摘要
以活性炭(GAC)为载体,通过浸渍-煅烧法负载Sn-Zn氧化物制备复合粒子电极(Sn-Zn@GAC),构建三维电催化体系用于高效降解亚甲基蓝(MB)染料废水.同时,探讨了该体系降解MB过程的活性物种类型与机理.结果表明:(1)Sn-Zn@GAC粒子表面Sn/Zn原子比(2.57∶1)接近理论值,其表面覆盖的金属氧化物主要为SnO_(2)和ZnSnO_(3),它们可促进粒子极化形成微电极,提升自由基(·OH、SO_(4)^(-)·、H_(2)O_(2))产率;(2)三维体系在20 min内对MB的去除率达98.8%,为二维电催化体系(41.97%)的2.35倍;而二维体系的能耗却是Sn-Zn@GAC三维体系的3.78倍;(3)SnZn@GAC粒子循环使用5次后,其协同二维电催化体系的去除率仍高于90%,Sn^(4+)和Zn^(2+)析出率分别低至0.20%和1.50%;(4)在活性自由基和电极的氧化作用下,MB经过去甲基化和脱酰胺、开环、氧化等,最终产物为无机物(CO_(2)和H_(2)O)和小分子有机物.
Using granular activated carbon(GAC)as a carrier,a composite particle electrode(Sn-Zn@GAC)loaded with Sn-Zn oxides was prepared via the impregnation-calcination method.A three-dimensional electrocatalytic system was constructed for degrading methylene blue(MB)efficiently.The active species types and degradation mechanisms during the MB degradation process were investigated.The results demonstrated that:①The Sn/Zn atomic ratio(2.57∶1)on the Sn-Zn@GAC surface closely matched the theoretical value.The surface was predominantly covered with SnO_(2) and ZnSnO_(3),which synergistically promoted particle polarization to form microelectrodes,significantly enhancing the yield of reactive species(·OH,SO_(4)^(-·),and H_(2)O_(2)).②The three-electrocatalytic dimensional system achieved 98.8%of MB removal rate within 20 min,which was 2.35 times higher than that of the two-dimensional one(41.97%).Meanwhile,the energy consumption of the two-dimensional electrocatalytic system was 3.78 times higher than that of the Sn-Zn@GAC three-dimensional one.③After five cycles of degrading MB,the removal rate of Sn-Zn@GAC microelectrodes in synergy with the two-dimensional electrocatalytic system remained above 90%.Meanwhile,Sn^(4+) and Zn^(2+) leaching rates were as low as 0.20%and 1.50%,respectively.④The degradation process of MB included reactions such as demethylation,deamination,ring-opening and oxidation,and ultimately MB was oxidized to small-molecule organic matters,CO_(2),and H_(2)O.
作者
李冬梅
李莎莎
詹志强
李弈锴
朱俊宇
孔悦颖
张津明
LI Dongmei;LI Shasha;ZHAN Zhiqiang;LI Yikai;ZHU Junyu;KONG Yueying;ZHANG Jinming(Faculty of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou 510006;Affiliated High School of South China Normal University,Guangzhou 510630;Guangzhou Foreign Language School,Guangzhou 510630)
出处
《环境科学学报》
北大核心
2025年第9期207-220,共14页
Acta Scientiae Circumstantiae
基金
国家自然科学基金面上项目(No.51378129,51108094)。
关键词
GAC粒子电极
Sn-Zn氧化物改性剂
Sn-Zn@GAC三维电催化体系
亚甲基蓝(MB)
活性自由基种类
电催化降解特性
activated carbon(GAC)particle electrodes
the modifiers-oxides of Sn and Zn
Sn-Zn@GAC three-dimensional electrocatalytic system
methylene blue(MB)
active free radical species
electrocatalytic degradation performance
