Ma Jun, Zhou Yanglin, Bai Xue, Chen Kai, Guan Bai-Ou
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 511443, China.
Nanoscale. 2019 Aug 29;11(34):15821-15827. doi: 10.1039/c9nr04274a.
The safe utilization of hydrogen as a clean fuel and industry material requires the reliable detection of a gas leakage; thus, hydrogen sensors with high sensitivity and fast response are in urgent demand. Among various hydrogen detection techniques, optical hydrogen sensors are especially attractive because of their intrinsic safety. Herein, by integrating an optical fiber with a suspended palladium (Pd)-decorated graphene, we demonstrate a fiber-optic hydrogen sensor with fast-response that is sensitive, compact and capable of remote detection. The suspended Pd-decorated graphene, attached to the optical fiber tip with an air cavity, forms a flexible Fabry-Pérot interferometer. Upon hydrogen absorption, the ultrathin Pd film facilitates a fast hydrogen dissociation and the ultrathin graphene enables an effective conversion of the Pd lattice expansion to Pd/graphene film displacement, which can be readily measured by fiber-optic interferometery. With a hybrid film of ∼5.6 nm-thick Pd and ∼3 nm-thick suspended graphene, a low detection limit of ∼20 parts per million (ppm) and a short response time of ∼18 s have been achieved. In addition to providing a compact and all-optical solution to sensitive and fast-response hydrogen detection, the rationally-designed sensor can be used for diverse chemical/gas sensing applications by replacing Pd with other functional materials.
将氢气作为清洁燃料和工业材料安全使用需要可靠地检测气体泄漏；因此，迫切需要高灵敏度和快速响应的氢气传感器。在各种氢气检测技术中，光学氢气传感器因其本质安全性而特别具有吸引力。在此，通过将光纤与悬浮的钯（Pd）修饰的石墨烯集成，我们展示了一种具有快速响应的光纤氢气传感器，该传感器灵敏、紧凑且能够进行远程检测。悬浮的Pd修饰的石墨烯通过空气腔附着在光纤尖端，形成一个灵活的法布里 - 珀罗干涉仪。在吸收氢气时，超薄的Pd膜有助于快速的氢解离，超薄的石墨烯能够将Pd晶格膨胀有效地转化为Pd/石墨烯膜的位移，这可以通过光纤干涉测量法轻松测量。对于约5.6纳米厚的Pd和约3纳米厚的悬浮石墨烯的混合膜，已实现约20百万分之一（ppm）的低检测限和约18秒的短响应时间。除了为灵敏和快速响应的氢气检测提供紧凑的全光学解决方案外，通过用其他功能材料替代Pd，这种合理设计的传感器还可用于各种化学/气体传感应用。
