Simple chemical solution coating and gas sensing properties of α-Fe2O3/chrysotile fibrous composites

α-Fe2O3/chrysotile fibrous composites were prepared by a simple chemical solution coating method for the gas sensitivity improvement of α-Fe2O3. X-ray diffraction (XRD) and atomic force microscope (AFM) analyses indicate that corundum-type α-Fe2O3 nanoparticles with a mean particle size ∼20 nm are dense and well-proportioned on the surface of chrysotile fibers due to the mechanism that positively charged Fe(OH)3 particles can be adsorbed onto the negatively charged chrysotile fibers in acidic liquids. The fabricated sensor devices were characterized for their electrical and gas sensing properties, it is found that the sensitivities of α-Fe2O3/chrysotile fibrous composites to H2 and CH4 all increase by ∼35% than those of the single α-Fe2O3 nanoparticles. Such simple coating treatment is an effective way in improving the continuities and gas sensing properties of nanogranular thick films.

► α-Fe2O3 nanoparticles were coated on fibrous chrysotile by a simple solution method. ► α-Fe2O3 particles were compact and well-proportioned on the surface of chrysotile. ► The sensitivity of α-Fe2O3 to H2 or CH4 was improved by such coating treatment. ► There is no relevant report on improving gas sensitivity by such coating treatment.