High-Performance Sn2+-Doped CuFe2O4-Based Resistance Gas Sensor for the Detection of the Sarin Simulant DMMP

HighlightsWhat are the main findings?A 2 mol% Sn2+-doped CuFe2O4sensor was produced for DMMP detection.The sensor demonstrated suitable sensing performance and selectivity toward DMMP.What is the implication of the main finding?The superior response–recovery characteristics and enhanced moisture resistance compared to the undoped sensor are relevant in gas-sensing applications.Sarin poses a serious threat to human health, necessitating the development of an appropriate sensing technology.Sarin is an extremely toxic and fast-acting chemical warfare nerve agent that poses a serious threat to human health, necessitating the development of appropriate sensing technologies. Dimethyl methylphosphonate (DMMP), which has a chemical structure similar to that of sarin but is non-toxic, is often used as a simulation agent in related research. Among promising gas-sensing materials, CuFe2O4exhibits suitable thermal stability. It is easily produced and has low toxicity. Its performance can be enhanced using heterogeneous ion doping to increase the number of surface defects and content of adsorbed oxygen. Therefore, a solvothermal method was adopted in this study to prepare CuFe2O4hollow microspheres that were subsequently doped with different ratios of Sn4+or Sn2+. Detailed characterizations of the obtained materials were conducted, and the corresponding CuFe2O4-based gas sensors were fabricated. Their gas-sensing performance against DMMP was studied to analyze and discuss the gas-sensing and sensitization mechanisms associated with Sn4+and Sn2+doping. The CuFe2O4-based sensor doped with 2 mol% Sn2+exhibited excellent gas-sensing performance in response to a 1 ppm concentration of DMMP, with response and recovery times of 12 and 63 s, respectively. Notably, its response to 1 ppm DMMP (16.27) was 3.3-fold higher than that to 1 ppm 2-CEES (4.98). The doped CuFe2O4sensor exhibited superior response–recovery characteristics and enhanced moisture resistance compared to the undoped sensor.