Synthesis And Adsorption Application For Dye Of Fe₃O₄-COOH/HKUST-1 Composites

The molecular structures of dyes are complex and stable resulting in the dyes is non-biodegradable in natural environment.The Dye wastewater without correct treatment contains lots of carcinogenic and toxic organic dyes which may cause serious water pollutions.So it is in utmost important to develop a proper method to treat dye wastewater.In this work,the FeCl3·6H2O and sodium acetate were used to synthesize Fe₃O₄ sphere.And the sodium acrylate was directly added into the precursor solution via solvothermal reaction to get the functional Fe₃O₄ sphere which surface had more carboxyl groups?Fe₃O₄-COOH?.Then the carboxylated Fe₃O₄ sphere was chose to be the support of copper-based MOFs which was called HKUST-1?Cu3[?BTC?2?H2O?]n,MOF-199?in the synthesis of magnetic MOFs hybrid materials?Fe₃O₄-COOH/HKUST-1?.The abundant carboxyl groups on the Fe₃O₄ sphere surface enhanced the interaction between Fe₃O₄ sphere and HKUST-1 through the connection of Cu2+ on HKUST-1 and carboxyl groups on the Fe₃O₄ sphere.The magnetic MOFs hybrid material was characterized by FT-IR,SEM,TEM,XRD,VSM,EDS and N2 adsorption.The results revealed the carboxyl on the surface of Fe₃O₄ sphere made it more easily to connect with HKUST-1.The magnetic MOFs hybrid material had excellent magnetic properties?23.65 emu g-1?and inherited large SBET and pore volume of the HKUST-1,the SBET reached 430.15 m2 g-1.Those good properties provided good foundation for next stepped adsorption experiment.At last,the thesis used the Fe₃O₄-COOH/HKUST-1 as adsorbent to adsorb the organic dye molecules in water solution,and studied the adsorption isotherm model,adsorption kinetics,absorption thermodynamics and circulation property.The adsorption kinetics and isotherms analysis indicated these sorption processes were better fitted to the pseudo-second-order and Langmuir equations,thermodynamic study showed the sorption processes were spontaneous and endothermic.Adsorption experiment data also showed the hybrid material possessed a high adsorption capacity for MB?118.6 mg g-1?and AO??131.7 mg g-1?,had high adsorption efficiency?94.3 %?after five adsorption cycles with ethanol/HCl?0.2 %,V/V?as eluent.