Solvothermal-assisted evaporation-induced self-assembly process for significant improvement in the textural properties of γ-Al₂O₃, and study dye adsorption efficiency

A comparative study of the textural properties of γ-Al2O3 prepared by solvothermal-assisted evaporation-induced self-assembly (SA-EISA) and conventional evaporation-induced self-assembly (EISA) processes has been carried out using aluminum isopropoxide, triblock copolymer-type nonionic surfactant (Pluronic P123) and ethanol. The solvothermal reaction was carried out at 100 °C for 24 h followed by slow drying at 60 °C for 48 h. The synthesized products were characterized by thermogravimetry analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) analysis, N2 adsorption–desorption study and transmission electron microscopy (TEM). The γ-Al2O3 prepared by SA-EISA process became stable up to 1000 °C. The powder prepared by SA-EISA process resulted in a significant increase in textural properties (BET surface area, pore volume and pore diameter) compared to that prepared by conventional EISA process. A better adsorption capacity for Congo red, a carcinogenic dye used in textile industry, was exhibited by the powders prepared by SA-EISA process. A proposed mechanism was illustrated for the formation of mesoporous γ-Al2O3 obtained by EISA and SA-EISA processes.