Preparation Of Co/Fe Bimetallic MOF Materials And The Application Of Oxygen Evolution Reaction In Electrochemical Water Splitting

With the excessive consumption of fossil fuels,people have been vigorously developing renewable energy sources.Clean and unlimited hydrogen for fuel cells and other energy-related storage devices can be produced by electrochemical water decomposition（2H₂O→2H₂+O₂）.Oxygen evolution is an important semi-reaction in water cracking.However,OER is a slow-moving process with high overpotential in both acidic and alkaline media,as it includes multi-step proton-coupled electron transfer and O-O bond formation.Therefore,the high-efficiency catalyst for accelerating the reaction is very necessary.As we all know,Pt,Ru,Ir,Ruo₂,Iro₂and other noble metal-based catalysts have been widely studied and made many remarkable achievements,but its low abundance,high cost and poor long-term stability hinder its wide application.Therefore,it is still a great challenge to find catalysts with high electrocatalytic activity,excellent durability and low cost.In this thesis,a simple hydrothermal method was used to prepare Co Fe bimetallic MOF water catalyst with excellent performance and good stability,and the synthesis strategy of single ligand and double ligand was chosen,a series of Co Fe-based MOF catalysts with good electrochemical properties were prepared.Firstly,the microstructure and composition of the catalyst can be controlled by adjusting the reaction temperature,reaction time and the ratio of reactants to feedstock.According to the literature investigation and many experiments,we determined that the optimum reaction temperature is 170°C and the optimum reaction time is12 hours,the optimal molar ratio of the reactants of the bimetallic monoligand was Co:Fe:ligand=0.15:0.04:0.2,and the optimal molar ratio of the reactants of the bimetallic Biligand was Co:Fe:Ligand 1:ligand 2=0.15:0.04:0.2:0.2.Co_0.15Fe_0.04-BTC_0.2（135）exhibited excellent overpotentialη=261mv（1.481V vs.RHE）at 10 m A cm^-2,with a Tafel slope of59.29 m V dec^-1.Co Fe-PTA/FDA exhibited an excellent OER overpotential=295 m V（1.525V vs.RHE）to 10 m A cm^-2,and a Tafel slope of 62.85 m V dec^-1.Both materials have excellent electrochemical properties and stability.