Preparation And Electrocatalysis Of Noble Metal Nanomaterials Based On Protein Amyloid Fibrils

The synthesis of nanostructure materials based on biotemplates has drawn increasedattention from research community due to their critical advantages of low consumption,environmental protection, small sizes and self-assembly. The one dimensional size andprotein skeleton of amyloid fibrils make these structures desirable nanomaterials toprepare a lot of nanostructure systems. In this paper, α-chymotrpsin amyloid fibrils(α-CTAFS) and insulin amyloid fibrils (INSAFs) were used as templates to control thesynthesis of one dimensional Pt nanoparticles chains (PtNPCs) and ultrathin Pt nanowires(UTPtNWs). The samples were characterized by TEM, SEM, PL, UV and electrochemicaltechniques. The details and results are summarized as follows:The α-chymotrpsin was used as templates to conduct Pt nanoparticles and theinfluence of pH on the growth of products was also demonstrated. Then, PtNPCs withdiameter ranging from15~20nm and length to micrometers were fabricated usingα-CTAFS as a sacrificial template, and the influences of reagent concentrations andreductants on the growth of PtNPCs were also studied. Electrochemical measurementobservations indicated that DMAB was a facile reducing agent to prepare PtNPCs with amore uniform particle size and higher catalytic activity on methanol oxidation (MOR) andoxygen reduction reaction (ORR) than that obtained by using NaBH4as reductant.The INSAFs were used as scaffolds to fabricate abundant of highly uniformsingle-crystalline UTPtNWs with diameter of about1.8nm and length of micrometers.Then, a facile NH3-processed protocol was employed to remove the INSAFs templatesand obtain pure UTPtNWs. The morphology and the structure of UTPtNWs werecharacterized by TEM, HRTEM, SAED and XRD. Cyclic voltammetry tests revealed thatthe template-removing UTPtNWs displayed a higher electrochemical active surface area(ECSA) of81.23m2/gPtthan our previously reported UTPtNWs with INSAFs templates(71.34m2/gPt)。Subsequently, the oxygen reduction reaction (ORR) activity of thetemplate-removing UTPtNWs was studied in relation to the activities of both commercialPt/C and Pt black electrocatalysts. Results indicated that our template-removingUTPtNWs showed a significant enhanced ORR performance than commercial Pt/C and Pt black catalysts.