Synthesis of Novel Kaolin-Supported g-C3N4/CeO2 Composites with Enhanced Photocatalytic Removal of Ciprofloxacin

Herein, novel ternary kaolin/CeO2/g-C(3)N(4)composite was prepared by sol-gel method followed by hydrothermal treatment. The self-assembled 3D "sandwich" structure consisting of kaolin, CeO(2)and g-C(3)N(4)nanosheets, was systematically characterized by appropriate techniques to assess its physicochemical properties. In the prerequisite of visible-light irradiation, the removal efficiency of ciprofloxacin (CIP) over the kaolin/CeO2/g-C(3)N(4)composite was about 90% within 150 min, 2-folds higher than those of pristine CeO(2)and g-C3N4. The enhanced photocatalytic activity was attributed to the improved photo-induced charge separation efficiency and the large specific surface area, which was determined by electrochemical measurements and N(2)physisorption methods, respectively. The synergistic effect between the kaolin and CeO2/g-C(3)N(4)heterostructure improved the photocatalytic performance of the final solid. The trapping and electron paramagnetic resonance (EPR) experiments demonstrated that the hole (h(+)) and superoxide radicals (center dot O-2(-)) played an important role in the photocatalytic process. The photocatalytic mechanism for CIP degradation was also proposed based on experimental results. The obtained results revealed that the kaolin/CeO2/g-C(3)N(4)composite is a promising solid catalyst for environmental remediation.