Prof. Zhang’s team from the Harbin Institute of Technology published an in-depth study in the International Journal of Extreme Manufacturing on using single-atom catalysts in gas sensing, providing a novel technique to improve gas sensor performance.
This paper reviews the structure and principle of semiconductor-based gas sensors, the synthesis methods of single-atom catalysts, the mechanisms by which single-atom catalysts enhance gas sensitivity, and their applications in the field of gas sensing. Image Credit: Xinxin He, Ping Guo, Xuyang An, Yuyang Li, Jiatai Chen, Xingyu Zhang, Lifeng Wang, Mingjin Dai, Chaoliang Tan and Jia Zhang.
Gas sensors are frequently used in medical health, environmental monitoring, and food safety. However, contemporary gas sensors suffer several problems, including limited sensitivity, extended response and recovery periods, and baseline drift.
This review focuses on using single-atom catalysts in gas sensing. It specifically describes the structure and concepts of semiconductor-based gas sensors and the most recent single-atom catalyst preparation techniques.
It also examines how single-atom catalysts improve gas sensitivity from two angles, summarizing their performance in gas sensing.
Since the catalytic process of target gas molecules on the sensitive material is essential to the operation of gas sensors, single-atom catalysts, with their exceptional atomic utilization and distinct physicochemical properties, make them competitive candidates for gas-sensitive materials.
The majority of gas sensors work by observing how gas molecules interact with oxygen chemisorbed on the surface of the sensing material. This interaction alters the number of charge carriers in the sensing material’s conduction band, changing the material’s resistance.
The study's results indicate that interactions between individual atoms and gas molecules might enhance gas reactions on the surface of delicate materials. Furthermore, the heterogeneous structures that develop inside sensitive materials might significantly help in the electron transport that occurs within the sensing material. As a result, gas sensors based on single-atom catalysts can attain greater sensitivity and faster reaction times.
Currently, impregnation, co-precipitation, one-pot pyrolysis, atomic layer deposition, sacrificial template methods, methods derived from metal-organic frameworks (MOFs), etc., are among the synthesis techniques used to create single-atom catalysts.
Single atoms prefer to gather into clusters during the synthesis and utilization processes. To create single-atom catalysts with high loading and stability, the interaction between single atoms and supports must be improved by altering the coordination environment of single atoms, among other things.
Furthermore, selecting gas-sensitive materials for a specific gas depends on experimental data and lacks theoretical support. Investigating the methods by which single atoms improve gas sensing capability may aid in understanding active sites, laying the groundwork for the rational design of gas-sensitive materials.
As a gas-sensitive material, single-atom catalysts have low detection limits and great selectivity, making them a promising material with several applications. They are predicted to contribute significantly to improving the sensitivity and selectivity of gas sensors.
Furthermore, they are highly likely to aid in creating high-performance gas sensors that can operate in extreme situations such as low temperature, low pressure, and oxygen-free environments.
Journal Reference:
He, X., et. al. (2024) Preparation of single atom catalysts for high sensitive gas sensing. International Journal of Extreme Manufacturing. doi:10.1088/2631-7990/ad3316