Oxygen plasma treatment to enhance the gas-sensing performance of ZnO to N-methyl pyrrolidone: Experimental and computational study

N-methyl pyrrolidone (NMP) is an important organic compound that is widely used in many industrial fields. Due to its volatility and toxicity, the detection of NMP content becomes crucial. Plasma treatment is an efficient method that utilizes high-energy ions generated by plasma to change the surface properties of materials, which can dramatically improve the performance of gas sensors. In this paper, ZnO nanorods were in-situ grown on ceramic tubes via hydrothermal method, followed by oxygen plasma treatment for different time, and the gas-sensing performance of the treated ZnO nanorods was investigated. In addition, the density functional theory calculation was used to explore the potential mechanism for the improvement of gas-sensing performance. The results show that ZnO treated with oxygen plasma for 60 s has more oxygen vacancies (45.53 %) and higher adsorption energy (−1.06 eV) to NMP. The ZnO-60 gas sensors have excellent selectivity to 100 ppm NMP at 210 °C, with a response value up to 197.58, low detection limit (94 ppb), and short response/recovery time (75 s/27 s). This study not only provides important theoretical and experimental basis for further optimizing the design and manufacture of gas sensors, but also provides strong support for environmental monitoring and human health protection.