Metal Oxide Modified Electrode And Its Sensitivity

Co3O4 and its carbon composite Co3O4/C were prepared by using cobalt-metal-organic framework as precursor.They were used to modify glassy carbon electrodes,and their sensitivity to glucose and dopamine were studied.XRD,SEM,XPS,BET and other methods were used to characterize the structure,morphology and composition of the material;electrochemical techniques were used to study the electrocatalytic performance,sensitivity,selectivity and stability of the modified electrode.The specific research content is as follows:Cobalt ion as the center metal ion,5-((4-carboxybenzyl)oxy)isophthalic acid and 1,4-bis(2-methylbenzimidazol-1-ylmethyl)Benzene were uesd.A cobalt-based metal-organic framework material with novel structure [Co(L)2(bmb)]n was obtained by hydrothermal synthesis.The material was pyrolyzed in an air atmosphere at 450 ℃ for 3 h to obtain Co3O4 with a curved flaky morphology.Co3O4 was used to modify glassy carbon electrode to study the sensitivity of Co3O4/GCE to glucose.The results show that Co3O4/GCE has excellent electrocatalytic oxidation activity on glucose;within the range of glucose concentration from 1 to 2000 μM,the peak current of Co3O4/GCE has a good linear relationship with glucose concentration and the detection sensitivity is 254.21 μA·m M-1·cm-2;When the glucose concentration is 2000～8000 μM,the oxidation peak current of Co3O4/GCE has a good linear relationship with the glucose concentration,and the sensitivity is 102.80 μA·m M-1·cm-2.The modified electrode shows good anti-interference ability and reproducibility.Co3O4/C composites were prepared by using cobalt-based metal-organic framework material ZIF-67 as precursor and pyrolyzed at 500 °C for 3 h to modify the glassy carbon electrode.Its sensitivity to dopamine was studied.The results show that the presence of carbon materials can effectively improve the conductivity of the electrode,and then improve the electrocatalytic activity of Co3O4/C/GCE towards dopamine.At the optimal potential of 0.40 V,Co3O4/C/GCE can linearly detect dopamine from 0.125 μM to 3000 μM with a sensitivity of 65.04 μA·m M-1·cm-2.Co3O4/C/GCE has good anti-interference ability,reproducibility and stability.ZIF-67 was etched with tannic acid as an etchant and pyrolyzed for 3 h in an atmosphere of 500 ℃ argon to obtain Co3O4/C composites.The sensitivity to dopamine was studied.Studies have shown that,compared with the Co3O4/C/GCE obtained by ZIF-67 without etching,the Co3O4/C modified electrode obtained by etching has more excellent sensitivity.Co3O4/C/GCE prepared by tannic acid etching for 2 min has the highest catalytic oxidation activity for dopamine,and can linearly detect dopamine at 20 ～ 200 μM and 200 ～ 800 μM with sensitivity of 479.90 μA·m M-1·cm-2 and 193.24 μA·m M-1·cm-2.The modified electrode shows good reproducibility and stability.Figure 45;Table 9;Reference 82...