富氧空位CoMoO_(4)的合成及其析氧反应性能

Synthesis and Oxygen Evolution Reaction Peformance of CoMoO_(4) with Abundant Oxygen Vacancies

通过添加硼氢化钠(NaBH_(4)),采用简易的水热-煅烧两步法,在碳布表面成功制备出富氧空位的纳米针状CoMoO_(4)(V-CoMoO_(4))。利用X射线衍射仪(XRD)、电子自旋共振波谱仪(ESR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线光电子能谱仪(XPS)等表征手段详细表征了V-CoMoO_(4)的物相、结构、形貌以及表面元素化学信息等。采用电化学工作站测试了V-CoMoO_(4)的析氧反应(OER)电催化性能。实验结果表明,NaBH_(4)是V-CoMoO_(4)富氧空位形成的关键,原因在于NaBH_(4)的强还原性可将CoMoO_(4)表面的Co^(3+)还原成Co^(2+)。通过丰富的氧空位和V-CoMoO_(4)特殊的形貌结构两者之间的协同效应,V-CoMoO_(4)的OER性能得到了显著增强。在1 mol/L KOH电解质溶液中,V-CoMoO_(4)的过电位为298.6 mV时电流密度达到100 mA/cm~2,并表现出良好的稳定性。

The nanoneedle CoMoO_(4)containing abundant oxygen vacancies(V-CoMoO_(4))were successfully prepared on the surface of carbon cloth by introducing the sodium borohydride(NaBH_(4))and using the simple two-step process of hydrothermal-calcination.The phase,structure,morphology and chemical information of surface elements of the V-CoMoO_(4)were characte-rized in detail by X-ray diffractometer(XRD),electron spin resonance(ESR)spectrometer,scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray photoelectron spectrometer(XPS).The oxygen evolution reaction(OER)electro-catalytic perfor-mance of the V-CoMoO_(4)was tested by an electrochemical workstation.The results show that NaBH_(4)is the key to the formation of abundant oxygen vacancies in V-CoMoO_(4),the reason is that the strong reducibility of NaBH_(4)can reduce Co^(3+)to Co^(2+)on the surface of CoMoO_(4).Through the synergistic effect of the abundant oxygen vacancies and the special morphological structure of the V-CoMoO,the OER peformance of the V-CoMoO_(4)is significantly improved.In 1 mol/L KOH electrolyte solution,the current density reaches 100 mA/cm~2 when the overpotential of the V-CoMoO_(4)is 298.6 mV,showing the good stability.