São Paulo State University (UNESP), Institute of Chemistry, Av. Prof. Francisco Degni 55, 14800-060, Araraquara, SP, Brazil.
Chemosphere. 2021 Aug;277:130258. doi: 10.1016/j.chemosphere.2021.130258. Epub 2021 Mar 16.
This study describes the characterization of Nontronite, a clay mineral with high content of structural iron, before and after iron incorporation and 600 °C heat treatment. The Nontronite was classified as a mesoporous material, with high absorption in the UV-Vis range and band gap energy of 1.9 eV, indicative of the presence of superficial hematite, also verified in XRD analysis. The heat treatment promoted a structure rearrangement and the conversion of other iron phases to hematite, allowing the formation of surface irregular sites on Nontronite and facilitating the access for the decomposition of HO into HO. Its catalytic activity in heterogeneous photo-Fenton process was evaluated during the degradation of the antibiotic sulfathiazole (STZ) and showed high activity achieving undetectable levels of STZ after 20 min under UV-LED irradiation and solar irradiation, and showing no iron leaching under controlled pH = 3. The degradation intermediates identified indicated hydroxylation as the main degradation route.
本研究描述了富铁结构的蒙脱石在铁掺入前后及 600°C 热处理前后的特性。蒙脱石被归类为中孔材料，在紫外-可见范围内具有高吸收性和 1.9eV 的带隙能，表明存在表面赤铁矿，这也在 XRD 分析中得到了验证。热处理促进了结构重排和其他铁相向赤铁矿的转化，在蒙脱石表面形成了不规则的位，有利于 HO 分解为 HO。在抗生素磺胺噻唑（STZ）的降解过程中，评价了其在非均相光芬顿反应中的催化活性，在 UV-LED 辐射和太阳辐射下 20 分钟后，达到了不可检测的 STZ 水平，且在控制 pH=3 下没有铁浸出，表现出很高的活性。鉴定出的降解中间产物表明，羟化是主要的降解途径。
