Synthesis Of Ordered Mesoporous Cobaltate/graphdiyne Composite For Glucose Electrochemical Sensing

Diabetes is a serious chronic disease that threatens human health worldwide.Therefore,the accurate and rapid detection of blood glucose concentration is of great significance for the diagnosis and treatment of diabetes.The development of enzymatic glucose sensors is greatly restricted by the disadvantages of high cost,poor stability,and harsh environmental requirements,which prompts researchers to construct a non-enzymatic glucose sensor with low cost,high stability and good selectivity.The key lies in the selection of electrode materials.More and more researchers have paid attention to transition metal oxides with low cost,abundant resources and excellent catalytic activity.However,the electrical conductivity of transition metal oxides is not particularly brilliant,and scientists have tried to modify them by compounding them with carbon materials.In this thesis,a series of ordered mesoporous spinel cobaltate/graphdiyne composites with high specific surface area and large pore size were designed and synthesized,and the effect of GDY as a cocatalyst and mesoporous materials on the glucose sensing performance was explored.1.A series of ordered mesoporous cobalt-based spinel ACo2O4(A=Cu,Zn,Ni)were synthesized by the nano-casting method using the ordered mesoporous silica KIT-6 as the hard template,and the GDY was compounded with it in different proportions by ultrasonic-assisted impregnation method to obtain A Co2O4/GDY composites.The experimental study found that CuCo2O4-GDY-25:1,NiCo2O4-GDY-50:1,ZnCo2O4-GDY-100;1(molar ratio)had the best electrical sensing performance,and their sensitivity was 6523μA·mM-1·cm-2,6058 μA·mM-1·cm-2,5250μA-mM-1·cm-2.The performance is 1.9,2.2,and 2.6 times higher than that of ACo2O4(3514 μA·mM-1·cm-2,2738 μA·mM-1·cm-2,1985 μA·mM-1·cm-2),which have excellent anti-interference and stability.2.By adjusting the positional composition of the regular octahedron of spinel ZnCo2O4,a series of micro-doped ordered mesoporous ZnB0.05Co1.95O4(B=Ni,Cr,Ga)were synthesized by the abovementioned mesoporous material synthesis method.material,and composited with GDY in different proportions by ultrasonic-assisted impregnation method.Taking ZnNi0.05Co1.95O4 as an example,the test was found that ZnNi0.05Co1.95O4-GDY-50:1 exhibited excellent glucose sensing performance with a sensitivity of 3668 μA·mM-1 cm-2,which is higher than that of ZnNi0.05Co1.95O4(2335 pA·mM-1·cm-2),and the composite showed excellent stability and anti-interference.On the basis,ZnCr0.05Co1.95O4 and ZnGa0.05Co1.95O4 were compounded in this ratio.The sensitivity is 3647 and 3365 μA·mM-1·cm-2,respectively,which are 1.6 times(2235 μA·mM-1·cm-2)and 1.4 times(241 6 μA·mM-1·cm-2)higher than those before compounding,respectively.3.A series of ordered mesoporous AB0.05Co1.95O4(A=Ni,Cu;B=Cr,Ga)are synthesized by nanocasting method by doping trace metal to the regular octahedral position composition of spinel NiCo2O4 and CuCo2O4,which is compounded with GDY in a specific ratio.(1)According to the previous exploration,NiB0.05Co1.95O4-GDY-50:1 was used as the optimal composite ratio to construct a nonenzymatic glucose sensor,and the composite material was found to have excellent catalytic activity.The sensitivity of NiCr0.05C1.95O4-GDY-50:1 is 6241 μA·mM-1·cm-2,which is 1.4 times higher than that of NiCr0.05Co1.95O4-GDY(4440μA·mM-1·cm-2).The sensitivity of NiGa0.05Co1.95O4-GDY-50:1 is 6787μA·mM-1·cm-2,which is higher than that of NiGa0.05Co1.95O4(3397μA·mM-1·cm-2)was increased by 2.0 times;(2)According to the previous exploration,CuB0.05Co1.95O4-GDY-25:1 was used as the optimal composite ratio to construct a non-enzymatic glucose sensor.It was found that the performance of the composite material was very different from that before the composite GDY was small,indicating that the synergy between CuB0.05Co1.95O4 and GDY is poor.