磁性CoFe2O4/g-C3N4复合纳米材料对环丙沙星的光催化降解研究

制备一种可回收的磁性复合纳米光催化材料CoFe₂O₄/g-C₃N₄, 并对其表面形貌、元素和化学组成、比表面积、官能团特征和晶体结构进行表征与分析。以环丙沙星(CIP)为代表性污染物, 在不同温度(300^oC, 400^oC和500^oC)和复合比例(CoFe₂O₄:g-C₃N₄ = 10%, 20%和40%, w/w)条件下, 考察磁性CoFe₂O₄/g-C₃N₄复合纳米材料的光催化降解能力。结果表明, 在优化的制备条件下, 投加0.9 g/L CoFe₂O₄/g-C₃N₄时, 对10 mg/L CIP (pH=6.6)的120分钟光降解率可以达到75.1% ± 0.1%。在外加磁场作用下, 该纳米材料可实现快速分离回收。经过5次循环回收利用后, 光催化能力仍能达到最初效率的 90%以上, 表现出较好的稳定性。荧光发射光谱图显示, CoFe₂O₄/g-C₃N₄复合纳米材料中的电子?空穴复合速率显著降低, 可以提高其对CIP的光催化效果。

Photocatalytic Degradation of Ciprofloxacin by Magnetic CoFe2O4/g-C3N4 Nanocomposites

Magnetic CoFe₂O₄/g-C₃N₄ nanocomposites were synthesized and its surface morphology, element and chemical composition, specific surface area, functional group characteristics and crystal structure were characterized. Targeting at quinolone antibiotics of ciprofloxacin (CIP), the photo-catalytic degradation of CIP by CoFe₂O₄/g-C₃N₄ nanocomposites was investigated at different calcination temperature (300^oC, 400^oC and 500^oC) and composite ratio (CoFe₂O₄:g-C₃N₄=10%, 20% and 40%, w/w). Under optimal synthesis and operating conditions, a maximum degradation efficiency of 75.1 ± 0.1% was achieved for 0.9 g/L CoFe₂O₄/g-C₃N₄ with 10 mg/L CIP (pH=6.6) within 120 min. With an external magnetic field, the CoFe₂O₄/g-C₃N₄ nanocomposites were easily and rapidly recycled, remaining >90% of the initial efficacy after 5 cycles and showing a considerable stability. Fluorescence spectra revealed a significant decrease in electron-hole recombination rates under light radiation, which contributed greatly to the increase of photo-degradation efficacy of CIP by CoFe₂O₄/g-C₃N₄nanocomposites.