Metal–organic frameworks (MOFs) derivatives are excellent electrocatalytic materials due to their own structural characteristics. However, it is still very essential to design a logical synthesis route of MOFs derivatives to avoid the adverse effects caused by the collapse of MOFs structure and improve its intrinsic catalytic activity. For these reasons, we designed and synthesized cobalt-based metal-organic framework (ZIF67) grown in situ at the edge of Co(OH)₂ nanosheets. Through adjusting the alcohol-water ratio of the reaction solution, the number of ZIF67 grown on the Co(OH)₂ can be controlled to make it grow uniformly at the edge of nanosheet. After the selenization reaction in a tube furnace, ZIF67 is transformed into CoSe₂ (Co-Z/Se-2) with a yolk-shell structure. This precisely designed synthetic route allows Co-Z/Se-2 to expose more active sites, which is conducive to electron transport and has good performance in both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). Co-Z/Se-2 as UOR catalyst only needs 1.390 V to reach 50 mA cm⁻². Co-Z/Se-2 as bifunctional catalysts, are assembled to be a urea electrolyzer cell. Co-Z/Se-2 || Co-Z/Se-2 only needs 1.490 V to drive 10 mA cm⁻², and can maintain a good stability for 20 h.

金属有机骨架（MOFs）衍生物因其自身的结构特征而成为出色的电催化材料。然而，设计MOFs衍生物的逻辑合成路线以避免由MOFs结构崩溃引起的不利影响并提高其固有的催化活性仍然非常重要。由于这些原因，我们设计并合成了在Co（OH）₂纳米片的边缘原位生长的钴基金属有机骨架（ZIF67）。通过调节反应溶液的醇水比，可以控制在Co（OH）₂上生长的ZIF67的数目，以使其在纳米片的边缘均匀生长。在管式炉中进行硒化反应后，ZIF67转化为CoSe ₂（Co-Z / Se-2）具有蛋黄壳结构。这种精确设计的合成途径使Co-Z / Se-2暴露出更多的活性位，这有利于电子传输，并且在尿素氧化反应（UOR）和析氢反应（HER）中均具有良好的性能。Co-Z / Se-2作为UOR催化剂仅需1.390 V即可达到50 mA cm ^-2。将作为双功能催化剂的Co-Z / Se-2组装成尿素电解槽。Co-Z / Se-2 || Co-Z / Se-2只需1.490 V即可驱动10 mA cm ^-2，并且可以保持20小时的良好稳定性。