介孔碳化钨纳米片团簇的制备及其电催化析氢性能

Mesoporous Tungsten Carbide Nanoflakes Globular Clusters:Preparation and Electrocatalytic Properties for Hydrogen Evolution

采用阳极氧化法与原位还原碳化法相结合,在电击穿条件下可控制备了具有介孔结构的碳化钨纳米片团簇(WC NFs)。通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、N_(2)吸附-脱附测试表征其物相、微观结构和孔径分布。在1 mol·L^(-1)H_(2)SO_(4)溶液中采用线性扫描伏安法、循环伏安法、计时电流法以及交流阻抗谱测试催化剂的电化学性能。结果表明,在650℃下还原碳化所制备的WC NFs具有最佳的电催化析氢性能,在电流密度为10 mA·cm^(-2)时过电位η_(10)仅为150 mV,Tafel斜率为56 mV·dec^(-1),并具有良好的循环稳定性。

Tungsten carbide nanoflakes globular clusters(WC NFs)with the typical mesoporous structure were prepared by controlled breakdown anodization by a gas-solid carburization process.The crystal phase,microstructure,and pore size distribution of the nanoflowers were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),and N_(2) adsorption-desorption test.The electrochemical properties were evaluated using linear sweep voltammetry,cyclic voltammetry,chronoamperometry,and electrochemical impedance spectroscopy in 1 mol·L^(-1) H_(2)SO_(4) solution.The results showed that as-prepared WC NFs exhibited enhanced superior hydrogen evolution performance in terms of a small η_(10)(overpotential to obtain a current density of 10 mA·cm^(-2))of 150 mV,a Tafel slope of 56 mV·dec^(-1),and outstanding long-term cycling stability.