Hydrothermal synthesis of Zn-doped α-Fe2O3 nanocubes for selective detection of triethylamine

With the growing attention on environment protection, gas sensors fabricated with metal oxide semiconductor (MOS) have stimulated increasing research interest because of their capability for fast detection of various harmful gases. Here, Zn-doped alpha-Fe2O3 nanocubes (ZFO NCs) with about 300-500 nm in edge length were successfully prepared via a surfactant-free hydrothermal route and their gas sensing properties were investigated by using as bare alpha-Fe2O3 NCs as reference. It was found that as applied as active materials for detecting volatile organic compounds (VOCs), the obtained ZFO NCs showed some impressively improved triethylamine (TEA) sensing performances, especially of better selectivity and higher sensitivity. The response (Ra/Rg) of the best ZFO sensor (ZFO-5) to 100 ppm TEA was as high as 64.3, and its selectivity coefficient (STEA/Ammonia) was 6.50, both of which were well above that of the pure alpha-Fe2O3 sensor. Besides, the ZFO-5 sensor also shows good stability and repeatability. The gas sensitive mechanism of the ZFO NCs was discussed.