Controllable Synthesis Of Mesoporous Carbon By A Template Method And Its Properties Of Dye Removal

Due to its abundant content of 2-50 nm pores, mesoporous carbon(MC) is famous for its huge specific surface area, great adsorption capacity, and tunable pore structure, etc. The most promising applications include catalysis, adsorption/separation, biological pharmaceutical synthesis, material construction and so on. On the other hand, it is worthy of pointing out the critical drawbacks which hinder the MC-based materials from commercial applications,including the absence of strong experimental evidences to reveal the adsorption behaviors and mechanism of MC, as well as the difficulty in the separation/recycling of MC-based adsorbent.In order to resolve the problems mentioned above, a feasible way is proposed in this work to prepare MC matt in low cost by making use of preliminarily-synthesized Ni(OH)2 gel as the template, and phenolic resin as the carbon precursor. The preparation processes involve homogeneous precipitation, resin impregnation, heating solidification, high-temperature carbonization and acid-etching purification. The synthesis of MC with different pore structures was controlled by adjusting the template content during the prepare process. Under the observations of scanning electron microscope(SEM) and transmission electron microscope(TEM), we can see the homogenous distribution of mesopores in MC. From the analysis of nitrogen cryo-sorption, we know that the template content behaves a great impact on the formation of pore structure and the total porosity, in particular, the content of mesopores.Furthermore, the as-prepared MC powder with different template content was employed as the adsorbant to remove a large-molecular dye molecular-- Bromocresol green(BCG)--from its aq. solution. The critical influence factors of adsorption performance, such as template content,temperature and the initial concentration were investigated in details. The paper also analyzes the corresponding adsorption dynamics, adsorption isotherm and adsorption thermodynamics. The results show that the adsorption capacity and the rate of adsorption increase with the increasing of ambient temperature and template content. According to the alternations of the adsorption thermodynamic parameters, MC obtains a greater driving force with the increase of template content in the process of adsorption, and thus can remove dye more effectively.In order to resolve the second problem mentioned above, TiO2 nanoparticles were introduced into the products to synthesize TiO2 modified pyrolytic carbon. The experimental results show that under the irradiation of ultraviolet light, the TiO2 modified carbon behaved an enhanced and sustainable ability of dye removal in comparison to that performed under natural light. The phenomena should be attributed to the effect of photocatalytic oxidation aroused byTiO2 particles, which resulted in the degradation of dye molecular under the stimulation of ultraviolet light and thus gave rise of a more lasting and enhanced adsorption of methylene blue(MB) dye. Additionally, Ni nanoparticles was also remained in the above-mentioned composite of TiO2 modified carbon, in which Ni was used to act as the template and to realize a magnetic performance simultaneously, which must be helpful to recycle the MC-based adsorbant and to avoid further environment pollution.The experimental results propose that the synthesis method by making use of gel template can be used to prepare MC matt with abundant content of mesopores, while additional performances including photocatalytic oxidation and magnetic-driving separation could be realized with the introduction of TiO2 and Ni nanoparticles, respectively. of the as-prepared MC materials have great potential of application in the fields of wastewater treatment, purification of potable water or environment protection, etc.