Flower-like In2O3/ZnO heterostructure with accelerated multi-orientation electron transport mechanism for superior triethylamine detection

Highlights: • 2D flower-like In₂O₃/ZnO composite derived from In₂O₃ precursor/ZIF-8 is gained. • Composite has flower-like In₂O₃/ZnO structure composed of needle-like nanorods. • Sensors show an excellent gas-sensing response of 188.01 to 100 ppm TEA at 120 °C. • Mechanism is mainly due to the accelerated multi-orientation electron transport. • In₂O₃-based sensors can be used for actual detecting area of seafood storage. Flower-like In₂O₃/ZnO heterostructures consisting of the assembled needle-like nanorods derived from In₂O₃ precursor/ZIF-8 have been prepared by a two-step approach. Flower-like In₂O₃/ZnO structures can be achieved by adjusting the nucleation competition and crystal surface matching of In₂O₃ and ZnO, leading to the enhancement of gas adsorption on the surface, chemical reaction kinetics, and the electron transport efficiency. In/Zn-2 sensors exhibit excellent gas-sensing response value of 188.01 to 100 ppm triethylamine at 120 °C as well as good gas selectivity, long-term stability, and linear relationship compared with pure In₂O₃, mainly attributed to the accelerated multi-orientation electron transport mechanism within flower-like In₂O₃/ZnO heterostructures. In addition, In/Zn-2 samples can be utilized to detect the practical triethylamine gas released during the storage of marine organism (fishes).