Synthesis of (ZrO2-Al2O3)/GO nanocomposite by sonochemical method and the mechanism analysis of its high defluoridation.

A nanocomposite of (ZrO2-Al2O3)/GO was successfully synthesized by a simple sonochemical method in this study. A special 3D network was formed in (ZrO2-Al2O3)/GO, which produced a large surface area and good distribution of metal oxide nanoparticles. The as-synthesized (ZrO2-Al2O3)/GO exhibits a maximum fluoride adsorption capacity of 62.2 mg/g, and an adsorption ability of 13.80 mg/g when the F- equilibrium concentration is 1 mg/L, both of which are higher than most previously reported defluoridation adsorbents, indicating that it is among the top adsorbents. Large amounts of drinking water contaminated by F- can be treated by (ZrO2-Al2O3)/GO to meet the WHO limit, indicating the high potential for practical application of the adsorbent. Based on the experimental analysis, the origin of the high defluoridation performance and the adsorption mechanism were discussed in detail. Due to the simple preparation, easy operation and high performance, the adsorbent and the related sonochemical method are considered to be significant for developing highly effective adsorbents.