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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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(a) Adsorption isotherms of two dyes on C1 and (b) Fitting plots of Langmuir isotherm models for two dyes on C1.
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f12: (a) Adsorption isotherms of two dyes on C1 and (b) Fitting plots of Langmuir isotherm models for two dyes on C1.

Mentions: Figure 12a shows the adsorption isotherms of the two dyes on C1 at 25°C. The results reveal that the porous material exhibits excellent adsorption ability toward two dyes. For example, the removal percentage can be as high as 99.2% and 97.2% when the initial concentrations were 300 mg L−1 for MB and 200 mg·L−1 for AF, respectively. In the low concentration range, the equilibrium adsorption capacities for all the dyes increase linearly with the increased initial concentrations. However, the linear growth of the adsorption capacities is retarded at higher initial concentrations because numerous dye molecules found difficulty in accessing vacant sites of the adsorbent, most of which have been occupied. The isotherms are all L-type, which reveals that the porous material has high affinity toward these dyes.


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)

(a) Adsorption isotherms of two dyes on C1 and (b) Fitting plots of Langmuir isotherm models for two dyes on C1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f12: (a) Adsorption isotherms of two dyes on C1 and (b) Fitting plots of Langmuir isotherm models for two dyes on C1.
Mentions: Figure 12a shows the adsorption isotherms of the two dyes on C1 at 25°C. The results reveal that the porous material exhibits excellent adsorption ability toward two dyes. For example, the removal percentage can be as high as 99.2% and 97.2% when the initial concentrations were 300 mg L−1 for MB and 200 mg·L−1 for AF, respectively. In the low concentration range, the equilibrium adsorption capacities for all the dyes increase linearly with the increased initial concentrations. However, the linear growth of the adsorption capacities is retarded at higher initial concentrations because numerous dye molecules found difficulty in accessing vacant sites of the adsorbent, most of which have been occupied. The isotherms are all L-type, which reveals that the porous material has high affinity toward these dyes.

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