摘要
本文以Co-BTC金属有机框架材料为前驱体,采用连续离子交换法和进一步的高温水热处理来合成片状Ag-CoSO4复合纳米材料.由于少量Ag的引入有利于增强导电性并加速电子转移过程,该催化剂在1 mol/L KOH电解质溶液中表现出优异的OER性能(在10 mA/cm2的电流密度下过电位仅为282 mV),其性能甚至比RuO2更好.催化剂中Ag的存在有利于促进Co(Ⅳ)的产生进而提高Co(Ⅳ)浓度,并且能够调控对氧物种的吸附能而促进OER过程*OOH中间物质的形成,加速了析氧反应过程的进行.极低含量Ag的使用(低于百分之一原子含量)使得催化剂的成本极大的降低.
Cobalt-based nanomaterials have been intensively explored as one of the most promising noble-metal-free oxygen evolution reaction (OER) electrocatalysts. However, most of their performances are still inferior to state-of-the-art precious metals especially for Ru and Ir.Herein, we apply a continuous ion exchange method and further hydrothermal treatment to synthesize the flake-like Ag-CoSO4 nanohybrids beginning from Co-BTC (BTC:benzene-1,3,5-tricarboxylic acid) metal-organic frameworks precursor. The catalyst exhibits superior OER performance under the alkaline electrolyte solution (a low overpotential of 282 mV at 10 mA/cm2 in 1 mol/L KOH), which is even better than RuO2 due to the improved conductivity and rapid electrons transfer process via introducing small amount of Ag. The existence of Ag in the hybrids is beneficial for increasing the Co(IV) concentration, thus promoting the *OOH intermediate formation process. Besides, due to the very low requirement of Ag content (lower than 1 atom%), the cost of the catalyst is also limited. This work provides a new insight for designing of inexpensive OER catalysts with high performance and low cost.
作者
李梦思
林志宇
陈乾旺
Meng-si Li;Zhi-yu Lin;Qian-wang Chen(Hefei National Laboratory for Physical Sciences at the Microscale,Department of Materials Science&Engineering and Collaborative Innovation Center of Suzhou Nano Science and Technology,University of Science and Technology of China,Hefei 230026,China;High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China)
基金
supported by the National Natural Science Foundation(No.21271163,No.1232211,No.21571168)
the Fundamental Research Funds for the Central Universities(WK2060140021)
the CAS/SAFEA International Partnership Program for Creative Research Teams and the Hefei Science Center CAS(2016HSC-IU011)
