She Xiaoyi, Yao Qiankun, Zou Qiushun, Yang Guowei, Shen Yang, Jin Chongjun
State Key Laboratory of Optoelectronic Materials and Technologies, Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices, School of Materials Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China.
ACS Appl Mater Interfaces. 2023 Mar 29;15(12):16244-16252. doi: 10.1021/acsami.2c22961. Epub 2023 Mar 20.
Hydrogen detection is crucial for the forthcoming hydrogen economy. Here, we present a visual, ultrasensitive, optical hydrogen sensor based on a tunable Fabry-Pérot (FP) resonator, which can fully release the volume expansion of palladium during hydrogenation and transfer this volume expansion into an optical signal. The FP resonator consists of a suspended polymethylmethacrylate/palladium (PMMA/Pd) bilayer on a gold (Au) square-hole array. The bottom of the gold square hole and hydrogen-sensitive PMMA/Pd bilayer form a dynamically tunable FP resonator. When hydrogen gas (H) is loaded, the hydrogen-induced lateral expanding stress concavely deforms the suspended bilayer downward to the substrate, narrowing the metal-air-metal gap at the center of the hole, and finally leading to a spectral blue shift. Our experimental results show a giant spectral shift of 279 nm with a reflectance variation of 57% on exposure to 0.6% H mixed with air. Such an ultrahigh optical response results in a significant color change, enabling visual hydrogen detection. In addition, the sensor has a H detection limit down to 0.1% and good recyclability. These advantages indicate that the sensor has excellent potential for hydrogen sensing applications.
氢气检测对于即将到来的氢经济至关重要。在此，我们展示了一种基于可调谐法布里 - 珀罗（FP）谐振器的可视化、超灵敏光学氢气传感器，该传感器能够在氢化过程中充分释放钯的体积膨胀，并将这种体积膨胀转化为光信号。FP谐振器由位于金（Au）方孔阵列上的悬浮聚甲基丙烯酸甲酯/钯（PMMA/Pd）双层组成。金方孔底部与氢敏感的PMMA/Pd双层形成一个动态可调的FP谐振器。当加载氢气（H）时，氢诱导的横向膨胀应力使悬浮双层向下凹形变形至基板，缩小孔中心处的金属 - 空气 - 金属间隙，最终导致光谱蓝移。我们的实验结果表明，在暴露于与空气混合的0.6% H时，光谱发生了279 nm的巨大偏移，反射率变化为57%。如此高的光学响应导致显著的颜色变化，实现了可视化氢气检测。此外，该传感器的氢气检测限低至0.
