Adsorption of Rutin from Aqueous Solution over an OMS-2-Modified ZrO2 Nanocomposite

Adsorption and purification of biological molecules with pharmacological functions over advanced adsorption materials are always a concern. In this work, manganese oxide octahedral molecular sieve (OMS-2)-modified ZrO2 nanocomposites (ZrO2-OMS-2) were fabricated and their adsorption performance towards rutin from aqueous solution was investigated. As-obtained nanocomposites were fully characterized by N-2 adsorption/desorption isothermal, ICP-AES, XRD, SEM and TEM, which indicates that OMS-2-modification significantly promoted the textural properties of the nanocomposites. 10 mol% Mn amount for ZrO2-OMS-2 showed the optimal adsorption capacity for rutin due to the enhanced specific surface aera (104 m(2)/g) and better ZrO2 dispersion. The adsorption rate of 85 % was realized over 10 mg of the optimal adsorbent and the desorption rate could reach nearly 100 % in 0.2 % TFA/methanol solution. Moreover, the adsorbent could be reused for at least 3 times. The adsorption behavior was fitted the pseudo-second-order model and Freundlich model. Kinetic and thermodynamic studies suggested that an endothermic chemosorption from Lewis acid-base paring on the surface of ZrO2-OMS-2 was responsible for the good adsorption. This work shows the positive effect of manganese oxide-modification for ZrO2 during adsorption process and the potential of ZrO2-based nanocomposites being adsorbents.

Automated summary

In this study, manganese oxide octahedral molecular sieve-modified zirconia nanocomposites were fabricated and their adsorption performance towards rutin was investigated. The results showed that manganese oxide modification significantly improved the textural properties of the nanocomposites. Moreover, the optimal adsorbent exhibited high adsorption rate and desorption rate, and could be reused for multiple times.