High-Performance Ppb Level NO2 Gas Sensor Based on Colloidal SnO2 Quantum Wires/Ti3C2Tx MXene Composite

Nitrogen dioxide is one origin of air pollution from fossil fuels with the potential to cause great harm to human health in low concentrations. Therefore, low-cost, low-power-consumption sensors for low-concentration NO2detection are essential. Herein, heterojunction by SnO2quantum wires, a traditional metal oxide NO2sensing material, and Ti3C2TxMXene, a novel type of 2D layered material, was synthesized using a simple solvothermal method for enhancing gas-sensing performance and reducing operating temperature. The operating temperature was reduced to 80 °C, with a best performance of 27.8 and a fast response and recovery time (11 s and 23 s, respectively). The SnO2and Ti3C2TxMXene composite exhibits high speed and low detection limit due to the construction of the heterojunction with high conductive Ti3C2TxMXene. The selectivity and stability of gas sensors are carried out. This could enable the realization of fast response, high-sensitivity, and selective NO2sensing under low operating temperatures.Keywords:Ti3C2TxMXene;SnO2;gas sensor;NO2;nanocomposite