Facile water-based synthesis and catalytic properties of platinum-gold alloy nanocubes

Controlled syntheses of noble metal based alloy nanocubes with {100} facets have attracted increasing attention due to their specific physical and chemical properties. This paper reports a facile, green and one-pot synthesis of platinum-gold alloy nanocubes (Pt-Au ANCs) with high yield and uniform size by a facile co-chemical reduction method. The detailed morphology, composition and structure of Pt-Au ANCs were fully characterized and their formation mechanism was investigated. The key synthesis strategy was the introduction of polyallylamine hydrochloride (PAH), which not only acted as a capping agent and facet-selective agent but also served as a complex-forming agent to effectively tune the reduction potentials of HAuCl4/Au and H2PtCl6/Pt pairs to very close values. In addition, the as-prepared Pt-Au ANCs possessed excellent colloidal stability in aqueous solution and exhibited superior catalytic activity toward the reduction of 4-nitrophenol (4-NP) compared to commercial Pt black.