Enhanced adsorption and separation of gallium using silica-based P507-TBP/SiO2–P adsorbent from sulfuric acid solution

Abstract

The designing of high adsorption capacity and selective porous materials to adsorb gallium (Ga) is essential for developing breakthrough Ga separation and purify methods based on resin adsorption to replace traditionally used extraction, chemical precipitation, and electrochemical method. Here, an advanced porous resin with the 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (P507) and tributyl phosphate (TBP) attached to the silica-based materials (SiO2–P) has been prepared, which are synthesized by vacuum impregnation followed by drying. At low concentration sulfuric acid solution (PH = 3.3), the synthetic adsorbent that simultaneously exhibits excellent Ga adsorption capacity and high separation ability (excellent adsorption capacity with 64.2 mg/g, and super-high separation ability with the Kd is over 1600). Adsorption and mechanism studies of Ga (III), using the above P507-TBP/SiO2–P resin, were carried out. IR, XPS, and BET, TG analysis were applied to confirm the resin were successful adsorb Ga (III) and the conversion of polymer to resin, respectively. More importantly, the P507-TBP/SiO2–P adsorbent can also be extended to the design of other silica-based materials for the challenging separate and purify other rare precious metals ions, indicating a very appealing application prospect.