Synthesis of Diatomite/g-C3N4 Composite with Enhanced Visible-light-responsive Photocatalytic Activity

Novel visible-light-responsive diatomite/g-C3N4 composite was successfully synthesized via a facile impregnation-calcination method. The sample was characterized by TG, XRD, FE-SEM, HR-TEM, FT-IR, XPS, UV-Vis-DRS, and PL spectra. The photocatalytic activities of samples were evaluated by degradation of RhB under visible light irradiation. Experimental results indicated that 2.32wt% diatomite/g-C3N4 composite exhibits high efficiency for the degradation of RhB. The photoreaction kinetics constant value is about 1.9 times as high as that of g-C3N4 under visible light irradiation. The radical trap experiments indicate that O-2(-) serves as the main active species for the photodegradation of RhB over 2.32wt% diatomite/g-C3N4 under visible light irradiation. The enhanced photo activity is mainly attributed to the electrostatic interaction between g-C3N4 and negatively charged diatomite, synergistic effect lead to the efficient migration of the photogenerated electrons and holes of g-C3N4.