Hu Huiyun, Liang Hongping, Fan Jincheng, Guo Lanpeng, Li Hao, de Rooij Nicolaas Frans, Umar Ahmad, Algarni Hamed, Wang Yao, Zhou Guofu
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China.
National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China.
ACS Appl Mater Interfaces. 2022 Mar 23;14(11):13186-13195. doi: 10.1021/acsami.1c20680. Epub 2022 Mar 11.
Formaldehyde (HCHO) sensing plays a critical role for indoor environment monitoring in smart home systems. Inspired by the unique hierarchical structure of cactus, we have prepared a ZnO/ANS-rGO composite for room-temperature (RT) HCHO sensing, through assembling hollow cactus-like ZnO nanorods with 5-aminonaphthalene-1-sulfonic acid (ANS)-modified graphene nanosheets in a facile and template-free manner. Interestingly, it was found that the ZnO morphology could be simply tuned from flower clusters to hollow cactus-like nanostructures, along with the increase of the reaction time during the assembly process. The ZnO/ANS-rGO-based sensors exhibited superior RT HCHO-sensing performance with an ultrahigh response (68%, 5 ppm), good repeatability, long-term stability, and an outstanding practical limit of detection (LOD: 0.25 ppm) toward HCHO, which is the lowest practical LOD reported so far. Furthermore, for the first time, a 30 m simulation test cabinet was adapted to evaluate the practical gas-sensing performance in an indoor environment. As a result, an instantaneous response of 5% to 0.4 ppm HCHO was successfully achieved in the simulation test. The corresponding sensing mechanism was interpreted from two aspects including high charge transport capability of ANS-rGO and the distinct gas adsorbability derived from nanostructures, respectively. The combination of a biomimetic hierarchical structure and supramolecular assembly provides a promising strategy to design HCHO-sensing materials with high practicability.
甲醛（HCHO）传感在智能家居系统的室内环境监测中起着关键作用。受仙人掌独特的分级结构启发，我们通过将空心仙人掌状ZnO纳米棒与5-氨基萘-1-磺酸（ANS）修饰的石墨烯纳米片以简便且无模板的方式组装，制备了用于室温（RT）HCHO传感的ZnO/ANS-rGO复合材料。有趣的是，发现在组装过程中随着反应时间的增加，ZnO的形态可以从花簇简单地调整为空心仙人掌状纳米结构。基于ZnO/ANS-rGO的传感器对HCHO表现出优异的室温传感性能，具有超高响应（68%，5 ppm）、良好的重复性、长期稳定性以及出色的实际检测限（LOD：0.25 ppm），这是迄今为止报道的最低实际检测限。此外，首次采用30米模拟测试柜来评估室内环境中的实际气敏性能。结果，在模拟测试中成功实现了对0.4 ppm HCHO的5%瞬时响应。相应的传感机制分别从ANS-rGO的高电荷传输能力和纳米结构衍生的独特气体吸附性两个方面进行了解释。仿生分级结构和超分子组装的结合为设计具有高实用性的HCHO传感材料提供了一种有前景的策略。
