MOFs衍生的CoZnSe@NC电催化剂的制备及析氧性能研究

Constructing MOFs-Derived CoZnSe@NC Electrocatalyst for Oxygen Evolution

摘要:

硒化锌因具有与铂类似的电子结构及低成本而受到广泛关注，但目前硒化锌主要应用于电催化析氢反应（HER）中，其析氧反应（OER）活性仍有待提高，并且传统方法合成的硒化锌粒子尺寸较大且分散性较差．基于此，以双金属CoZn-ZIF为前驱体（Co作为OER活性成分，可有效提高材料的OER性能），通过一步高温硒化得到双金属CoZnSe和氮掺杂碳复合材料（记为CoZnSe@NC）．利用X射线粉末衍射（XRD）和扫描电子显微镜（SEM）对复合材料的结构和形貌进行表征，并对其电催化析氧性能进行了测试．结果表明：双金属CoZnSe@NC较单金属ZnSe@NC具有更好的OER性能（10和50 mA/cm²电流密度下CoZnSe@NC的过电位分别为268和354 mV）；此外，CoZnSe@NC经长时间多电流步骤（Multi-Current Steps）测试后性能基本保持不变，展现了较好的电化学稳定性．

Abstract:

Zinc selenide has received widespread attention because their electronic structure is similar to platinum and low cost. However， zinc selenide is mainly used in the electrochemical hydrogen evolution reaction （HER）， and their oxygen evolution reaction （OER） performance still needs to be improved. Besides， zinc selenide nanoparticles synthesized by traditional methods have large size and poor dispersion. This paper uses the bimetallic CoZn-ZIF as the precursor （Co as the active component of OER， which is expected to improve the OER performance of ZnSe）， and obtains the bimetallic CoZnSe and nitrogen-doped carbon composite material （denoted as CoZnSe@NC） through one-step high-temperature selenization. The structure and morphology of the composite material were characterized by X-ray powder diffraction （XRD） and scanning electron microscope （SEM）， and the electrocatalytic oxygen evolution performance was also tested. The results show that bimetallic CoZnSe@NC has better OER performance than monometallic ZnSe@NC （the overpotential of CoZnSe@NC at current densities of 10 mA/cm² and 50 mA/cm² are 268 mV and 354 mV， respectively）. In addition， the performance of CoZnSe@NC remained basically unchanged after a long-term multi-current steps test， showing better electrochemical stability.