Preparation And Application In Environmental Protection Of The N-containing Carbon-Based Porous Materials

Due to the easy access to high specific surface area and high pore volume, carbon-based porous materials are becoming prevalent materials for adsorption. In this article, carbon-based porous materials with high adsorption capacity are prepared through doping N-containing groups. After that, these materials are applied into environment protection.First, fish scales are employed to be raw materials of N-doped porous carbon, because the protein in the fish scales shows high N content. It is found that N content decreases with temperature increasing, and with activator adding. Through adding some activator and modulating activation temperature, the N-doped porous carbon with high specific surface area ?3206 m²/g? is successfully prepared. Taking the retained nitrogen groups as active sites, we graft PEI onto the N-doped porous carbon to synthesize the N-rich carbon-based material. Both N content and the reduction capability of the material are enhanced.Then, all the as-synthesized materials are applied into Cr??? adsorption in wasted water. Because more basic sites can lead to a tendency to get positive charge in the acid solution, N-rich carbon-based material shows advantages on Cr??? removal at relatively low concentration. Especially, it can remove 100.00 ?±0.01?-%Cr??? when the concentration is under 150 mg/L. The Langmiur maximum capacity of this carbon attains 322.58 mg/g. The adsorption behavior fits pseudo-second-order model. Chemical adsorption exists in the process during which Cr??? is reduced into Cr?III?, which is low-toxic. It is found that the material after adsorption can be applied in anode material in Li ion battery. Cr??? performs as an active substrate, which makes the composite a great anode of high capacity.Finally, N-doped porous carbons are employed in CO₂ adsorption. It is found that carbon activated at 750? shows the highest CO₂ capacity of 171 mg/g at 25? and can keep 91.8% of the initial capacity after 10 cycles. Besides, this carbon shows CO₂/N₂ selective adsorption at a high rate. The isosteric heat of adsorption is also high. All these data indicates that this N-doped porous carbon has potential in CO₂ adsorption.