Porous FeVO4 nanorods: synthesis, characterization, and gas-sensing properties toward volatile organic compounds

Abstract

This study reports a facile hydrothermal approach for the synthesis of shape-controlled FeVO4·1.1H2O nanorods and the subsequent conversion into FeVO4 nanorods upon calcination at 500 °C for 2 h. The lengths of the synthesized FeVO4 nanorods vary from 0.7–3.5 μm, with the widths ranging from 70–270 nm. The proposed synthesis strategy does not involve the use of surfactants and requires only a very short reaction time, which is highly beneficial for the scale-up preparation. The anions of the Fe precursor are found to directly influence the shape and composition of the resultant hydrated FeVO4 products, due to the differences in their ionic strength and their abilities to intercalate into the layered structure of FeVO4·1.1H2O. The Cl− ions are particularly useful in limiting the growth of the nanorods in the lateral direction without being strongly intercalated into the layered structure. The porous FeVO4 nanorods exhibit higher selectivity and sensitivity toward n-butanol compared to FeVO4 nanoparticles, due to the high surface area and porosity. The findings demonstrate for the first time the potential of nanosized FeVO4 as a sensor material for the detection of volatile gases.