钴
催化作用
析氧
化学
氧化钴
产量(工程)
纳米材料
无定形固体
过渡金属
纳米技术
化学工程
无机化学
电化学
材料科学
物理化学
冶金
有机化学
工程类
电极
作者
Lukas Reith,Carlos A. Triana,Faezeh Pazoki,Mehran Amiri,May Nyman,Greta R. Patzke
摘要
The oxygen evolution reaction (OER) is a key bottleneck step of artificial photosynthesis and an essential topic in renewable energy research. Therefore, stable, efficient, and economical water oxidation catalysts (WOCs) are in high demand and cobalt-based nanomaterials are promising targets. Herein, we tackle two key open questions after decades of research into cobalt-assisted visible-light-driven water oxidation: What makes simple cobalt-based precipitates so highly active-and to what extent do we need Co-WOC design? Hence, we started from Co(NO3)2 to generate a precursor precipitate, which transforms into a highly active WOC during the photocatalytic process with a [Ru(bpy)3]2+/S2O82-/borate buffer standard assay that outperforms state of the art cobalt catalysts. The structural transformations of these nanosized Co catalysts were monitored with a wide range of characterization techniques. The results reveal that the precipitated catalyst does not fully change into an amorphous CoOx material but develops some crystalline features. The transition from the precipitate into a disordered Co3O4 material proceeds within ca. 1 min, followed by further transformation into highly active disordered CoOOH within the first 10 min. Furthermore, under noncatalytic conditions, the precursor directly transforms into CoOOH. Moreover, fast precipitation and isolation afford a highly active precatalyst with an exceptional O2 yield of 91% for water oxidation with the visible-light-driven [Ru(bpy)3]2+/S2O82- assay, which outperforms a wide range of carefully designed Co-containing WOCs. We thus demonstrate that high-performance cobalt-based OER catalysts indeed emerge effortlessly from a self-optimization process favoring the formation of Co(III) centers in all-octahedral environments. This paves the way to new low-maintenance flow chemistry OER processes.
科研通智能强力驱动
Strongly Powered by AbleSci AI