Synthesis of UiO-66 series metal–organic framework composites and the adsorption effect on gallium

Abstract

It is an urgent problem to alleviate the contradiction between the supply and demand of gallium (Ga) resources and improve the extraction and utilization efficiency of Ga resources. The GO/UiO-66-NH2 composite adsorbent was synthesized by hydrothermal synthesis of graphene oxide (GO) and UiO-66-NH2 series metal–organic skeleton, which was employed for efficient recovery and extraction of Ga in solution. The morphology, structure, elemental composition, and chemical properties of the composite adsorbent were studied by a series of batch experiments, respectively. The effects of the amount of adsorbent, adsorption time, initial concentration, and pH value of the solution on the adsorption effect were investigated. Results found that the adsorption mechanism of Ga by 4-GO/UiO-66-NH2 is mainly ion exchange forming chelate, accompanied by electrostatic interaction. The optimized adsorption conditions for reaching the saturated adsorption capacity of 661.67 mg/g Ga were found to be pH 9 and the temperature 313 K. The results of thermodynamic study pointed out the adsorption of Ga is spontaneous and feasible. The aforementioned results demonstrate that GO/UiO-66-NH2 composite adsorbent has strong adsorption performance and application potential for the recovery and exploitation of Ga, offering practical and theoretical support for the future development and utilization of Ga resources.