MOF-derived α-Fe2O3 porous spindle combined with reduced graphene oxide for improvement of TEA sensing performance

Abstract

Recently, metal organic frameworks (MOFs) received more and more attentions in gas sensors due to their characterizations of well-defined morphologies and open-metal sites. Here, pure α-Fe2O3 spindles were prepared by using the Fe-MIL-88 as precursor and the product was successfully combined with 1 wt% reduced graphene oxide (rGO) through a simple solvothermal method. The element compositions and microstructures were characterized by a series of techniques. According to the consequences, pure α-Fe2O3 spindles exhibited porous nanostructures and were adhered adequately on the surface of rGO. And the length-width ratio of most α-Fe2O3 spindles is about 4:1. Furthermore, the sensor based on rGO/α-Fe2O3 nanocomposites displayed better gas sensing performances than pure α-Fe2O3 spindles and the sensitivity increased from 12.18 to 34.33 towards 100 ppm triethylamine (TEA) at 300 °C. At the same time, rGO/α-Fe2O3 nanocomposites also possessed superior selectivity and short response/recover times. The enhanced sensors performance can be ascribed to the porous nanostructures and P/N heterojunction between α-Fe2O3 and rGO.