Construction of ZnCo2O4 decorated ZnO heterostructure materials for sensing triethylamine with dramatically enhanced performance

Abstract

In this paper, a sensor based on a novel ZnCo₂O₄/ZnO nanosheet-like p–n heterostructure was designed using a one-step hydrothermal method and utilized to dramatically improve the sensitivity toward triethylamine (TEA) gas. The structure, constituent elements and their valence states of ZnCo₂O₄/ZnO were tested using various methods. The 5 at%-ZnCo₂O₄/ZnO sensor was found to have the best sensing performance. The response value of this sensor toward 100 ppm triethylamine (TEA) at the optimum operating temperature of 280 °C (78.68) was almost 12 times higher than that of the ZnO sensor (6.58). The TEA's linear response, superior to that of the pure ZnO sensor, is more selectable and reproducible when the concentration range is between 5 and 80 ppm. A heterostructure of p–n was designed to enhance the gas-sensitive response effectively. This study refines the mechanism of the heterojunction to improve its gas-sensitive performance and provides a new strategy for the design of gas-sensitive materials.