title: Hollow Ag/MnO2Nanostructures with Controllable Shells: Synthesis and Oxygen Reduction Reaction Catalytic Performance.
abstract: Novel hollow Ag/MnO2nanostructures with controlled shell composition and structure were designed and synthesized. In the present synthetic procedure, silver nanocrystals were oxidized by KMnO4, and MnO2was heterogeneously formed on the surface of silver nanocrystals, then released Ag+was photoreduced to silver adjacent to MnO2. By simply changing the photoreduction moment, simultaneously with or after the addition of KMnO4, hollow Ag/MnO2structures with different shell architectures-a monolayered shell composed of evenly mixed silver and MnO2and a double-layered shell composed of an inner MnO2layer and an outer silver layer-can be obtained. Furthermore, the morphology of the hollow structure can be tuned by selecting different silver precursors, and the ratio of silver to MnO2in the shell can also be controlled by adjusting the ratio in the original reaction mixture. Electrochemical measurements revealed significantly enhanced catalytic performance in the oxygen reduction reaction for the prepared hollow structures. Compared with the Ag/MnO2composite, the onset potentials positively shift by about 50.0 mV and limiting current densities are nearly 2.0 times higher.
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Xinfu
authors.initials: X
authors.lastname: Zhao
authors.affiliation: National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.|National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Xiuling
authors.initials: X
authors.lastname: Jiao
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Pang
authors.affiliation: School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, P.R. China.|National Engineering Research Center for Colloidal Materials, Shandong University, Jinan, 250100, P.R. China.
authors.forename: Dairong
authors.initials: D
authors.lastname: Chen
keywords: electrochemistry; nanostructures; redox chemistry; silver; synthesis design