Facile engineering of metal-organic framework derived SnO2-ZnO composite based gas sensor toward superior acetone sensing performance

Aiming to achieve high-sensitivity disease diagnosis, it is of great significance to continuously improve the sensing performance of metal oxide based sensors. The morphology and component of metal oxides can be rationally engineered by using metal-organic frameworks as highly versatile platforms. Herein, the bimetallic Sn/Zn-ZIF-8 is synthesized by self-assembly, and then SnO2-ZnO hollow nanoparticles are obtained by using bimetallic Sn/Zn-ZIF-8 as precursor. The obtained SnO2-ZnO composite maintained the dodecahedral structure of Sn/Zn-ZIF-8, and in which SnO2 is orthogonal due to the framework-induced effect. Based on the unique structure and composition of SnO2-ZnO, 6% SnO2-ZnO exhibits excellent selectivity, high response, low detection limit (0.82 ppb) and good response linearity between response and concentration of acetone, showing the potential of the practical application in clinical diagnosis of diabetic patients. In-depth discussions reveal that the excellent sensing performance can be attributed to the n-n heterostructure of SnO2-ZnO that is favorable for electron transport, the larger adsorption energy to acetone that results from orthogonal SnO2, and the abundant active reaction sites provided by the dodecahedral mesoporous structure. This synthetic strategy may provide an effective method for the facile engineering of high-performances metal oxide-based sensors toward practical health assessment.