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Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes.

Meng L, Zhang X, Tang Y, Su K, Kong J - Sci Rep (2015)

Bottom Line: The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates.On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red.Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Space Applied Physics and Chemistry, Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.

ABSTRACT
The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g(-1) and 1084.5 mg·g(-1) for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

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Nitrogen adsorption–desorption isotherms and the corresponding pore size distribution (PSD) calculated using adsorption branch of the BJH algorithm for (a) C1 and (b) C2.
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f8: Nitrogen adsorption–desorption isotherms and the corresponding pore size distribution (PSD) calculated using adsorption branch of the BJH algorithm for (a) C1 and (b) C2.

Mentions: It is well-known that the maximum pyrolysis temperature plays a critical role in determining the nature of the resultant PDCs, in particular, the SSA and pore size distribution49. In order to investigate the influence of pyrolysis temperature on microstructure of the materials, two types of samples under different pyrolysis condition were prepared to determine the specific surface area by N2 absorption–desorption measurement, i.e. C1 (PSZ:PDVB:NiCp2 = 1:2:0.04, 600°C) and C2 (PSZ:PDVB:NiCp2 = 1:2:0.04, 750°C). As shown in Figure 8a, the adsorption–desorption curve of C1 demonstrates a steep increase at very low relative pressures, which is a typical characteristic of microporous material with type I isotherm. Subsequently, a slow increase in the adsorption amount occurs during the relative pressure range of 0.4–0.8, indicating the presence of a few mesopores. Thus, the adsorption can be considered as multilayer adsorption and capillary condensation in these mesopores by nitrogen molecules when P/P0 is below and above 0.4, respectively. The calculated BET surface area and pore volume for C1 are 251.6 m2·g−1 and 0.09 cm3·g−1, respectively.


Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes.

Meng L, Zhang X, Tang Y, Su K, Kong J - Sci Rep (2015)

Nitrogen adsorption–desorption isotherms and the corresponding pore size distribution (PSD) calculated using adsorption branch of the BJH algorithm for (a) C1 and (b) C2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4300473&req=5

f8: Nitrogen adsorption–desorption isotherms and the corresponding pore size distribution (PSD) calculated using adsorption branch of the BJH algorithm for (a) C1 and (b) C2.
Mentions: It is well-known that the maximum pyrolysis temperature plays a critical role in determining the nature of the resultant PDCs, in particular, the SSA and pore size distribution49. In order to investigate the influence of pyrolysis temperature on microstructure of the materials, two types of samples under different pyrolysis condition were prepared to determine the specific surface area by N2 absorption–desorption measurement, i.e. C1 (PSZ:PDVB:NiCp2 = 1:2:0.04, 600°C) and C2 (PSZ:PDVB:NiCp2 = 1:2:0.04, 750°C). As shown in Figure 8a, the adsorption–desorption curve of C1 demonstrates a steep increase at very low relative pressures, which is a typical characteristic of microporous material with type I isotherm. Subsequently, a slow increase in the adsorption amount occurs during the relative pressure range of 0.4–0.8, indicating the presence of a few mesopores. Thus, the adsorption can be considered as multilayer adsorption and capillary condensation in these mesopores by nitrogen molecules when P/P0 is below and above 0.4, respectively. The calculated BET surface area and pore volume for C1 are 251.6 m2·g−1 and 0.09 cm3·g−1, respectively.

Bottom Line: The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates.On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red.Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

View Article: PubMed Central - PubMed

Affiliation: MOE Key Laboratory of Space Applied Physics and Chemistry, Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University, Xi'an, 710072, P. R. China.

ABSTRACT
The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g(-1) and 1084.5 mg·g(-1) for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

Show MeSH