Metal-organic Gels Derived Porous Carbon Materials And Adsorption Properties

Metal-organic frameworks (MOFs), constructed by metal (clusters) and carboxylate, N-involved ligand, have attracted much attention as promising nanoporous materials due to tunable pore sizes and high surface areas, intriguing architectures and various applications in gas storage and separation, catalysis, drug delivery and so on. Inspired by their outstanding characters, MOFs have been demonstrated as alternative precursors to construct metal/metal oxides or nanoporous carbons with uniform heteroatom decoration, long-range ordering and high porosity via general pyrolysis, and a large amount of MOF-derived carbon materials have been developed for diverse applications. There are still some aspects that should be noticed seriously. It is subject to costly and time consuming in the synthetic process of MOFs, and some toxic and teratogenic reagents are usually employed in preparing MOFs, which limit the application in industry. For the consciousness of protecting environment, most reported works are opposite and negative. So it is necessary to employ the environmentally friendly regents in the whole process. Similar to MOFs, metal-organic gels (MOGs) are a novel class of extended structures based on coordination complexes, they show comparable bonding connectivity but different structural regularity, so the microporous MOF particles can be utilized as building units to generate MOGs or meso/macroporous gel matrix through a self-assembly process.There have been many pioneering studies on the core-shell metal/metal oxides MOFs to date, most of these MOFs were synthesized by a versatile step-by-step strategy by using metal or metal oxides as templates to confine the structures of MOFs. Since metal oxides can provide metal ions, the self-template synthetic strategy may be another alternative way for the synthesis of MOFs. In this way, MOFs can grow outside the surface of templates without any surface modification through sacrificing metal oxide templates themselves.Considering environmental protection and the adsorption cost, in this work, we select the MOG templates to generate metal/metal oxides and nanoporous carbon materials. The main contents of this thesis are as follows:1. Magnetic porous carbon composite with high surface area has been prepared from a Fe-based metal-organic gel (MOG) template via a facile method. Magnetic nanoparticles are embedded in the carbon matrixes in the magnetic composite. The obtained magnetic porous carbon composite can be applied to remove organic dyes from an aqueous solution. It exhibits excellent adsorption capacity, fast adsorption kinetics and perfect reusability for the organic dyes removal.2. Nanoporous carbon adsorbent with high surface area (2477 m2g-1) and pore volumn has been prepared from Al-based MOG and characterized using several methods. The structure of nanoporous carbon is well-developed microporous. Adsorption capacity for the removal of organic dye (methyl orange) from aqueous solution has also been studied and the nanoporous carbon exhibit high adsorption (917 mg g-1) and fast adsorption kinetics.3. Urchin-like FeOOH@MIL-100(Fe) hollow spheres with core-shell structures have been successfully fabricated via a simple self-template strategy, where FeOOH hollow spheres not only act as the template but also provide Fe3+ ions for the formation of MIL-100(Fe).The experiments show that the reaction time are crucial for good control of FeOOH@MIL-100(Fe) hollow spheres.