KOH碱化处理对Fe_3N纳米颗粒电催化制氢性能影响  

KOH Alkalized Fe_3N Nanoparticles on Electrocatalytic Hydrogen Evolution Reaction

作　　者：王辉 俞有幸[1] WANG Hui;YU You-Xing(School of Material Science and Engineering, Beihang University, Beijing 100191, China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191

出　　处：《无机材料学报》2018年第6期653-658,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(51201004)~~

摘　　要：采用KOH溶液在通电条件下对Fe_3N纳米颗粒表面改性的方法,探究了碱化处理对Fe_3N纳米颗粒电催化性能的影响。采用XRD、TEM、EDX、XPS、拉曼光谱和傅立叶变换红外光谱对碱化前后的Fe_3N样品进行形貌和成分的表征,采用时间电流曲线、LSV曲线、Tafel斜率、交流阻抗法和CV曲线对碱化前后的Fe_3N样品进行电催化制氢(HER)性能的分析。结果表明,用KOH处理的Fe_3N样品,平均晶粒尺寸由(80±10)nm缩小为(70±10)nm,形状由破碎的链状结构变为椭圆形结构,物相由e-Fe_3N相部分转变为α-Fe2O3相;尺寸、形貌和成分的改变,使得碱化后的样品有更多的电催化活性位点暴露。由电流密度为10 m A/cm2的过电位0.429 V降为0.204 V,Tafel斜率由103 m V/dec降为95 m V/dec。过电势降低,交流阻抗变小,电化学活性面积增大,表明KOH碱化处理后的样品电催化制氢的能力得到大大提高。Surface modification of Fe3N nanoparticles by KOH solution under electrification conditions was carried out, and effect of alkalization on the catalytic performance of Fe3N nanoparticles was investigated. Morphology and composition of Fe3N nanoparticles and alkalized Fe3N nanoparticles were characterized by XRD, TEM, EDX, XPS, Raman spectra, and Fourier Transform Infrared spectroscopy. Electrocatalytic hydrogen evolution reaction （HER） performance of Fe3N nanoparticles and alkalized Fern nanoparticles was analyzed by time-current curve, linear sweep voltammetry, Tafel slope, AC impedance method, and CV curve. It was found that, for alkalized Fe3N nanoparticles, their average grain sizes decreased from （80±10） nm to （70±10） nm. Their morphology changed from broken chain structure to elliptical structure, while their the phase changed partly from 6-FeaN to a-Fe2O3, which brought about more exposed electrocatalytic activity sites when compared with the Fe3N before alkalization. Overpotential at 10 mA/cm^2 the alkalized FeaN nanoparticles was reduced from 0.429 V to 0.204 V and Tafel slope was reduced from 103 mV/dec to 95 mV/dec. Low opening voltage, small Tafel slope, low over-potential, small AC impedance and larg chemically active surface area were achieved by the alkalized FeaN nanoparticles, demonstrating that alkalized FeaN is a promising excellent electrocatalyst for water splitting.

关 键 词：Fe3N纳米颗粒 KOH碱化处理 电催化 析氢反应 

分 类 号：O646[理学—物理化学]