CoBx/Co3O4电催化剂的制备及其氧析出性能

Preparation and Electrocatalytic Activities for Oxygen Evolution Reaction of CoBx/Co3O4 Catalyst

采用NaBH4溶液处理经水热、热处理步骤制得Co3O4纳米棒,得到表面富含氧空位以及无定型CoBx的Co3O4(CoBx/Co3O4)氧析出(OER)电催化剂。利用X射线衍射(XRD)、场发射扫描电镜(FESEM)、透射电镜(TEM)、X射线光电子能谱仪(XPS)等技术表征了催化剂的物相、微观形貌、元素组成以及表面化学键结构等。通过电化学工作站测试了电极材料的OER活性、稳定性、电化学阻抗等。结果表明,经NaBH4处理后,Co3O4表面高价态Co被还原至低价态Co,最终其表面有无定型CoBx的生成,并含有大量氧空位,有效提升了OER性能。在1.0 mol·L^-1 KOH电解质溶液中,达到10 mA·cm^-2的电流密度时,CoBx/Co3O4所需的过电位由Co3O4的346 mV降至298 mV。

Herein,the room‑temperature treatment of Co3O4 nanorods via NaBH4 aqueous solution results in situ generation of amorphous CoBx nanosheets on nanorods(CoBx/Co3O4)electrocatalyst with abundant oxygen vacancies.The X‑ray diffractometer(XRD),field emission scanning electron microscope(FESEM),transmission electron microscope(TEM),and X‑ray photoelectron spectroscope(XPS)were applied to investigate the crystal structures,morphologies,element distribution,and chemical states of the prepared electrocatalysts.The activity,stability,and electrochemical impedance spectroscopy(EIS)were recorded by an electrochemical workstation.The amorphous CoBx and oxygen vacancies were formed on surface of Co3O4 nanorods as active sites after treatment via NaBH4.The CoBx/Co3O4 showed excellent performance for oxygen evolution reaction(OER)with lower overpotential of 298 mV than that of Co3O4(346 mV)to achieve a current density of 10 mA·cm^-2 in 1.0 mol·L^-1 KOH.