ZnO-templated Ni-based bifunctional catalyst for efficient anion exchange membrane water electrolysis

초록

Recently, anion exchange membrane water electrolysis (AEMWE) has garnered increasing attention due to its potential to utilize non-precious catalysts. Consequently, there has been significant focus on developing catalysts for operation under alkaline conditions. This study reports the electrochemical synthesis of a Ni-based bifunctional catalyst with high activity toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). A ZnO nanorod template was formed on Ni foam via an electrochemical technique to enhance the catalyst's surface area and hydrophilicity. Subsequently, a NiFe-NiMoP/ZnO catalyst was fabricated through sequential electrodeposition of NiMoP and NiFe. The method provided abundant active sites for both HER and OER through amorphous phases and heterogeneous interfaces, resulting in low overpotentials of 132 mV for HER and 290 mV for OER at a current density of 100 mA cm-2 in 1 M KOH. In a full-cell AEMWE setup, the NiFe-NiMoP/ZnO catalyst, employed as both anode and cathode, achieved a cell voltage of 1.87 V to deliver a current density of 1 A cm-2 at 50 degrees C, maintaining stability over 200 h. These findings highlight the potential of the NiFe-NiMoP/ZnO catalyst as an efficient bifunctional catalyst for AEMWE, offering a promising pathway for the development of advanced electrodes in practical applications.

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