Enhanced humidity sensing properties of SmFeO3-modified MoS2 nanocomposites based on the synergistic effect

The SmFeO3-modified MoS2 (SmFeO3@MoS2) nanocomposites are successfully synthesized by the electrospinning combining with a hydrothermal method. The SmFeO3, MoS2 and SmFeO3@MoS2 are characterized by the X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, and fabricated into humidity sensors to investigate its humidity sensing properties. The results show that the impedance variation of the SmFeO3@MoS2 humidity sensor is more than five orders of magnitude within the whole relative humidity (RH) range of 11% to 95% RH at 10 Hz, 100 times higher than that of the MoS2 humidity sensor (three orders of magnitude). The response and recovery times of the SmFeO3@MoS2 humidity sensor are 1.5 s and 29.8 s, which are greatly shorter than those of the SmFeO3 humidity sensor (10 s and 180 s). The maximum hesteresis of the SmFeO3@MoS2 humidity sensor is less than 2% RH. The enhanced humidity sensing properties of SmFeO3@MoS2, which are superior to those of SmFeO3 and MoS2, are ascribed to the synergistic effect between SmFeO3 and MoS2. The modification of the SmFeO3 on the MoS2 surface is proved to improve the properties of the MoS2 based humidity sensor and this work can provide an effective way to enhance humidity sensing properties of a sensor.