Synthesis, characterization and enhanced visible light photocatalytic activity of Bi2WO6/Ni–Al layered double hydroxide composites

Abstract

Bi2WO6/Ni–Al layered double hydroxide (LDH) composites assembled from Bi2WO6 and Ni–Al LDH composites were prepared by a simple hydrothermal method. The as-prepared composites were characterized by XRD, SEM, FT-IR, UV–Vis DRS, XPS, and N2 adsorption–desorption techniques. The results showed that the Bi2WO6/Ni–Al LDH composites heterojunction exhibited greatly increased specific surface area, improved the visible light absorption, and promoted the electron–hole pairs generated and separation efficient. Furthermore, the photocatalytic performance of Bi2WO6/Ni–Al LDH composites toward degradation of rhodamine B, safranine T, and tetracycline tightly depended on the mass fraction of LDH. At the LDH weight loading of 5 wt%, the photocatalytic degradation efficiency of Bi2WO6/Ni–Al LDH-5 composites reached 83.98, 99.74, and 84.51% within 8.0, 4.0, and 11.0 h, respectively. The enhanced activity of Bi2WO6/Ni–Al LDH-5 composites may be attributed to the concerted photocatalysts effect between two constituents of as-prepared composites. A possible photocatalytic mechanism was proposed according to various performance characterization and experimental results. In addition, the as-prepared catalysts showed remarkable reusability and stability in four successive cycles. It is wished that the Bi2WO6/Ni–Al LDH composites could be used as photocatalysts for energy transformation and environmental treatment. This material provides new ideals for degradation of organic compounds pollutants.