Designing and preparing an efficient bifunctional catalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is crucial for achieving electrochemical water splitting. Constructing amorphous/crystalline heterojunctions catalysts are considered an effective method to enhance bifunctional catalytic activity, In this work, we developed an interfacial engineering strategy to prepare a three-dimensional amorphous NiFe layered double hydroxide/crystalline CoMo bimetallic phosphide heterojunction bifunctional composite material NiFe-LDH@CoMo–P on nickel foam using a simple and efficient electrodeposition method. Combining the crystalline CoMo–P for enhanced HER catalytic activity with the amorphous NiFe-LDH for superior OER catalytic activity ensures the bifunctional catalytic performance. Moreover, the formation of unique amorphous/crystalline heterointerfaces accelerates electron transfer, inducing electron rearrangement at the interface and resulting in more suitable Gibbs adsorption energies for catalytic reaction intermediates. This significantly enhances the catalytic reaction kinetics and improves the electrocatalytic activity. Density functional theory (DFT) calculations and experimental studies have shown that the d-band center of the active sites in NiFe-LDH@CoMo–P catalyst shifts towards the Fermi level, thereby optimizing the adsorption strength of catalytic reaction intermediates on the catalyst surface. In 1 M KOH, as a bifunctional catalyst, NiFe-LDH@CoMo–P/NF requires an anodic overpotential of 236 mV to achieve an OER current density of 20 mA cm, and a cathodic overpotential of −49 mV to achieve a HER current density of −10 mA cm. The study provides a new approach for the efficient and low-cost preparation of amorphous/crystalline heterojunction bifunctional catalysts.

中文翻译：

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电沉积法合成非晶态 NiFe-LDH/结晶 CoMo 双金属磷化物异质结双功能催化剂用于高效分解水


设计和制备用于析氢反应（HER）和析氧反应（OER）的高效双功能催化剂对于实现电化学水分解至关重要。构建非晶/晶异质结催化剂被认为是增强双功能催化活性的有效方法，在这项工作中，我们开发了一种界面工程策略来制备三维非晶NiFe层状双氢氧化物/晶CoMo双金属磷化物异质结双功能复合材料NiFe-LDH使用简单高效的电沉积方法在泡沫镍上@CoMo–P。将用于增强 HER 催化活性的结晶 CoMo-P 与用于卓越 OER 催化活性的非晶 NiFe-LDH 相结合，确保了双功能催化性能。此外，独特的非晶/结晶异质界面的形成加速了电子转移，诱导界面处的电子重排，从而产生更适合催化反应中间体的吉布斯吸附能。这显着增强了催化反应动力学并提高了电催化活性。密度泛函理论（DFT）计算和实验研究表明，NiFe-LDH@CoMo–P催化剂中活性位点的d带中心向费米能级移动，从而优化了催化反应中间体在催化剂表面的吸附强度。在 1 M KOH 中，作为双功能催化剂，NiFe-LDH@CoMo–P/NF 需要 236 mV 的阳极过电位才能实现 20 mA cm 的 OER 电流密度，需要 -49 mV 的阴极过电位才能实现 HER 电流密度为−10 mA cm。 该研究为高效、低成本制备非晶/晶异质结双功能催化剂提供了一种新方法。