The synthesis of structurally ordered non‐noble intermetallic cobalt stannide (CoSn₂) nanocrystals and their utilization for high‐performance electrocatalytic overall water‐splitting is presented. The structurally and electronically beneficial properties of the tetragonal CoSn₂ exhibit a considerably low overpotential for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) on fluorine‐doped tin oxide (FTO) and Ni foam (NF). Loss of Sn from the crystal lattices and oxidation of Co under strongly alkaline conditions furnishes highly disordered amorphous active CoO_x(H), the catalytically active structure for OER. The Co⁰ atoms in the CoSn₂ act as active sites for HER and the presence of Sn provides efficient electrical conductivity. This intermetallic phase is a novel type of cost‐effective and competitive bifunctional electrocatalysts and predestinated for overall water‐splitting devices: A two‐electrode electrolyzer with CoSn₂ on NF delivers a cell voltage of merely 1.55 V at 10 mA cm⁻² maintaining long‐term stability.

中文翻译：

---

高效电催化整体水分解的结构有序金属间化合物钴锡纳米晶体

介绍了结构有序的非贵金属间锡化钴（CoSn ₂）纳米晶体的合成及其在高性能电催化总水分解中的应用。四方CoSn ₂的结构和电子特性对掺氟氧化锡（FTO）和泡沫镍（NF）上的氧释放反应（OER）和氢释放反应（HER）表现出极低的过电势。晶格中Sn的损失以及Co在强碱性条件下的氧化会提供高度无序的非晶态活性CoO _x（H），这是OER的催化活性结构。CoSn _2中的Co ⁰原子充当HER的活性位点，并且Sn的存在提供了有效的电导率。这种金属间相是一种新型的经济高效且具有竞争力的双功能电催化剂，预定用于整体水分解装置：NF上带有CoSn _2的双电极电解槽在10 mA cm ^-2时仅提供1.55 V的电池电压，可保持较长的使用寿命长期稳定性。