Synthesis of Fe2O3–ZnWO4 nanocomposites and their enhanced acetone sensing performance

Abstract

α-Fe2O3 nanodrums loaded with different decoration densities of ZnWO4 nanoparticles (Fe2O3–ZnWO4 nanocomposites) have been successively synthesized by a two-step wet-chemical method. The decoration density of ZnWO4 nanoparticles can be controlled by regulating the doses of zinc and tungsten sources in the reaction solutions. To demonstrate the functional properties of ZnWO4 nanoparticles, the gas sensing properties of the pristine α-Fe2O3 nanodrums and all the Fe2O3–ZnWO4 nanocomposites were systematically compared. The response of the best Fe2O3–ZnWO4 nanocomposites (Fe2O3-(1)ZnWO4) to 50 ppm acetone is as high as 39.2, which is 15.7 times higher than that of the pristine α-Fe2O3 nanodrums. The response and recovery times are only 16 and 35 s, respectively. A cross-response test showed that the Fe2O3-(1)ZnWO4 nanocomposites have high selectivity, and their response to acetone is 3.2–7.6 times higher than to other volatile organic compounds (VOCs). The short-term stability test showed that the Fe2O3-(1)ZnWO4 sensor has excellent stability and repeatability when exposed to acetone vapor. The enhanced gas sensing performance of the Fe2O3–ZnWO4 nanocomposites can be attributed to the synergistic effects of the combination of the α-Fe2O3 and ZnWO4 materials and the polarity properties of the target gas molecules, which are discussed in detail.