Center for Water Resource Cycle, Korea Institute of Science and Technology , Seoul 136-791, Korea.
Environ Sci Technol. 2014 Jul 15;48(14):8086-93. doi: 10.1021/es5002902. Epub 2014 Jun 26.
Nanosized zerovalent iron (nFe0) loaded with a secondary metal such as Ni or Cu on its surface was demonstrated to effectively activate periodate (IO4-) and degrade selected organic compounds at neutral pH. The degradation was accompanied by a stoichiometric conversion of IO4- to iodate (IO3-). nFe0 without bimetallic loading led to similar IO4- reduction but no organic degradation, suggesting the production of reactive iodine intermediate only when IO4- is activated by bimetallic nFe0 (e.g., nFe0-Ni and nFe0-Cu). The organic degradation kinetics in the nFe0-Ni(or Cu)/IO4- system was substrate dependent: 4-chlorophenol, phenol, and bisphenol A were effectively degraded, whereas little or no degradation was observed with benzoic acid, carbamazepine, and 2,4,6-trichlorophenol. The substrate specificity, further confirmed by little kinetic inhibition with background organic matter, implies the selective nature of oxidant in the nFe0-Ni(or Cu)/IO4- system. The comparison with the photoactivated IO4- system, in which iodyl radical (IO3•) is a predominant oxidant in the presence of methanol, suggests IO3• also as primary oxidant in the nFe0-Ni(or Cu)/IO4- system.
负载在表面的二次金属（如 Ni 或 Cu）的纳米零价铁（nFe0）被证明可以在中性 pH 值下有效地激活高碘酸盐 (IO4-) 并降解选定的有机化合物。降解伴随着 IO4- 到碘酸盐 (IO3-) 的化学计量转化。没有双金属负载的 nFe0 导致类似的 IO4- 还原但没有有机降解，这表明只有当 IO4- 被双金属 nFe0（例如 nFe0-Ni 和 nFe0-Cu）激活时才会产生反应性碘中间体。nFe0-Ni(或 Cu)/IO4- 体系中的有机降解动力学取决于底物：4-氯苯酚、苯酚和双酚 A 被有效降解，而苯甲酸、卡马西平和 2,4,6-三氯苯酚则几乎没有或没有降解。底物特异性，进一步通过背景有机物的动力学抑制作用得到证实，表明 nFe0-Ni(或 Cu)/IO4- 体系中氧化剂具有选择性。与光激活 IO4- 体系的比较表明，在甲醇存在下碘酰基自由基 (IO3•) 是主要氧化剂，这表明在 nFe0-Ni(或 Cu)/IO4- 体系中 IO3• 也是主要氧化剂。
