Efficient Adsorption of Dye Pollutant by Anchoring Zr-MOF@GO Composite Matrix Microspheres: Performance and Mechanism Insights

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 k₂ = 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.