Posted in | News | Nanosensors

Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor

1D nanowires are of tremendous relevance for gas-sensing technologies due to their large surface-to-volume ratio and efficient electronic transportation routes. In an article published in the journal ACS Applied Nano Materials, colloidal solvothermal synthesis of super-thin palladium nanowires (PdNWs) has been reported for use in rapid, sensitive Hsensor devices. 

Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor

Study: Ultrathin Palladium Nanowires for Fast and Hysteresis-Free H2 Sensing. Image Credit: Alexander Limbach/

The Undeniable Importance of Hydrogen Sensing

Hydrogen (H2) is a colorless, tasteless gas with a large energy density frequently regarded as a more environmentally friendly and renewable substitute to traditional power sources like fossil fuels. As such, hydrogen is often placed at the heart of a futuristic energy systems where it answers any and all power demands ranging from transport to household heating and electric power production.

Hydrogen is, however, an extremely combustible element with a smaller explosive threshold of 4 % in the atmosphere, a lower igniting energy, and a high penetration through various substances. Sensory technologies that detect hydrogen quickly and reliably are necessary because of its extremely combustible nature and tendency to generate an explosive combination in air. Such detectors ought to be power efficient, minimal in expense, and most significantly, capable of detecting hydrogen in a timely and dependable manner.

Palladium-based Chemiresistive Sensors are the Hydrogen Sensors of Choice

Although not every single criterion for hydrogen detectors have been set, significant endeavors have been made to meet the goal of one second reaction period to 1% hydrogen. So far, some optical hydrogen detectors have managed to achieve this but their the total cost of constructing optical hydrogen detectors remains expensive.

Chemiresistive detectors are favored over other forms of hydrogen detectors due to their inexpensive price and simplicity of production, and also their easy-to-read outputs. Among chemiresistive sensing elements, palladium (Pd) is favored for ambient temperature hydrogen sensing due to its distinctive capability to reversibly and selectively produce PdHx in the presence of hydrogen at ambient settings.

What is the Best Synthesis Method for One-Dimensional Nanowires for H2 Sensing?

1D nanowires offer considerable benefits for gas-sensing technologies. Although earlier identified lithography-synthesized palladium nanowires (PdNWs) for hydrogen detection have an increased surface-to-volume ratio and excellent electrical characteristics, they do not inherently possess high catalytic activity and may necessitate additional adjustments to enhance their output. Furthermore, the size of lithographically manufactured palladium nanowires is constrained by manufacturing capacities, which restricts their capability.

The lithographic synthesis of palladium nanowires with diameters of <10 nm, for example, remains a difficult and costly job.

Palladium nanowires with extremely large aspect ratios and tiny diameters may be created via solution-phase synthesis. Nonetheless, they are frequently topped with ligands or surfactants that are hard to detach and impair overall sensing capabilities. An ozone-generating ultraviolet (UVO) source of light is an efficient method of eliminating ligands from the exterior of nanomaterials, which might reveal active spots for quick hydrogen breakdown and sensing and lower contact impedance at nanowire connections.

Key Findings of the Study

In this study, the researchers described a simple and sustainable solvothermal fabrication of extremely thin palladium nanowires (diameters from 3 to 5 nm).

The nanostructures then underwent UVO treatment to remove any organic ligands that had been bound to their exterior. UVO-treated palladium nanowires were distributed in toluene to make a nano-ink, which was then utilized to construct a detector on an IDE using a straightforward drop-cast approach.

The resultant sensor demonstrated hysteresis-free and rapid reaction to 1% hydrogen in air, with reaction and recovering durations of 3.4 and 11 seconds, respectively, as well as strong durability and consistency through repeated rounds of exposure to 1% hydrogen in the atmosphere.

The sensor detected 1 to 0.1 percent hydrogen in air throughout a wide span of temperatures (15 to 80 °C) and demonstrated remarkable specificity of responsiveness to hydrogen when compared to equivalent amounts of CO, CH4, and CO2. The sensor's excellent functionality might be ascribed to its ligand-free exterior, extremely thin diameter, and the existence of catalysis hot spots caused by lattice strain at the PdNWs' twin borders.


Kumar, A., Thundat, T., & Swihart, M. T. (2022). Ultrathin Palladium Nanowires for Fast and Hysteresis-Free H2 Sensing. ACS Applied Nano Materials. Available at:

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Shaheer Rehan

Written by

Shaheer Rehan

Shaheer is a graduate of Aerospace Engineering from the Institute of Space Technology, Islamabad. He has carried out research on a wide range of subjects including Aerospace Instruments and Sensors, Computational Dynamics, Aerospace Structures and Materials, Optimization Techniques, Robotics, and Clean Energy. He has been working as a freelance consultant in Aerospace Engineering for the past year. Technical Writing has always been a strong suit of Shaheer's. He has excelled at whatever he has attempted, from winning accolades on the international stage in match competitions to winning local writing competitions. Shaheer loves cars. From following Formula 1 and reading up on automotive journalism to racing in go-karts himself, his life revolves around cars. He is passionate about his sports and makes sure to always spare time for them. Squash, football, cricket, tennis, and racing are the hobbies he loves to spend his time in.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Rehan, Shaheer. (2022, April 11). Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor. AZoNano. Retrieved on May 18, 2024 from

  • MLA

    Rehan, Shaheer. "Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor". AZoNano. 18 May 2024. <>.

  • Chicago

    Rehan, Shaheer. "Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor". AZoNano. (accessed May 18, 2024).

  • Harvard

    Rehan, Shaheer. 2022. Ultrathin Nanowires Boost Speed of Response in H2 Gas Sensor. AZoNano, viewed 18 May 2024,

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Your comment type

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.