Curling-like Bi2WO6 microdiscs with lamellar structure for enhanced gas-sensing properties

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 Bi2WO6 structures. 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 Bi2WO6 sensor may be attributed to the unique structures, the good crystallization and large surface area.