| The rapid development of industry leads to a series of environmental problem, and how to effectively protect environment with the social development has become the focus of people’s attention. This thesis is devoted to design and synthesize novel functional porous materials that are used in environmental protection. In order to directly capture CO2from industrial flue gas, we synthesize MgO-loaded porous materials though co-precipitation and muti-coating methods, and explore the relationship between structure and performance. Based on this, self-supporting porous MgO is synthesized by using sol-gel method. Furthermore, we study the formation process of g-C3N4material, and prepare porous g-C3N4with enhanced activity though controlled thermal reaction and ZnCl2template.1. A novel MgO-based porous adsorbent has been synthesized in a facile co-precipitation method for the first time, in order to provide a candidate for trapping CO2in flue gas at high temperature. The resulting composite exhibits a mesoporous structure with a wide pore size distribution, due to the even dispersion and distribution of microcrystalline MgO in the framework of alumina to form a concrete-like structure. These sorbents can capture CO2at high temperature (150-400℃), possessing high reactivity and stability in cyclic adsorption-desorption processes, providing competitive candidates to control CO2emission.2. MgO is loaded in the pore of mesoporous silica though in situ coating and impregnation methods. Firstly, we adjust the distribution of pre-coated MgO and make it forming even passivation layer, then, a given amount of MgO is introduced in the in situ coated MgO/SBA-15material by impregnation method. We assess the CO2adsorption capacities of these materials at different temperature and calculate the adsorptive efficiency based on some hypotheses, finding that muti-coating method can improve the activity of MgO. In order to decress the mass of carrier, MSn-x samples are corroded with NaOH solution, and the obtained materials show much higher CO2adsorption capacities.3. A new preparative route of porous magnesia is reported in this paper to fabricate pores in magnesia through in situ carbonization. New foam-like magnesia materials were synthesized via one-pot pathway using P123and PEO as templates and magnesium nitrate as precursor, forming the as-made Mg2+-block-polymer-rich composites at first. These composites were converted to magnesia-carbon monolith in the calcination under nitrogen, and then formed the foam-like MgO after the succeeding calcination in air to remove carbon species. Foam-like magnesia samples possess the interconnected porous architecture and cavity, and their framework were constructed by nano-crystalline MgO; they have the large surface area (101-130m2g-1) and pore volume (0.24-0.36cm3g-1) as well as multiple-length-scale porosity (macro-and mesopores). Apart from the advantage of synthesis, this porous magnesia exhibits a considerably high capacity in the CO2adsorption in the temperature range of25℃-200℃.4. Porous g-C3N4was synthesized by a facile template-free method to control the reaction of polymer according to Le Chatelier’s principle. The resulting porous g-C3N4material has high Brunauer-Emmett-Teller (BET) surface area (201-209m2g-1) and large pore volume (0.50-0.52m3g-1), and shows a ten times enhanced photocatalytic activity for methyl orange (MO) photodegradation under visible light (λ>420nm) irradiation. Moreover, Porous g-C3N4materials are also synthesized by using ZnCl2as a template, and the adding amount of ZnCl2obviously affects the pore structure of products. Photodegradation of MO experiment shows that porous can adsorb lots of MO, leading to an enhanced photocatalytic activity of porous g-C3N4... |
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