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℃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.

Zhi Li;Yongguang Xiao;Fu Liu;Xiangyu Yan;Daotong You;Kaiwei Li;Lixi Zeng;Mingshan Zhu;Gaozhi Xiao;Jacques Albert;Tuan Guo

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;Department of Electronics,Carleton University,Ottawa K1S 5B6,Canada;Advanced Electronics and Photonics Research Center,National Research Council of Canada,Ottawa K1A 0R6,Canada;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519000,China

光：科学与应用（英文版）

[1]Zhi Li;Yongguang Xiao;Fu Liu;Xiangyu Yan;Daotong You;Kaiwei Li;Lixi Zeng;Mingshan Zhu;Gaozhi Xiao;Jacques Albert;Tuan Guo-.Operando optical fiber monitoring of nanoscale and fast temperature changes during photo-electrocatalytic reactions)[J].光：科学与应用（英文版）,2022(09):2086-2097

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