A Selective Blocking Method To Control the Overgrowth of Pt on Au Nanorods

Abstract

A method for the preparation of smooth deposits of Pt on Au nanorods is described, involving sequential deposition steps with selective blocking of surface sites that reduces Pt-on-Pt deposition. The Au–Pt nanorods prepared by this method have higher long-term stability than those prepared by standard Pt deposition. Electrochemical data show that the resulting structure has more extended regions of Pt surface and enhanced activity toward the carbon monoxide oxidation and oxygen reduction reactions.

Interfacial Structures and Bonding in Metal-Coated Gold Nanorods

“…The effect of smoothing Pt deposition and increasing its coverage of Au also resulted in greater stability of the NRs. STEM-HAADF carried out on the same samples after more than 18 months showed that the NRs prepared with CO blocking retained their structure [82].…”

“…The method involved sequential Pt deposition steps and exploited the difference in binding energies of carbon monoxide (CO) on Au and Pt surfaces. STEM-HAADF, EDX and electrochemical [82]. Copyright 2013 American Chemical Society measurements all indicated that using CO blocking after the first deposition step resulted in the coverage of remaining exposed Au sites with Pt deposited in the subsequent step rather than continued growth at the ends of the NRs.…”

“…However, the driving force responsible for the interfacial structure of any given system cannot easily be determined by simply considering these parameters in isolation, so we have used computer simulations to assist with the analysis and interpretation of the experimental results. In addition to the AuPd and AuRh systems mentioned above, we have also considered the related AuPt system, for which structural and chemical studies have recently been carried out [82,83].…”

“…Nevertheless, the results from these simulations underline the importance of taking special care in kinetic modelling of such systems to determine the key kinetic processes and to verify whether or not they change within the temperature range under study. 82 R.L. Chantry et al…”

“…The results from this study are summarised in Fig. 11 [82]. The method involved sequential Pt deposition steps and exploited the difference in binding energies of carbon monoxide (CO) on Au and Pt surfaces.…”