Photodegradation of organic dye by ZnCrLa-layered double hydroxide as visible-light photocatalysts

In this study, lanthanum containing Zn/Cr-Layered double hydroxide (LDH) was synthesis by co-precipitation method and it was used as photo catalyst in the photo degradation of methylene blue. Physicochemical characterization was carried out by X-ray diffraction, Fourier transform infrared, UV–Vis diffuse reflectance spectroscopy, field emission scanning electron microscopy and transmission electron microscopy techniques. Results showed that the photo catalytic activity of Zn/Cr/La-LDH sample is higher than Zn/Cr-LDH sample. Kinetic research showed that the reaction rate constant Zn/Cr/La-LDH is approximately 1.4 times higher than the apparent reaction rate constant of ZnCr-LDH. The stability of the samples was characterized through cyclic photo catalytic test. Results indicated no observable performance degradation for prepared photo catalyst even after four recycles. This work provides an insight into designing and synthesizing new Zn/Cr/La-LDH hybrid materials with good photo catalytic performance.