Bio-inspired Synthesis And Properties Of Noble Nanomaterials By HaNPV

Noble metal nanomaterials have an irreplaceable role in the fields of catalysts in organic chemical reaction,full cells and sensors,due to their unique physical and chemical properties.The design and synthesis of noble metal nanomaterials with various structures is an important hot topic in the current nanotechnology.Bio-inspired synthesis has provided a mild and environmentally friendly method for the synthesis of nanostructured materials because of their advantages of the functional diversity,cheap,available and renewable.In this paper,the natural helicoverpa armigera nucleopolyhedrosis virus?HaNPV?was selected as the source of biomolecules.A variety of protein molecules with specific structures and functions were obtained by controlling the purification and alkaline hydrolysis method.Then,noble metal?Pt,Pd and Au?nanocatalysts with various morphologies and compositions were synthesized.Finally,the elecrtocatalytic properties of the samples were investigated,and the prepared samples were used as catalysts in acid fuel cell or alkaline fuel cell.The details and results are summarized as follows:?1?Porous Pt nanoclusters and Pt nanostars were synthesized by using the lattice-like protein.The influences of treatment time in alkali solution and pH on the structure of the protein,as well as the Pt nanostructures,were investigated.Combining with the results of FTIR and blank control experiment,it reveals that the lattice-like protein was worked as a functional template during the synthesis of Pt nanostructures.Cyclic voltammetry results showed that the catalytic activities of Pt nanoclusters and Pt nanostars,towards methanol oxidation in acid solution,were much higher than the Pt nanoparticles which synthesized without protein.?2?We demonstrated the spontaneous formation of small,uniform and highly crystalline Pd@PdO nanoparticles along helicoverpa armigera nucleopolyhedrosis virus?HaNPVs?biotemplates without external reducing agents.The influences of concentration of the precursor solution and reductant on the structure of the samples were investigated.Combining with the results of FTIR and UV-vis,the function of HaNPVs was discussed.The results of EDS,XRD and XPS revealed the small Pd nanoparticles coexisting with PdO.The obtained Pd@PdO NPs were well dispersed on the carbon supports.The resultsof electrochemical measurement showed that Pd@PdO NPs/C catalyst exhibited superior electrocatalytic performance towards ethanol and methanol electrooxidation than the Pd@PdO NPs samples,and the presence of PdO can enhance the electrooxidation activity.?3?Using the polyhedrin solution,Au nanoparticles and Au network nanowires were prepared respectively.The influences of incubation time,concentration of precursor and polyhedrin solution on the structure of the samples were investigated.Combining with the results of FTIR,UV-vis and XPS,the function of polyhedrin was discussed.The results revealed that the polyhedrin acted both as reducing and capping agents in the growth of Au nanotrutures.The results from electrochemical measurement showed that the catalytic activities of Au nanotrutures synthesized by polyhedrin were much higher than the Au nanoparticles which were synthesized without polyhedrin.?4?Using the polyhedrin solution,the Pt,Pd and Pt-Pd alloy nanomaterials with virous shapes were prepared.The influences of the concentration of precursor and polyhedrin solution on the samples were investigated.It revealed that the precursor solutions had small influence on the structures of polyhedrin frameworks.The results of FTIR,UV-vis and XPS revealed that the polyhedrin acted both as shape guide agent and stabilizer in the growth of nanotrutures.And,the polyhedrin had an extremely weak reducibility for Pt salt solution,and almost no reducibility for Pd salt solution.?5?Cyclic voltammetry was used to study the electrocatalytic performance of the Pt,Pd and Pt-Pd alloy nanocatlysts towards methanol or ethanol electro-oxidation.The influences of carbon supports?multi-walled carbon nanotube,MWCNT or carbon black,CB?on the Pd nanostructures were investigated.The results indicated that MWCNT and CB supports could significantly enhance the performance of PdNPs and PdNWs toward the ethanol electroxidation reaction?EOR?,and the enhancement for PdNPs was more apparent.The catalytic activities of the as-prepared Pt NW/CB and PdNW/CB were much higher than that of PtNP/CB and PdNP/CB.While,the PtPdNW/CB showed the highest activity,its mass current density of MOR was 10010 A g^-1,the mass current density of EOR was 8500 A g^-1,both higher than that of commercial Pt/C and Pd/C catalysts.