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 In 2 O 3 hollow microtubes. Subsequently, the surface of In 2 O 3 hollow microtubes was decorated by the Pr-doped SnO 2 nanoparticles (NPs) in solution under stirring, and the Pr-SnO 2 /In 2 O 3 composite was obtained. Various characterization techniques confirmed the successful preparation of the Pr-SnO 2 NPs/In 2 O 3 composite. The specific surface area of the composite reached 72.07 m2/g. The sensing performance of the SnO 2 , Pr-SnO 2 , In 2 O 3 , SnO 2 /In 2 O 3 , and Pr-SnO 2 /In 2 O 3 sensors to ethanol gas were systematically investigated. Among these sensors, at the optimal working temperature, the Pr-SnO 2 /In 2 O 3 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. • Pr-SnO 2 /In 2 O 3 composite with hollow microtube was prepared via step-by-step method. • The composite combined rare earth doping, heterojunction and special structure. • The composite exhibited superior sensing properties to ethanol with response of 75 to 50 ppm. • The mechanism is explained by comparing the sensing performance of each component unit. [ABSTRACT FROM AUTHOR]