Enhanced photodegradation of Rhodamine B by coupling direct solid-state Z-scheme N-K2Ti4O9/g-C3N4 heterojunction with high adsorption capacity of UiO-66

N-K2Ti4O9/g-C3N4/UiO-66 ternary composites were successfully synthesized by a solvothermal method, and were characterized by powder X-ray diffraction, UV–vis diffuse reflectance spectroscopy, the valence band X-ray photoelectron spectroscopy, field emission transmission electron microscopy, photoluminescence emission spectra and N2 adsorption-desorption. Photocatalytic activities of N-K2Ti4O9, g-C3N4, UiO-66, N-K2Ti4O9/g-C3N4 binary composites and the ternary composites were investigated by the degradation of Rhodamine B (RhB) under visible light irradiation. The results show that the ternary composites exhibit higher photocatalytic activity as compared with the binary composites and the pure materials. The synergistically enhanced photocatalytic activity of the ternary composites is due to coupling direct solid-state Z-scheme N-K2Ti4O9/g-C3N4 heterojunction with high adsorption capacity of UiO-66 for RhB.