Preparation And Electrochemical Sensing Of Novel Precious/transition Metals@carbon-based Nanocomposites

Carbon nanomaterials and noble/transition metal nanoparticles have many specific physical and chemical properties such as light,electricity,magnetism,heat,mechanics,and machinery,so they have attracted widespread attention from scientists.Many carbon nanomaterials and noble/transition metal nanoparticles are widely used in various scientific fields.We build novel noble/transition metal nanoparticles@carbon nanocomposites to realize their electrochemical biosensing and electrocatalysis.The dissertation mainly consists of the following several aspects:1.We have designed a left/right-handed double helix carbon nanotubes@Polypyrrole@Au nanoparticles nanocomposites@left/right-cysteine?L/D-DHCNT@PPy@AuNPs@L/D-Cys?as a novel chiral amino acids biosensor,and this chiral amino acid biosensor interface was successfully constructed via a facile and environment-friendly process.The chiral amino acid biosensor interface has enhanced conductivity,sensitivity,and chiral recognition ability,and can simultaneously electrochemical recognize and quantitative determinate tyrosine?Tyr?,tryptophan?Trp?and glutamic acid?Glu?in their racemic solutions based on potential difference and current ratio.In addition,the electrochemical chiral biosensor interface enables the detection of Tyr in tablets.2.Carbon quantum dots?CQD?encapsulated in super small platinum nanocrystals core-shell architecture/nitrogen doped graphene hybrid nanocomposite?CQD@PDA@PtNCs-NGR?was design synthesized.Without using any capping reagent,stabilizers and surfactant,small size of the CQD was served as template and anchoring point for the synthesis of PtNCs with a super small size and a uniform distribution.Combine the high dispersed PtNCs with high specific surface area and high conductivity of NGR,the CQD@PDA@PtNCs-NGR shows excellent electrocatalytic performance towards the biosensing of DNA damage biomarker 8-Hydroxy-2?-deoxyguanosine?8-OH-dG?.Moreover,the fabricated CQD@PDA@PtNCs-NGR realize the detection of 8-OH-dG in practical samples,and the detection of 8-OH-dG has the advantages of wide linear range,high sensitivity,and low detection limit.3.We creatively synthesize ferric oxide@cupric oxide alloy ball on nitrogen-doped graphene?NG@Fe₂O₃/CuO alloy ball?electrocatalyst.It is worth noting that nitrogen doping,reduction of graphene oxide and conversion of Cu[Fe?CN?₆]·XH₂O cube precursor into Fe₂O₃/CuO alloy ball can be simultaneously realized by facile one-step calcination.Moreover,synergistic effects between the nitrogen-doped graphene and Fe₂O₃/CuO alloy ball can enhance the overall electrocatalytic performance and long-term durability and stability of the catalyst by playing specific roles.4.Multi-core-shell structure Co/FeC@nitrogen doped hollow carbon?Co/FeC@NHC?with tunable carbon shell thickness is well crafted by a novel and simple strategy.Novel core-shell structure consisting of polydopamine?PDA?shell with different thickness and bimetal-based metal-organic frameworks?MOFs?Co/Fe core with cubic morphology are first prepared,followed by a thermal and etching treatments to fabricate hollow composite materials composed of multiple Co/FeC cores evenly distributed in nitrogen doped carbon shell.We optimized and obtained Co/FeC@NHC-1 with the best electrocatalytic performance.Co/FeC@NHC-1 shows the highest electrocatalytic activity,excellent stability and durability for oxygen evolution reaction?OER?.