Electrochemical water splitting requires efficient, low‐cost water oxidation catalysts to accelerate the sluggish kinetics of the water oxidation reaction. A rapid photocorrosion method is now used to synthesize the homogeneous amorphous nanocages of Cu‐Ni‐Fe hydr(oxy)oxide as a highly efficient electrocatalyst for the oxygen evolution reaction (OER). The as‐fabricated product exhibits a low overpotential of 224 mV on a glassy carbon electrode at 10 mA cm−2 (even lower down to 181 mV when supported on Ni foam) with a Tafel slope of 44 mV dec−1 for OER in an alkaline solution. The obtained catalyst shows an extraordinarily large mass activity of 1464.5 A g−1 at overpotential of 300 mV, which is the highest mass activity for OER. This synthetic strategy may open a brand new pathway to prepare copper‐based ternary amorphous nanocages for greatly enhanced oxygen evolution.

The interface between two material phases typically exhibits unique electronic states distinct from their pure phases, thus, providing a very promising channel to construct catalysts with excellent activity and stability. Here, water‐induced formation of Ni2P–Ni12P5 through a one‐step phosphorization of nickel foam (NF) is demonstrated for the first time. The abundant interfaces endow Ni2P–Ni12P5/NF with excellent electrocatalytic hydrogen evolution reaction (HER) activity in alkaline condition, with an overpotential of 76 mV at a current density of 10 mA cm−2 and of 147 mV at a current density of 100 mA cm−2, and a Tafel slope of 68.0 mV dec−1. The Ni2P–Ni12P5/NF also exhibits better durability than Pt/C/NF during HER at relatively large overpotential. Density functional theory calculations show that the electronic states at the Ni2P–Ni12P5 interface are greatly altered, which enables optimal hydrogen adsorption, accelerates the charge transfer kinetics, and thus enhances the HER electrocatalytic activity. Superior overall water‐splitting performance is also obtained by combining Ni2P–Ni12P5/NF with NiFe–layered double hydroxide (LDH) oxygen evolution reaction (OER) catalyst. Overpotentials of the cell for achieving 10 mA cm−2 are only 324 mV. This work provides a facile method for the preparation of interfaces between different nickel phosphide polymorphs toward HER.

Figure 3. a) Polarization curves b) Tafel plots and c) Mass activity and TOF comparison of AN-CuNiFe, AN-NiFe, NiFeLDH and IrO 2 in 1 m KOH solution on glassy carbon electrode, d) Chronopotentiometry of AN-CuNiFeatacurrent density of 10 mA cm À2 with TEM image of the AN-CuNiFesample after 12 hin-dark test inserted, scale bar is 100 nm. Angewandte Chemie Communications 4191

An efficient nickel-catalyzed regioselective hydroarylation of 1,3-dienes with aryl halides and a silane has been developed, affording a range of allylic arenes in good to excellent yields under mild conditions. This method exhibits broad substrate scope, and excellent functional group tolerance. Late-stage modification of complex architectures was demonstrated.

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