Brookite TiO2 decorated α-Fe2O3 nanoheterostructures with rod morphologies for gas sensor application

In this paper, brookite-TiO2/alpha-Fe2O3 heterostructured nanorods were synthesized by a facile two-step solution approach without using any templates or surfactants. alpha-Fe2O3 nanorods were first successfully obtained via a simple solution method at room temperature. The alpha-Fe2O3 nanorods were further employed as supports to construct nanoheterostructures for gas sensor application. The gas sensor based on the as-fabricated TiO2/alpha-Fe2O3 nanoheterostructures exhibited an excellent gas-sensing performance, with markedly enhanced responses in comparison with the pristine alpha-Fe2O3 nanorod sensor, and fast response-recovery speeds as well as good reproducibility to Volatile Organic Pollutants (VOPs), such as methanol, ethanol, n-butanol, acetone, ether, xylene, toluene and benzene, demonstrating its potential application in detecting these VOPs. The enhanced gas-sensing behavior should be attributed to the unique porous alpha-Fe2O3 nanorod morphology, the strong interfacial interaction between TiO2 and alpha-Fe2O3, the presence of TiO2/alpha-Fe2O3 heterojunctions and the catalytic effect of brookite TiO2 nanoparticles. The as-prepared TiO2/alpha-Fe2O3 nanoheterostructures may also lead to novel applications in other fields, such as lithium-ion batteries, catalysis, and waste water treatment.