One-pot synthesis of Au-based nanocrystals via a platinum group metal anion controlled growth strategy in citrate medium

Abstract

The platinum group metals (PGM; Pd, Pt, Ir, etc.) possess unique chemical and physical properties, which often vary dramatically with their size, morphology, crystal structure, phase and composition. However, due to their high cost, insufficient activity, poor stability and scarcity of resources, combining PGM with a second metal to generate bimetallic nanocrystals is considered an efficient method for reducing PGM usage and enhancing activity, especially as in the case of the Au–PGM bimetallic system. The present work introduces a new way for controllable synthesis of Au-based nanocrystals by the simple addition of PGM anion precursors into an aqueous solution of the citrate/HAuCl₄ mixture containing in situ Au nanowires (NWs), at room temperature without the aid of additional reducing agents. Here, the reaction process of a series of PGM anions with the in situ Au NW templates has been studied systematically. This work opens up new possibilities for the facile manufacture of Au-based low PGM content nanocrystals.