title: Effect of structure-directing agents on facile hydrothermal preparation of hierarchical γ-Al2O3 and their adsorption performance toward Cr(VI) and CO2.
abstract: Hierarchical flower-like and sphere-like mesoporous γ-Al2O3 microparticles were successfully prepared by a facile hydrothermal method followed by a calcination process using sodium aluminate as aluminum source, urea as precipitating agent, and Pluronic F127 (EO106PO70EO106), polyacrylic acid sodium (PAAS), and mixed F127-PAAS as structure-directing agents (SDAs), respectively. Effects of the SDAs on the phase structure, morphology, textural properties, surface alkaline, and the adsorption performance toward Cr(VI) and CO2 of the as-prepared samples were comparatively studied by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N2 adsorption-desorption, CO2 temperature programmed desorption (CO2-TPD), and UV-Vis spectrophotometric method. The results indicate that the sphere-like γ-Al2O3 obtained by using F127 as the SDA shows the best adsorption performance toward Cr(VI) with a high adsorption rate of 95% and adsorption capacity of 5.7 mg/g when the adsorption reaches equilibrium for 4h at room temperature. However, the flower-like γ-Al2O3 obtained by using PAAS as the SDA has the biggest CO2 adsorption capacity of 1.04 mmol/g at room temperature. This work provides a simple and practical way to prepare potentially bifunctional γ-Al2O3 adsorbent for the removal of pollutants in water and air treatment from cheap sodium aluminate by using different SDAs.
authors.affiliation: School of Chemical Engineering, State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, PR China.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Ge
authors.forename: Kejian
authors.initials: K
authors.lastname: Deng
authors.forename: Weiquan
authors.initials: W
authors.lastname: Cai
authors.forename: Jiaguo
authors.initials: J
authors.lastname: Yu
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Liu
authors.forename: Jiabin
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000327:Adsorption; D000537:Aluminum Oxide / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D013499:Surface Properties; D013696:Temperature
chemical_list: D002857:Chromium; D002245:Carbon Dioxide; C074702:chromium hexavalent ion; D000537:Aluminum Oxide