Nitrogen and sulfur co-doped CNT-COOH as an efficient metal-free catalyst for the degradation of UV filter BP-4 based on sulfate radicals
Nitrogen and sulfur co-doped CNT-COOH as an efficient metal-free catalyst for the degradation of UV filter BP-4 based on sulfate radicals
复制标题
氮硫共掺杂 CNT-COOH 作为高效无金属催化剂，用于降解基于硫酸根的紫外线滤光剂 BP-4
DOI：
10.1016/j.apcatb.2016.01.036
复制
发表时间：
2016-06-15
影响因子：
22.1
通讯作者：
Wang, Zunyao
中科院分区：
文献类型：
--
作者：
Liu, Hui;Sun, Ping;Wang, Zunyao
以含氧官能团（COOH或OH）修饰的碳纳米管（CNTs）为碳源，采用热分解法首次制备了氮（N）和硫（S）共掺杂的多壁碳纳米管（CNTs）催化剂。采用SEM、TEM、BET、XPS、XRD、FT-IR和拉曼光谱等手段对碳纳米管进行了表征。此外，新材料被用作催化剂，用于活化过一硫酸盐（PMS）降解二苯甲酮-4（BP-4）。结果表明，COOH基团在S掺杂过程中起着重要作用。此外，二元（N和S）掺杂的CNT-COOH（NS-CNT-COOH）对PMS降解BP-4表现出显着增强的催化活性。该活性水平比单一（N）掺杂的CNT-COOH和二元（N和S）掺杂的CNT的活性水平高约5倍，并且其甚至超过金属催化剂CuFe 2 O 4的活性水平。催化性能的提高归因于引入的吡啶和吡咯的N原子和噻吩的S原子产生的活性中心。考察了各种因素对NS-CNT-COOH催化活性的影响。结果表明，BP-4的降解率随催化剂负载量、氧化剂浓度和反应温度的升高而增大。相比之下，NS-CNT-COOH对过硫酸盐（PDS）和H2 O2没有表现出显著的催化活性。在NS-CNT-COOH/PMS系统的情况下，提出了BP-4降解的可能途径，并基于检测到的中间体。该机制是合理的前沿电子密度的理论计算，这是以前没有报道。此外，矿化，毒性，稳定性和可重复使用性测试表明，开发的催化剂，NS-CNT-COOH，具有实际应用的希望。(C)© 2016 Elsevier B. V.版权所有。
By using CNTs functionalized by oxygenic functional groups ( COOH or OH) as the carbon source, novel catalysts of nitrogen (N) and sulfur (S) co-doped multi-walled carbon nanotubes (CNTs) were prepared for the first time by thermal decomposition. The obtained CNTs were characterized by SEM, TEM, BET, XPS, XRD, FT-IR and Raman spectroscopy. Additionally, the new material was used as a catalyst for the activation of peroxymonosulfate (PMS) for the degradation of benzophenone-4 (BP-4). Results indicated that the COOH group plays an important role in the S doping process. Moreover, binary (N and S)-doped CNT-COOH (NS-CNT-COOH) exhibited a notably enhanced catalytic activity towards PMS for degrading BP-4. This activity level was approximately five-fold greater than that of singly (N)-doped CNT-COOH and binary (N and S)-doped CNT, and it even exceeded that of the metal catalyst CuFe2O4. The enhanced catalytic performance was attributed to the active sites generated by the introduced pyridinic and pyrrolic N atoms and thiophenic S atoms. The effects of various factors on the catalytic activity of NS-CNT-COOH were studied. Results revealed that the degradation efficiency of BP-4 increased with catalyst load, oxidant concentration and reaction temperature. In contrast, NS-CNT-COOH exhibited no remarkable catalytic activity towards peroxodisulfate (PDS) and H2O2. In the case of the NS-CNT-COOH/PMS system, a possible pathway for BP-4 degradation was proposed and based on detected intermediates. The mechanism was justified by theoretical calculations of the frontier electron densities, which have not been reported previously. Furthermore, mineralization, toxicity, stability and reusability tests suggested that the developed catalyst, NS-CNT-COOH, holds promise for practical application. (C) 2016 Elsevier B.V. All rights reserved.