Combustion synthesized hierarchically porous WO3 for selective acetone sensing

An easy, inexpensive combustion route was designed to synthesize hierarchically porous WO3. The tungsten source was fresh peroxiotungstic acid by dissolving tungsten powder into hydrogen peroxide. To promote the combustion reaction, a combined fuel of both glycine and hydrazine hydrate was used. The microstructure was well-connected pores comprised of subunit nanoparticles. Upon exposing towards acetone gas, the porous WO3 based sensor exhibits high gas response, rapid response and recovery, and good selectivity in the range of 5-1000 ppm under working temperature of 300 degrees C. This excellent sensing performance was plausibly attributed to the porous morphology, which hence provides more active sites for the gas molecules' reaction. (C) 2016 Elsevier B.V. All rights reserved.