Core–Shell Nanocomposites Based on Gold Nanoparticle@Zinc–Iron-Embedded Porous Carbons Derived from Metal–Organic Frameworks as Efficient Dual Catalysts for Oxygen Reduction and Hydrogen Evolution Rea

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• 作者：Jia Lu ; Weijia Zhou ; Likai Wang ; Jin Jia ; Yunting Ke ; Linjing Yang ; Kai Zhou ; Xiaojun Liu ; Zhenghua Tang ; Ligui Li ; Shaowei Chen
• 刊名：ACS Catalysis
• 出版年：2016
• 出版时间：February 5, 2016
• 年：2016
• 卷：6
• 期：2
• 页码：1045-1053
• 全文大小：555K
• ISSN：2155-5435

文摘

Core–shell nanocomposites based on Au nanoparticle@zinc–iron-embedded porous carbons (Au@Zn–Fe–C) derived from metal–organic frameworks were prepared as bifunctional electrocatalysts for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER). A single Au nanoparticle of 50–100 nm in diameter was encapsulated within a porous carbon shell embedded with Zn–Fe compounds. The resulting Au@Zn–Fe–C hybrids exhibited apparent catalytic activity for ORR in 0.1 M KOH (with an onset potential of +0.94 V vs RHE, excellent stability and methanol tolerance) and for HER as well, which was evidenced by a low onset potential of ?0.08 V vs RHE and a stable current density of 10 mA cm^–2 at only ?0.123 V vs RHE in 0.5 M H₂SO₄. The encapsulated Au nanoparticles played an important role in determining the electrocatalytic activity for ORR and HER by promoting electron transfer to the zinc–iron-embedded porous carbon layer, and the electrocatalytic activity was found to vary with both the loading of the gold nanoparticle cores and the thickness of the metal–carbon shells. The experimental results suggested that metal-embedded porous carbons derived from metal–organic frameworks might be viable alternative catalysts for both ORR and HER.