Facile synthesis of an α-Fe2O3–TiO2-MXene heterojunction for enhanced acetone gas sensors

Acetone is harmful to the environment and human health. Therefore, research on acetone sensors for its high-efficiency detection is necessary. Herein, an α-Fe2O3-TiO2-MXene heterojunction was synthesized using a simple precipitation method, and its sensitivity towards acetone was systematically investigated. The response value of the sensor based on the α-Fe2O3-TiO2-MXene heterojunction to 50 ppm acetone was 24 at 150 °C, which was more than one-quarter of that of pure α-Fe2O3 (5.3). The best response and recovery time were 10 s and 6 s, respectively. The sensors also showed good stability and selectivity. The excellent gas sensitivity was mainly attributed to the formation of heterojunctions, which improved the carrier-transport efficiency and the specific surface area for gas molecular adsorption.