Chaaban Maya, El-Rassy Houssam
Department of Chemistry, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, 1107 2020 Beirut, Lebanon.
ACS Omega. 2020 Oct 16;5(42):27401-27412. doi: 10.1021/acsomega.0c03828. eCollection 2020 Oct 27.
Highly porous nickel-aluminum oxide aerogels were prepared according to a one-pot sol-gel process and dried under supercritical carbon dioxide conditions. Although the surface properties of these materials were very appealing for applications in catalysis, these aerogels were never applied in adsorption. The nickel effect on the structure and surface properties of the aerogels has been investigated via a broad range of structural, textural, and morphology characterization of the aerogels before and after heat treatment. The adsorption capacity of the as-synthesized and calcined aerogels for azo dyes was assessed under various experimental conditions. The presence of nickel in the aerogel boosts tremendously the surface reactivity and improves noticeably the adsorption capacity of the material. The adsorption capacities for the nickel-aluminum oxide aerogel with 40% nickel ( ) are 900 mg g for methyl orange, 1484 mg g for orange II, and 1660 mg g for Congo Red. The adsorption process is exothermic and follows pseudo-second-order kinetics.
采用一锅法溶胶-凝胶工艺制备了高度多孔的镍铝氧化物气凝胶，并在超临界二氧化碳条件下干燥。尽管这些材料的表面性质在催化应用中非常有吸引力，但这些气凝胶从未应用于吸附。通过对热处理前后气凝胶进行广泛的结构、织构和形态表征，研究了镍对气凝胶结构和表面性质的影响。在各种实验条件下评估了合成态和煅烧态气凝胶对偶氮染料的吸附容量。气凝胶中镍的存在极大地提高了表面反应活性，并显著提高了材料的吸附容量。含40%镍（ ）的镍铝氧化物气凝胶对甲基橙的吸附容量为900 mg/g，对橙黄II的吸附容量为1484 mg/g，对刚果红的吸附容量为1660 mg/g。吸附过程是放热的，遵循准二级动力学。
