title: A general method for the rapid synthesis of hollow metallic or bimetallic nanoelectrocatalysts with urchinlike morphology.
abstract: We have reported a facile and general method for the rapid synthesis of hollow nanostructures with urchinlike morphology. In-situ produced Ag nanoparticles can be used as sacrificial templates to rapidly synthesize diverse hollow urchinlike metallic or bimetallic (such as Au/Pt) nanostructures. It has been found that heating the solution at 100 degrees C during the galvanic replacement is very necessary for obtaining urchinlike nanostructures. Through changing the molar ratios of Ag to Pt, the wall thickness of hollow nanospheres can be easily controlled; through changing the diameter of Ag nanoparticles, the size of cavity of hollow nanospheres can be facilely controlled; through changing the morphologies of Ag nanostructures from nanoparticle to nanowire, hollow Pt nanotubes can be easily designed. This one-pot approach can be extended to synthesize other hollow nanospheres such as Pd, Pd/Pt, Au/Pd, and Au/Pt. The features of this technique are that it is facile, quick, economical, and versatile. Most importantly, the hollow bimetallic nanospheres (Au/Pt and Pd/Pt) obtained here exhibit an area of greater electrochemical activity than other Pt hollow or solid nanospheres. In addition, the approximately 6 nm hollow urchinlike Pt nanospheres can achieve a potential of up to 0.57 V for oxygen reduction, which is about 200 mV more positive than that obtained by using a approximately 6 nm Pt nanoparticle modified glassy carbon (GC) electrode. Rotating ring-disk electrode (RRDE) voltammetry demonstrates that approximately 6 nm hollow Pt nanospheres can catalyze an almost four-electron reduction of O(2) to H(2)O in air-saturated H(2)SO(4) (0.5 M). Finally, compared to the approximately 6 nm Pt nanoparticle catalyst, the approximately 6 nm hollow urchinlike Pt nanosphere catalyst exhibits a superior electrocatalytic activity toward the methanol oxidation reaction at the same Pt loadings.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Jilin, PR China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Guo
authors.forename: Shaojun
authors.initials: S
authors.lastname: Dong
authors.forename: Erkang
authors.initials: E
authors.lastname: Wang
mesh_terms: D002384:Catalysis; D004563:Electrochemistry; D049329:Nanostructures / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010316:Particle Size; D010984:Platinum / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D009942:Organometallic Compounds; D012834:Silver; D010984:Platinum