MoO3/Ti3C2Tx MXene nanocomposites with rapid response for enhanced ethanol-sensing at a low temperature

Ethanol, as one of the most widely used volatile organic compounds (VOCs), can cause serious harm to the human respiratory system when exposed to low concentrations of ethanol gas for a long time. Here, we successfully prepared MoO3/Ti3C2Tx MXene nanocomposites by a simple hydrothermal synthesis method, realizing the effective monitoring of low-concentration ethanol gas (1.61@1 ppm). The specific surface area of MoO3/ Ti3C2Tx MXene nanocomposites (61.044 m2/g) is doubled compared with Ti3C2Tx MXene (33.385 m2/g), which provides more reaction centers and active sites for ethanol molecules. Meanwhile, the gas-sensing results revealed that MoO3/Ti3C2Tx MXene nanocomposites show outstanding selectivity and reproducibility, as well as fast response-recovery (10/49 s). Subsequently, the possible sensing mechanism of the composite was further discussed in detail in combination with density functional theory (DFT). This work provides a new sensing design strategy for detecting VOCs at low-temperature.

Automated summary

MoO3/Ti3C2Tx MXene nanocomposites were successfully prepared by a simple hydrothermal synthesis method, achieving effective monitoring of low-concentration ethanol gas (1.61@1 ppm). The MoO3/Ti3C2Tx MXene nanocomposites have a doubled specific surface area (61.044 m2/g) compared to Ti3C2Tx MXene (33.385 m2/g), providing more reaction centers and active sites for ethanol molecules. The gas-sensing results showed outstanding selectivity, reproducibility, and fast response-recovery (10/49 s). The possible sensing mechanism of the composite was discussed in detail with density functional theory (DFT). This work provides a new sensing design strategy for detecting VOCs at low-temperature.