Synthesis and gas sensing properties of β-Fe2O3 derived from Fe/Ga bimetallic organic framework

The synthesis of stable β-Fe2O3 with high activity is the basis for its application in the fields of gas sensing and catalysis etc. Preparation of Metal oxide semiconductors by metal-organic frameworks (MOFs) is a promising technology for gas-sensitive detection due to the ease of designable crystal phase and shape of the materials. In this work, MIL53 (Fe/Ga) bimetallic organic frameworks (bi-MOF) were used to design and synthesize β-Fe2O3 with stable crystalline phase for efficient gas detection. These bi-MOF-derived β-Fe2O3 maintain the porous framework structure of the MIL-53(Fe/Ga) precursor, providing more active sites and generating abundant oxygen vacancies. Compared with the commonly used α-Fe2O3, the sensor based on bi-MOF-derived β-Fe2O3 (FGO) showed faster response/recovery time and better response to ethanol. These properties indicate that it is feasible to control the crystal structure of β-Fe2O3 with good gas-sensitive properties by introducing Ga ions into mil-53(Fe).