UV light-assisted persulfate activation by Cu-0-Cu2O for the degradation of sulfamerazine
UV light-assisted persulfate activation by Cu-0-Cu2O for the degradation of sulfamerazine
复制标题
Cu-0-Cu2O 紫外光辅助过硫酸盐活化降解磺胺甲基嘧啶
DOI：
10.1016/j.seppur.2020.117321
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发表时间：
2020
影响因子：
8.6
通讯作者：
Liu Yong
中科院分区：
文献类型：
--
作者：
Wang Bingqing;Fu Tao;An Baohua;Liu Yong
由于硫酸根具有较高的氧化还原电位，基于硫酸根的高级氧化工艺（SRAOP）在废水处理领域受到越来越多的关注。SRAOP的关键是开发高效、稳定的催化剂，使过硫酸盐（PS）活化产生硫酸根自由基。Cu_2O是一种良好的PS活化剂和光催化剂。但由于其稳定性差、易发生电子空穴复合等原因，其催化活性较低。理论上，Cu-0可以还原Cu 2+形成Cu+，从而通过形成异质结来减少电子和空穴从Cu 2 O的复合。采用简单的球磨法合成了（CuCu 2 O）-Cu-0。对所制备的Cu-0-Cu 2 O进行了表征，并将其用于紫外光照射下PS对磺胺甲基嘧啶（SMZ）的降解。在Cu-0-Cu 2 O/PS/UV体系中，SMZ和TOC的去除率分别在30 min内达到100%，30%，5次循环后SMZ的去除率仅下降了12.2%。Cu-0-Cu 2 O对PS的高活化效率和良好的催化稳定性是由于Cu-0和Cu 2 O的光生电子促进了Cu 2+向Cu+的转化。淬灭实验表明，羟基自由基和硫酸根自由基有助于SMZ的降解。但自由基的浓度和分数受溶液初始pH值的影响。鉴定了9种中间产物，提出了降解途径，包括硫氮键的断裂、甲基的氧化和苯环的羟基化。考察了初始pH、PS浓度、Cu-0-Cu 2 O投加量和SMZ初始浓度对SMZ降解的影响。该研究提供了一种有效的催化剂，可以同时激活PS和利用紫外线形成光生电子，可以促进有机污染物的降解和矿化。
Sulfate radicals-based advanced oxidation process (SRAOP) has received increasing attention in the wastewater treatment area because sulfate radicals have high redox potential. The key for SRAOP is to develop high efficient catalysts that can effectively and stably activate persulfate (PS) to produce sulfate radicals. Cu2O is a good activator of PS and photo-catalyst. However, its catalytic activity is relatively low because of the poor stability and the recombination of electron and holes. In theory, Cu-0 can reduce Cu2+ to form Cu+, which can decrease the recombination of electron and holes from the Cu2O by the formation of heterojunction. In this study, (CuCu2O)-Cu-0 was synthesized by a simple ball-milling method. The as-prepared Cu-0-Cu2O was characterized and used to activate PS for sulfamerazine (SMZ) degradation by means of UV illumination. In the Cu-0-Cu2O/PS/UV system, the removals of 100% SMZ and 30% TOC within 30 min were achieved, respectively, and the removal efficiency of SMZ decreased by only 12.2% after 5 cycles. The high efficiency and good catalytic stability of Cu-0-Cu2O for the activation of PS were due to that Cu-0 and photo-induced electron of Cu2O promoted the conversion of Cu2+ to Cu+. Quenching experiments demonstrated that the hydroxyl radicals and sulfate radicals contributed to SMZ degradation. However, the concentrations and fractions of radicals was affected by the initial pH of solution. Nine intermediate products were identified, and the degradation pathways were proposed, including the fission of sulfur and nitrogen bond, the oxidation of methyl group and the hydroxylation of benzene ring. The effects of initial pH, PS concentration, Cu-0-Cu2O dosage and SMZ initial concentration on the degradation of SMZ were investigated. This study provided an effective catalyst that could simultaneously activate PS and utilize UV to form photo-induced electron, which could enhance the degradation and mineralization of organic pollutants.