The highly sensitive ethanol sensor based on nanocomposites of ZnOgrown on 2D TiCTnanosheet.

Ethanol is a harmful volatile organic compound (VOC) for human health. Currently, zinc oxide (ZnO) is one of the most popular metal oxide semiconductors for VOCs detection but suffering from a lack of selectivity, poor response, and slow response/recovery speeds. Herein, we successfully synthesized the ZnO/TiCTnanocomposites via a facile hydrothermal method, in which ZnO nanoparticles were uniformly grown on two-dimensional (2D) TiCTnanosheets. As a result, the ZnO/TiCTnanocomposites showed a significant improvement in the ethanol-sensing performance, when it compared to the pure ZnO and TiCTsamples. In particular, ZnO doped with 5 mg of TiCTshowed an ultra-high response (79) to 100 ppm ethanol, a short response/recovery time (22 s/34 s to 50 ppm ethanol), a low limit of detection (1 ppm) and a long-term stability. The excellent ethanol sensing properties are mainly attributed to the coupling effect between ZnO and TiCTof composites. The ZnO nanoparticles are uniformly distributed on the 2D TiCTplatform, which can provide more gas adsorption sites. Simultaneously, the presence of hybrid heterojunctions further enhances the response in the sensing process.