摘要
The development of effective detection methods for nitrogen reduction reaction (NRR) products remains hindered by complex procedures, reagent instability, and limited sensitivity caused by the typically low ammonia yield. To overcome these limitations, a Janus WSSe/WS₂ heterostructure-based surface enhanced Raman spectroscopy (SERS) platform for rapid and sensitive detection of electrochemical ammonia products is developed. The heterostructure is synthesized using a chemical vapor reaction (CVR) method, achieving large-area, uniform thin films with asymmetric chalcogen coordination, overcoming the scalability limitations of conventional SERS platforms. This structural asymmetry induces a built-in electric field, enhancing charge transfer and molecular interactions at the surface. The resulting SERS platform demonstrates excellent detection performance, with a limit of 1 × 10−13 M for crystal violet and 5 nM for NH₄Cl, and a broad linear range up to 5 mM. Compared with traditional colorimetric methods, the Janus WSSe/WS₂ heterostructure-based SERS platform offers reagent-free, stable detection with faster response times. Importantly, there is strong agreement between SERS and traditional colorimetric assays, validating the practical applicability. This synergistic material-design–sensing strategy not only accelerates ammonia detection from hours to minutes but also provides a new way for integrating Janus TMD thin films into advanced, real-time molecular diagnostics for energy and environmental systems.
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•A large-area Janus WSSe/WS2 thin film synthesized by chemical vapor reaction is proposed for the direct detection of NRR products.•The Janus WSSe/WS2 heterostructure provides surface dipole for SERS enhancement.•The platform achieved a remarkable LOD of 1 × 10−13 M and 5 × 10−9 M for CV and ammonia chloride.