Highly selective ethanol gas sensor based on CdS/Ti₃C₂T_<i>x</i> MXene composites

Sensing of hazardous gases has an important role in ensuring safety in a variety of industries as well as environments. Mainly produced by the combustion of fossil fuels and other organic matter, ethanol is a dangerous gas that endangers human health and the environment. Stability and sensing sensitivity are major considerations when designing gas sensors. Here, a superior ethanol sensor with a high response and fast recovery was synthesized by "wrapping" CdS nanoparticles on metallic Ti₃C₂T _<i>x</i> MXene using a simple method. CdS nanoparticles were uniformly covered on the Ti₃C₂T _<i>x</i> MXene surface, forming a "rice crust"-like heterostructure. The sensor displayed good detection of ethanol gas at room temperature. Response signals up to 31% were obtained for ethanol molecules (20 ppm) with quick recovery (41 s). The performance of the ethanol sensor was evaluated across a range of concentrations (5-100 ppm) and relative humidity (60% and 90% RH) at room temperature. Our method could open up a new strategy for the development of ethanol sensors.