Synthesis of porous UiO-66-NH2-based mixed matrix membranes with high stability, flux and separation selectivity for Ga(III)

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 421; p. 129748
• Main Authors: Zhang, Mengmeng, Sun, Qian, Wang, Yuejiao, Shan, Weijun, Lou, Zhenning, Xiong, Ying
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2021
• Subjects: Gallium; Mixed matrix membranes; Recovery; Separation; UiO-66-NH2; UiO-66-NH2; Gallium; Separation; Recovery; Mixed matrix membranes
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.129748

The porous THB functionalized UiO-66-NH2 MMMs have been successfully synthesized via electrospinning. The prepared MMMs possesses the superior acid/alkaline resistance, durableness, stability and cyclicity owing to strong π-π interaction of THB, U6N and TPU. And its maximum adsorption capacity for Ga(III) is 96.18 mg g−1, which is higher than UiO-66-NH2 and reported adsorbents. [Display omitted] •Porous MOF-based MMMs with excellent stability was fabricated by strong π-π interaction.•MMMs retains excellent stability after soaked in 5 mol L-1 HCl 7 days or after 9 cycles.•It has high water flux (greater than300 L m-2h−1) and rejection of Ga(III) after 12 h working.•It has better adsorption capacity (96.18 mg g−1) and selectivity than other sorbents. Reported powdery adsorbents with poor adsorption efficiency and stability make it imperative to develop novel materials to extract gallium ions (Ga(III)) from effluents. Herein, UiO-66-NH2-based mixed matrix membranes (TPU/0.1THB/U6N-1.5 MMMs) via electrospinning is firstly reported for separation and recovery of Ga(III). TPU/0.1THB/U6N-1.5 MMMs efficiently overcomes multiple bottlenecks of powder UiO-66-NH2, including poor stability, reusability and adsorption capacity. Its maximum adsorption for Ga(III) is 96.18 mg·g−1 at pH 10.0. It has superiority in selective adsorption of Ga(III) from Al(III), Cu(II), Zn(II), Co(II) coexistence solution. Adsorption capacity of TPU/0.1THB/U6N-1.5 for Ga(III) reaches more than 80% after 9 cycles. Specially, it still retains excellent mechanical strength, flexibility and structural integrity after 12 h filtration, or after 9 adsorption-desorption cycles, even soaked in 5 mol·L-1 HCl for a week. TPU/0.1THB/U6N-1.5 MMMs also improves the problem of low water flux. TPU/0.1THB/U6N-1.5 with high MOFs loading possess high water flux of 382.2 L·m−2·h−1 with a permance of 382.2 L·m−2·h−1·bar−1 and rejection rates of 90% for Ga(III). The main adsorption mechanism of TPU/0.1THB/U6N-1.5 is based on the chelation between phenolic hydroxyl groups of MMMs and Ga(III) at pH 10.0. Overall, the as-prepared TPU/0.1THB/U6N-1.5 has potential for water treatment through the process of membrane adsorption.