Showing papers on "BET theory published in 2021"
TL;DR: In this article, a heterogeneous Fenton-like catalysts biochar modified CuO2 (CuFeO2/BC) were fabricated by hydrothermal method without additional chemical reducing agent.
Abstract: The heterogeneous Fenton-like catalysts biochar modified CuFeO2 (CuFeO2/BC) were fabricated by hydrothermal method without additional chemical reducing agent. The systematic characterization demonstrated that higher CuFeO2 particles dispersion and larger BET surface area of CuFeO2/BC catalyst contributed to higher catalytic activity towards the tetracycline (TC) degradation compared to pure-phase CuFeO2. The optimum conditions for TC removal were 598.63 mg L-1 of CuFeO2/BC-1.0, 57.63 mM of H2O2 and pH = 6.27 according to the result of a response surface methodology based on the central composite design. The CuFeO2/BC-1.0 exhibited an excellent reusability and good stability by recycling degradation. The OH was evidenced to the main active radical by scavenging experiments and electron spin resonance. The XPS revealed that the high catalytic efficiency was attributed to the synergistic effect of Fe3+/Fe2+ and Cu2+/Cu+ redox cycles, and the degradation intermediates of TC and toxicity analysis were evaluated.
286 citations
TL;DR: CeTiOx with nanotube structure was used for selective catalytic reduction with NH3 (NH3-SCR) to remove NOx as mentioned in this paper, in which more than 98 % NO conversion can be achieved in the range of 180−390°C with 100 % N2 selectivity.
Abstract: Cerium and titanium oxides are considered as promising alternative catalysts for selective catalytic reduction with NH3 (NH3-SCR) to remove NOx. However, the poor SO2 or H2O tolerance and stability limit their practical applications. Herein, CeTiOx with nanotube structure (CeTiOx-T) was prepared by hydrothermal method and used for NH3-SCR reaction. CeTiOx-T shows the excellent catalytic activity, SO2 and H2O tolerance and stability, in which more than 98 % NO conversion can be achieved in the range of 180−390 °C with 100 % N2 selectivity. The characterizations verify that CeTiOx-T exhibits amorphous structure due to the strong interaction between Ce and Ti to form short-range ordered Ce-O-Ti species. As results, CeTiOx-T displays the larger BET surface area, more surface Bronsted acid amounts and chemisorbed oxygen, leading to its higher NH3-SCR performance. In situ DRIFTS results suggest the SCR reaction mainly follow L-H and E-R mechanisms at low and high temperature for over CeTiOx-T, respectively.
149 citations
TL;DR: CAC-5 (modified AC) exhibits better CO2 adsorption performance, which can be attributed to the formation of the CO2-philic active sites on AC surface by N-species, and the high IAST selectivity factor for N-doped ACs indicates their excellent Adsorption selectivity for CO2 over N2.
145 citations
TL;DR: KOH-activated biochar (KOHBC) exhibited much higher adsorption capacities than unactivated DFBC and metal ions spiked into natural and laboratory waste water systems exhibited high sorption capacities.
113 citations
TL;DR: In this paper, the authors focused on adsorption of dimethoate by using highly adsorptive porous membrane based on metal organic framework@cellulose acetate (Cu-BTC@CA).
Abstract: The current study focused on adsorption of dimethoate by using highly adsorptive porous membrane based on metal organic framework@cellulose acetate (Cu-BTC@CA). The porous Cu-BTC@CA membrane was prepared in two steps; formation of porous CA membrane and secondly, Cu-BTC was in-situ synthesized within the porous CA membrane. The preparation was performed to incorporate different ratios of Cu-BTC (20–60%) within the CA membrane to study their efficiency in the adsorption of dimethoate. Micro-crystals Cu-BTC was successfully immobilized in the macroporous CA membrane with pore diameter of 112.6–496.0 nm. The BET surface area was significantly increased from 78.4 m2/g for CA membrane to 965.8 m2/g for 40% Cu-BTC@CA membrane. Adsorption of dimethoate upon the synthesized membrane was fitted well to Langmuir isotherm and pseudo-second order model. The adsorption capacity was observably enhanced from 207.8 mg/g for CA membrane to 282.3–321.9 mg/g for Cu-BTC@CA membrane. Incorporation of 40% Cu-BTC resulted in acceleration of the dimethoate adsorption by factor of 2.1. The applied membrane showed quite good recyclability and the adsorption efficiency was reduced by 22.5% after 5 recycles. The synthesized Cu-BTC@CA membrane could be promisingly applied in the effective removal of pesticides with sufficient recoverability, and in general environmental purposes.
102 citations
TL;DR: In this paper, three Fe-based MOFs with significantly different porous properties and open metal sites were applied as adsorbents to remove TCH, and the adsorption mechanism was investigated using experiments and computations.
84 citations
TL;DR: Ordered mesoporous carbon (OMC), a moderately new member of the carbonaceous family of adsorbents, has arisen as a potential adsorbent because of its distinct features such as high BET surface area, large pore size and porosity volume, tunable surface chemistry and thermo-mechanical stability as discussed by the authors.
81 citations
TL;DR: In this article, the authors demonstrate the conversion of water caltrop shell into N-doped porous carbons for CO2 capture, which involves a three-step procedure, i.e., carbonization of water calctrop shell, post-nitriding by melamine, and KOH activation.
Abstract: Adsorption via sorbents is considered an attractive technology that can effectively separate CO2 from flue gas. Optimal adsorption performance can be achieved through the utilization of specific sorbents with superior CO2 adsorption capacity. This work demonstrates the conversion of water caltrop shell into N-doped porous carbons for CO2 capture, which involves a three-step procedure, i.e., carbonization of water caltrop shell, post-nitriding by melamine, and KOH activation. The developed adsorbents possess plentiful porous structures and high nitrogen content, with BET surface area up to 2384 m2 g−1 and N content of 8.48 wt%, respectively. CO2 adsorption measurements show that the studied sorbents have good CO2 adsorption abilities, as high as 4.22 and 6.06 mmol g−1 at 25 and 0 °C under ambient pressure, respectively. A comprehensive investigation found that CO2 uptake of as-synthesized adsorbents is dictated by the synergistical interplay of N content and narrow microporous volume. Additionally, they exhibit fast CO2 adsorption kinetics, excellent reversibility and stability, good CO2/N2 selectivity, applicable heat of adsorption and high dynamic CO2 adsorption capacity. This work provides a general method of the preparation of N-doped porous carbonaceous sorbents from waste biomass. The inexpensiveness precursors along with simple preparation procedure highlight the great potential of biomass-based carbons in CO2 capture and many other applications.
77 citations
TL;DR: In this paper, the elimination of methyl violet dye (MVD) and Nile blue dye (NBD) from water solution using a CNT/MgO/CuFe2O4 magnetic composite powder produced by co-precipitation was investigated.
Abstract: In the present study, the elimination of methyl violet dye (MVD) and Nile blue dye (NBD) from water solution using a CNT/MgO/CuFe2O4 magnetic composite powder produced by co-precipitation was investigated. The BET analysis showed that the generated magnetic composite is a mesoporous material (based on IUPAC classification) and its specific surface area value is 127.58 m2/g. Also, the magnetic composite powder had a crystalline structure and a magnetic saturation of 12.137 emu/g. In the adsorption process, the effect of various effective parameters such as working pH, temperature, adsorbent dose, initial concentration of dye solutions, and time was investigated. The maximum capacity of monolayer adsorption for MVD and NBD was determined to be 36.46 mg/g and 35.60 mg/g, respectively. The results showed that the experimental data follow the pseudo-second-order (PSO) model. Based on the intra-particle diffusion (IPD) model, more than one mechanism is involved in the adsorption process. The values of Gibbs free energy parameter were determined negatively for both types of dyes, indicates the adsorption of the desired dyes is spontaneous. The enthalpy values (ΔH°) indicated that the removal of the cationic dye is exothermic and the magnetic composite powder has a good ability to adsorb MVD and NBD from aqueous solution at low temperatures. The magnetic composite powder could be used several times in the adsorption process of MVD and NBD without a significant reduction in the removal efficiency. The results showed that the CNT/MgO/CuFe2O4 magnetic composite powder can be successfully used in textile wastewater treatment.
76 citations
TL;DR: In this paper, a solvothermal template-free method was used to synthesize hollow microspheres containing oxygen vacancies (OVs-BWO) for photocatalytic nitrogen fixation.
73 citations
TL;DR: In this article, a novel adsorbent, GO/Fe3O4/OPO3H2/PCN-222, was successfully synthesized via graphene oxide modification with magnetic particles, carboxyl and phosphorous-containing groups, and a mesoporous Zr-MOF, to give the nominal composite.
TL;DR: In this paper, three photoactive conjugated microporous polymers (CMPs) were synthesized through cross-couplings of 1,3,6,8-tetraethynylpyrene (Py-T, as a common monomer building block) with 2,7-dibromo-9H-fluorene (F-Br2), tris(4-bromophenyl)amine (TPA-Br3), and 1,1,2-2,2,tetrakis(
TL;DR: In this paper, two novel uranium adsorbents, phosphorylated hyper-cross-linked bisphenol A (PHCP-1) and fluorene-9-bisphenolate (PHP-2), were separately synthesized via Friedel-Crafts reaction followed by phosphorylation using phosphorus oxychloride.
TL;DR: The produced UAJS can be a better adsorbent for treating the heavy metal polluted wastewater and observe that UAJS holds higher capacity as compared with RJS.
TL;DR: In this paper, macroporous C/Co composites were successfully fabricated via in situ carbonization of ZIF-67@SiO2 precursors and subsequent removal of the SiO2 with diameter of ~60nm.
TL;DR: In this paper, the surface properties and surface functional group diversity of the synthesized modified activated carbons by various methods were investigated. But the authors focused on surface properties, such as the surface area, micro-mesopore volume, and average pore diameter.
TL;DR: In this article, a composite consisting of ZIF-67 and graphene oxide (GO) was successfully synthesized by a facile in-situ synthesis method and applied in hydrogen release from the methanolysis of NaBH4.
TL;DR: In this article, a nanosheet MFI zeolite (NZ) with ultrathin lamellar structure, large average pore diameter, high BET surface area and large pore volume was synthesized in order to enhance the adsorption performance.
TL;DR: In this paper, the performance of optimized acacia wood-based activated carbon (AWAC) as an adsorbent for methylene blue (MB) dye removal in aqueous solution was evaluated.
01 Mar 2021
TL;DR: A zero valent iron-loaded nano-bentonite intercalated carboxymethyl chitosan (nZVI@nBent-CMC) composite was fabricated and characterized by FT-IR, TEM and TEM-EDX as discussed by the authors.
Abstract: A zero valent iron-loaded nano-bentonite intercalated carboxymethyl chitosan (nZVI@nBent–CMC) composite was fabricated and characterized by FT-IR, TEM, TEM–EDX, XRD, BET surface area, and zeta pote...
TL;DR: In this paper, a good adsorbent and ion-exchange material, i.e., titanate nanotubes (TNTs), was employed for adsorption of ciprofloxacin (CIP), a model PPCPs.
TL;DR: In this paper, the authors reported the preparation and characterization of activated carbon fibers (ACF) from banana tree pseudo-stem and applied them on adsorption of methylene blue (MB) dye using the bath and fixed bed systems.
TL;DR: In this article, high-carbon fly ash (HCFA) was used to produce the zeolite-carbon composites of faujasite and gismondite structures (named NaX-C and NaP1-C, respectively) in pilot scale using the single-step hydrothermal conversion.
TL;DR: In this article, the adsorption kinetics of zeolitic imidazolate framework-7 (ZIF-7) were analyzed with Methylene Blue (MB) and Brilliant Green (BG) dyes.
TL;DR: In this paper, the authors investigated the efficiency of biochar prepared from sewage sludge at 450°C (SSB-450), as an adsorbent for the removal of Remazol Brilliant Blue R (RBBR) from an aqueous solution.
Abstract: Biochar derived from sewage sludge has emerged as an alternative for sustainable utilization as a soil amendment. However, the use of sewage sludge biochar (SSB) has been less explored in the field of wastewater treatment. Therefore, the purpose of this study was to investigate the efficiency of biochar prepared from sewage sludge at 450 °C (SSB-450), as an adsorbent for the removal of Remazol Brilliant Blue R (RBBR) from an aqueous solution. Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used to characterize SSB-450, with maximum RBBR removal efficiency. The removal of RBBR from aqueous solution by SSB-450 was investigated in batch mode at varying adsorbent dose, contact time, initial RBBR dye concentration temperature and pH. The BET analysis showed the type IV isotherm that indicates the mesoporous structure of SSB-450. The total pore volume and BET specific surface area of SSB-450 particles were found to be 3.936 cm −3/g and 12.447 m2/g, respectively. The RBBR dye adsorption ( q e ) at equilibrium by SSB-450 was found to increase from 8.56 to 80.6 mg g−1 with an increase in initial dye concentration from 10 to 100 mg L−1. The maximum monolayer adsorption capacity (qmax) was 126.59 mg/g of SSB-450, determined by the Langmuir adsorption model. At various RBBR dye concentrations (10 to 100 mg/g), the range of the separation factor ( R L ) was 0.98–0.9, which indicates the favourable adsorption of RBBR dye onto the surface of SSB-450. Besides, Evans blue and triphenyl tetrazolium chloride (TTC) staining of Allium cepa L. roots germinated with dye solutions revealed that biochar treated residual RBBR was non-cytotoxic.
TL;DR: In this paper, a pomegranate fruit peel activated carbon (PFPAC) was prepared using potassium hydroxide impregnation and carbon (IV) oxide gasification methods for the remediation of Methylene blue (MB) from aqueous solution.
TL;DR: In this article, an augmented simplex centroid mixture design was used to obtain a high surface area activated carbon using as reactants KOH, K2CO3 and K2C2O4.
TL;DR: In this paper, the MOF-525/GO composite was obtained for the adsorption of tetracycline (TC) in water by improving the synthesis process.
TL;DR: In this paper, the porosity and CO2 uptake of the carbon materials were characterized by the N2 and CO 2 adsorption/desorption techniques, and the results showed a dominant microporous structure in the carbon derived from both bamboo and solid residue.
Abstract: Bamboo and its solid residue after hydrothermal treatment were converted successfully into porous carbon by physical activation with the CO2 agent. The solid residue exhibits a higher potential to form activated carbon thanks to its very low ash content (almost 0%). The porosity and CO2 uptake of the carbon materials were characterized by the N2 and CO2 adsorption/desorption techniques. The results showed a dominant microporous structure in the carbon derived from both bamboo and solid residue. The highest BET surface area that the carbon material from bamboo could achieve was 976 m2 g−1, meanwhile, this value at the carbon prepared from solid residue activated at the same temperature was 1496 m2 g−1. The microporosity structure of activated carbon could be stimulated and enhanced at the optimal condition of CO2 activation. The CO2 adsorption capacity of the carbon made from bamboo and the solid residue was also analyzed with good capacity (3.4 mmol g−1) comparing to the 3 reference materials at the same condition of adsorption (293 K, 1 atm).
TL;DR: This work demonstrated a facile solvent-free method for production of the exfoliated LDHs modified BC composite, and well illustrated the BM effects which can extend their practical use in environment.