Amorphous Cobalt Oxide Nanoparticles as Active Water‐Oxidation Catalysts. Issue 19 (2nd August 2017) - Chen, Zheng
Abstract: Artificial photosynthesis requires the practical use of efficient, robust, and economical water‐oxidation catalysts (WOCs) for chemical‐fuel production. The synthesis of amorphous cobalt oxide nanoparticles (ca. 2 nm) is reported as a WOC with a turnover frequency up to 8.6 s −1 in the photocatalytic Ru(bpy)3 2+ –Na2 S2 O8 system (bpy=2, 2′‐bipyridyl). This activity is unprecedented in heterogeneous cobalt‐based WOCs and is even comparable to that of a state‐of‐the‐art homogeneous cobalt‐based polyoxometalate catalyst. With the help of experimental and computational X‐ray absorption spectroscopy, the atomic structure of the synthesized amorphous cobalt oxide nanoparticles was characterized, and it consists of a one‐dimensional chain of dimeric edge‐sharing CoO6 octahedra. Theoretical calculations suggest that this structure was able to promote O−O bond coupling, unlike crystalline cobalt oxide WOCs, which led to the enhanced water‐oxidation activity. Abstract : WOC of life : Amorphous cobalt oxide nanoparticles (2 nm) composed of one‐dimensional chains of dimeric edge‐sharing octahedra are extremely active towards water oxidation with a turnover frequency (TOF) value reaching 8.6 s −1 in the photocatalytic Ru(bpy)3 2+ –Na2 S2 O8 (bpy=2, 2′‐bipyridyl) system.