Enhanced gas sensing properties at low working temperature of iron molybdate/MXene composite

Fe2(MoO4)3/MXene nanocomposites were prepared via a single hydrothermal method. The structure, morphology and crystal phase of the composite samples were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption technique. The results indicated the nanocomposites were consisted of Fe2(MoO4)3 microspheres distributed among MXene layers, and were featured with high specific surface area (47.0 m2/g). MXene played a crucial role in the hydrothermal process, which might facilitate the preferential crystal growth of Fe2(MoO4)3 and restrain the agglomeration of Fe2(MoO4)3 nanosheets. Compared with pure Fe2(MoO4)3 microspheres, the synthesized composites showed higher gas response at lower working temperature. Moreover, the sensors based on the composites exhibited rapid response-recovery (18s and 24s), good reversibility and long-term stability. These excellent gas sensing performances were supposed to relate to its high surface area, unique structure and good conductivity of MXene.