Abstract:

The magnetic carbonyl iron particles were used as the carrier and loaded with nano TiO₂ to prepare composite photocatalysts, and the surface of the composite catalysts was hydrophobically and lipophilically modified to prepare the loaded nano TiO₂ composite photocatalysts with hydrophobicity and lipophilicity characteristics, and the crystalline phase composition and microscopic morphology of the composite photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FTIR), and ultraviolet-visible spectroscopy (UV). The hydrophobic and lipophilic properties of the catalytic materials were evaluated, the magnetic recycling properties were evaluated. The degradation effects of the common zeolite-loaded TiO₂ catalysts and the hydrophobically modified carbonyl iron loaded TiO₂ catalysts were comparatively investigated on the three petroleum hydrocarbon pollutants, and the influences of the loading amount of the catalysts and recycling on the degradation efficiencies of the petroleum hydrocarbons were further examined. The results showed that the hydrophobically modified carbonyl iron loaded TiO₂ catalyst has hydrophobic and lipophilic properties, which can make the non-polar petroleum hydrocarbon pollutants contact with the active sites of the catalytic material in a better way, and it is easy to be recycled under the magnetic field due to the magnetic nature of the catalytic material particles; the novel catalytic material has a better degradation efficiency of petroleum hydrocarbon pollutants in water, the maximum removal rate of the conventional TiO₂/zeolite catalysts for the pollutants was about 75%, while the maximum removal rate of TiO₂/modified carbonyl iron could reach 95%, and the degradation rate was faster. Degradation effect was improved with the increase of the catalyst concentration, but the degradation effect was decreased when the concentration was further increased to 4 g·L^-1, During repeated use, the activity of the composite photocatalytic material does not decrease significantly, indicating that the composite catalytic material has good stability.

Key words: surface, support, catalyst, photocatalytic degradation, petroleum hydrocarbons

摘要：

采用磁性羰基铁颗粒作为载体，负载纳米TiO₂制成复合光催化剂，并对复合催化剂表面进行疏水亲油改性，制备得到具有疏水亲油特性的负载型纳米TiO₂复合光催化剂。采用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、红外光谱仪（FTIR）和紫外-可见光谱仪（UV）等，表征了复合催化材料的晶相组成和微观形貌，评价了催化材料的疏水亲油性能、磁回收性能，对比研究了普通沸石负载型TiO₂催化剂和疏水改性羰基铁负载型TiO₂催化剂对三种石油烃污染物降解效果，并进一步考察了催化剂加载量和循环使用对石油烃降解效率的影响。结果表明，疏水改性羰基铁负载型TiO₂催化剂具有疏水亲油特性，可使得非极性石油烃类污染物能更好地与催化材料的活性位点接触，且由于催化材料颗粒具有磁性，在磁场作用下易于回收；新型催化材料对水中的石油烃类污染物具有更好的降解效率，常规TiO₂/沸石催化剂的光解效果对污染物的最大去除率为75%左右，而TiO₂/改性羰基铁的最大去除率可以达到95%，且降解速率更快，随着催化剂浓度的增加，降解效果提高，但当浓度进一步增加至4 g·L^-1时，降解效果下降；在重复使用过程中，复合光催化材料活性降低不明显，说明复合催化材料的稳定性较好。

关键词: 表面, 载体, 催化剂, 光催化降解, 石油烃