Porous ZrO2 sheets synthesized using an ionothermal method and their absorption properties

Abstract

In this study, porous ZrO₂ sheets were synthesized using an ionothermal method combined with heat treatments at 400, 600 and 800 °C. Following ionothermal synthesis, NH₄Zr₂F₉ with a sheet-like structure was obtained. After heat treatment, the NH₄Zr₂F₉ was transformed into monoclinic ZrO₂ with a porous sheet structure. The ZrO₂ was characterized using XRD, FT-IR, FE-SEM TEM, TG-DTA, BET, and zeta potential analysis. The specific surface area of the samples increased with heat treatment temperature, being 12, 17, and 19 m² g⁻¹ for 400, 600, and 800 °C, respectively. In addition, measurement of the zeta potential of the samples in KCl solution showed that all samples were negatively charged at pH 7, and had different isoelectric points. Adsorption was evaluated using methylene blue and methyl orange and the results indicated that samples heated at different temperatures possessed different selectivities for cationic and anionic dyes.