Preparation Of HKUST-1-derived Carbon Materials And Its Adsorption Properties For Dyes

With the development of modern industry,the problem of environmental pollution is becoming more and more serious.Dye wastewater,which is highly biotoxic,carcinogenic,and difficult to biodegrade,is one of the causes of water pollution problems,the resource recovery and harmless treatment of dye wastewater can effectively prevent water pollution.As an efficient and inexpensive treatment technology,adsorption technology is widely used in the field of pollutants treatment in water.Metal-Organic Frameworks（MOFs）-derived porous carbon materials have excellent pore structure and good stability,it has remarkable effects on the adsorption of pollutants in water.In particular,the size effect of the charred precursors and the charring conditions have an important influence on the physicochemical properties and adsorption performance of the MOFs-derived carbon materials.Therefore,in this thesis,the size effect of crystals and the effect of charring conditions on HKUST-1-derived carbon materials were investigated by using HKUST-1crystals as charring precursors,and its adsorption performance on rhodamine B（Rh B）,methylene blue（MB）and methyl orange（MO）in water were also studied.The two main parts are as follows:（1）HKUST-1 crystals of different sizes（50 nm,10-20μm,200-300μm）were used as charring precursors,and HKUST-1-derived carbon materials（N₂）were prepared by low-temperature charring under N₂ atmosphere.The materials were characterized by XRD,SEM,TG,N₂ adsorption-desorption,FT-IR and UV-Vis spectroscopy.The charring temperature（300℃）and charring time（0.5 h）of HKUST-1-derived carbon materials were determined.The size effect of HKUST-1 crystals on the physicochemical properties and adsorption performance of HKUST-1-derived carbon materials（N₂）were investigated.The results showed that CS-300-N₂ had the highest adsorption rate for anionic dye（MO）.However,CM-300-N₂ and CB-300-N₂ had significant adsorption capacity for cationic dyes（Rh B,MB）and had excellent adsorption selectivity of cationic dyes（Rh B,MB）on mixed dyes（Rh B/MO,MB/MO）.（2）HKUST-1 crystals of different sizes were used as charring precursors,and HKUST-1-derived carbon materials（CO₂）were prepared by low-temperature charring（300℃0.5 h）under CO2 atmosphere.The materials were characterized by XRD,SEM,N₂adsorption-desorption,FT-IR,and UV-Vis spectroscopy,and the effect of using CO₂ as the charring atmosphere on the physicochemical properties and adsorption performance of the HKUST-1-derived carbon materials were also illustrated.The results showed that CM-300-CO₂ had the highest adsorption capacity for Rh B and MB solutions and had superior adsorption selectivity for cationic dyes（Rh B,MB）in mixed dyes（Rh B/MO,MB/MO）,and could effectively separate anionic dye（MO）.CM-300-CO2 had a superior pore structure and abundant adsorption sites,which was more suitable for the adsorption of MB solution,and its adsorption rate can reach almost 100%.The CM-300-CO₂ still had a high adsorption rate（>90%）for MB dye after 3 cycles.In summary,HKUST-1-derived carbon materials（N₂,CO₂）are excellent adsorbent materials,which have significant advantages in water purification,energy conservation,and environmental protection.