Scientists have developed a new class of gas sensors using bismuth sulfide (Bi2S3) that can detect hazardous gases with greater sensitivity and selectivity at room temperature—an advance that could improve safety in industrial, environmental, and medical settings.
Study: Recent Progress with Bismuth Sulfide for Room-Temperature Gas Sensing. Image Credit: Rainer Fuhrmann/Shutterstock.com
A recent article in the journal Chemosensors offers a detailed review of the latest progress in gas sensors based on bismuth sulfide Bi2S3. The paper highlights the growing importance of these sensors in detecting hazardous gases across a range of fields—including agriculture, industry, food safety, and medical diagnostics. With the ability to monitor toxic gases such as nitrogen dioxide (NO2), hydrogen sulfide (H2S), and volatile organic compounds (VOCs), these sensors play a vital role in maintaining safe environments and mitigating risks linked to gas leaks.
The review also emphasizes the expanding use of gas sensors in emerging applications like smart home systems and wearable technology. The authors focus on the design, optimization, and potential research pathways for Bi2S3, positioning it as a promising material for the next generation of gas sensing technologies.
Background
The paper explores the structural and functional properties of Bi2S3, underscoring its potential for detecting toxic gases. Bi2S3 stands out for its semiconducting nature, high surface area, and adaptability at the nanoscale—features that enhance its sensing performance. However, limitations such as reduced gas adsorption due to nanostructure aggregation can hinder sensor efficiency.
To address these challenges, researchers have proposed several strategies, including morphological design, defect engineering, and the development of heterostructures. These approaches aim to tailor the properties of Bi2S3 to improve sensitivity, selectivity, and overall sensor reliability.
Current Strategies
The article outlines several methods for enhancing the room-temperature sensing capabilities of Bi2S3. A key approach is morphological design, which involves modifying the material’s physical structure using different synthesis techniques. By creating nanowires, nanobelts, nanorods, and nanosheets, scientists can increase the surface area and number of active sites for gas interaction. However, issues like restacking and aggregation of these nanostructures can reduce their effectiveness.
To mitigate these drawbacks, researchers have developed hierarchical nanostructures. These complex architectures offer greater surface accessibility and improve gas diffusion and adsorption. Techniques such as self-assembly and advanced synthesis have been employed to build these optimized nanoarchitectures.
Another promising avenue is defect engineering. By deliberately introducing sulfur vacancies and other structural defects, researchers can enhance electron transfer in Bi2S3 films, increasing the density of active sites. This directly improves sensitivity and shortens response and recovery times—particularly in detecting gases like NO2.
The construction of heterostructures—where Bi2S3 is combined with other materials—is also showing encouraging results. These hybrid structures improve charge carrier separation and introduce additional active sites, leading to better selectivity and sensitivity for target gases such as NO2 and H2S.
Results and Discussion
The review underscores substantial improvements in Bi2S3-based gas sensors in terms of sensitivity, selectivity, response speed, and long-term stability. Experimental findings show that hierarchical structures significantly enhance performance, especially for NO2 detection. Carefully designed morphologies and defect-introduced materials exhibit faster response times while maintaining high sensitivity.
The paper also explores the link between Bi2S3’s structural features and its ability to differentiate between gases. While Bi2S3 shows strong responsiveness to both NO2 and H2S, its similar reaction to each presents a challenge in mixed-gas environments, where distinguishing between gases becomes critical. This limitation calls for deeper investigation into ways to boost selectivity.
The authors point to the need for a better understanding of how Bi2S3 interacts with different gases. Gaining more insight into these interactions could help design sensors that more accurately identify and quantify specific gases, minimizing false positives and improving reliability in real-world applications.
Conclusion
Recent progress in Bi2S3-based gas sensors reflects meaningful advances in material science and sensor engineering. Techniques such as morphological tuning, defect creation, and heterostructure development have all contributed to improved sensor performance in terms of sensitivity, selectivity, and durability. Bi2S3 clearly holds promise for future gas-sensing technologies across a range of fields.
Still, challenges remain—particularly when it comes to reliably distinguishing between gases like NO2 and H2S in complex environments. Addressing these limitations through continued research will be essential to fully realize the practical potential of Bi2S3-based sensors.
Journal Reference
Ma R., Lei H., et al. (2025). Recent Progress with Bismuth Sulfide for Room-Temperature Gas Sensing. Chemosensors 13(4):120. DOI: 10.3390/chemosensors13040120, https://www.mdpi.com/2227-9040/13/4/120