Research Of The Electro-catalytic Performance Based On Metal Organic Framework/Graphene Composite Material

As an important branch of electrochemistry,electro-catalysis has been widely used in the fields of energy storage,environmental detection,biomedicine and so on.Electrode materials usually play a very important role in the electro-catalysis.Metal organic frameworks（MOFs）is a new kind of porous material.It not only has the high specific surface area and porosity,but also has variable structure and is easy to be tailored.Moreover,the metal center ions of MOFs usually have good electrochemical activity,so MOFs can be used in electrochemical reaction as electrode materials.However,the electrochemical applications of pure MOFs still suffer from the intrinsic deficiency such as the instability,easy to collapse and the poor conductivity.The surface of graphene oxide（GO）contains a variety of oxygen-containing groups,so it is easy to be combined with other materials through reaction.And the graphene oxide could be reduced to graphene which has the excellent electrical conductivity and mechanical properties.Based on this,a series of MOF-GO composites which had the same ligands and different metal ions were prepared by solvothermal reaction and GO was reduced to graphene（ERGO）by the electrochemical method in this work.Then the composites MOF-ERGO were applied in the electro-catalysis.This composition of MOF and GO not only solves the instability of MOFs,but also enhances the conductivity of the material.The specific contents of this work are as follow:（I）The Cu-MOF and Cu-MOF-GO were used as the modified material for the simultaneous determination of catechol（CT）and hydroquinone（HQ）by the differential pulse voltammetry（DPV）.The experimental results indicated that the Cu-MOF-ERGO-5/GCE showed wide detection range and lower detection limit for the detection CT and HQ when the mass percentage of doped GO was 5%,polymerization cycles was 5 and the pH value of PBS was 6.The linear ranges of CT and HQ were obtained as 0.1-566μM and 0.1-476μM respectively with corresponding same detection limits of 0.1 M.（II）M-MOF（M=Cu,Fe,Ni,Al）and M-MOF-GO-n（n represents the added GO contents based on the total mass of starting solid materials）were synthesized by the same organic ligand.The prepared M-MOF and M-MOF-GO-n composites were characterized by XRD,FT-IR,Raman and SEM.The composites were fabricated on the electrode surface by electro-polymerization and the M-MOF-ERGO-n/GCE was obtained after electrochemically reduced by the cyclic voltammetry.The hydrogen evolution behavior of the modified electrode in N₂ saturated 0.5 M H₂SO₄ solution was tested by linear voltammetry（LSV）.The experimental results show that the content of graphene had a significant effect on the overpotential and Tafel slope of the hydrogen evolution reaction.The overpotential and Tafel slope decreased and the catalytic properties would improve only when a certain amount of GO was doped.Differentmetalcentersshoweddifferentcatalyticperformance.Fe-MOF-ERGO-2/GCE showed the highest performance for the hydrogen evolution reaction with an onset potential of-0.100 V,an overpotential of-0.214 V at 10mA/cm²and a low Tafel slope of 115 mV/dec.M-MOF-ERGO/GCE showed good detection performance,anti-interference ability,stability and reproducibility in the sample detection of CT and HQ.In addition,the M-MOF-ERGO/GCE had low overpotential and fast hydrogen evolution rate after doped GO.It’s catalytic activity was improved.The M-MOF-ERGO/GCE was useful to the further reserch about electrocatalyst.