Porous Iron Molybdate Nanorods: In situ Diffusion Synthesis and Low-Temperature H2S Gas Sensing

In the paper, we developed an in situ diffusion growth method to fabricate porous Fe-2(MoO4)(3) nanorods. The average diameter and the length of the porous nanorods were 200 nm and 1.2-4 mu m, respectively. Moreover, many micropores existed along axial direction of the Fe-2(MoO4)(3) nanorods. In terms of nitrogen adsorption-desorption isotherms, calculated pore size was in the range of 4-115 nm, agreeing well with the transmission electron microscope observations. Because of the uniquely porous characteristics and catalytic ability at low temperatures, the porous Fe-2(MoO4)(3) nanorods exhibited very good H2S sensing properties, including high sensitivity at a low working temperature (80 degrees C), relatively fast response and recovery times, good selectivity, and long-term stability. Thus, the porous Fe-2(MoO4)(3) nanorods are very promising for the fabrication of high-performance H2S gas sensors. Furthermore, the strategy presented here could be expended as a general method to synthesize other hollow/porous-type transition metal molybdate nanostructures by rational designation in nanoscale.