Dung Dao Thi, Lam Do Van, Roh Euijin, Ji Sanghyeon, Yuk Jong Min, Kim Jae-Hyun, Kim Hyunuk, Lee Seung-Mo
Korea Institute of Machinery and Materials (KIMM), 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, South Korea.
University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea.
Nanoscale. 2023 Jan 27;15(4):1794-1805. doi: 10.1039/d2nr05686k.
The design of nanostructured materials for efficient bifunctional electrocatalysts has gained tremendous attention, yet developing a fast and effective synthesis strategy remains a challenge. Here, we present a fast and scalable synthetic method of Ni/Co/CoO@C nanorods for efficient overall water splitting. Using microwave synthesis, we first produced a unique Ni-MOF@Co-MOF in a few minutes. Subsequently, we transformed the MOF@MOF into hybrid Ni/Co/CoO nanoparticles covered with graphitic carbon in a few seconds using laser-scribing. The prepared bimetallic catalysts showed remarkably low overpotentials of 246 mV for the oxygen evolution reaction (OER) and 143 mV for the hydrogen evolution reaction (HER) at a current density of 30 mA cm. An electrolyzer assembled with the bimetallic catalysts delivered a high current density of 20 mA cm at a voltage of 1.6 V and exhibited good durability (nearly 91.6% retention even after a long-running operation of 24 h at a voltage of 1.52 V). Our proposed method could serve as a powerful method for creating various multimetallic hybrid nanocatalysts with unique hierarchical structures from diverse MOFs.
用于高效双功能电催化剂的纳米结构材料设计已引起广泛关注，但开发一种快速有效的合成策略仍然是一项挑战。在此，我们展示了一种用于高效全水解的Ni/Co/CoO@C纳米棒的快速且可扩展的合成方法。利用微波合成，我们在几分钟内首先制备出一种独特的Ni-MOF@Co-MOF。随后，我们使用激光刻写在几秒钟内将MOF@MOF转变为覆盖有石墨碳的混合Ni/Co/CoO纳米颗粒。所制备的双金属催化剂在电流密度为30 mA cm时，析氧反应（OER）的过电位低至246 mV，析氢反应（HER）的过电位低至143 mV。用该双金属催化剂组装的电解槽在1.6 V电压下可提供20 mA cm的高电流密度，并表现出良好的耐久性（即使在1.52 V电压下长时间运行24 h后，仍保持近91.6%的电流密度）。我们提出的方法可作为一种强大的方法，用于从各种金属有机框架（MOF）制备具有独特分级结构的各种多金属混合纳米催化剂。
