Nanoparticles with ordered mesostructures benefit from advantages resulting from the remarkable and complementary property of the mesochannels and quantum effects in the nanoscale. Their open-framework structures, large surface area and porosity, and nanosize make ordered mesoporous nanoparticles useful in adsorption, [1][2][3] controlled drugs release, [4][5][6][7][8][9] cellular delivery, [10][11][12][13][14][15][16] energy storage, [17][18][19][20][21][22] and catalysis.[23] Among mesoporous nanoparticles, silicates have been extensively synthesized by a well-controllable process based on sol-gel chemistry. Mesoporous carbon materials have many advantages over silica materials, such as electrical conductivity, chemical inertness, hydrophobic property, which enable them to be widely used as supercapacitors, [17,18] fuel cells, [19,20] lithium batteries, [22] and hydrophobic drugs carriers.[12] Similar to silica, carbon nanoparticles are nontoxic, biocompatible, and nonimmunogenic, which allows them to be used extensively in cellular delivery. [15,16] Therefore, many efforts have been made to fabricate mesoporous carbon nanoparticles. In general, a nanocasting strategy was adopted by employing nanosized mesoporous silica as a hard template. [15,[24][25][26][27][28][29] Nevertheless, nanocasting is a very fussy, highcost, and thus industrial unfeasible method.[30] Also, the mesostructures and morphologies of the replicated carbon nanoparticles are limited to the parent silica template. However, small mesoporous carbon nanoparticles are difficult to obtain by hard-templating approach because of the aggregation and cross-linking tendency of the nanosized silicate templates and the carbon resource. [10,11] Recently, an organic-organic assembly method has been successfully developed to synthesize ordered mesoporous carbons with various structures by using amphiphilic triblock copolymers as a soft template and phenolic resol as a carbon source. [31][32][33][34][35][36][37] Two routes can be used to prepare the mesoporous carbon materials, one is the well-known evaporation induced selfassembly (EISA) method in ethanol solution, and another is aqueous solution route under a "hydrothermal" [38][39][40][41] conditions at a low temperature of 60-70 8C. Morphologies of the mesoporous carbon materials synthesized from the EISA strategy are usually films and monolithic, whereas the aqueous route usually yields powder carbon materials with particle sizes in the micrometer or millimeter scale. More recently, mesoporous carbon microspheres with the diameter over 50 mm were synthesized by a suspension assisted method, which was developed by Long and co-workers. [42] In this work, the spherical diameters were limited to micrometer-sized emulsion droplets. In this case, ordered mesoporous carbon nanoparticles are difficult to synthesize under the present conditions. To the best of our knowledge, there are no reports of the direct synthesis of ordered mesoporous carbon nanoparticles, especially nanospheres with uniform size.Herein, ...
Nanoparticles with ordered mesostructures benefit from advantages resulting from the remarkable and complementary property of the mesochannels and quantum effects in the nanoscale. Their open-framework structures, large surface area and porosity, and nanosize make ordered mesoporous nanoparticles useful in adsorption, [1][2][3] controlled drugs release, [4][5][6][7][8][9] cellular delivery, [10][11][12][13][14][15][16] energy storage, [17][18][19][20][21][22] and catalysis. [23] Among mesoporous nanoparticles, silicates have been extensively synthesized by a well-controllable process based on sol-gel chemistry. Mesoporous carbon materials have many advantages over silica materials, such as electrical conductivity, chemical inertness, hydrophobic property, which enable them to be widely used as supercapacitors, [17,18] fuel cells, [19,20] lithium batteries, [22] and hydrophobic drugs carriers. [12] Similar to silica, carbon nanoparticles are nontoxic, biocompatible, and nonimmunogenic, which allows them to be used extensively in cellular delivery. [15,16] Therefore, many efforts have been made to fabricate mesoporous carbon nanoparticles. In general, a nanocasting strategy was adopted by employing nanosized mesoporous silica as a hard template. [15,[24][25][26][27][28][29] Nevertheless, nanocasting is a very fussy, highcost, and thus industrial unfeasible method. [30] Also, the mesostructures and morphologies of the replicated carbon nanoparticles are limited to the parent silica template. However, small mesoporous carbon nanoparticles are difficult to obtain by hard-templating approach because of the aggregation and cross-linking tendency of the nanosized silicate templates and the carbon resource. [10,11] Recently, an organic-organic assembly method has been successfully developed to synthesize ordered mesoporous carbons with various structures by using amphiphilic triblock copolymers as a soft template and phenolic resol as a carbon source. [31][32][33][34][35][36][37] Two routes can be used to prepare the mesoporous carbon materials, one is the well-known evaporation induced selfassembly (EISA) method in ethanol solution, and another is aqueous solution route under a "hydrothermal" [38][39][40][41] conditions at a low temperature of 60-70 8C. Morphologies of the mesoporous carbon materials synthesized from the EISA strategy are usually films and monolithic, whereas the aqueous route usually yields powder carbon materials with particle sizes in the micrometer or millimeter scale. More recently, mesoporous carbon microspheres with the diameter over 50 mm were synthesized by a suspension assisted method, which was developed by Long and co-workers. [42] In this work, the spherical diameters were limited to micrometer-sized emulsion droplets. In this case, ordered mesoporous carbon nanoparticles are difficult to synthesize under the present conditions. To the best of our knowledge, there are no reports of the direct synthesis of ordered mesoporous carbon nanoparticles, especially nanospheres with uniform size.Herei...
In the study, activated alumina was modified by calcium chloride, and after modification the phosphorus removal from aqueous solution increased by 13% or so. Then the activated alumina with and without treatment were subjected to characterization by the methods of the BET and SEM, and the adsorption characteristics of modified activated alumina were further studied at different contact time, pH values, adsorbent dosage levels and initial phosphorus concentration. Moreover, the equilibrium adsorption data for phosphorus were better fitted to Langmuir adsorption isotherm, and it means that the uptake of phosphorus preferably followed the monolayer adsorption process.
To optimize the conditions of modification and understand the absorption mechanism of activated carbon, the orthogonal test was used to select the best conditions of ammonia-modified activated carbon. The changes of activated carbon’s specific surface area, pore volume and surface acidic oxygen-containing functional groups were determined before and after modification by ammonia, and the equilibrium adsorption model for phenol was also explored. The results show that under the conditions of ammonia concentration of 10%, soaking time of 2h, activation time of 2.5h and activation temperature of 500°C, the best removal rate could be obtained. The specific surface area and pore volume of modified activated carbon were increased, whereas the acidic oxygen-containing groups of its surface were significantly reduced by 57.88% after modification. It means the surface polarity of carbon was decreased, and which was conducive to the adsorption of phenol, since phenol was a weakly polar substance. Both Freundlich and Langmuir model could reflect the adsorption behavior of modified activated carbon for phenol, while the Freundlich model was more properly, but for the unmodified activated carbon, Freundlich model was more suited to describe the adsorption behavior of phenol than Langmuir model.
To improve the adsorption efficiency of activated carbon for phenol, copper nitrate was used to modify activated carbon. In detail, the absorption properties of modified activated carbon was studied by investigating the effects of adsorption time, pH, amount of modified activated carbon and initial concentration of phenol on the adsorption. And the dynamic and adsorbent model were obtained and explored. It shows that the removal rate of modified activated carbon for phenol was higher than the unmodified carbon, and the best removal rate can be obtained under the conditions of pH about 5, adsorption time of 2h, modified activated carbon dosage of 1.0g. The quasi-two rate equation was better to reflect the dynamics of modified activated carbon for phenol, with the initial concentration of phenol increased, equilibrium adsorption capacity and initial adsorption rate were greater. Both Freundlich and Langmuir model could reflect the adsorption behavior of modified activated carbon for phenol, while the Langmuir model was more properly.
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