Tuning the structure of a hierarchically porous ZrO2 for dye molecule depollution

A novel strategy that tailors porous zirconia structures via a control of zirconium alkoxide reactivities has been developed. This control was achieved by limiting the amount of water present in the system through the use of an acetonitrile medium. Varying the amount of water present during the reaction has led to a better understanding of the self-formation phenomenon of hierarchical porosity. The choice of zirconium alkoxide precursor has also been studied. The porosity of the zirconia can be altered simply by tuning the water:acetonitrile ratio. A significant change in the porous structure has been observed with increasing water content. This revelation has led to a better understanding of the formation of hierarchically porous structures and the development of a very efficient and simple method to tailor hierarchical porosity over different length scales. The synthesized zirconia products, with differing porous structures, showed a very high adsorption capacity for dye molecules in aqueous solution. A relationship between the porous structure and the adsorption capacity of dye molecules has been evidenced, suggesting their potential application in water treatment as decontamination materials.

A novel strategy has been developed to prepare hierarchically porous zirconia by controlling the hydrolysis and condensation reactions of zirconium alkoxides by using acetonitrile to limit the amount of water in the reaction medium. An evolution of the porous structure has been observed on increasing water content. The synthesized materials present a high adsorption capacity towards dye molecules, which is greatly influenced by their porous structure.Figure optionsDownload as PowerPoint slideHighlights
► Zirconium alkoxide precursor.
► Self-formation phenomenon to hierarchically porous zirconias.
► Varying the water–acetonitrile ratio.
► Tuning porous zirconia structures for dye molecule depollution.