Demina Polina A, Voronin Denis V, Lengert Ekaterina V, Abramova Anna M, Atkin Vsevolod S, Nabatov Boris V, Semenov Anton P, Shchukin Dmitry G, Bukreeva Tatiana V
Shubnikov Institute of Crystallography of FSRC "Crystallography and Photonics", Russian Academy of Sciences, Moscow 119333, Russia.
Saratov State University, Saratov 410012, Russia.
ACS Omega. 2020 Feb 19;5(8):4115-4124. doi: 10.1021/acsomega.9b03819. eCollection 2020 Mar 3.
The photocatalytic degradation of organic molecules is one of the effective ways for water purification. At this point, photocatalytic microreactor systems seem to be promising to enhance the versatility of the photoassisted degradation approach. Herein, we propose photoresponsive microcapsules prepared via layer-by-layer assembly of polyelectrolytes on the novel CaCO/TiO composite template cores. The preparation of CaCO/TiO composite particles is challenging because of the poor compatibility of TiO and CaCO in an aqueous medium. To prepare stable CaCO/TiO composites, TiO nanoparticles were loaded into mesoporous CaCO microparticles with a freezing-induced loading technique. The inclusion of TiO nanoparticles into CaCO templates was evaluated with scanning electron microscopy and elemental analysis with respect to their type, concentration, and number of loading iterations. Upon polyelectrolyte shell assembly, the CaCO matrix was dissolved, resulting in microreactor capsules loaded with TiO nanoparticles. The photoresponsive properties of the resulted capsules were tested by photoinduced degradation of the low-molecule dye rhodamine B in aqueous solution and fluorescently labeled polymer molecules absorbed on the capsule surface under UV light. The exposure of the capsules to UV light resulted in a pronounced degradation of rhodamine B in capsule microvolume and fluorescent molecules on the capsule surface. Finally, the versatility of preparation of multifunctional photocatalytic and magnetically responsive capsules was demonstrated by iterative freezing-induced loading of TiO and magnetite FeO nanoparticles into CaCO templates.
有机分子的光催化降解是水净化的有效方法之一。就此而言，光催化微反应器系统似乎有望增强光辅助降解方法的多功能性。在此，我们提出通过在新型CaCO/TiO复合模板核上逐层组装聚电解质制备光响应微胶囊。由于TiO和CaCO在水性介质中的相容性较差，CaCO/TiO复合颗粒的制备具有挑战性。为了制备稳定的CaCO/TiO复合材料，采用冷冻诱导负载技术将TiO纳米颗粒负载到介孔CaCO微粒中。通过扫描电子显微镜和元素分析，对CaCO模板中TiO纳米颗粒的类型、浓度和负载迭代次数进行了评估。在聚电解质壳组装后，CaCO基质溶解，形成负载TiO纳米颗粒的微反应器胶囊。通过在水溶液中光诱导降解低分子染料罗丹明B以及在紫外光下对吸附在胶囊表面的荧光标记聚合物分子进行测试，研究了所得胶囊的光响应特性。将胶囊暴露于紫外光下会导致胶囊微体积内的罗丹明B和胶囊表面的荧光分子显著降解。最后，通过将TiO和磁铁矿Fe₃O₄纳米颗粒反复冷冻诱导负载到CaCO模板中，证明了多功能光催化和磁响应胶囊制备的多功能性。
