Zhong Xin, Ye Xiao-Yu, Wu Di, Zhang Kai-Xin, Huang Wei
Department of Environment Science and Engineering, Beijing Normal University Zhuhai 519000 China
RSC Adv. 2019 Oct 10;9(55):32328-32337. doi: 10.1039/c9ra05574f. eCollection 2019 Oct 7.
In this study, the removal performance for rhodamine B (RB) by persulfate (PS) activated by the CuFeO catalyst in a heterogeneous catalytic system under LED light irradiation was investigated. The effect of vital experimental factors, including initial solution pH, CuFeO dosage, PS concentration, co-existing anion and initial RB concentration on the removal of RB was systematically studied. The removal of RB was in accordance with the pseudo first-order reaction kinetics. Over 96% of 20 mg L RB was removed in 60 min using 0.5 g L CuFeO catalyst and 0.2 mM PS at neutral pH. In addition, free radical quenching experiments and electron spin resonance (EPR) experiments were performed, which demonstrated the dominant role of sulfate radical, photogenerated holes and superoxide radical in the CuFeO/PS/LED system. The morphology and physicochemical properties of the catalyst were characterized by XRD, SEM-EDS, TEM, N adsorption-desorption isotherm, UV-vis DRS, and XPS measurements. Moreover, 18.23% and 38.79% total organic carbon (TOC) removal efficiency was reached in 30 min and 60 min, respectively. The catalyst revealed good performance during the reusability experiments with limited iron and copper leaching. Eventually, the major intermediates in the reaction were detected by GC/MS, and the possible photocatalytic pathway for the degradation of RB in the CuFeO/PS/LED system was proposed. The results suggest that the CuFeO/PS/LED system has good application for further wastewater treatment.
本研究考察了在LED光照射下的非均相催化体系中，CuFeO催化剂活化过硫酸盐（PS）对罗丹明B（RB）的去除性能。系统研究了初始溶液pH值、CuFeO用量、PS浓度、共存阴离子和初始RB浓度等重要实验因素对RB去除的影响。RB的去除符合准一级反应动力学。在中性pH条件下，使用0.5 g/L的CuFeO催化剂和0.2 mM的PS，60分钟内可去除超过96%的20 mg/L RB。此外，进行了自由基猝灭实验和电子自旋共振（EPR）实验，结果表明硫酸根自由基、光生空穴和超氧自由基在CuFeO/PS/LED体系中起主导作用。通过XRD、SEM-EDS、TEM、N吸附-脱附等温线、UV-vis DRS和XPS测量对催化剂的形貌和物理化学性质进行了表征。此外，30分钟和60分钟时总有机碳（TOC）的去除效率分别达到18.23%和38.79%。在可重复使用性实验中，催化剂表现出良好的性能，铁和铜的浸出量有限。最终，通过GC/MS检测了反应中的主要中间体，并提出了CuFeO/PS/LED体系中RB降解的可能光催化途径。结果表明，CuFeO/PS/LED体系在进一步的废水处理中具有良好的应用前景。
