Design and synthesis of highly catalytically active, low-cost, and stable electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are the greatest challenges in electrochemical water splitting. In this work, we synthesized an efficient Ce-doped NiFe-layered double hydroxide (LDH) electrocatalyst directly on a nickel foam (NF) substrate at room temperature using an electrodeposition technique. A well-connected nanosheet array forming a three-dimensional (3D) network on the substrate provided a large electrochemical surface area with abundant catalytically active sites. Ce doping in the NiFe-LDH electrocatalyst was vital to enhancing its catalytic performance for the OER and HER. The optimized Ce-doped NiFe-LDH required overpotentials of 175 and 147 mV for the OER and HER, respectively, to achieve a current density of 10 mA cm⁻² in 1 M KOH. The Ce-doped electrocatalyst outperformed bare NiFe-LDH, which required overpotentials of 197 and 175 mV for the OER and HER, respectively. However, when Ce-doped NiFe-LDH was used as a bifunctional catalyst for full water splitting, it needed only 1.59 V to achieve a current density of 10 mA cm⁻² and exhibited excellent stability over 40 hours at 20 mA cm⁻². The enhanced electrochemical performance of Ce-doped NiFe-LDH was ascribed primarily to its unique 3D network, which increased the electrochemical surface area, and to the number of active sites created with Ce doping. The route used in the present study to enhance the catalytic activity of NiFe-LDH can be used to develop various electrocatalysts for water splitting and other catalytic applications.

中文翻译：

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先进且高效的铈辅助NiFe-LDH电催化剂可用于整体水分解†

设计和合成用于氧气析出反应（OER）和氢气析出反应（HER）的高催化活性，低成本和稳定的电催化剂是电化学水分解中的最大挑战。在这项工作中，我们使用电沉积技术在室温下直接在泡沫镍（NF）衬底上直接合成了一种高效的掺Ce的NiFe层状双氢氧化物（LDH）电催化剂。良好连接的纳米片阵列在基板上形成三维（3D）网络，提供了具有丰富催化活性位的大电化学表面积。NiFe-LDH电催化剂中的Ce掺杂对于增强其对OER和HER的催化性能至关重要。对于OER和HER，优化的Ce掺杂NiFe-LDH分别需要175和147 mV的过电势，^-1 in MOH中的^-2。掺Ce的电催化剂的性能优于裸露的NiFe-LDH，这对于OER和HER分别需要197和175 mV的过电势。然而，当Ce掺杂的NiFe-LDH用作满水分解的双功能催化剂，它仅需要1.59 V达到10毫安cm 2的电流密度^-2和在20mA厘米表现出优异的稳定性超过40小时^-2。掺Ce的NiFe-LDH增强的电化学性能主要归因于其独特的3D网络，该网络增加了电化学表面积，并归因于Ce掺杂产生的活性位点的数量。本研究中用于增强NiFe-LDH催化活性的途径可用于开发各种用于水分解和其他催化应用的电催化剂。