School of Marine Sciences , Guangxi University , Nanning 530004 , China.
Guangxi Laboratory on the Study of Coral Reefs in the South China Sea , Nanning 530003 , China.
ACS Sens. 2020 Feb 28;5(2):571-579. doi: 10.1021/acssensors.9b02519. Epub 2020 Feb 17.
During the detection of industrial toxic gases, such as triethylamine (TEA), poor selectivity and negative humidity impact are still challenging issues. A frequently reported strategy is to employ molecular sieves or metal-organic framework (MOF) membranes so that interference derived from surrounding gases or water vapor can be blocked. Nevertheless, the decline in the response signal was also observed after coating these membranes. Herein, an alternative strategy that is based on a hydrophobic, TEA adsorption-selective p-n conjunction core-shell heterostructure is proposed and is speculated to simultaneously enhance selectivity, sensitivity, and humidity resistance. To verify the practicability of the proposed strategy, a thickness-tunable nitrogen-doped carbon (N-C) shell-coated α-FeO nano-olive (N-C@α-FeO NO)-based core-shell heterostructure that is obtained via a unique all-vapor-phase processing method is selected as the research example. After forming the core-shell heterostructure, a relatively hydrophobic and TEA adsorption-selective N-C@α-FeO NO surface was experimentally confirmed. Particularly, a chemiresistive sensor that comprises N-C@α-FeO NOs exhibits satisfactory selectivity and response magnitude to TEA when compared with the sensor using α-FeO NOs. The detection limit can even reduce to be 400 ppb at 250 °C. Furthermore, the sensor based on N-C@α-FeO NOs shows desirable humidity resistance within the relative humidity (RH) range of 30-90%. For practical usage, a sensing prototype based on the N-C@α-FeO NO probe is fabricated, and its satisfactory sensing performance further confirms the potential for future applications in industrial organic amine detection. These promising results show a bright future in enhancing the humidity resistance and selectivity as well as sensitivity of chemiresistive sensors by simply designing a hydrophobic and target gas adsorption (e.g., TEA) preferred p-n junction core-shell heterostructure.
在检测工业有毒气体（如三乙胺（TEA））时，选择性差和湿度影响仍是挑战。一种常见的策略是使用分子筛或金属-有机骨架（MOF）膜，以阻挡来自周围气体或水蒸气的干扰。然而，在涂覆这些膜后，也观察到响应信号下降。在此，提出了一种基于疏水性、TEA 吸附选择性 p-n 结核壳异质结构的替代策略，据推测可同时提高选择性、灵敏度和抗湿度能力。为了验证所提出策略的实用性，选择了通过独特的全气相处理方法获得的厚度可调氮掺杂碳（N-C）壳涂覆的α-FeO 纳米橄榄（N-C@α-FeO NO）基核壳异质结构作为研究示例。形成核壳异质结构后，实验证实形成了相对疏水性和 TEA 吸附选择性的 N-C@α-FeO NO 表面。特别是，与使用α-FeO NO 的传感器相比，包含 N-C@α-FeO NOs 的化学电阻传感器对 TEA 表现出令人满意的选择性和响应幅度。在 250°C 时，检测限甚至可以降低到 400 ppb。此外，基于 N-C@α-FeO NOs 的传感器在相对湿度（RH）范围为 30-90%时表现出良好的抗湿度能力。为了实际使用，基于 N-C@α-FeO NO 探头的传感原型被制造，其令人满意的传感性能进一步证实了其在工业有机胺检测中的未来应用潜力。这些有希望的结果表明，通过简单设计疏水性和目标气体吸附（例如 TEA）优先的 p-n 结核壳异质结构，可以提高化学电阻传感器的湿度、选择性和灵敏度。
