Changes in surface chemistry of activated carbons by wet oxidation

Moreno‐Castilla, Carlos; López-Ramón, M.V.; Carrasco‐Marín, Francisco

doi:10.1016/s0008-6223(00)00048-8

Cited by 813 publications

(442 citation statements)

References 41 publications

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“…The pore size distribution was determined by means of the density functional theory (DFT) method using Nova Quantachrome software. The pH PZC (point of zero charge) of the ACs was determined according to the procedure described by Moreno-Castilla et al (2000).…”

Section: Characterization Of Acsmentioning

confidence: 99%

Effect of micropore size distribution on phenol adsorption on steam activated carbons

Lorenc-Grabowska

2015

Adsorption

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The adsorption of phenol on microporous activated carbons (ACs) produced in laboratory from polyethyleneterephtalate (PET), furfuryl alcohol (PFA), polyacrylonitrile (PAN) and anthracene oil pitch (ASN) have been studied. The ACs have been obtained by carbonization and subsequent steam activation at 850°C to 50 % burn off. For comparison, commercial activated carbons from coconut shell, and CWZ 22 carbon have been applied. All studied ACs are predominantly microporous and have neutral or basic surface characteristics. The pseudo second kinetic model and Langmuir equation were found to fit the experimental data very well. A very good correlation between the volume of pores with a width smaller than 1.4 nm (V 1.4 ) and the volume of phenol calculated from Langmuir monolayer capacity (q m ) was found. Based on that, it can be concluded that the phenol adsorption is governed mainly by micropore filling through the p-p dispersion interaction in micropores smaller than double molecular diameter of phenol.

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Section: Characterization Of Acsmentioning

confidence: 99%

Effect of micropore size distribution on phenol adsorption on steam activated carbons

Lorenc-Grabowska

2015

Adsorption

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“…The pH PZC (point of zero charge) of the ACs was determined by mixing 0.25 g of sample with 10 cm 3 of CO 2 -free distilled water, according to the procedure described by Moreno-Castilla et al (2000).…”

Section: Characterization Of Acsmentioning

confidence: 99%

“…The concentration of oxygen and nitrogen functional groups on the carbon surface of AC can be enhanced through appropriate treatment. Wet oxidation using different oxidants (HNO 3 , H 2 O 2 , (NH 4 ) 2 S 2 O 8 ) is the most common approach used to incorporate oxygen groups into the AC surface (Moreno-Castilla et al 2000). Nitrogen groups are predominantly introduced by reaction with ammonia and other nitrogen-containing compounds such as urea and melamine (Przepiórski et al 2004;Seredych et al 2008;Chen et al 2012).…”

Section: Introductionmentioning

confidence: 99%

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

et al. 2015

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Surface-modified hemp stem-based activated carbons (HACs) were prepared and used for the adsorption of atrazine from aqueous solution, and their adsorption performance was examined. A series of HACs were prepared by potassium hydroxide activation of hemp stems, followed by subsequent modification by thermal annealing, oxidation with nitric acid and amination. The resultant HACs differed in surface chemistry, while possessing similar porous structure. The surface group characteristics were examined by X-ray photoelectron spectroscopy and measurement of the point of zero charge (pH PZC ). The adsorption of atrazine from aqueous solution was performed in static conditions. The Langmuir-Freundlich and Langmuir models gave a better fit for equilibrium isotherms compared with the Freundlich model. The atrazine adsorption process was controlled by an intraparticle diffusion mechanism with a significant contribution from film diffusion. The presence of oxygen and nitrogen functionalities on the carbon surface was found to be undesirable for atrazine adsorption. The superior adsorbent was obtained by heat treatment of HAC in an inert atmosphere at 700°C, resulting in a very high adsorption capacity due to its enhanced hydrophobicity. The adsorption of atrazine on the studied HACs mainly involves p-p dispersive interactions between the atrazine ring and the graphene layers of carbon.

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“…The data were analyzed to obtain: (1) the specific surface area using the BET method at p/p 0 < 0.15 (S BET ); (2) the amount of nitrogen adsorbed at a relative pressure (p/p 0 ) of 0.98 in order to determine the total pore volume (V T ); (3) the micropore volume by applying the Dubinin-Radushkevich equation up to p/p 0 , 0.15 (V DR ); (4) the mesopore volume (V mez ) calculated as the difference between the V T and V DR ; and (5) the pore size distribution (PSD) in terms of microporosity by means of the density functional theory (DFT) method using Nova Quantachrome software and the Kelvin equation for mesoporosity. The pH PZC (point of zero charge) of the ACs was determined by mixing 1 g of each AC with 1 3 20 ml of CO 2 -free distilled water, according to the procedure described by Moreno-Castilla et al [28].…”

Section: Characterization Of the Acsmentioning

confidence: 99%

Tailoring mesoporosity of poly(furfuryl alcohol)-based activated carbons and their ability to adsorb organic compounds from water

Lorenc-Grabowska

Rutkowski

2018

J Mater Cycles Waste Manag

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In this work it was shown that polymers can be recycled into a promising adsorbent for organic dyes and phenols waste removal. For this, a series of activated carbons (ACs) were produced from mixture of ferrocene or titanium acetylacetonate with poly(furfuryl alcohol) (PFA) by steam activation. The introduction of ferrocene as Fe precursor was found to be an efficient catalyst in mesoporosity development during carbonization and subsequent steam activation at 850 °C, whereas the polymer based only and titanium-doped ACs are typically microporous. The porous structure parameters were determined from nitrogen adsorption isotherms measured at 77 K. Scanning electron microscopy was applied to monitor the metal distribution of metal-loaded char and the surface morphology of activated carbons. The adsorption capacity was found to be dependent mainly on pore size distribution. In the case of phenol adsorption, the adsorption was defined by volume of pore with size 0.8-1.4 nm; whereas, for Congo red best fit was observed for volume of pore with size 2-5 nm.

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Changes in surface chemistry of activated carbons by wet oxidation

Cited by 813 publications

References 41 publications

Effect of micropore size distribution on phenol adsorption on steam activated carbons

Effect of micropore size distribution on phenol adsorption on steam activated carbons

Adsorption of atrazine on hemp stem-based activated carbons with different surface chemistry

Tailoring mesoporosity of poly(furfuryl alcohol)-based activated carbons and their ability to adsorb organic compounds from water

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