Cu-doped Fe2O3 porous spindles derived from metal-organic frameworks with enhanced sensitivity to triethylamine

Abstract

The introduction of other elements can be an effective method to promote gas sensing performances in recent years due to the generation of oxygen vacancy defects. In this work, by using MIL-88-Fe as the precursor, Cu-doped α-Fe2O3 porous spindles have been successfully prepared through a simple solvothermal method. According to a series of morphological characterizations, α-Fe2O3 still remained the morphology of spindle and exhibited distinctly particle surfaces. The existence of Cu ions restrains the growth of crystalline grains and enables the α-Fe2O3 spindles to acquire a higher specific surface area and smaller pore sizes. Referring to the gas sensing properties, 0.5 wt% Cu-doped α-Fe2O3 spindles demonstrated the superior sensitivity towards triethylamine (TEA) at 240 °C with rapid response/recover. And the gas sensing mechanism can be ascribed to the formation of oxygen vacancy helped by the Cu ions. The more generation of oxygen vacancies means that the higher amount of molecules tend to be adsorbed on sample's surfaces, which is beneficial for the enhancement of gas sensing performances.