Rapid-response Ti3C2 MXene@Sulfur nanosheet composite for resistive ammonia sensing

The development of rapid, sensitive ammonia (NH 3 ) sensors is crucial for emergency response as NH 3 poses serious health risks. We report a high-performance chemiresistive sensor based on Ti 3 C 2 MXene@sulfur nanosheet (MXene@S-NSs) composites that addresses the conductivity limitations of pure S-NSs. The composite combines MXene’s excellent conductivity with S-NSs’ semiconductor properties to create room-temperature NH 3 sensors with exceptional performance: 3 ppt detection limit, 375 % response signal, and remarkably fast response/recovery times of 5 s/4s − representing a significant improvement over pure S-NSs sensors. This enhancement arises from optimized charge transport through p-n heterojunctions and sulfur vacancies in the composite structure. The MXene@S-NSs material demonstrates outstanding sensitivity, stability, and response speed, making it particularly suitable for emergency NH 3 monitoring applications. This work not only presents a practical sensor solution but also establishes an effective materials design strategy for developing next-generation gas sensors through rational 2D material hybridization. The successful integration of MXene and S-NSs provides a blueprint for creating advanced sensing materials with tailored electronic properties and performance characteristics.