Glucose-assisted synthesis of hierarchical NiO-ZnO heterostructure with enhanced glycol gas sensing performance

Abstract

Heterojunction has been proposed as an effective approach to improve the gas sensing performance with good response and low operating temperature. In this work, a one-step hydrothermal method was employed to synthesize a novel flower-like hierarchical NiO-ZnO (G-NiO-ZnO) heterostructure with the assistance of glucose and further calcination treatment. The gas sensors based on G-NiO-ZnO heterojunction exhibit a response of 142.0 toward 100 ppm glycol at relatively low operating temperature about 140 °C with excellent repeatability and long-term stability, which is mainly attributed to the stable hierarchical porous structure with a large specific surface area and the massive oxygen vacancy defects generated during the synthesis process. In general, this work paves a solid foundation for directly synthesizing G-NiO-ZnO heterojunction in a one-step approach and demonstrates a great practical application potential for efficient glycol gas detecting.