Zirconium oxide (ZrO2) exhibits great potential in the remediation of arsenic-polluted water. In this study, tetragonal zirconium oxide (t-ZrO2) with high lattice defects was facilely fabricated by regulating the Zr-metal-organic framework (MOF) (UiO-66) with sodium acetate modulator and examined to adsorb arsenic from water. Benefitting from the synergistic effects of mesopores structure and lattice defect, t-ZrO2 exhibited ultrahigh adsorption capacity and faster kinetics towards both arsenate (As(V)) and arsenite (As(III)). The Langmuir adsorption capacity for As(V) and As(III) of 147.5 mg g-1 and 352.1 mg g-1 on t-ZrO2 in exothermic process, respectively, significantly outperforming reported counterparts in literature (generally ≤100 mg g-1). The faster adsorption kinetic of both As(III) and As(V) on t-ZrO2 is defined favorably by the pseudo-second-order model over a wide pH (3-11). Furthermore, arsenic is mainly captured by t-ZrO2 via forming Zr-O-As bonds through occupying coordinatively unsaturated zirconium atoms adsorption sites revealed by the X-ray photoelectron spectroscopy (XPS) spectrum and Fourier-transformed infrared (FTIR) spectra analysis. This study offers a new strategy for designing ultrahigh performance Zr-MOF-derived adsorbents for capturing arsenic.
Keywords: Adsorption; Arsenic; Lattice defect; MOF-Derived; Tetragonal zirconium oxide.
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