Fabrication of Pd-decorated TiO2/MoS2 ternary nanocomposite for enhanced benzene gas sensing performance at room temperature

Abstract

A high-performance benzene gas sensor based on Pd-decorated TiO2/MoS2 ternary nanocomposite was demonstrated in this paper. The morphologies, microstructures and composition of the Pd-TiO2/MoS2 nanocomposite were sufficiently examined by X-ray diffraction (XRD), energy dispersive spectrometer (EDS), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS), confirming its successful preparation and reasonability. The benzene-sensing performances of the Pd-TiO2/MoS2 sensor were investigated upon exposure to various concentrations of benzene vapor from 100 ppb to 100 ppm at room temperature. The experimental results showed that the sensor has a high response, short response-recovery time, good repeatability and selectivity toward benzene gas, which is largely superior to that of the pure TiO2 and MoS2 sensors. In addition, the influence of Pd loading in the nanocomposite on the benzene-sensing was investigated. The sensing mechanism of the Pd-TiO2/MoS2 sensor was attributed to the synergistic effect of the ternary nanostructures, combining the modulation of potential barrier with electron transfer. This work indicates that the synthesized Pd-TiO2/MoS2 ternary nanocomposite is an excellent candidate for constructing high-performance benzene sensor for various applications.