NiCo- MOF-74的制备及其电催化氧气析出性能

Preparation of NiCo-MOF-74 and its electrocatalytic oxygen precipitation performance

采用简单的一步水热法制备了不同Ni、Co物质的量比的双金属NiCo-MOF-74催化剂,利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和N2吸/脱附法(BET)对催化剂进行了结构表征,并且在1 mol/L KOH电解液中通过线性伏安法评价了催化剂的氧气析出反应(OER)催化性能。结果表明:所制备的催化剂中含有C、O、Co、Ni 4种元素,并且具有棒状多面体结构和较高的结晶度,当Ni含量较低时,催化剂具有较好的OER催化活性,当Ni的摩尔分数超过10%时,催化剂的OER催化性能随着Ni含量的增加而下降。通过调节原料中Ni、Co的物质的量比,制得的Ni0.5Co9.5-MOF-74样品具有最好的OER催化性能,其在电流密度为10 mA/cm^2时的过电压仅为352 mV,在相同测试条件下稳定性优于RuO2。

Bimetallic NiCo-MOF-74 catalysts with different Ni/Co molar ratios have been prepared by a simple one-step hydrothermal method.The catalysts were characterized by XRD,SEM,XPS and BET.The catalytic activities of NiCo-MOF-74 in the oxygen evolution reaction(OER) were evaluated by linear sweep voltammetry(LSV) in 1 mol/L KOH electrolyte.The results show that the prepared MOF catalysts contain C,O,Ni and Co elements.The catalysts have high crystallinity and a bar-polyhedron structure.However,when the content of Ni is low,the catalyst has excellent activity for OER.When the content of Ni exceeds 10%,the activity for OER decreases with further increases in the content of Ni.By adjusting the molar ratio of Ni/Co in the raw material,Ni0.5Co9.5 MOF-74 was prepared and this material shows the best activity for OER,with an overvoltage at a current density of 10 mA/cm^2 of only 352 mV.Under the same test conditions,the stability of this material is better than that of RuO2.