and are covered by the MXene layer. The introduction of MXene improves the conductivity of the composite material, and the gas response can be easily detected at low temperatures. The high surface area of the composite material leads to a high gas-sensitive response. The enhanced gas-sensing performance of 100 ppm of n-butanol (S=43.1) and xylene (S=39.5) indicates its potential application in gas sensors.

Literature link:

https://dx.doi.org/10.1016/j.jallcom.2019.152785.

Source: MXene Frontier

This information originates from the Internet for academic exchange only. If infringement please contact us to delete immediately