Synthesis Of Ni-based Nanomaterials And Its Application In Glucose Sensor And Glucose Fuel Cell

Electrochemical sensing and fuel cells are widely used in electrochemical analysis and green energy fields,the principle of their work is to convert chemical signals into electrical signals through redox reaction.while glucose fuel cell can be used in implantable power supply or other power supply through glucose oxidation.Therefore,the oxidation reaction of glucose on the electrode surface is very important to the sensing performance of equipment and the performance of fuel cell,and the efficiency of oxidation reaction depends largely on the performance of electrochemical catalyst.Recently,because of its high activity,high electron transfer rate and low price,transition metal materials have been widely studied and applied in electrochemical sensors and fuel cells.Among them,nickel-based materials have been paid more and more attention as electrochemical catalysts,but they will be gradually passivated with the progress of electrochemical reaction on the electrode surface,resulting in a decrease in the efficiency of glucose catalytic oxidation.So it is urgent to develop a kind of nickel-based materials with simple preparation,excellent performance and low cost to make up for this defect.In this dissertation,nickel-based transition metal nanomaterials with good electrochemical performance,green and low cost were prepared by hydrothermal method,calcination method and microwave method,this method is applied to the construction of electrochemical sensing and fuel cell system.The main research results are as follows:（1）Ternary transition metal Ni_0.5Cu_0.5Co₂O₄nanorods were prepared and their properties in electrochemical sensing and glucose fuel cells were investigated by adjusting the proportion of ternary components and controlling the growth of one-dimensional rod-like structure.The results show that Ni_0.5Cu_0.5Co₂O₄nanorods have better electrocatalytic activity for glucose oxidation than single-component Cu Co₂O₄and Ni Co₂O₄.It shows high sensitivity(859.31μA·m M^-1·cm^-2and528.81μA·m M^-1·cm^-2)in enzyme-free glucose electrochemical sensing（S/N=3）,with a linear range of 5-3000μM and 3000-7000μM,respectively.In addition,the glucose fuel cell assembled with Ni_0.5Cu_0.5Co₂O₄nanorods as anode catalyst has high fuel cell performance,and the maximum power density is 413.7μW·cm^-2.The remarkable improvement in the electrochemical performance of Ni_0.5Cu_0.5Co₂O₄nanorods may be due to their unique one-dimensional rod-like structure and the introduction of third metal atoms into the spinel lattice of Cu Co₂O₄or Ni Co₂O₄to improve their electrical conductivity and charge transfer rate.（2）Assemble metal/metal carbide（Ni/Ni₃C/C₃N₄）nanosheets with a two-dimensional sheet-like structure,and study the effect of changing the ratio of Ni and Ni₃C on their electrochemical performance,while exploring their applications in electrochemical sensing and glucose fuel cells..In this work,we propose a highly efficient GOR catalyst with two-dimensional sheet structure prepared by a one pot self-assembly process using urea and nickel acetate as precursors.The prepared Ni/Ni₃C/C₃N₄nanosheets with a thickness of less than 50nm are composed of many Ni/Ni₃C nanoparticles anchored on the C₃N₄sheet with a diameter of less than5nm.Electrochemical characterization confirmed that Ni/Ni₃C/C₃N₄nanosheets had excellent GOR properties.The battery equipped with Ni/Ni₃C/C₃N₄nanosheet anode has 599.68μW·cm^-2.In addition,excellent non enzymatic glucose sensing performance was also obtained on the Ni/Ni₃C/C₃N₄nanosheet electrode,ranging from 1-1000μM,the sensitivity of 395.08μA·m M^-1·cm^-2,and in the range 1000μM-12000μM,the sensitivity of 163.64μA·m M^-1·cm^-2.The low detection limit is 0.33μM,which has good stability and repeatability.It is possible that the high performance of Ni/Ni₃C/C₃N₄nanosheets is attributed to the synergistic effect of Ni/Ni₃C and C₃N₄.（3）By calcining Ni/PANI precursors to form Ni O/CR in situ,introducing a small amount of precious metals and adjusting the proportion,and by microwave-assisted deposition of precious metal Pt,Pt/Ni O/CRs electrocatalysts were successfully obtained.The Pt/Ni O/CRs-2 prepared has good electrochemical performance for GOR,high activity,good anti poisoning ability and good stability.As anode electrode,Pt/Ni O/CRs-2 shows a greatly enhanced power density in DGFC(1617.6μW·cm^-2),showing higher sensitivity in NEGS applications(348.54μA·m M^-1·cm^-2and136.56μA·m M^-1·cm^-2).The improvement of electrochemical performance of Pt/Ni O/CRs-2 may be due to the synergistic effect of Pt and Ni O on carbon rods.First of all,platinum deposition can not only promote charge transfer,but also induce more Ni O/CR active sites for GOR.Of course,the strong anchoring between conductive carbon rod and nano catalyst will inevitably lead to excellent electrochemical performance.In view of the low Pt content and high GOR efficiency,Pt/Ni O/CRs-2may be a promising catalyst for glucose fuel cells and sensor applications.（4）The electrochemical performance of polyaniline was improved by synthesizing Ni S（α-Ni S andβ-Ni S）catalysts with different crystalline phases.It was found that the combination of binary crystalline Ni S and PANI can significantly improve their oxidative activity against glucose.The prepared Ni S/PANI NRs have good anti-interference ability and good stability for GOR.As anode electrodes,Ni S/PANI NRs exhibit high power density(1343.39μW·cm^-2).It has shown a high sensitivity in NEGS applications(682.21μA·m M^-1·cm^-2).The improvement in the electrochemical performance of Ni S/PANI NRs may be due to the synergistic effect of Ni S and polyaniline nanorods to generate more active sites.Ni S/PANI NRs may be a promising catalyst for glucose fuel cell and sensor applications.