Li Jing, Xiang Yi, Ma Weibin, Fu Xinglan, Huang Yuehua, Li Guanglin
College of Engineering and Technology, Southwest University, Chongqing 400715, China.
College of Resources and Environment, Southwest University, Chongqing 400715, China.
Ecotoxicol Environ Saf. 2021 Nov 18;228:112995. doi: 10.1016/j.ecoenv.2021.112995.
Rapid and sensitive detection of mercury vapor is of great significance for environmental protection and human health. But the detection method enabling low detection limitation and rapid response at room temperature simultaneously has rarely been reported. In this work, we propose a gold particles decorated reduced graphene oxide sensor for mercury vapor detection. After adding the gold particles, the reduced graphene oxide sensors' response sensitivity increase by more than 16 times and the response time significantly decreases, which is far less below the results reported by others. The sensor performance improvement should attribute to the distribution of the decorated gold particles, which insert into the layered graphene sheets, as demonstrated by the SEM and XRD results. The increased layer spacing of graphene sheets is conductive to the faster entry/exit of mercury vapor and increases the effective sensing area of graphene. What's more, the first-principles calculation results confirm the mercury-philicity of gold particles, which also contributes to the increased sensitivity. We further test more performance of the gold particles decorated reduced graphene oxide sensor to mercury vapor, which shows a linear response, low detection limit and good repeatability. The proposed sensor shows rapid response/recovery (6/8 s), low detection limit (0.01 ng/mL), linear response, good repeatability and room temperature detection simultaneously, which shows great application potential for mercury vapor detection.
快速灵敏地检测汞蒸气对环境保护和人类健康具有重要意义。但是，同时具备低检测限和室温下快速响应的检测方法鲜有报道。在这项工作中，我们提出了一种用于汞蒸气检测的金颗粒修饰还原氧化石墨烯传感器。添加金颗粒后，还原氧化石墨烯传感器的响应灵敏度提高了16倍以上，响应时间显著缩短，远低于其他文献报道的结果。传感器性能的提升应归因于修饰的金颗粒的分布，扫描电子显微镜（SEM）和X射线衍射（XRD）结果表明，这些金颗粒插入到层状石墨烯片中。石墨烯片层间距的增加有利于汞蒸气更快地进入/逸出，并增加了石墨烯的有效传感面积。此外，第一性原理计算结果证实了金颗粒对汞的亲合性，这也有助于提高灵敏度。我们进一步测试了金颗粒修饰还原氧化石墨烯传感器对汞蒸气的更多性能，结果表明该传感器具有线性响应、低检测限和良好的重复性。所提出的传感器同时具备快速响应/恢复（6/8秒）、低检测限（0.01 ng/mL）、线性响应、良好的重复性以及室温检测能力，在汞蒸气检测方面展现出巨大的应用潜力。
