Cobalt-doped indium oxide/molybdenum disulfide ternary nanocomposite toward carbon monoxide gas sensing

This paper demonstrated a high-performance carbon monoxide (CO) gas sensor based on cobalt (Co)-doped indium oxide (In2O3) nanoparticles/molybdenum disulfide (MoS2) nanoflowers nanocomposite. Co-In2O3 nanoparticles were synthesized by a co-precipitation method, and flower-like MoS 2 was prepared by one-step hydrothermal route. Layer-by-layer self-assembly technique was employed to fabricate Co-In2O3/MoS2 film sensor on an epoxy substrate with interdigital electrodes. Scanning electron microscopy (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) were carried out to fully examine the morphology, microstructure, and elementary composition of the as-prepared samples. The CO-sensing characteristics of the Co-In2O3/MoS2 film sensor were systematically investigated under room temperature through exposing the sensor to various concentration of CO gas. The Co-In2O3/MoS2 sensor achieved high sensitivity, fast response/recovery speed, excellent repeatability and stable longterm stability. An approach of combining gas-sensing experiments with density-functional theory (DFT) simulation based on first-principle was used to further explore the CO-sensing mechanism of the Co-In2O3/MoS2 sensor. The Co2+ ion doping, and heterojunctions created at interfaces of Co-In2O3 and MoS2 were attributed to the high-performance CO sensing. (C) 2018 Elsevier B.V. All rights reserved.