High performance ethanol sensor based on Pr-SnO2/In2O3 composite

Metal-organic framework (MOF) can be used as sacrificial templates for preparing metal oxides with unique hollow structures. The heterojunction formed between two metal oxides is conducive to improvement of gas sensor performance. Herein, MOF compounds containing In with hexagonal prism morphology were synthesized first, and then annealed to obtain uniform hexagonal In2O3 hollow microtubes. Subsequently, the surface of In2O3 hollow microtubes was decorated by the Pr-doped SnO2 nanoparticles (NPs) in solution under stirring, and the Pr-SnO2/In2O3 composite was obtained. Various characterization techniques confirmed the successful preparation of the Pr-SnO2 NPs/In2O3 composite. The specific surface area of the composite reached 72.07 m2/g. The sensing performance of the SnO2, Pr-SnO2, In2O3, SnO2/In2O3, and Pr-SnO2/In2O3 sensors to ethanol gas were systematically investigated. Among these sensors, at the optimal working temperature, the Pr-SnO2/In2O3 sensor displayed the best sensing performance with a response value of 75 towards 50 ppm ethanol, and further exhibited good linearity coefficient, selectivity, reproducibility, and long-term stability.