Pt nanoclusters anchored on hollow Ag-Au nanostructures for electrochemical oxidation of methanol

Abstract

The synthetic method of Pt nanoclusters-anchored hollow Ag-Au nanostructures and measurements of their electrocatalytic properties for methanol oxidation reaction (MOR) were reported here. In this synthesis, uniform Ag nanospheres were prepared by reduction of silver nitrate (AgNO3) with sodium borohydride (NaBH4) in the mixed solution of EDTA and Pluronic P123, and then hollow Ag-Au nanostructures were synthesized via galvanic replacement of the as-prepared Ag nanospheres with Au3+. Finally, reduction of potassium tetrachloroplatinate (Ⅱ) (K2PtCl4) with ascorbic acid was performed to deposit Pt nanoclusters on the surface of hollow Ag-Au nanostructures. It should be noted that optimized conditions, including involvement of EDTA, Pluronic P123, CTAB, and slow injection of HAuCl4 solution by syringe pump, play a key role in our synthesis. The hollow interior of Pt nanoclusters-anchored Ag-Au nanostructures and change in the size of Pt nanoclusters by varying the injected molar ratio of Pt/Au were observed by transmission electron microscopy (TEM). And other morphological, compositional and optical information of the obtained nanoscale materials were analyzed by X-ray diffraction analysis (XRD), inductively coupled plasma mass spectrometry (ICP-MS), and ultraviolet-visible spectroscopy (UV-vis). The electrocatalytic ability of the obtained Pt nanoclusters-anchored hollow Ag-Au nanostructures toward MOR was confirmed by the results of cyclic voltammetric (CV) measurements. The ease of three-step synthetic strategy and good electrocatalytic performance of the Pt nanoclusters-anchored hollow Ag-Au nanostructures displayed their promising potential in the utilization of electrochemical oxidation of methanol.