Synthesis of CuAl-layered double hydroxide/MgO2 nanocomposite catalyst for the degradation of organic dye under dark condition

Abstract

Water pollution as a result of releasing organic and inorganic pollutants is the main concern and health risk factor for human beings. To minimize the effect of toxicity from pollutants, enormous method has been applied. In this report, the CuAl-layered double hydroxide/MgO2 composite catalysts were synthesized via in-situ growth of magnesium peroxide on the layered double hydroxide (LDH) sheet. The preparations of the catalysts were performed with varying the ratio of LDH: MgO2 which was abbreviated as CuAl-LDH/MgO2-35, CuAl-LDH/MgO2-50, and CuAl-LDH/MgO2-65 for 35:65, 50:50, and 65:35% weight ratios, respectively. The prepared catalysts were characterized and evaluated for methyl orange (MO) dye degradation at room temperature under dark conditions. Among the catalysts, CuAl-LDH/MgO2-50 showed an excellent Fenton-like reaction under neutral condition at which 97% of MO was degraded in the 100 min reaction. However, CuAl-LDH, MgO2, CuAl-LDH/MgO2-35, and CuAl-LDH/MgO2-65 catalysts degrade only 61, 8, 35, and 69% of MO dye. The highest degradation efficiency for CuAl-LDH/MgO2-50 could be due to the presence of optimum amount of copper along with the sufficient amount of generated hydrogen peroxide from MgO2 to run the Fenton-like reaction process. Moreover, the catalyst can also be able to use repeatedly with a minimum loss of activity. In general, the result suggests that CuAl-LDH/MgO2 composite is an option for the degradation of organic pollutants.