Enhanced Gas Adsorption and Robust Multi-Interface Charge Transfer in Ternary Co₃O₄/ZnIn₂S₄/Pt Heterostructure Arrays for Efficient Triethylamine Detection

The resistive gas sensors based on semiconductor materials provide an effective strategy for the detection of harmful gases. However, the limitations of surface gas adsorption activity and interface charge transfer efficiency of semiconductor sensing materials, as well as the complex device fabrication process, pose significant challenges to the development of sensors. Here, a ternary Co₃O₄/ZnIn₂S₄/Pt heterostructure arrays gas sensor is designed, which consists of Co₃O₄ nanowire arrays grown in situ on an alumina flat substrate as backbones, ultrathin ZnIn₂S₄ nanosheets wrapped around the surface of Co₃O₄ nanowires, and highly dispersed Pt nanoparticles on the outermost layer. It enables superior sensing performance for the detection of the volatile organic compound triethylamine, which exhibits a significant response of ∼118.97 (<i>R</i>_a/<i>R</i>_g) toward 100 ppm of triethylamine at a relatively low working temperature of 200 °C, along with excellent response/recovery speed, selectivity, and enduring stability (over 3 months). Based on first-principles calculation and a series of spectroscopic characterization (including in situ spectroscopy), it is revealed that the heterostructure arrays exhibited enhanced adsorption activity for both oxygen and triethylamine molecules. Most importantly, the robust p-n heterointerface (Co₃O₄/ZnIn₂S₄) and semiconductor-metal heterointerface (Co₃O₄/Pt, ZnIn₂S₄/Pt) are formed in the ternary heterostructure, achieving efficient multi-interface charge transfer characteristics. In addition, thanks to the design of in situ 1D/2D/0D porous array structures, the ternary Co₃O₄/ZnIn₂S₄/Pt heterostructure arrays not only have large specific surface areas for gas reaction but also simplify device manufacturing. This research offers novel perspectives on boosting the gas sensing performance of semiconductor materials through the comprehensive design of ternary heterostructures with robust multi-interfaces.