Facile synthesis of g-C3N4/montmorillonite composite with enhanced visible light photodegradation of rhodamine B and tetracycline

A novel g-C3N4/montmorillonite (CN/M) composite with enhanced visible light photocatalytic activity was synthesized via a facile two-step process including wet-chemical and calcination method. The microstructure, interfacial and optical properties of the obtained CN/M composites were characterized by scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), surface area measurement (BET) and UV-visible diffused reflectance spectroscopy (UV-vis DRS). It is indicated that a tight interfacial combination between g-C3N4 nanosheets and montmorillonite layers was formed in the composite photocatalysts. Compared with the other reference samples, the as-received CN/M composites possess significantly enhanced photocatalytic activity towards rhodamine B and tetracycline. The optimal mass ratio of g-C3N4 with respect to montmorillonite is determined to be 31.86 wt% and the corresponding reaction constant rate is almost 3.0 times that of the pure g-C3N4 under visible light. The enhanced photocatalytic activity of the g-C3N4/montmorillonite composite could be attributed not only to its relatively higher surface area and enhanced light -adsorption ability under visible light but also the synergistic effect arising from the tight combination between g-C3N4 and montmorillonite due to the electrostatic interaction, which leads to efficient separation of the photo-generated charge carriers. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.