JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY;
OCT 1 2021.
Web of Science Citations:
Kaolinite-titania adsorbents/photocatalysts were prepared by functionalizing a kaolinite with titanium(IV) triethanolaminate isopmpoxide by the sol-gel route. These materials were characterized by various techniques and applied in adsorption studies (kinetic and equilibrium) of the herbicides diuron, hexazinone, and tebuthiuron. Photodegradation studies were also conducted with the materials submitted to heat-treatment at 400, 700, or 1000 degrees C. The basal spacing increased from 0.71 to 1.08 nm when pure kaolinite was functionalized with titanium triethanolaminate units. The materials displayed FTIR bands of -CH, -NH2, and Ti-OH groups, thereby confirming that titanium alkoxide was present in the kaolinite interlayer space. The pseudo second-order model was the best for describing the kinetic adsorption process. In the equilibrium study, the Langmuir model best described the adsorption mechanism. The photodegradation studies showed that the kaolinite-titania nano-composites heat-treated at 400 and 700 degraded diuron, hexazinone, and tebuthiumn efficiently due to the presence of metakaolin and formation of the anatase phase. (AU)