Layer-by-layer assembled In2O3 nanocubes/flower-like MoS2 nanofilm for room temperature formaldehyde sensing

This paper reports a room-temperature formaldehyde gas sensor using layer-by-layer assembled indium oxide (In2O3) nanocube/flower-like molybdenum disulfide (MoS2) nanocomposite as sensing film. The In2O3/MoS2 nanofilm was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM) and Brunauer-Emmett-Teller (BET) measurement. The investigation of the In2O3/MoS2 nanofilm for formaldehyde vapor sensing was performed at room temperature. The experimental results showed that the gas sensing performances of In2O3/MoS2 nanofilm was superior to that of the In2O3 nanocube and MoS2 single counterparts, and high response, fast response/recovery time as well as outstanding repeatability was demonstrated. The enhanced sensing performance of the In2O3/MoS2 nanofilm was attributed to their unique nanostructure, high ratio of accessible sites for gas diffusion, and special interactions between the formaldehyde gas and the nanofilm.