Ou Qianhui,Xiong Yan,Chen Li,He Deyong,Zhou Chuxiang,Wang Lan
The nanocomposite materials are highly promising candidates for adsorption applications in dyed wastewater due to their distinctive structural properties. In this work, the nanocomposite hybrids of UiO-66@GO were first synthesized by specifically anchoring Zr-based metal organic framework (MOF) of UiO-66 onto graphene oxide (GO) nanolayer through solvothermal method. Then the composite matrix microspheres (CMMs) of UiO-66@GO were subsequently prepared by embedding the obtained UiO-66@GO nanocomposite into sodium alginate (SA) microspheres through self-assembly cross-linking process. Finally, the prepared UiO-66@GO CMMs were applied for the adsorption of organic dye pollutant and showed efficient water purification performance. As a result, the UiO-66@GO CMMs exhibited selective cationic dye adsorption for Rhodamine B (RhB + ). The experimental results revealed that the adsorption kinetics followed by the pseudo-second-order (PSD) model with rate constant k 2 = 0.95 × 10 –3 g mg −1 min −1 , and the thermodynamics followed by the Langmuir model with adsorption capacity of 345.66 mg mg −1 . Notably, the UiO-66@GO CMMs demonstrated excellent adsorption removal of a significant removal efficiency of 98% towards 10 ppm Rh-B and a rapid adsorption response time of ~ 5 min. Meanwhile, the UiO-66@GO CMMs maintained long-term stability with adsorption efficiency > 95% over 30 days and effective reuse with resorption efficiency > 90% using DMF-H₂O as eluent. In this study, SA has served as a porous supporting matrix to immobilize UIO-66@GO nanoparticles, having mitigated issues of aggregation and leaching common to nanoscale adsorbents while improving reusability. The synergistic effect between UIO-66 and GO has further enhanced pollutant adsorption capacity, demonstrating significant potential for dye wastewater treatment applications.
Metal–organic frameworks (MOFs) are being intensively explored as filler materials for polymeric proton exchange membranes (PEMs) due to their potentials for the systematic design and modification of proton-conducting properties. S-UiO-66, a stable MOF with functional groups of −SO3H in its ligands, was selected here to prepare S-UiO-66@graphene oxide (GO) hybrid nanosheets via a facile in situ growth procedure, and then a series of composite PEMs were prepared by hybridizing S-UiO-66@GO and sulfonated poly(ether ether ketone) (SPEEK). The resultant hybrid nanosheets not only possessed abundant −SO3H groups derived from the ligands of S-UiO-66 but also yielded a uniform dispersion of S-UiO-66 onto GO nanosheets, thus effectively eliminating the agglomeration of S-UiO-66 in the membrane matrix. Thanks to the well-tailored chemical composition and nanostructure of S-UiO-66@GO, the as-prepared SPEEK/S-UiO-66@GO composite PEMs present a significant increase in their proton conductivity under various conditions. In particular, the proton conductivity of the SPEEK/S-UiO-66@GO-10 membrane was up to 0.268 S·cm–1 and 16.57 mS·cm–1 at 70 °C-95% RH and 100 °C-40% RH (2.6 and 6.0 times that of recast SPEEK under the same condition), respectively. Moreover, the mechanical property of composite membranes was substantially strengthened and the methanol penetration was well-suppressed. Our investigation indicates the great potential of S-UiO-66@GO in fabricating composite PEMs and also reveals that the high proton conductivity of MOFs can be fully utilized by means of MOF/polymer composite membranes.
Sheng Feng,Guiliang Zhu,Lili Cao,Runbai Wang,Shuguang Liu
In the work, the layered TiO 2 NS/UiO-66/GO composites were successfully prepared through an in-situ method. Two-dimensional TiO 2 NS combined with UiO-66/GO to form a layered structure. The prepared samples were characterized by X-ray diffraction, thermogravimetric analysis, Brunauer–Emmett–Teller test, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, UV–Vis DRS and PL spectra. TiO 2 NS/40%UiO-66/GO exhibited the most efficient adsorption (20 and 1.3 times those of TiO 2 NS and UiO-66/GO, respectively) through absorbing Congo red (CR). It also displayed the strongest photocatalytic activity (29 and 2 times those of TiO 2 NS and UiO-66/GO, respectively) for degrading CR dye under visible-light irradiation (λ ≥ 420 nm). The removal rate of CR was nearly 100%. Besides, TiO 2 NS/40%UiO-66/GO showed excellent stability even after four cycling runs of adsorbing and photodegrading CR. The results showed that TiO 2 NS/UiO-66/GO composites were highly efficient adsorption and catalytic bifunctional materials. TiO 2 NS/UiO-66/GO composites provide an important basis for combining metal organic frameworks/GO with photocatalytic semiconductors to improve absorption and photocatalytic performance to better treat organic wastewaters.