Department of Civil and Environmental Engineering, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; School of Chemical and Biological Engineering, Institute of Chemical Process (ICP), Institute of Engineering Research, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Department of Civil and Environmental Engineering and Institute of Construction and Environmental Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Water Res. 2024 Apr 1;253:121343. doi: 10.1016/j.watres.2024.121343. Epub 2024 Feb 20.
A dye-sensitized photocatalysis system was developed for degrading persistent organic contaminants using solid waste (i.e., red mud, RM) and peroxymonosulfate (PMS) under visible light. Complete degradation of acid orange 7 (AO7) was achieved in RM suspension with PMS, where the co-existence of amorphous FeO(OH)/α-FeO was the key factor for PMS activation. The experimental results obtained from photochemical and electrochemical observations confirmed the enhanced PMS activation due to the Fe-OH phase in RM. DFT calculations verified the acceleration of PMS activation due to the high adsorption energy of PMS on FeO(OH) and low energy barrier for generating reactive radicals. Compared to the control experiment without AO7 showing almost no degradation of other organic contaminants (phenol, bisphenol A, 4-chlorophenol, 4-nitrophenol, and benzoic acid), photo-sensitized AO7* enhanced electron transfer in the Fe/Fe cycle, dramatically enhancing the degradation of organic contaminants via radical (OH, SO, and O) and non-radical (dye* and O) pathways. Therefore, the novel finding of this study can provide new insights for unique PMS activation by heterogeneous Fe(III) containing solid wastes and highlight the importance of sensitized dye on the interaction of PMS with Fe charge carrier for the photo-oxidation of organic contaminants under visible light.
采用固相废弃物（赤泥，RM）和过一硫酸盐（PMS）在可见光下开发了一种敏化光催化体系，用于降解持久性有机污染物。在含有 PMS 的 RM 悬浮液中，完全降解了酸性橙 7（AO7），其中无定形 FeO(OH)/α-FeO 的共存是 PMS 活化的关键因素。光化学和电化学观察的实验结果证实了 RM 中 Fe-OH 相增强了 PMS 的活化。DFT 计算证实了 PMS 的活化加速，这是由于 PMS 在 FeO(OH)上的高吸附能和生成反应性自由基的低能垒。与没有 AO7 的对照实验相比，几乎没有降解其他有机污染物（苯酚、双酚 A、4-氯苯酚、4-硝基苯酚和苯甲酸），光敏化 AO7增强了 Fe/Fe 循环中的电子转移，通过自由基（OH、SO 和 O）和非自由基（染料和 O）途径显著增强了有机污染物的降解。因此，本研究的新发现可为通过含异质 Fe(III)的固体废弃物独特地活化 PMS 提供新的见解，并强调敏化染料在 PMS 与 Fe 电荷载体相互作用中对可见光下有机污染物光氧化的重要性。
