Enhanced formic acid gas-sensing property of WO3 nanorod bundles via hydrothermal method

WO3 nanorod bundles were prepared via a facile hydrothermal method with Na2SO4 as structure directing agent. Field-emission scanning electron microscopy (FESEM) and transmission electronic microscopy (TEM) images indicate that the WO3 nanorod bundles consist of hierarchically nanostructured bundles assembled with smaller nanorod subunits. Furthermore, the gas-sensing properties of the as-prepared WO3 were tested to a series of organic gases. The WO3 nanorod bundles display a significantly better sensing performance (100 ppm formic acid, RalRg = 51.3) than commercial WO3 (100 ppm formic acid, RalRg = 1.8) for the detection of formic acid. The results demonstrated that the WO3 nanorod bundles have a potential application in formic acid sensors. (C) 2015 Elsevier B.V. All rights reserved.