Controlled synthesis of hierarchical tungsten oxide hydrates for efficient acetone detection

Abstract

The detection of acetone is of great significance for environmental safety and human health. Micromorphology control is a feasible pathway to obtaining excellent gas-sensitive materials. In this study, three types of hierarchical WO3·H2O, including nanoplates, hollow spheres and nanospheres, were controlled synthesis by a simple hydrothermal method. Their morphologies and growth mechanisms were studied by various characterization methods, and their acetone sensing performances were tested via a static distribution method. The results indicate that the sensor based on the hierarchical WO3·H2O hollow spheres exhibits higher sensitivity, better selectivity and faster response speed towards acetone than two other morphologies at the optimum operating temperature (300 ℃). Specifically, the response value reaches 21.4–50 ppm acetone, and the response/recovery times are 3.6 s/6.0 s. The superior performance and fast response characteristics of the hollow WO3·H2O are mainly attributed to its high specific surface area, unique pore structure, abundant surface active sites, and suitable energy level structure. This work enlightens some thoughts on the functionalization of tungsten-based gas sensors and efficient detection of acetone.