Highly Sensitive Hydrogen Sensor Based on an Optical Driven Nanofilm Resonator

• Published in: ACS applied materials & interfaces Vol. 14; no. 25; pp. 29357 - 29365
• Main Authors: Luo, Junxian, Liu, Shen, Chen, Peijing, Chen, Yanping, Zhong, Junlan, Wang, Yiping
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 29.06.2022
• Subjects: Surfaces, Interfaces, and Applications; palladium; hydrogen sensor; optomechanical resonator; optical fiber sensor; nanofilm
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.2c04105

Nanofilm resonators combine ultracompact and highly mechanically sensitive properties, making them intriguing devices for sensing applications. For trace hydrogen detection, we demonstrate an optomechanical nanofilm resonator by employing a Pd- and Au-decorated graphene onto a fiber end facet. The Pd layer is a sensitive layer for selective absorption of hydrogen. Hydrogen sensing is achieved by all-optical measuring of the resonant frequencies shift of the optomechanical nanofilm resonator induced by hydrogen-related mechanical stress change. Using the approach, we realize highly sensitive hydrogen sensing at room temperature with a low detection limit, challenging the state-of-the-art. When the measured hydrogen concentration increases from 0 to 1000 ppm (v/v), the mechanical resonance frequencies of the sensor at 511.7 kHz, 1253.4 kHz, and 2231.7 kHz blue-shift by 100.4 kHz, 257.5 kHz, and 400.6 kHz, respectively. The response and recovery time are 120.3 and 91.3 s at a 1000 ppm hydrogen concentration. Such a sensor exhibits a low detection limit of 741 ppb and good repeatability in the measurement process, which makes the practical application of the sensor possible.