One‐Pot Synthesis of Cobalt‐Doped Pt–Au Alloy Nanoparticles Supported on Ultrathin α‐Co(OH)2 Nanosheets and Their Enhanced Performance in the Reduction of p‐Nitrophenol

Abstract

Cobalt‐doped Pt–Au alloy nanoparticles with a narrow size distribution and small sizes of ca. 4 nm were deposited on ultrathin α‐Co(OH)2 nanosheets through a one‐pot method. The whole process could be divided into two steps: coreduction by NaBH4 and subsequent partial oxidation by air. The compositions of the as‐prepared y‐PtxAu100–x/Co(OH)2 (x = 0, 25, 50, 75, 100, y = 1 %, 10 %) materials can be accurately controlled by adjusting the amounts of the raw materials. The structure of y‐PtxAu100–x/Co(OH)2 was affected by the doped cobalt. The effects of ultrathin α‐Co(OH)2 nanosheets and the chemical composition of PtxAu100–x NPs on the catalytic activity for the reduction of 4‐nitrophenol (4‐NP) were investigated systematically. 1 %‐Pt50Au50/Co(OH)2 exhibits the most significantly enhanced catalytic activity. Its much higher activity than those of 1 %‐Pt/Co(OH)2, 1 %‐Au/Co(OH)2, and a physical mixture of Pt50Au50 nanoparticles and ultrathin α‐Co(OH)2 nanosheets suggests that there is a synergy between the Pt and Au and between the PtxAu100–x nanoparticles and the supports.