Department of Chemistry, Institute of Materials Design, Hanynag University , Seongdong-gu, 04763 Seoul, Republic of Korea.
Department of Energy and Materials Engineering, Dongguk University , 04620 Seoul, Republic of Korea.
ACS Appl Mater Interfaces. 2017 May 31;9(21):18015-18021. doi: 10.1021/acsami.7b05588. Epub 2017 May 16.
One of the challenges in obtaining hydrogen economically by electrochemical water splitting is to identify and substitute cost-effective earth-abundant materials for the traditionally used precious-metal-based water-splitting electrocatalysts. Herein, we report the electrochemical formation of a thin film of nickel-based Prussian blue analogue hexacyanoferrate (Ni-HCF) through the anodization of a nickel substrate in ferricyanide electrolyte. As compared to the traditionally used Nafion-binder-based bulk film, the anodically obtained binder-free Ni-HCF film demonstrates superior performance in the electrochemical hydrogen evolution reaction (HER), which is highly competitive with that shown by a Pt-plate electrode. The HER onset and the benchmark cathodic current density of 10 mA cm were achieved at small overpotentials of 15 mV and 0.2 V (not iR-corrected), respectively, in 1 M KOH electrolyte, together with the long-term electrochemical durability of the film. Further, a metal-HCF-electrode-based full water-splitting device consisting of the binder-free Ni-HCF film on a Ni plate and a one-dimensional Co-HCF film on carbon paper as the electrodes for the HER and the oxygen evolution reaction (OER), respectively, was designed and was found to demonstrate very promising performance for overall water splitting.
通过在铁氰化物电解质中对镍基底进行阳极氧化，制备了镍基普鲁士蓝类似物六氰合铁酸盐（Ni-HCF）的薄膜。与传统使用的基于 Nafion-粘结剂的体相薄膜相比，阳极获得的无粘结剂 Ni-HCF 薄膜在电化学析氢反应（HER）中表现出优异的性能，其性能与 Pt 板电极相当。在 1 M KOH 电解质中，该薄膜在小过电势 15 mV 和 0.2 V（未进行 iR 校正）下分别达到了 HER 的起始电位和基准阴极电流密度 10 mA cm，同时还具有长期的电化学耐久性。此外，还设计了一种基于金属-HCF 电极的全水分解装置，该装置由 Ni 板上的无粘结剂 Ni-HCF 薄膜和碳纸上的一维 Co-HCF 薄膜组成，分别作为 HER 和析氧反应（OER）的电极，该装置被发现对整体水分解具有很有前景的性能。
