Preparation And Electrochemical Properties Of Cu And CuAg Micro/Nano Metal Materials

The unique effects of nano materials?surface effects,volume effects,quantum size effects,etc.?determine their special functions that conventional materials do not have.Among them,micro/nano metal materials are one category of the most important materials,and are widely used in fuel cells,electrochemical decomposition of water to produce hydrogen,electrochemical analysis and detection technology,biosensing,electrochemical sensing and other fields.Thus,the exploration of simple,green,mild and controllable methods for preparing micro/nano metal materials is pursued by many researchers.In this thesis,we mainly prepare micro/nano structure metals by square-wave potential method,chemical dealloying method and hydrogen bubble templated electrodeposition method for applications of electrocatalytic oxygen evolution reaction and non-enzymatic glucose detection.The main contents are as follows:1.Rapid preparation of coral-like Cu/CuO micro/nano structure substrate by electrochemical method.Firstly,the micro/nano coral-like Cu?c-Cu?was prepared by using square wave potential pulses in a blank H₂SO₄ solution.Next,the micro/nano coral-like Cu surface was oxidized to obtain micro/nano coral-like CuO/Cu in a blank KOH solution.Finally,appropriate amounts of?CoFe?OH_x was loaded on the coral-like CuO/Cu by successie ionic layer adsorption and reaction?SILAR?.By changing the ratio of metal ions in the precursor solutions and the numbers of SILAR,the electrocatalytic performance of?CoFe?OH_x/CuO/c-Cu for oxygen evolution reaction?OER?can be controlled.That is a highly efficient and stable electrocatalyst for OER can be controllably obtained at an ionic layer level.The electrocatalyst of?CoFe?OH_x/CuO/c-Cu under optimized conditions exhibits a very low overpotential of 275 mV?with no IR compensation?at a current density of 10 mA cm^-2,and good stability in 1 mol dm^-3KOH solution.2.Rapid preparation of nanoporous copper-silver thin films for non-enzymatic glucose electrochemical sensor by chemical de-alloying method.The nanoporous copper-silver thin film was prepared by soaking a smooth Cu-Ag-Zn electrode in a blank KOH solution without adding any templates and precursors in solutions.The prepared thin film exhibits excellent performance for non-enzymatic glucose detection,such as wide linear range up to 6 mmol dm^-3,short response time?4 s?,superior sensitivity(3572?A(mmol dm^-3)^-1cm^-2),low detection limit(0.37?mol dm^-3),good anti-interference and long-time stability?4 weeks?,and it was used to successfully test the glucose concentration in human blood.3.Micro/nano porous copper-silver thin films were prepared for substrate of oxygen evolution reaction and non-enzymatic glucose sensor by electrodeposition using hydrogen bubble template method.This method is simple,low cost and no post-treatment process.The prepared CuAg thin film exhibits excellent performance in non-enzymatic glucose detection,such as a wide linear range up to 7.11 mmol dm^-3,high sensitivity(3662?A(mmol dm^-3)^-1cm^-2),low detection limit(0.26?mol dm^-3),long-term stability?5 weeks?and reliable accuracy for detecting glucose in human blood.In addition,after?CoFe?OH_x was loaded on this porous copper-silver substrate by SILAR,it exhibits excellent electrocatalytic activity for OER with a very low overpotential of 269 mV?with no IR compensation?at a current density of 10 mA cm^-2and long-term stability in 1 mol dm^-3KOH solution.