Center for Catalytic Science & Technology, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, USA.
J Am Chem Soc. 2013 Mar 20;135(11):4516-21. doi: 10.1021/ja400555q. Epub 2013 Mar 12.
Oxygen evolution from water by use of earth-abundant element-based catalysts is crucial for mass solar fuel production. In this report, a mesoporous cobalt oxide with an ultrahigh surface area (up to 250 m(2)·g(-1)) has been fabricated through Mg substitution in the mesoporous Co3O4 spinel, followed by a Mg-selective leaching process. Approximately a third of Mg cations were removed in the leaching process, resulting in a highly porous cobalt oxide with a significant amount of defects in the spinel structure. The activated mesoporous cobalt oxide exhibited high oxygen evolution activities in both the visible-light-driven Ru(bpy)3-persulfate system and the Ce(4+)/Ce(3+) chemical water oxidation system. Under a strong acidic environment, a high turnover frequency (TOF) of ~2.2 × 10(-3) s(-1) per Co atom was achieved, which is more than twice the TOF of traditional hard-templated, mesoporous Co3O4.
通过使用基于丰富地球元素的催化剂将水转化为氧气，对于大规模太阳能燃料生产至关重要。在本报告中，通过在介孔尖晶石 Co3O4 中进行 Mg 取代，然后进行 Mg 选择性浸出，制备了具有超高表面积（高达 250 m2·g-1）的介孔氧化钴。在浸出过程中大约有三分之一的 Mg 阳离子被去除，导致尖晶石结构中具有大量缺陷的高度多孔氧化钴。活化的介孔氧化钴在可见光驱动的Ru(bpy)3-过硫酸盐系统和 Ce(4+)/Ce(3+)化学水氧化系统中均表现出高的氧气析出活性。在强酸性环境下，每钴原子的高周转频率（TOF）达到约 2.2×10-3 s-1，是传统硬模板介孔 Co3O4 的 TOF 的两倍多。
