Efficient and stable electrocatalytic water splitting plays a critical role in energy storage and conversion but is strongly restricted by the low activity and stability of catalysts associated with the complicated oxygen evolution reaction (OER). This work provides a strategy to fabricate an advanced NiFe-based catalyst to steadily speed up the OER based on a strong amorphous–amorphous coupling effect generated through amorphous CuS that induces the formation of amorphous NiFe layered double hydroxide (LDH) nanosheets (A-NiFe NS/CuS). The presence of the strong coupling effect not only modifies the electronic structure of catalytic sites to accelerate the reaction kinetics but also enhances the binding between the catalyst and substrate to strengthen the durability. In comparison to well-grown core–shell crystalline NiFe LDH on CuO, the as-synthesized amorphous A-NiFe NS/CuS gives a low overpotential of 240 mV to achieve 100 mA cm–2 and shows robust stability under 100 h of operation at the same current density. Therefore, amorphous–amorphous coupling between catalyst–substrate by elaborate and rational engineering yields an opportunity to design efficient and robust NiFe-based OER catalysts.

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Direct seawater electrolysis (DSE) coupled with renewable energy can maximize the sustainability of hydrogen energy acquisition by effectively alleviating the dependence on pure water resources. In a practical sense, the parallel chlorine evolution reaction (CER) of DSE opens up an opportunity to hit ″two birds with one stone″ by the dual values of anode and cathode. However, the biggest challenge is how to control the selectivity of CER to balance its values and drawbacks. Here, we use the different nucleation rates of iridium and barium ions in a weak basic solution and subsequent acid etching to devise an IrOx nanocluster (IrOx-Cs) supported BaCO3. The catalyst–support interaction between IrOx-Cs and BaCO3 enables repelling the Cl– near the electrode interface layer to achieve a controlled CER selectivity. Additionally, the mass activity of the prepared IrOx-Cs@BaCO3 is as high as 1402 A g–1 Ir, which is 7.12 times higher than that of IrO2 oxides in unbuffered seawater. The photovoltaic-electrolysis device paired by IrOx-Cs@BaCO3 with controlled CER activity and Pt demonstrated that valuable active chlorine and H2 can be simultaneously obtained, with the flexibility to bind to different ion exchange membranes.

Electrochemical water splitting coupled with renewable energy offers a promising avenue for energy conversion and storage, but it is also extremely suppressed by the sluggish kinetics of oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, a multi‐layer architecture strategy was utilized by the in situ growth for cobalt phosphate of Hopeite‐like phase (Co‐H) on NiCo‐layered double hydroxide (NiCo‐LDH) to prepare a self‐supported electrode (Co‐H/NiCo@NF). The Co‐H formed over the NiCo‐LDH shows a unique sea urchin‐like morphology. The Co‐H/NiCo@NF displays excellent HER and OER activity, requiring only overpotentials of 180 mV and 350 mV to deliver 100 mA cm−2, consequently, be capable to generate an appealing cell potential of 1.76 V for overall water splitting at the corresponding current density. In addition, the prepared Co‐H/NiCo@NF has long‐term stability against 500 mA cm−2 and exhibits a trend of increased activity, which may associate with the structural reconstructions to form new phases and the strong bonding between layers. These findings demonstrate that the multi‐layer architecture with fine‐component modulation is a promising strategy for the development of robust and efficient cobalt phosphate electrocatalysts, and the role of multi‐layer in the evolution of structural reconstructions deserves further investigation.

Developing Ir-based catalysts with robust OER performance by a simple, green and efficient way is critical for scaling up the PEM to megawatt-levels. Here, we report that the low concentration...