Zhikun Dai, Rui Gao, Qianqian Li, Mengting Qin, Jing Yang, Ran Niu*, Jiang Gong*

Facile synthesis of dual-functional ZIF-8-based evaporators towards high-performance in seawater desalination and uranium extraction

Journal of Environmental Chemical Engineering (2024) Accept.  (IF2024 = 7.4)

Interfacial solar evaporation, which utilizes the inexhaustible solar energy to desalinate freshwater, is highly promising to solve freshwater shortage. However, when dealing with polluted water such as radioactive uranium solution, the effective adsorption of uranium is critical to avoid environmental pollution. Herein, we report the facile construction of zeolitic imidazolate framework-8 (ZIF-8)/carbon nanotube (CNT)/gelatin evaporator via a simple dip coating method for simultaneous seawater desalination and uranium extraction. Benefiting from the incorporated CNT, the evaporator shows good light absorption and photothermal conversion. The evaporator reaches a high evaporation rate of 4.1 kg m^-2 h^-1 under 1 Sun irradiation, which surpasses many advanced evaporators. Furthermore, the nitrogen-containing ZIF-8 and gelatin enable the uranium adsorption through water transport and self-heating effect, since the water evaporation enables UO₂²⁺ diffusion and the photothermal effect facilitates UO₂²⁺ adsorption. Consequently, the equilibrium adsorption of UO₂²⁺ is reached within 60 min, with the high UO₂²⁺ adsorption capacity of 179.6 mg g^-1. This work provides a new opportunity for simultaneous freshwater generation and uranium adsorption, which contributes to achieving carbon neutrality and uranium adsorption.