Biotemplated fabrication of hierarchically γ-AlO(OH)/CuMgAl-LDH for removal of Congo red

摘要

Hierarchically porous gamma-AlO(OH)/CuMgAl-LDH with high specific surface area and superior adsorption performance toward Congo Red (CR) were successfully synthesized by combining the biotemplated and hydrothermal method. Hexagonal CuMgAl-LDH nanosheets and honeycombed gamma-AlO(OH) nanosheets interwove into 3D hierarchically porous structure through in-situ growths onto the surface of hollow Al2O3 fibers that were made from kapok template. The effects of various limiting factors including contact time, pH value and initial concentrate of CR on the adsorption capacity were investigated gamma-AlO(OH)/CuMgAl-LDH synthesized under the hydrothermal temperature of 160 degrees C had the maximum monolayer adsorption capacity of 155.76 mg g(-1), which was attributed to the higher BET surface area and 3D hierarchically porous structure. It was found that the CR adsorption by gamma-AlO(OH)/CuMgAl-LDH was spontaneous and exothermic and the adsorption process was well fitted with the Langmuir isotherm model and the pseudo second order kinetics model.