ZrO2 nanoparticles confined in metal organic frameworks for highly effective adsorption of phosphate. (November 2018) - Liu, Tao
Abstract: Highly dispersed ZrO2 particles confined in the MIL-101 (denoted as MIL-101@Zr(DS)) with varied ZrO2 loading amounts were prepared by the double solvents method. For comparison, ZrO2 loaded MIL-101 samples were synthesized by the conventional impregnation method (denoted as MIL-101@Zr(I)) and the deposition method (denoted as MIL-101@Zr(D)). The characterization results indicated that for MIL-101@Zr(DS), ZrO2 particles were dominantly confined in MIL-101 with a much higher dispersion as compared with MIL-101@Zr(I) and MIL-101@Zr(D). The maximum phosphate adsorption capacity and ZrO2 content normalized phosphate adsorption capacity of the MIL-101@Zr(DS) were 21.28 mg P·g −1 and 1120.0 mg P·g −1, respectively. Additionally, the ZrO2 content normalized phosphate adsorption capacity was significantly larger than that for MIL-101@Zr(I) and MIL-101@Zr(D) as well as the reported values for other Zr-based adsorbents. The effects of solution chemistry on phosphate adsorption to MIL-101@Zr(DS), MIL-101@Zr(I) and MIL-101@Zr(D) were also examined. Compared with MIL-101@Zr(I) and MIL-101@Zr(D), the adsorption of phosphate on MIL-101@Zr(DS) was less affected by the coexistence of anions and dissolved humic acid. Increasing pH from 3 to 12 led to decreased phosphate adsorption capacity of MIL-101@Zr(DS) from 10.38 mg P·g −1 to 2.03 mg P·g −1 . Accordingly, used MIL-101@Zr(DS) could be effectively regenerated under alkaline conditions and exhibited stable adsorption-desorption performance. Graphical abstract: Image 1 Highlights: ZrO2 nanoparticles confined in MIL-101 was first prepared by double solvents method. ZrO2 was dispersed at molecular level in MIL-101 pores due to the confinement effect. ZrO2 -loaded MIL-101 had an extraordinarily high efficiency for phosphate adsorption.