Physisorption induced p-xylene gas-sensing performance of (C4H9NH3)2PbI4 layered perovskite

A novel organic-inorganic layered perovskite compound (C 4 H 9 NH 3 ) 2 PbI 4 has been synthesized through a simple and high-yield solution method. For the first time, this layered perovskite was used as a candidate material for gas sensors. Gas sensors based on (C 4 H 9 NH 3 ) 2 PbI 4 provided unique gas-sensing properties toward 1–800 ppm p -xylene (p-C 8 H 10 ) at the working temperature of 140 °C, including fast response, quick response-recovery, good selectivity and repeatability. The as-prepared (C 4 H 9 NH 3 ) 2 PbI 4 gas sensor can detect as low as 1 ppm concentration of p -xylene with a response of 11.8 at 140 °C. In situ diffuse reflectance Fourier transform infrared (DRFTIR) measurement shows that the p -xylene sensing mechanism can be mainly attributed to physical adsorption, which is different from other common gas-sensing metal oxides that are based on adsorption-redox-desorption mechanism.