Layered MoTe2/ZnO heterojunctions for sensitive TEA sensors at room temperature

The morphology of layer stacked MoTe 2 was adjusted by the liquid phase exfoliated method, and the MoTe 2 /ZnO heterojunctions were further prepared to enhance the gas sensing performance of MoTe 2 -based sensor to triethylamine (TEA) gas. The MoTe 2 /ZnO heterojunction sensor displayed a high response of 91.9% to 10 ppm TEA at room temperature, which is approximately 3.53 times that of the pure MoTe 2 sensor (26.02%). The construction of the MoTe 2 /ZnO heterojunction also enhanced the selectivity and the recovery rate of TEA gas. The sensor mechanism of TEA gas was analyzed by using AC impedance spectroscopy, in-situ diffuse reflectance infrared Fourier transformations spectroscopy (DRIFTS), and density functional theory (DFT). It was found that the improvement of gas sensing performance was mainly due to the formation of a heterojunction structure, which increased the adsorption energy and charge transfer between TEA gas and the sensing material.