Study On Amorphous Nickel-based Alloys For Enzyme-free Glucose Sensing And Electrocatalytic Oxygen Evolution Reaction

Rapid and sensitive detection of glucose concentration play an important role in clinical medicine,food industry,biological analysis,environmental monitoring and other fields.Enzyme-free glucose sensor was developed on the basis of the electrocatalytic oxidation of glucose taken place on electrode surface.Because it has overcome the inherent shortcoming of glucose oxidase enzyme-free glucose sensors,have attracted ever increasing concerns.Heterogeneous earth abundant transition metal based electrocatalysts,such as of Fe,Co,or Ni,have been reported as the most promising candidates for electro catalysis due to their relatively low costs,rich valence state changes and electronic structure.Especially,nickel-based alloy materials are the favored in view of their metastable state and excellent electron transfer characteristics.Compared with crystalline alloys,amorphous Ni-based alloys can provide more coordination unsaturated sites and higher density of active sites,and they are outstanding ideal materials for the construction of high performance electrocatalysts.Herein,three kinds of amorphous Ni-based alloy were prepared and used as electrocatalyst for glucose sensing and oxygen evolution reaction(OER).The main work is as follows:1.Ni-B/NF was prepared via simply and rapid electroless deposition with dipping Ni foams into NiCl₂ precursors and NaBH₄reducing solutions alternatively.Electrochemical measurements demonstrate that Ni-B/NF has excellent catalytic activity for glucose oxidation and can be used as an efficient enzyme-free electrochemical sensor,with a short response time less than 10 s,a wide detection range from 5?M to 2.66 mM,a response sensitivity of 8.25 mA?mM^-1?cm^-2,and a low detection limit of 5?M(S/N=3).Moreover,the selectivity and reliability for practical application in blood glucose detection of the as-fabricated sensor were also investigated in detail.2.Amorphous Ni-P nanoparticles anchoring on Ni foam(Ni-P/NF)was prepared through a facile electroless deposition approach.As an integrated electrode,Ni-P/NF exhibits excellent catalytic activity towards glucose oxidation,with a high sensitivity of13.89 mA?mM^-1?cm^-2,a low detection limit(LOD)of 1?M,a wide detection ranges from 2?M to 0.54 mM,and a quick response(<10 s).The selectivity and reliability for practical application in blood glucose detection were also investigated in detail.3.Amorphous Ni-P nanoparticles(Ni-P/NF)based on nickel foam were prepared and used as a monolithic catalyst for electrochemical oxygen evolution reactions.The experimental results show that Ni-P/NF as an OER electrocatalyst in alkaline solution shows significant catalytic activity.At a current density of 50 mA?cm^-2,only a 360 mV overpotential is required,additional the Ni-P/NF shows good stability for OER.