Abstract

Self-assembled curling-like Bi₂WO₆ microdiscs, consisting of closely packed nanosheets with thickness of 50 nm, have been successfully synthesized by a simple solvothermal route. This structure was characterized by field emission scanning electron microscopic (FESEM) and transmission electron microscopy (TEM). The results show that the Bi₂WO₆ samples are mostly microdiscs in shape and have an average side thickness of 500 nm. The time-dependent morphology of the Bi₂WO₆ samples has been investigated, and gas sensors based on these products were fabricated for ethanol detection. The sensor based on the curling-like Bi₂WO₆ nanostructures shows much better sensing properties than other Bi₂WO₆structures. The response of the curling-like Bi₂WO₆ sensor to 100 ppm ethanol is about 11.9 with the response time of 1 s. The dramatic improvement in sensing properties of the present curling-like Bi₂WO₆sensor may be attributed to the unique structures, the good crystallization and large surface area.