A unique core–shell nanostructured oxygen evolution reaction (OER) catalyst composed of an electrochemically inactive crystalline iron oxide core and an active amorphous nickel phosphide shell is presented, and this catalyst results in superior OER activity. Even activators enhancing the activity of the OER catalyst by promoting the redox reactions are reported, but here the exclusive position of iron in the nanostructures indeed boosted the efficiency due to ideal placement. Moreover, these nanostructures are also prepared in a sophisticated mechanistic approach in which selectively one metal is phosphidated and the other is not. Interestingly, in the absence of iron, nickel phosphide crystallized in a different shape, but in the presence of iron, this specifically formed amorphous Ni_xP became more efficient for promoting the OER. Details of the formation of this active catalyst are studied; the electrochemical reactions are investigated, and the OER activity is compared with that of different leading metal phosphides.

中文翻译：

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惰性氧化铁核对活性磷化镍壳的协同作用，可显着增强放氧反应活性

提出了一种独特的核-壳纳米结构的氧析出反应（OER）催化剂，该催化剂由电化学惰性的结晶氧化铁核和活性的无定形磷化镍壳组成，这种催化剂具有出色的OER活性。据报道，甚至通过促进氧化还原反应而提高OER催化剂活性的活化剂，但由于理想的放置方式，铁在纳米结构中的排他性确实提高了效率。而且，这些纳米结构还以复杂的机械方法制备，其中选择性地一种金属被磷化而另一种不被磷化。有趣的是，在没有铁的情况下，磷化镍以不同的形状结晶，但是在有铁的情况下，这会专门形成无定形的Ni _xP变得更加有效地促进了OER。研究了这种活性催化剂的形成细节。研究了电化学反应，并将OER活性与不同的主要金属磷化物进行了比较。