PSS-Assisted Hydrothermal Synthesis of Hierarchical γ-Al2O3 Nanostructures with Enhanced Adsorption Performance Towards CO2

Series of hierarchical gamma-Al2O3 nanostructures with enhanced adsorption performance towards CO2 were successfully synthesized via a facilely hydrothermal method-calcination route using AlCl3 center dot 6H(2)O as aluminum source, CH3COOK as precipitant and poly(sodium 4-styrenesulfonate) (PSS) as structure directing agent, respectively. Effects of PSS concentration on the phase structure, morphologies, textural properties of the as-prepared gamma-Al2O3 and their adsorption performance towards CO2 at 25 degrees C were comparatively characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), N-2 adsorption-desorption techniques. It was shown that PSS plays an important role in controlling the morphologies, textural properties and adsorption performance of the gamma-Al2O3. The gamma-Al2O3 obtained without PSS shows irregular massive particles. With increasing its concentration to 2, 4 and 6 g.L-1, respectively, the corresponding gamma-Al2O3 show irregular nanorods cluster-like micron particles, spherical-like cluster composed of nanorods and interwoven fibrous micron particles, respectively, and their specific surface area and pore volume gradually increase in turn. In comparison with the gamma-Al2O3 obtained without PSS, the gamma-Al2O3 obtained with PSS show higher adsorption capacity and faster adsorption kinetics. Especially, when the PSS concentration is 6 g.L-1, the gamma-Al2O3 has the highest adsorption capactiy of 0.68 mmol.g(-1), and shows stable adsorption capactiy after consecutive recycle times of 6.