Electrochemical Properties Of Two-Dimensional Metal-Organic Framework Nanomaterials And Their Applications In Glucose Electrochemical

Owing to their advantages of large surface area,more active sites exposed,adjustable morphology and pore size,two-dimensional metal-organic framework compounds（MOF）have attracted more and more attention in the field of electroanalytical chemistry.In this paper,a hybrid two-dimensional monometallic center MOF nanomaterial and four different shapes of a total of 12 bimetallic center MOF nanomaterials were prepared.The glucose electrochemical sensor based on these two types of composite materials were constructed,the capacitive behavior and electrocatalytic behavior of these composites were studied,and the new method for glucose determination were established.This research can provide ideas for the controlled synthesis of materials with better electrochemical performance,and also provide a reference for the construction of higher-performance glucose electrochemical sensing methods.This paper is divided into three parts.1. Reviewed the two-dimensional bimetallic MOF and its application status in electrochemical sensing research,prospected its application prospect in electrochemical sensing research;introduced the content and significance of the research in this paper.2. Ultra-thin two-dimensional（2D）Cu-TCPP（tetra（4-carboxyphenyl）porphyrin）MOF nanosheets were grown on nickel oxide（NiO）nanoparticles,and 2D NiO/Cu-TCPP MOF hybrid nanosheets were synthesized.A glucose electrochemical sensor based on NiO/Cu-TCPP MOF hybrid nanosheets was constructed;the morphology,composition,structure and electrochemical properties of the composite nanomaterials on the sensing interface and their effects on the sensor response were studied;a new analytical method to detect glucose was established.The experimental results show that NiO/Cu-TCPP MOF is a two-dimensional sheet structure with a specific capacitance value up to 2284 F g^-1(5A g^-1),and the initial specific capacitance value of 82.09%was maintained after 1000 cycles;The glucose oxidation peak potential obtained by using the glucose electrochemical sensor was reduced to 0.5 volts,the peak shape of the oxidation peak was sharper,and the peak current was maximum;The linear range of glucose detection was 2.8–0.3′10³μM,the detection limit was 0.95μM（signal-to-noise ratio is 3）,sensitivity was 4.6μAμM^-1cm^-2,and for 0.05m M dopamine（DA）,ascorbic acid（AA）,uric acid（UA）had the anti-jamming capability.Compared with the MOF materials reported in the literature,the specific capacitance value of NiO/Cu-TCPP MOF was increased by 2 times,and the synergistic catalytic effect of NiO and two-dimensional Cu-TCPP MOF made the composite materials electrocatalysis stronger.3. By adjusting the ratio of Ni/Co and the volume of the solvent,a total of 12 Ni/Co-TCPP MOF composite materials with 4 morphologies including flake,film,flower,and rod were synthesized.Glucose electrochemical sensors based on 12 Ni/Co-TCPP MOF composite materials were constructed;the relationship between the morphology,composition,structure of the composite nanomaterials at its interface,and its capacitive,electrocatalytic properties were studied;the relationship between the electrocatalytic properties of the composite material and the sensor response performance was studied,and a new method of glucose electrochemical sensing was established.The experimental results show that at a current density of 5Ag^-1,the specific capacitances of materials with different morphologies were:film-like:（Ni:Co=3:1）1875 Fg^-1;flower-like:（Ni:Co=2:1）208 Fg^-1/（Ni:Co=1:2）625 Fg^-416/1166/1583/375/398/1332 Fg^-1;rod shape:（Ni:Co=1:1）400 Fg^-1.And the film-like MOF material with Ni:Co=3:1 exhibited the highest specific capacitance.After 2000 cycles of testing,the initial specific capacitance retention rates of materials with different morphologies were:film-like:（Ni:Co=3:1）91%;flower-like:（Ni:Co=2:1）90%/（Ni:Co=1:2）75%/（Ni:Co=1:3）83%/（Ni:Co=1:1）83%;flake:（Ni:Co=1:1）82%/84%/87%/77%/79%/90%;rod shape:（Ni:Co=1:1）87%.Ni:Co=3:1 film-like MOF material exhibited the best cycle stability,and still maintains the highest initial specific capacitance value,which can reach 91%.Among the glucose electrochemical sensors based on Ni/Co-TCPP MOF composite materials with different morphologies,the film-shaped Ni/Co-TCPP MOF-1 exhibited the best electrocatalytic performance for glucose,the electrochemical sensor constructed with this material exhibited more symmetrical peak shape,reduced peak potential to 0.4V and maximum peak current,the linear range of glucose detection was from 1.0μM to 3.8 m M,the detection limit was 0.9μM and the sensitivity was 3.2μAμMcm^-2;It had an anti-interference effect on 0.05 m M dopamine（DA）,ascorbic acid（AA）,uric acid（UA）and acetaminophen（AP）.It is found that compared with the MOF hybrid nanocomposites in the second chapter,the film-like materials have the advantages of better capacitance cycle stability,which is 1.1 times of that in the second chapter;Compared with the pseudo capacitor nanomaterials reported in the literature,this material has the advantages of higher capacitance(1875 Fg^-1,5 Ag^-1)and better cycle stability（91%,2000cycles）;Compared with the sensor constructed based on the single-metal center MOF hybrid nanosheet in Chapter 2,the linear range of the sensor is expanded by two orders of magnitude;Compared with the sensors reported in the literature,the sensor has the advantages of 20times higher sensitivity and two orders of magnitude wider linear range.