Wang Wenhao, Zhang Lu, Kang Yanli, Yu Feng
Key Laboratory for Green Processing of Chemical Engineering of Xinjiang Bingtuan, School of Chemistry and Chemical Engineering, Shihezi University, Shihezi 832003, China.
Harbin Institute of Technology, School of Science, Shenzhen 518055, China.
Nanomaterials (Basel). 2021 Nov 30;11(12):3261. doi: 10.3390/nano11123261.
(1) Background: Toluene gas is widely used in indoor decoration and industrial production, and it not only pollutes the environment but also poses serious health risks. (2) Methods: In this work, TiO-CoFeO-Ag quaternary composite gas-sensing material was prepared using a hydrothermal method to detect toluene. (3) Results: The recombination of electron-hole pairs was suppressed, and the light absorption range was expanded after constructing a heterojunction and doping with Ag, according to ultraviolet-visible (UV-vis) diffuse reflectance spectra and photoluminescence spectroscopy. Moreover, in the detection range of toluene gas (3 ppm-50 ppm), the response value of TiO-CoFeO-Ag increased from 2 to 15, which was much higher than that of TiO-Ag (1.7) and CoFeO-Ag (1.7). In addition, the working temperature was reduced from 360 °C to 263 °C. Furthermore, its response/recovery time was 40 s/51 s, its limit of detection was as low as 10 ppb, and its response value to toluene gas was 3-7 times greater than that of other interfering gases under the same test conditions. In addition, the response value to 5 ppm toluene was increased from 3 to 5.5 with the UV wavelength of 395 nm-405 nm. (4) Conclusions: This is primarily due to charge flow caused by heterojunction construction, as well as metal sensitization and chemical sensitization of novel metal doping. This work is a good starting point for improving gas-sensing capabilities for the detection of toluene gas.
(1) 背景：甲苯气体广泛应用于室内装饰和工业生产，它不仅污染环境，还会带来严重的健康风险。(2) 方法：在本研究中，采用水热法制备了TiO-CoFeO-Ag四元复合气敏材料用于检测甲苯。(3) 结果：根据紫外可见（UV-vis）漫反射光谱和光致发光光谱，构建异质结并掺杂Ag后，电子-空穴对的复合受到抑制，光吸收范围扩大。此外，在甲苯气体检测范围（3 ppm - 50 ppm）内，TiO-CoFeO-Ag的响应值从2增加到15，远高于TiO-Ag（1.7）和CoFeO-Ag（1.7）。此外，工作温度从360℃降至263℃。而且，其响应/恢复时间为40 s/51 s，检测限低至10 ppb，在相同测试条件下对甲苯气体的响应值比其他干扰气体大3 - 7倍。另外，在395 nm - 405 nm的紫外波长下，对5 ppm甲苯的响应值从3增加到5.5。(4) 结论：这主要归因于异质结构建引起的电荷流动，以及新型金属掺杂的金属敏化和化学敏化。这项工作是提高甲苯气体检测气敏性能的良好开端。
