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

Abstract

In this paper, brookite-TiO₂/α-Fe₂O₃ heterostructured nanorods were synthesized by a facile two-step solution approach without using any templates or surfactants. α-Fe₂O₃ nanorods were first successfully obtained via a simple solution method at room temperature. The α-Fe₂O₃ nanorods were further employed as supports to construct nanoheterostructures for gas sensor application. The gas sensor based on the as-fabricated TiO₂/α-Fe₂O₃ nanoheterostructures exhibited an excellent gas-sensing performance, with markedly enhanced responses in comparison with the pristine α-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 α-Fe₂O₃ nanorod morphology, the strong interfacial interaction between TiO₂ and α-Fe₂O₃, the presence of TiO₂/α-Fe₂O₃ heterojunctions and the catalytic effect of brookite TiO₂ nanoparticles. The as-prepared TiO₂/α-Fe₂O₃ nanoheterostructures may also lead to novel applications in other fields, such as lithium-ion batteries, catalysis, and waste water treatment.