Castanheira Bruna, Brochsztain Sergio, Otubo Larissa, Teixeira Antonio Carlos S C
Department of Chemical Engineering, University of São Paulo, Av. Prof. Luciano Gualberto, tr. 3, São Paulo 380, SP, Brazil.
Federal University of ABC, Av. dos Estados, 5001, Santo André, SP 09210-580, Brazil.
J Hazard Mater. 2023 Feb 5;443(Pt B):130224. doi: 10.1016/j.jhazmat.2022.130224. Epub 2022 Oct 20.
In this work, periodic mesoporous organosilicas (PMO) functionalized with the organic sentisizer naphthalenediimide (NDI) were employed as heterogeneous catalysts for the photodegradation of the antibiotic sulfadiazine (SDZ), taken as a model for contaminants of emerging concern (CECs). The catalysts, designated as PMONDI, were prepared by surfactant-directed co-condensation of the precursor N,N'-bis(3-triethoxysilylpropyl)- 1,4,5,8-naphthalenediimide with tetraethoxysilane. The synthesized PMONDI were characterized using transmission electron microscopy, nitrogen adsorption isotherms and small and large angle x-ray scattering. The performance of PMONDI catalysts in the photodegradation of SDZ was compared to that of TiO nanoparticles impregnated into SBA-15 mesoporous silica (TiO/SBA-15), under irradiation with a Hg lamp with a bandpass filter of 320-500 nm. Under optimal conditions, PMONDI degraded 100% of the SDZ in 45 min, while the total degradation of SDZ was achieved only after 150 min with TiO/SBA-15. PMONDI also performed better than TiO/SBA-15 in reuse tests. The mechanism of photodegradation with PMONDI involves the formation of excited triplet states of NDI (NDI*) upon irradiation, which can then react with molecular oxygen to form reactive oxygen species, which degrade SDZ. Analysis of the SDZ degradation products indicated two main pathways: (1) hydroxylation of the aniline ring and (2) SO extrusion and rearrangement, followed by oxidation of the aniline ring to nitrobenzene. In conclusion, the great potential of the PMONDI materials as photocatalysts for CECs degradation was demonstrated in this work, encouraging further research on these materials for the degradation of pollutants.
在本研究中，用有机敏化剂萘二酰亚胺（NDI）功能化的周期性介孔有机硅（PMO）被用作多相催化剂，用于光降解抗生素磺胺嘧啶（SDZ），SDZ被视为新出现的关注污染物（CEC）的模型。将这些催化剂命名为PMONDI，通过前体N，N'-双（3-三乙氧基硅丙基）-1,4,5,8-萘二酰亚胺与四乙氧基硅烷的表面活性剂导向共缩合制备而成。使用透射电子显微镜、氮吸附等温线以及小角和大角X射线散射对合成的PMONDI进行了表征。在320-500 nm带通滤光片的汞灯照射下，将PMONDI催化剂在SDZ光降解中的性能与浸渍在SBA-15介孔二氧化硅中的TiO纳米颗粒（TiO/SBA-15）的性能进行了比较。在最佳条件下，PMONDI在45分钟内降解了100%的SDZ，而TiO/SBA-15仅在150分钟后才实现SDZ的完全降解。在重复使用测试中，PMONDI的性能也优于TiO/SBA-15。PMONDI光降解的机制涉及照射时NDI激发三重态（NDI*）的形成，然后它可以与分子氧反应形成活性氧物种，从而降解SDZ。对SDZ降解产物的分析表明有两条主要途径：（1）苯胺环的羟基化和（2）SO的挤出和重排，随后苯胺环氧化为硝基苯。总之，本研究证明了PMONDI材料作为光催化剂用于CEC降解的巨大潜力，这鼓励对这些材料进行进一步研究以用于污染物的降解。
