In situ reduction for synthesis of nano-sized Cu₂O particles on MgCuAl-LDH layers for degradation of orange II under visible light

Cu₂O-MgAl-LDH composites were synthesized from MgCuAl-layered double hydroxides (LDHs) as precursors using ascorbic acid for reduction of Cu²⁺. The synthesized precursor materials and composites were characterized by XRD, TEM, XRF, XPS and UV-vis diffuse reflectance spectroscopy. The results showed that the Cu₂O nanoparticles were evenly distributed on the LDH nano-sheets, which greatly improved the catalytic property of Cu₂O. For example, the Cu₂O-Mg₇Al₅-LDH composite removed about 90% of Orange II while pure Cu₂O removed only about 70% of the dye through photocatalytic degradation. The Cu₂O-LDH composites showed very high efficiency in degrading Orange II dye because of uniform distribution of Cu₂O nanoparticles on the surfaces of LDH with less amount of copper than in pure Cu₂O. The Cu₂O-LDH composites developed here are potential photocatalysts for dye degradation in water purification.