Reductive Activity of Adsorbed Fe(II) on Iron (Oxyhydr)Oxides for 2-Nitrophenol Transformation
Reductive Activity of Adsorbed Fe(II) on Iron (Oxyhydr)Oxides for 2-Nitrophenol Transformation
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DOI：
10.1346/ccmn.2010.0580507
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发表时间：
2010-10
影响因子：
2.2
通讯作者：
Liang Tao;Fangbai Li;Yong-kui Wang;Kewen M Sun
中科院分区：
文献类型：
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作者：
Liang Tao;Fangbai Li;Yong-kui Wang;Kewen M Sun
铁（II）在矿物表面的吸附是提高铁（II）的还原活性的关键步骤，因此受到了广泛的关注。本研究利用循环伏安法（CV）阐明了Fe（II）吸附在Fe（氧合）氧化物（γ-FeOOH， α-FeOOH和α-Fe2O3）上对2-硝基苯酚（2-NP）还原转化的作用。对Fe（II）吸附和2-NP还原动力学的研究表明，pH升高会导致矿物表面吸附Fe（II）的密度升高，进而导致2-NP还原反应速率加快。CV试验表明，Fe（II）活性的增强是由于Fe(III)/Fe（II）偶对峰氧化电位（EP）的负移。吸附铁（II）的反应性与pH值的相关性得到了三个线性关系（ln kvs）。EPvs pH值。pH和lnkv。EP)。本研究表明，吸附的Fe（II）种的还原活性可以用活性Fe（II）种的EP值来表示。此外，电化学方法可以作为研究吸附铁（II）在地下环境中还原活性的有效工具。
Much attention has been paid to the adsorption of Fe(II) onto mineral surfaces as it is a crucial step in enhancing the reductive activity of Fe(II) species. The present study elucidates the role of Fe(II) adsorbed on Fe (oxyhydr)oxides (γ-FeOOH, α-FeOOH, and α-Fe2O3) for the reductive transformation of 2-nitrophenol (2-NP), using cyclic voltammetry (CV). Studies of Fe(II) adsorption and 2-NP reduction kinetics showed that an increase in pH gave rise to an elevated density of adsorbed Fe(II) on mineral surfaces, which further resulted in an enhanced reaction rate of 2-NP reduction. In addition, CV tests showed that the enhanced activity of Fe(II) species is attributed to the negative shift of peak oxidation potential (EP) of the Fe(III)/Fe(II) couple. The dependence of adsorbed Fe(II) reactivity on pH values was proven by the three linear correlations obtained (ln kvs. pH, EPvs. pH, and ln kvs. EP). The present study demonstrated that the reductive activity of adsorbed Fe(II) species can be indicated by the EP value of active Fe(II) species. Moreover, the electrochemical approach can be used as an effective tool to study the reductive activity of adsorbed Fe(II) species in subsurface environments.