Controlled Synthesis of Octahedral Platinum-Based Mesocrystals by Oriented Aggregation

Ping Zhong; Hongpo Liu; Jie Zhang; Yadong Yin; Chuanbo Gao

doi:10.1002/chem.201606023

Controlled Synthesis of Octahedral Platinum-Based Mesocrystals by Oriented Aggregation

Chemistry. 2017 May 17;23(28):6803-6810. doi: 10.1002/chem.201606023. Epub 2017 Mar 27.

Authors

Ping Zhong¹, Hongpo Liu¹, Jie Zhang², Yadong Yin³, Chuanbo Gao¹

Affiliations

¹ Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710054, P. R. China.
² School of Science, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, P. R. China.
³ Department of Chemistry, University of California, Riverside, California, 92521, USA.

PMID: 28221006
DOI: 10.1002/chem.201606023

Abstract

Designed synthesis of noble metal mesocrystals is of great significance for a variety of applications. Here, the synthesis of octahedral Pt-Ag alloy mesocrystals with precisely controlled morphology, size, and exposing facets, formed by oriented aggregation of their crystallites, is reported. The critical role of bromide was revealed in regulating the overall octahedral morphology of the Pt-Ag mesocrystals, by bridging the interactions between the capping agent and the Ag-modified Pt crystallites. The size of the mesocrystals was precisely controlled in a broad range by tuning the number of the seeds, all retaining their octahedral morphology. Based on this understanding, octahedral Pt-Ag mesocrystals exposing {1 1 1} facets have been obtained in a highly controllable and reproducible manner. This material showed excellent electrocatalytic activity and stability in oxygen reduction reactions (ORR). It is hoped that the current synthesis provides new insights that pave the way to diverse faceted nanocrystals/mesocrystals for high-performance catalytic and many other applications.

Keywords: electrocatalysis; mesocrystals; morphology control; oriented aggregation; platinum.