Influence of nitric acid concentration on the characteristics of active carbons obtained from a mineral coal

Preparation of Activated Carbon from Green Coconut Shell and its Characterization

“…3300-2500 cm -1 shows the presence of O-H stretch and carboxylic group. At 1320-1000 cm -1 (strong) frequency shows C-O stretch and functional group presents are alcohol, carboxylic acid, esters and ethers [45]. A band at 1400 cm -1 was only can be attributed to the plane N-H bending vibration [46,47].…”

Effect of Chemical Oxidation on the Adsorption Properties of Cationic Dye on Activated Carbons Prepared from Locally Atropa belladonna

“…Some works pointed out that the basicity of these samples is probably due to oxygen free Lewis basic sites, which are usually ascribed to π-electrons of graphitic planes [11,12]. Thus, the obtained carbon from HNO 3 oxidation with lower pH ~ 4 seems to be the best acidic carbon because it has the lowest amount of basic oxygen functional groups as compared to AC-S and AC-S/A samples.…”

“…Generally, the adsorption capacity of ACs significantly depended on their surface chemistry and is largely influenced by both quantity and type of the surface functional groups. Accordingly, many studies have considerable interests in the improvement of the surface chemistry properties of ACs via chemical oxidation and reported their relations with the adsorption of dyes and heavy metals in the last two decades [3][4][5][6][7][8][9][10][11][12][13].…”

Preparation of granular activated carbons from yellow mombin fruit stones for CO2 adsorption

“…The use of biochar materials as adsorbents is usually limited due to their low specific surface area so that, to overcome this drawback, chemical and physical activation methods have been described (Caglayan and Aksoylu, 2013;Yi et al, 2012;Jung and Kim, 2014;Rosas et al, 2010;Foo and Hameed, 2012;Khelifi et al, 2010;El Hannafi et al, 2008;Sekirifa et al, 2013;Aworn et al, 2008). The physical activation methods generally consist in a controlled gasification by oxidizing gases, such as steam, CO 2 or air, at high temperature, up to 1000 C, of a sample previously carbonized at T < 700 C. In opposition, the chemical activation methods involve a chemical reaction of the precursor with a dehydrating chemical agent, such as KOH, H 3 PO 4 or ZnCl 2 , to reduce tar formation and particle shrinkage during the subsequent thermal decomposition treatment, resulting in highly porous carbons (Jung and Kim, 2014;Aygün et al, 2003;Lim and Srinivasakannan, 2010;Sekirifa et al, 2013;Aworn et al, 2008;Mattson and Marck, 1971;Ju arez-Gal an et al, 2009).…”