Akkari Marwa, Bardaoui Afrah, Djebbi Mohamed Amine, Amara Abdesslem Ben Haj, Chtourou Radhouane
Laboratory of Nanomaterials and Systems for Renewable Energies (LaNSER), Research and Technology Center of Energy, Technopôle Borj-Cedria, Hammam-Lif, Tunis, Tunisia.
LR Ressource Matériaux et Ecosystème, Faculty of Sciences of Bizerte, University of Carthage, 7021, Zarzouna, Tunisia.
Environ Sci Pollut Res Int. 2022 Sep;29(44):67159-67169. doi: 10.1007/s11356-022-20539-w. Epub 2022 May 6.
This work is devoted to the development of Ag-ZnO/sepiolite photocatalysts as novel nanostructured materials by the immobilization of Ag-doped ZnO on the surface of fibrous clay. Herein, innovative Ag-ZnO/sepiolite photocatalysts were successfully prepared through a simple hydrothermal route using diverse Ag dopant concentrations (2 and 5%). Structural, morphological, and optical properties of the obtained photocatalysts were characterized by XRD, TEM, MEB, and DRS-UV-Vis spectroscopy. The results confirmed that Ag-doped ZnO nanoparticles with a diameter of 10-30 nm are homogeneously distributed on the sepiolite fibers' surface. The silver dopant was effectively incorporated into the zinc oxide, leading to a slight distortion of the hexagonal wurtzite structure and a reduction of the bandgap energy with increased silver doping. The photocatalytic activity towards the degradation of methylene blue (MB) dye was analyzed for all the samples under UV-Vis light. Compared to ZnO alone and undoped ZnO/SEP, the Ag-ZnO/SEP5% nanostructured materials exhibited a significantly improved photocatalytic activity, with full decolorization after 4 h of UV-Vis irradiation (60 W). The photocatalysis of organic pollutants matched well with a pseudo-first-order kinetic. The enhanced photocatalytic activity was ascribed to the low bandgap energy (3 eV), the reduction of the recombination of electron hole, and the sepiolite support.
本工作致力于通过将掺银氧化锌固定在纤维状粘土表面来开发新型纳米结构材料Ag-ZnO/海泡石光催化剂。在此，通过简单的水热法，使用不同的银掺杂浓度（2%和5%）成功制备了创新型Ag-ZnO/海泡石光催化剂。通过XRD、TEM、MEB和DRS-UV-Vis光谱对所得光催化剂的结构、形态和光学性质进行了表征。结果证实，直径为10-30nm的掺银氧化锌纳米颗粒均匀分布在海泡石纤维表面。银掺杂剂有效地掺入氧化锌中，导致六方纤锌矿结构略有畸变，且随着银掺杂量的增加带隙能量降低。对所有样品在紫外-可见光下对亚甲基蓝（MB）染料降解的光催化活性进行了分析。与单独的氧化锌和未掺杂的ZnO/SEP相比，Ag-ZnO/SEP5%纳米结构材料表现出显著提高的光催化活性，在紫外-可见光照射（60W）4小时后完全脱色。有机污染物的光催化符合准一级动力学。光催化活性的增强归因于低带隙能量（3eV）、电子空穴复合的减少以及海泡石载体。
