Mn-doped ZnO/SnO2-based yarn sensor for ammonia detection

Metal oxide semiconductor (MOS) gas sensing materials have high operating temperatures and often use rigid materials as substrates, making them difficult to be widely applied in the field of wearable electronic devices. In this work, the sheath-core structure electrospun nanofiber core-spun yarn (ES-PY) was prepared using the coaxial electrospun yarn technology, and then the poly (dopamine) was polymerized on its surface to obtain the poly (dopamine) nanofiber core-spun yarn (PDA-PY). ZnO/SnO2/Mn metal oxide semiconductor nanoparticles (ZS/Mn-NPs) were synthesized via a two-step hydrothermal process by doping Mn into ZnO/SnO2. These were subsequently loaded onto the surface of PDA-PY to produce the yarn sensor (ZS/Mn-PY).The combination of the nano-size effect of the nanofibers and the doping-promoting effect of the Mn-doped metal oxide semiconductor further increases the adsorption sites of the gas molecules so that the sensor exhibits excellent gas sensitivity to ammonia (NH3), with a response up to 13.13 (Ra/Rg) in an ammonia atmosphere at a concentration of 100 ppm, and still up to 2.61 when exposed to an ammonia atmosphere at a concentration as low as 10 ppm at room temperature. In addition, it retains the excellent flexibility and strength of the core yarn. And provides a simple and effective method for preparing flexible textile gas sensor.