Theodorakopoulos George V, Katsaros Fotios K, Papageorgiou Sergios K, Beazi-Katsioti Margarita, Romanos George Em
Institute of Nanoscience and Nanotechnology, N.C.S.R. "Demokritos", Ag. Paraskevi, 15310 Athens, Greece.
School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Street, Zografou, 15780 Athens, Greece.
Materials (Basel). 2022 Jan 3;15(1):326. doi: 10.3390/ma15010326.
In this study, efficient commercial photocatalyst (Degussa P25) nanoparticles were effectively dispersed and stabilized in alginate, a metal binding biopolymer. Taking advantage of alginate's superior metal chelating properties, copper nanoparticle-decorated photocatalysts were developed after a pyrolytic or calcination-sintering procedure, yielding ceramic beads with enhanced photocatalytic and mechanical properties, excellent resistance to attrition, and optimized handling compared to powdered photocatalysts. The morphological and structural characteristics were studied using LN porosimetry, SEM, and XRD. The abatement of an organic pollutant (Methyl Orange, MO) was explored in the dark and under UV irradiation via batch experiments. The final properties of the photocatalytic beads were defined by both the synthesis procedure and the heat treatment conditions, allowing for their further optimization. It was found that the pyrolytic carbon residuals enabled the adhesion of the TiO nanoparticles, acting as binder, and increased the MO adsorption capacity, leading to increased local concentration in the photocatalyst vicinity. Well dispersed Cu nanoparticles were also found to enhance photocatalytic activity. The prepared photocatalysts exhibited increased MO adsorption capacity (up to 3.0 mg/g) and also high photocatalytic efficiency of about 50% MO removal from water solutions, reaching an overall MO rejection of about 80%, at short contact times (3 h). Finally, the prepared photocatalysts kept their efficiency for at least four successive photocatalytic cycles.
在本研究中，高效的商用光催化剂（德固赛P25）纳米颗粒在藻酸盐（一种金属结合生物聚合物）中得到了有效分散和稳定。利用藻酸盐卓越的金属螯合性能，通过热解或煅烧烧结程序制备了铜纳米颗粒修饰的光催化剂，得到的陶瓷珠具有增强的光催化和机械性能、优异的耐磨性能，与粉末状光催化剂相比，其操作性能也得到了优化。使用压汞法、扫描电子显微镜（SEM）和X射线衍射（XRD）研究了其形态和结构特征。通过批量实验，在黑暗和紫外光照射条件下探究了有机污染物（甲基橙，MO）的去除情况。光催化珠的最终性能由合成程序和热处理条件共同决定，这使得它们能够进一步优化。研究发现，热解碳残余物能够使TiO纳米颗粒作为粘合剂附着，并提高了MO吸附容量，导致光催化剂附近的局部浓度增加。还发现分散良好的铜纳米颗粒增强了光催化活性。所制备的光催化剂表现出增加的MO吸附容量（高达3.0 mg/g），并且在短接触时间（3小时）内从水溶液中去除MO的光催化效率也很高，约为50%，MO的总去除率达到约80%。最后，所制备的光催化剂在至少四个连续的光催化循环中保持了其效率。
