Synthesis, Characterization Of Porous Carbons And Their Applications In Photocatalysis

Porous carbon materials have attracted much attention due to their specific properties. In this work, we fabricated porous carbon with controlled pore structure by selecting different carbon precursors via hard template method. The composite of TiO₂/porous carbon was prepared by loading TiO₂ on the porous carbon materials using sol-gel method, and its photocatalytic activities on degradation of dye were also investigated.Three-dimensionally ordered macroporous SiO₂/graphitized carbon, TiO₂/graphitized carbon, and the resultant graphitic carbon were fabricated via in-situ pyrolysis of nickel-impregnated polystyrene arrays, which were used as both template and carbon source for the generation of macroporous composite at lower temperature. The prepared samples were characterized by powder X-ray diffraction, N2 adsorption, Raman spectroscopy, thermogravimetic analysis, SEM, TEM and HRTEM. The graphitization degree and the content of graphitic carbon in the composite were dependent on the pyrolysis temperature and confinement effect of macroporous oxides skeleton. The composite of SiO₂/graphitized carbon exhibited long-range ordered structure at the pyrolysis temperature ranging from 600 to 1000°C. The high pyrolysis temperature leads to the higher degree of graphitization. photocatalytic degradation of Rhodamine B(Rh B)and eosin Y were used as the probe reaction, we investigated the photocatalytic activity of TiO₂/graphitized carbon composite. It was found that under UV light irradiation, The degradation of both Rh B and eosin Y followed kinetic first-order reaction, the TiO₂/graphitized carbon showed higher activity than P25 in the degradation of Rhodamine B. Its higher photoactivity may be related to the good electronic conductivity of graphitized carbon, the intimate contact between TiO₂ and graphitized carbon, as well as the interconnected macroporosity.Monodisperse silica particles with tunable diameter from 16.8 nm to 39 nm were facilely prepared through seed growth process. The silica particles with different diameter were used as template and sucrose as carbon precursor for the generation of ultra-large mesoporous carbon materials with tunable pore size (from 12.4 nm to 34.5 nm) and three-dimension interconnected mesopores structure. As a result, when the monodisperse silica particles were used as template, carbon materials with continuous tunable pore size, high BET surface area and pore volume could be achieved. By changing the molar ratio of sucrose/silica, the surface area and pore volume of the final carbon materials could be tuned in the range of 1055-1579 m²/g and 2.50-5.64 cm³/g.The mesoporous graphitized carbons were catalytically synthesized with the assistance of metal Ni by pyrolyzing polystyrene in the interstices of closed-packed silica spheres at 950°C. By using colloidal silica or the mixed colloidal silica as templates, mesoporous graphitized carbon with high surface area were prepared. It was found that with the assistance of nanosized Ni, we fabricated mesoporous graphitized carbons at lower temperature. The specific surface area and total pore volume of the resulting graphitized carbon were highly dependent on the proportion of two type of colloidal silica with different particle size. The TiO₂ loaded on mesoporous graphitized carbon materials showed improved photoactivity than pure anatase in term of photocatalytic degradation of Rhodamine B and phenol under otherwise the identical condition.