Low temperature synthesis of plasmonic molybdenum nitride nanosheets for surface enhanced Raman scattering

Molybdenum nitride (δ-MoN) is an important functional material due to its impressive catalytic, energy storage, and superconducting properties. However, the synthesis of δ-MoN usually requires extremely harsh conditions; thus, the insight into δ-MoN is far behind that of oxides and sulfides of molybdenum. Herein, we report that ultrathin δ-MoN nanosheets are prepared at 270 °C and 12 atm. WN, VN, and TiN nanosheets are also synthesized by this method. The δ-MoN nanosheets show strong surface plasmon resonance, high conductivity, excellent thermal and chemical stability as well as a high photothermal conversion efficiency of 61.1%. As a promising surface enhanced Raman scattering substrate, the δ-MoN nanosheets exhibit a 8.16 × 10⁶ enhanced factor and a 10^-10 level detection limit for polychlorophenol.