In meeting the energy demand of green resources, the fabrication of effective yet cheap electrocatalytic active catalysts for the rate‐limiting half reaction, oxygen evolution reaction (OER), of electrochemical water splitting is highly desired. In this study, it is presented that a deliberately deposited amorphous FeOOH layer can drastically promote the electrocatalytic OER activity of CoSe₂. Unlike the pristine CoSe₂ which is consumed gradually, the amorphous FeOOH layer facilitates the capture and fixation of dissolved Co²⁺ ions, which is confirmed by the stable element contents during OER process. As a result, a low overpotential of 253 mV (@ j = 40 mA cm⁻²) is displayed by CoSe₂@FeOOH nanorod arrays (NAs) on carbon cloth (CC) with a small Tafel slope of 69 mV dec⁻¹, which are comparable or even lower than the state‐of‐the‐art OER electrocatalysts. In addition, the long‐time durability test indicates the remarkable stability of this material over 20 h. These outcomes provide new perception in design and large scale fabrication of cheap yet effective heterostructured OER catalysts.

中文翻译：

---

非晶态FeOOH装饰的CoSe2纳米棒异质结构阵列，用于高效水氧化

为了满足绿色资源的能源需求，迫切需要制造有效而廉价的电催化活性催化剂，用于电化学水分解的限速半反应，放氧反应（OER）。在这项研究中，提出故意沉积的非晶态FeOOH层可以大大提高CoSe ₂的电催化OER活性。与逐渐消耗的原始CoSe ₂不同，无定形的FeOOH层有助于捕获和固定溶解的Co ²⁺离子，这在OER过程中稳定的元素含量得到了证实。结果，CoSe ₂显示出253 mV（@ j  = 40 mA cm ^-2）的低过电势Tafel斜率小的69 mV dec ^-1的碳布（CC）上的@FeOOH纳米棒阵列（NAs）与现有的OER电催化剂相当甚至更低。此外，长期耐久性测试表明该材料在20小时内具有出色的稳定性。这些结果为廉价但有效的异质结构OER催化剂的设计和大规模生产提供了新的认识。