Synthesis And Electrocatalytic Properties Of Metal-organic Framworks-based Materials

Porous materials derived from MOFs-based had active metal catalytic sites and controllable structures,which had wide application value in the field of electrocatalysis.The electrocatalytic activity of MOFs-based derived materials can be improved by doping or compounding.In order to use these advantages,a series of electrocatalysts with high electrocatalytic activity were prepared by pyrolysis,compounding and phosphating with iron-based metal organic skeleton as precursor,which were used in the study of electrocatalytic hydrogen evolution and electrocatalytic oxidation of dopamine.Fe₂O₃@Ni_xCo_y-LDH with flower-like layered structure was prepared based on Fe₂O₃derived from ferric organic framework and compounded with Ni Co layered double hydroxide.The effects of Ni/Co mole ratio and phosphating on the activity of electrocatalytic hydrogen evolution were investigated.With the molar ratio of Ni/Co=1:2,and phosphating on Fe₂O₃@Ni_xCo_y-LDH,Fe₂O₃@P-Ni₁Co₂-LDH had a low hydrogen evolution overpotential（223 m V）at the current density of 10 m A·cm^–2and a low Tafel slope(81.1 m V·dec^–1).Meanwhile,it showed good stability in electrocatalytic process.Fe Ni alloy nanoparticles coated carbon matrix coated(Fe_xNi_1-x@C)were prepared by high temperature calcination in inert atmosphere using Fe Ni-MOF as precursor.Fe_xNi_1-x@C_250-800was prepared by curing Fe Ni-MOF at 250℃for 2 h,and then calcining to 800℃,Fe_xNi_1-x@C_250-800maintained the morphology of Fe Ni-MOF nanorods.When the mass ratio of Na H₂PO₂and Fe_xNi_1-x@C_250-800was 10:1,Fe_xNi_1-x@C_250-800,P_（10:1）had good hydrogen evolution activity.At the current density of 10 m A·cm^–2,the hydrogen evolution overpotential is 189 m V,and the Tafel slope is 91.9 m V·dec^–1.Meanwhile,Fe_xNi_1-x@C_250-800,P_（10:1）showed good stability.Fe/Fe₃O₄@C composites were prepared by calcining Fe-MOF precursor at high temperature in inert atmosphere.The electrocatalytic behavior of calcination products towards DA oxidation was investigated.With the temperature of 650℃,Fe/Fe₃O₄@C_-650/GCE had the highest catalytic activity for DA oxidation.Fe/Fe₃O₄@C_-650/GCE based on CV and DPV method showed wide linear range and high sensitivity in DA determination.In addition,the sensor shows reproducibility and stability,and can be applied to the determination of DA in serum samples.Figure 37;Table 4;Reference 113...