Large-Scale Nanofiber Manufacturing| Material design and mechanisminterpretation of metal oxidenanofibers for improving gassensitivity

Professor Wang Chunlan from Xi'an Polytechnic University & Professor Lu Hongbing from Shaanxi Normal University: Material Design Strategies for Enhancing Gas Sensitivity in Metal Oxide Nanofibers

High-performance multifunctional gas sensors developed from various morphologies of metal oxide nanomaterials play pivotal roles in industrial, medical, and firefighting applications. Notably, metal oxide nanofibers (MOx NFs) with high specific surface area, excellent porosity, and porous structures can effectively overcome traditional materials' shortcomings of poor sensing performance, long response time, and weak stability, making them crucial for gas sensing.

Recently, Professor Wang Chunlan from Xi'an Polytechnic University and Professor Lu Hongbing from Shaanxi Normal University reviewed material design strategies for enhancing gas sensitivity in MOx NFs, including: 

1) Metal/nonmetal doped/modified MOx NFs; 

2) MOx-based heterojunction NFs (MOx/MOx heterojunction NFs, MOF-based/MOx heterojunction NFs, MOF-based MOx/MOF-based MOx heterojunction NFs); 

3) 2D material/MOx heterojunction NFs (graphene/MOx heterojunction NFs, TMDs/MOx heterojunction NFs); 

4) Metal-doped/modified MOx-based heterojunction NFs; 

5) Special morphologies of MOx NFs (MOx aligned NFs, MOx/MOx Janus NFs, MOx/MOx core-shell NFs). The review particularly explains gas-sensing enhancement mechanisms for each material design system, aiming to deepen understanding of relationships between material design, sensing mechanisms, and performance through comprehensive research reports.

Despite significant progress, several scientific and practical challenges remain unresolved, pointing to future research directions: 

1) Exploring new materials (black phosphorus, MXene, crystalline/amorphous multi-metal oxides like InGaZnO) for constructing MOx NF heterostructures, and developing other NF morphologies like helical and cross-linked structures; 

2) Reducing operating temperatures while maintaining performance, especially for room-temperature air quality monitoring; 

3) Addressing humidity interference and other environmental factors (illumination, radiation, dust); 

4) Expanding detection to special gases like nerve agents and rare gases; 

5) Developing high-performance MOx NF sensors (FET-based, conductometric, chemicapacitive); 

6) Enhancing practical applications for indoor/outdoor/vehicle environmental monitoring, rapid disease detection through human-emitted trace gases, flexible wearables integrated into textiles, and food quality assessment for fruits, seafood, and meats.

In conclusion, with advancing material designs and sensing technologies, high-performance MOx NF-based gas sensors will undoubtedly open new frontiers in smart and wearable technologies, playing indispensable roles.