Recent Advances in Optical Hydrogen Sensor including Use of Metal and Metal Alloys: A Review

Abstract

Optical sensing technologies for hydrogen monitoring are of increasing importance in connection with the development and expanded use of hydrogen and for transition to the hydrogen economy. The past decades have witnessed a rapid development of optical sensors for hydrogen monitoring due to their excellent features of being immune to electromagnetic interference, highly sensitive, and widely applicable to a broad range of applications including gas sensing at the sub-ppm range. However, the selection of hydrogen selective metal and metal alloy plays an important role. Considering the major advancements in the field of optical sensing technologies, this review aims to provide an overview of the recent progress in hydrogen monitoring. Additionally, this review highlights the sensing principles, advantages, limitations, and future development.

Critical Sensing Modalities for Hydrogen: Technical Needs and Status of the Field to Support a Changing Energy Landscape

“…Many of these methods are covered in a recent review. 93 In some cases these sensor designs are amenable to lithographic fabrication of waveguide devices that can also be integrated with light sources and detectors. In fact, recent advances in the integration of microphotonic elements such as waveguides, light sources and detectors in silicon-based electronics 94 should aid in packaging these sensors for commercial applications.…”

“…WO 3 is a classic absorption-based colorimetric sensor, where hydrogen reduction catalyzed by Pd causes a color change from colorless to blue. 106 Although this simple visual readout is desirable, sensitivities are generally low, and regeneration of the sensor requires elevated temperatures (∼200 °C) which may act as an ignition source above the hydrogen LEL. Similarly, limited examples exist in which palladium catalysts reduce organic dyes to produce visible color changes, however these transformations are not reversible and exhibit low detection limits.…”

“…There are a number of other interferometric sensing architectures including hollow fibers, fibers with discrete metal coatings, and waveguides fabricated on surfaces using lithography. Many of these methods are covered in a recent review . In some cases these sensor designs are amenable to lithographic fabrication of waveguide devices that can also be integrated with light sources and detectors.…”

Recent Developments in Sensor Technologies for Enabling the Hydrogen Economy

“…Many recent reviews on this topic are available in the literature. 52,[249][250][251][252][253] Sensors using different regions of the electromagnetic spectrum are available today for many gases. The different electromagnetic regions are: UV (200-400 nm), near-IR (700 nm-2.5 μm) or mid-IR (2.5-14 μm) and while UV radiation interacts to cause electronic transitions, IR radiation interacts with molecular vibrational and rotational states (mid-IR: fundamental; near-IR: overtone and combination).…”

A dual-band hydrogen sensor based on Tamm plasmon polaritons

“…When exposed to hydrogen gas, the surface of Pd metal adsorbs hydrogen molecules and decomposes them into hydrogen atoms. 42,43 Subsequently, these hydrogen atoms enter the interior of the Pd lattice, causing its expansion and forming PdH, thus changing the optical properties of Pd. 44,45 The optical properties of Pd to PdH can be calculated using the data on the refractive index (n) and extinction coefficient (k) of PdH after hydrogenation in ref.…”