Key points are not available for this paper at this time.
α-Fe 2 O 3 @ZIF-71 nanomaterials, with an average width of 100 nm, were synthesized on Al 2 O 3 ceramic tubes via a two-step hydrothermal method. The ZIF-71 ligands were modified via a secondary hydrothermal treatment. Gas-sensing experiments demonstrated that the modified α-Fe 2 O 3 @ZIF-71(NBIM) exhibited enhanced selectivity and sensing response toward NO 2 . At 220 °C, its response to 10 ppm of NO 2 was 17.20, which is 1.9 times that of pristine α-Fe 2 O 3 and 1.4 times that of unmodified α-Fe 2 O 3 @ZIF-71. When triethylamine was the interfering gas, the material’s selectivity was 1.5 times that of α-Fe 2 O 3 @ZIF-71 and 3.3 times that of α-Fe 2 O 3 . With NO as the interfering gas, α-Fe 2 O 3 @ZIF-71(NBIM)’s selectivity was 1.2 times that of α-Fe 2 O 3 @ZIF-71 and 1.4 times that of α-Fe 2 O 3 . Meanwhile, the grand canonical Monte Carlo (GCMC) method was employed to investigate the sieving effects of four types of ZIF-71 with different pendant groups. On the other hand, density functional theory (DFT) was utilized to analyze the adsorption mechanisms of NO 2 on α-Fe 2 O 3 and α-Fe 2 O 3 @ZIF-71(NBIM) nanomaterials. The DFT analysis results were in good agreement with the experimental results. The findings indicated that α-Fe 2 O 3 @ZIF-71(NBIM) enhanced the selectivity and response value of metal oxide gas sensors, providing an approach to improve the selectivity and response value of metal oxide gas sensors.
Wang et al. (Mon,) studied this question.