MOFs-derived Co-doped In₂O₃ hollow hexagonal cylinder for selective detection of ethanol

Shape controlled preparation and doping are important means to improve the gas sensitivity of metal oxide semiconductor materials. In this work, pure and Co-doped In2O3 porous hollow hexagonal cylinders were suc-cessfully prepared using metal-organic frameworks (MOFs) MIL-68(In) as self-sacrificial template. The size of the MIL-68(In) hexagonal cylinder is uniform, and the In2O3 obtained after pyrolysis better inherits the shape of the MIL-68(In), but becomes hollow, and the cylinder surfaces are porous. The product has a large specific surface area (46.52 m(2)/g), and the doping of Co significantly increases the oxygen vacancy of the material. The Co-doped sample obtained by pyrolysis at 500 degrees C has excellent gas sensing performances to ethanol gas, its sensitivity to 100 ppm ethanol gas at 210 degrees C is 14.6, response/recovery time is 21 s and 107 s, and the sensing selectivity to ethanol is also good.