以KAl(SO4)2和尿素为前驱体,通过微波水热法于180°C反应20 min,经600°C焙烧2 h制得分级多孔γ-Al2O3空心微球.所制备的样品被用于吸附典型有机染料刚果红(CR)溶液.结果表明,制备的γ-Al2O3空心微球直径为0.8–1.0μm,厚度约为200 nm.此γ-Al2O3空心微球具有高的比表面积(243 m2g–1)和分级大孔-中孔结构,此结构非常有利于液相过程中的质量传递.微波水热法制备的γ-Al2O3空心微球比水热法制备的γ-Al2O3和商用的γ-Al2O3样品显示出更快和更强的吸附性能.此样品的吸附数据很好地符合假二级速率方程和Langmuir吸附理论模型.从Langmuir吸附理论模型计算得到微波水热法制备的γ-Al2O3空心微球的最大吸附量(qmax)25°C时高达515.4 mgg–1.由于具有分等级结构、高比表面积、大的孔容和吸附能力,微波水热法制备的γ-Al2O3空心微球样品有望成为一种具有很好应用潜力的环境吸附剂.%Hierarchical nanostructuredγ-Al2O3 hollow microspheres were synthesized from KAl(SO4)2 and urea precursors by the microwave-assisted hydrothermal (MAH) method at 180 °C for 20 min followed by calcination at 600 °C for 2 h. The as-prepared sample was used to remove the organic dye Congo red (CR) from aqueous solution. The results showed that the obtainedγ-Al2O3 hollow microspheres are about 0.8–1.0 μm in diameter with a shell thickness of approximately 200 nm. Theγ-Al2O3 hollow microspheres have a high surface area of 243 m2g–1 and a hierarchical meso-macroporous structure, which is beneficial for mass transfer in liquid processes. Therefore, the preparedγ-Al2O3 hollow microspheres exhibit faster adsorption and enhanced adsorption performance for CR than particles prepared by the hydrothermal method and commercialγ-Al2O3. The adsorption kinetic data follow the pseudo-second-order equation and the equilibrium data fit well to the Langmuir model. The maximum adsorption capacity (qmax) of the obtainedγ-Al2O3 hollow microspheres calculated by the Langmuir model is up to 515.4 mgg–1 at 25 °C. Theγ-Al2O3 hollow microspheres prepared by the microwave-assisted hydrotherm method show promise as an adsorbent for environmental applications due to their hierarchical porous structure, high surface area, large pore volume, and adsorption capacity.
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