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

Fe-2(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 Fe-2(MoO4)(3) microspheres distributed among MXene layers, and were featured with high specific surface area (47.0 m(2)/g). MXene played a crucial role in the hydrothermal process, which might facilitate the preferential crystal growth of Fe-2(MoO4)(3)and restrain the agglomeration of Fe-2(MoO4)(3)nanosheets. Compared with pure Fe-2(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. (C) 2019 Elsevier B.V. All rights reserved.