Li Zhi, Xiao Yongguang, Liu Fu, Yan Xiangyu, You Daotong, Li Kaiwei, Zeng Lixi, Zhu Mingshan, Xiao Gaozhi, Albert Jacques, Guo Tuan
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou, 511443, China.
Guangdong Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou, Guangdong, 511443, China.
Light Sci Appl. 2022 Jul 13;11(1):220. doi: 10.1038/s41377-022-00914-5.
In situ and continuous monitoring of thermal effects is essential for understanding photo-induced catalytic processes at catalyst's surfaces. However, existing techniques are largely unable to capture the rapidly changing temperatures occurring in sub-μm layers at liquid-solid interfaces exposed to light. To address this, a sensing system based on a gold-coated conventional single-mode optical fiber with a tilted fiber Bragg grating inscribed in the fiber core is proposed and demonstrated. The spectral transmission from these devices is made up of a dense comb of narrowband resonances that can differentiate between localized temperatures rapid changes at the catalyst's surface and those of the environment. By using the gold coating of the fiber as an electrode in an electrochemical reactor and exposing it to light, thermal effects in photo-induced catalysis at the interface can be decoded with a temperature resolution of 0.1 °C and a temporal resolution of 0.1 sec, without perturbing the catalytic operation that is measured simultaneously. As a demonstration, stable and reproducible correlations between the light-to-heat conversion and catalytic activities over time were measured for two different catalysis processes (linear and nonlinear). These kinds of sensing applications are ideally suited to the fundamental qualities of optical fiber sensors, such as their compact size, flexible shape, and remote measurement capability, thereby opening the way for various thermal monitoring in hard-to-reach spaces and rapid catalytic reaction processes.
原位和连续监测热效应对于理解催化剂表面的光致催化过程至关重要。然而，现有技术在很大程度上无法捕捉在暴露于光的液-固界面亚微米层中快速变化的温度。为了解决这个问题，提出并展示了一种基于涂有金的传统单模光纤的传感系统，该光纤的纤芯中刻有倾斜的光纤布拉格光栅。这些器件的光谱传输由密集的窄带共振梳组成，能够区分催化剂表面局部温度的快速变化和环境温度的变化。通过将光纤的金涂层用作电化学反应器中的电极并使其暴露于光下，可以在不干扰同时测量的催化操作的情况下，以0.1°C的温度分辨率和0.1秒的时间分辨率解码界面光致催化中的热效应。作为示例，针对两种不同的催化过程（线性和非线性）测量了光热转换与催化活性随时间的稳定且可重复的相关性。这类传感应用非常适合光纤传感器的基本特性，如紧凑的尺寸、灵活的形状和远程测量能力，从而为在难以到达的空间进行各种热监测和快速催化反应过程开辟了道路。
