Paper-Based Hydrogen Sensors Using Ultrathin Palladium Nanowires

Abstract

Hydrogen (H2), as a chemical energy carrier, is a cleaner alternative to conventional fossil fuels with zero carbon emission and high energy density. The development of fast, low-cost, and sensitive H2 detection systems is important for the widespread adoption of H2 technologies. Paper is an environment-friendly, porous, and flexible material with great potential for use in sustainable electronics. Here, we report a paper-based sensor for room-temperature H2 detection using ultrathin palladium nanowires (PdNWs). To elucidate the sensing mechanism, we compare the performance of polycrystalline and quasi-single-crystalline PdNWs. The polycrystalline PdNWs showed a response of 4.3% to 1 vol % H2 with response and recovery times of 4.9 and 10.6 s, while quasi-single-crystalline PdNWs showed a response of 8% to 1 vol % H2 with response and recovery times of 9.3 and 13.0 s, respectively. The polycrystalline PdNWs show excellent selectivity, stability, and sensitivity, with a limit of detection of 10 ppm H2 in air. The fast response of ultrathin polycrystalline PdNW paper-based sensors arises from the synergistic effects of their ultrasmall diameter, high-index surface facets, strain-coupled grain boundaries, and porous paper substrate. This paper-based sensor is one of the fastest chemiresistive H2 sensors reported and is potentially orders of magnitude less expensive than current state-of-the-art H2-sensing solutions. This brings low-cost, room-temperature chemiresistive H2 sensing closer to the performance of ultrafast optical sensors and high-temperature metal oxide-based sensors.

Review—Recent Progress in the Design of Chemical Hydrogen Sensors

“…4. 64 They compared the performance of polycrystalline and quasi-single-crystalline PdNWs in order to better understand the sensing mechanism. The polycrystalline PdNWs exhibited a 4.3% to 1 vol% hydrogen response, with recovery times of 4.9 and 10.6 s, whereas the quasi-single-crystalline PdNWs displayed an 8% to 1 vol% hydrogen response, with response and recovery times of 9.3 and 13.0 s, respectively.…”

Paper-based sustainable biosensors

“…68,69 Herein, paper-based devices provide multipurpose, inexpensive, and accurate systems for sensing humidity, gases, chemicals, strain, and biological species. 10,[69][70][71][72] However, it is difficult to simplify a set of characteristics of papers due to the differences in their material compositions, structures, and fabrication methods. For example, printing paper is composed of a high filler content, which can be either natural (e.g., limestone, talc, and clay) or synthetic…”

“…The use of paper as a flexible, porous, and degradable cellulosic material with an environment-friendly nature has shown great potential to be applied in sustainable biosensors, bioelectronics and other areas. 68,69 Herein, paper-based devices provide multipurpose, inexpensive, and accurate systems for sensing humidity, gases, chemicals, strain, and biological species. 10,[69][70][71][72] However, it is difficult to simplify a set of characteristics of papers due to the differences in their material compositions, structures, and fabrication methods.…”

“…68,69 Herein, paper-based devices provide multipurpose, inexpensive, and accurate systems for sensing humidity, gases, chemicals, strain, and biological species. 10,[69][70][71][72] However, it is difficult to simplify a set of characteristics of papers due to the differences in their material compositions, structures, and fabrication methods. For example, printing paper is composed of a high filler content, which can be either natural (e.g., limestone, talc, and clay) or synthetic alternatives (e.g., precipitated calcium carbonate, gypsum, and titanium dioxide) and distinguish the cost, thickness, structure, pore size, strength, and exterior form of the paper, and other characteristics based on its type and quantity.…”

Ultrafast (∼0.6 s), Robust, and Highly Linear Hydrogen Detection up to 10% Using Fully Suspended Pure Pd Nanowire

“…To selectively detect hydrogen, palladium (Pd) has been known as the most appealing sensing material due to its reversible reactivity to hydrogen, − forming palladium hydride (PdH x ). However, the fundamental issue in Pd associated with the phase transition of PdH x , depending on hydrogen concentration and catalytic property, has been a critical impediment to satisfy the requirements of a fast response time , as well as measurement range − and robustness. ,, Material-oriented approaches such as alloying with other metals − and Pd-based compounds − have been exploited to reduce activation energy to advance response speed, and the resulting PdAu , and PdTa nanoparticles were able to optically detect hydrogen with a subsecond response time.…”