Preparation And Performance Research Of Electrocatalysts Based On ZIF-67

Nowadays,the world economy is developing rapidly,but at the same time the energy shortage and environmental problems have become more and more sharp gradually.So as soon as possible to find alternatives to fossil fuels has become a major issue in the development of the new era.The development of electrocatalytic decomposition of water has a long history,but still face the problem of waste of the electric energy during the water decomposition.Finding suitable electrocatalyst materials is the key to solve this problem.Because of its special structure,MOF has become a hot spot of research,and it has great potential in the water splitting.Firstly,Co-MOF precursor ZIF-67 was prepared and then sintered at 700?,800? and 900?,respectively.The crystal phase and pore structure of the material were characterized by measurements of XRD,TEM and nitrogen adsorption and desorption,and a series of tests were carried out on the electrical properties of the material.The effect of etching and sintering temperature on the catalytic process was further investigated.The test results show that after etching the surface area of the material is bigger.Compared to other samples,the nitrogen doping amount of which was sintered at 800? is up to 2.88%,it has higher degree of graphitization,the ID/IG was 0.943,and the surface area is 464.401cm2/g.the electrochemical properties test results show that,the sample sintered at 800? has better catalytic performance,the overpotential is-306 mV when the current density reached 10mA/cm2,the value of Tafel slope is 98mV/dec,the electronic transfer resistance of the sample is 29.6?,and after calculated,the double layer capacitance of the sample is 2.605mF/cm2.Experimental results show that the catalytic performance of the sample prepared at 800? is better,and it has better stability.Fe doped ZIF-67 was prepared and sintered at 800?.Through the results of XRD and TEM indicated that the Fe element successfully doped into the MOF structure,the 5% dopant amount of nitrogen doping amount is up to 7.03%,it has the highest degree of graphitization,the ID/IG is 0.935 and surface area of 466.9cm2/g.The results show that the catalytic properties of Fe doping 5% sample is the best,its overpotential is-209 mV when the current density reached 10mA/cm2,Tafel slope value is 80mV/dec,the electrochemical impedance calculation of electronic transfer resistance of the material is 23.6?,and then through cyclic voltammograms under different scan speeds,the double layer capacitor of the material is 5.06mF/cm2.The results show that the sample of 5% Fe doping sintered at 800? has the best catalytic properties,and its stability is also very good.