Synthesis And Electrochemical Properties Of Nanoporous Metal/Graphene Composites

In recent years,nanoporous metal materials have become a research hotspot in the field of novel functional nanomaterials with their unique three-dimensional nanoporous and nano-ligament structure and a series of novel physicochemical properties.The nanoporous materials have attracted much attention in electrocatalytic,biomedical sensors and new energy sources.Graphene?GR?materials are combined with nanoporous metal materials due to their high specific surface area,electron mobility and other properties to obtain graphene composite nanomaterials with high catalytic performance,which are used in food analysis and detection of biological small molecules.In this thesis,nanoporous platinum iron?NP-PtFe?,nanoporous cerium oxide?NP-CeO₂?,nanoporous copper?NP-Cu?,nanoporous nickel platinum?NP-NiPt?were prepared by the combination of melt quenching and dealloying techniques.The nanoporous metal material prepared above was combined with the GR material,and then the nanoporous metal/GR composite material were used as electrode modification materials in electrochemical sensor.The main contents are as follows:1.NP-PtFe,NP-CeO₂,NP-Cu were prepared by melt quenching-de-alloying method,and were then combine with GR material to modify glassy carbon electrode?GCE?.Electrochemical sensors exhibiting fast,sensitive and anti-interference performance were constructed based on NP-PtFe/GR/GCE,NP-CeO₂/GR/GCE,and NP-Cu/GR/GCE.The NP-PtFe/GR/GCE modified electrode has better electrocatalytic performance for bisphenol A?BPA?than the bare electrode,GR/GCE,NP-Pt/GCE and NP-PtFe/GCE modified electrodes,showing good linearity and low detection limit in the 0.2?M-96?M substrate range,with a value of 0.17?M?S/N=3?.Compared to bare electrode,GR/GCE and the NP-CeO₂/GCE modified electrode,NP-CeO₂/GR/GCE modified electrode has stronger electrocatalytic activity for melamine.The detection range is 0.05?M-20?M,and the detection limit is 0.08?M?S/N=3?.NP-Cu/GR/GCE modified electrode is easier to interact with carbendazim than bare electrode,GR/GCE and NP-Cu/GCE modified electrode,and exhibits better electrocatalytic performance in electrochemical detection,such as larger bottom.The catalytic range is 0.5?M-30?M and the lower detection limit is 0.09?M?S/N=3?.At the same time,this series of modified electrodes have good reproducibility,stability and selectivity,and successfully applied to the detection of BPA,melamine and carbendazim.The excellent catalytic performance of electrochemical sensors is attributed to the higher porosity,larger specific surface area and good electrical conductivity of graphene nanocomposites.Therefore,the construction of NP-PtFe/GR/GCE,NP-CeO₂/GR/GCE and NP-Cu/GR/GCE electrochemical sensors provides a trace detection method for BPA,melamine and carbendazim in food with a quick and easy way.2.Firstly,NP-Ni was prepared by melt quenching-de-alloying method,and then NP-NiPt is prepared by simple displacement reaction with noble metal element?Pt?in noble metal salt?chloroplatinic acid?solution,and finally graphene material with good conductivity and large specific surface area was composited,and a simple NP-NiPt/GR/GCE modified electrode was constructed by drop coating method,which was successfully used for the electrochemical detection of biomolecular dopamine?DA?.The electrochemical sensor constructed by NP-NiPt/GR/GCE modified electrode was compared with bare electrode,GR/GCE and NP-NiPt/GCE.The NP-NiPt/GR/GCE modified electrode has the lowest peak potential and the highest sensitivity,good repeatability,reproducibility and selectivity.The detection range is 0.5?M-300?M,and the detection limit is at least 0.41?M?S/N=3?,and it is successfully applied to the electrochemical detection of biologically active molecules.Trace analysis of key biological small molecule DA in metabolic physiological processes provides a good approach.