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[Display omitted] • Fe single-atom adsorbents based on BNCO (Fe-BNCO) was synthesized. • Fe-BNCO-0.5 exhibits excellent adsortpin capacity for DBT (49.7 mg S/g). • Fe-doping results in a decrease of the crystallininty and a higher specific surface area. • The enhanced performance is sourced from the newly formed S-Fe coordination bond. Adsorbents with high adsorption capacity and selectivity have long been the pursuit of researchers in the field of adsorptive desulfurization. In this study, a novel single-atom adsorbent comprised of iron (Fe) integrated into C, O co-doped hexagonal boron nitride (Fe-BNCO) has been successfully synthesized. This unique material demonstrates outstanding adsorption capabilities, boasting an adsorption capacity of 49.7 mg S/g and excellent selectivity for adsorptive desulfurization. Notably, this adsorption capacity is 48.6 % higher than that of pure BNCO. The incorporation of the Fe element into boron nitride materials induces a reduction in crystallinity and an increase in specific surface area, resulting in a higher number of available adsorption sites. Combining experimental analysis with theoretical calculations, we propose that the exceptional adsorption performance of Fe-BNCO can be attributed to the formation of S-Fe coordination interaction, while maintaining the existing π-π interactions. This study advances our understanding of adsorbents with high adsorption capacity and selectivity, providing valuable insights for the field of adsorptive desulfurization. [ABSTRACT FROM AUTHOR]

In this work, salix mongolica, pretreated by FeCl3 and ZnCl2, was applied as a precursor to prepare the magnetic biochar (MBC, containing γ-Fe2O3) with the method of one-step pyrolysis. According to the characterization results of MBC (SEM, XPS, XRD, FTIR, VSM, BET), the features of biochar and the magnetic properties of iron oxides were combined in a composite of MBC. The magnetic biochar can be used as adsorbent for sulfadimidine sodium (SMS) and norfloxacin (NOR) removal from aqueous solution and subsequently removed from the medium by a simple magnetic process. The adsorption characteristics of SMS and NOR from aqueous solution by MBC have been investigated. The adsorption kinetics was best described by Elovich model. The equilibrium data was best fitted by the Freundlich isotherm and Koble-Corrigan model implying the adsorption process mainly was multilayer adsorption on heterogeneous surfaces. The maximum adsorption capacity for SMS and NOR was 251 mg/g and 210 mg/g at 308 K, respectively. The values of thermodynamic parameters were calculated indicating the process of adsorption was an endothermic and spontaneous process. The adsorption mechanism may be attributed to the π–π dispersion, the hydrophobic interaction, hydrogen bonding or the electrostatic interaction between the MBC and the molecule of NOR or SMS. [ABSTRACT FROM AUTHOR]

To obtain the adsorption strength is the key point for materials design and parameters optimization in chemical engineering. Here we report a simple but accuracy method to estimate the adsorptive energies by counting the number of π-orbital involved atoms based on theoretical computations for hexagonal boron nitride (h-BN) and graphene. Computational results by density function theory (DFT) as well as spin-component scaled second-order Møller-Plesset perturbation theory (SCS-MP2) both confirm that the adsorptive energies correlate well with the number of π-orbital involved atoms for π-orbital contained molecules. The selected molecules (adsorbates) are commonly used in chemical industry, which contains C, N, S, O atoms. The predicted results for the proposed formulas agree well with the current and previous DFT calculated values both on h-BN and graphene surfaces. Further, it can be also used to predict the adsorptive energies for small π-orbital contained molecules on BN and carbon nanotubes. The interaction type for these adsorptions is typical π-π interaction. Further investigations show that the physical origin of these interactions source from the polar interactions between the adsorbents and adsorbates. Hence, for separation or removal of aromatic molecules, how to modify the aromaticity and polarity of both adsorbents and adsorbates will be the key points for experiments. [ABSTRACT FROM AUTHOR]

• Mechanism of CO2 adsorption on biomass derived carbon was explained using DFT methods. • Building the relationship between nucleophilicity and adsorption capacity of biochar. • Carboxyl and diketone groups are the most active O-containing sites. • TG-MS experiments proved the effect of nucleophilicity group of biochar on CO 2 adsorption. CO 2 adsorption is an important issue for sustainable development today. In this study, zigzag edge and armchair edge cluster models containing oxygen-containing groups were established, and the interaction with CO 2 molecules was calculated based on Density functional theory. The results indicated that the carboxyl and diketone groups have the CO2 adsorption capacity. The relationship between CO 2 adsorption performance and nucleophilicity of O-containing groups was established. A subsequent TG-MS experiment also proved that the introduction of nucleophilic group can promote interaction between CO 2 and carbon surface. [ABSTRACT FROM AUTHOR]

[Display omitted] • The species which Al atom anchoring on B site of h-BN is more stable. • The Al_edge_B 1 and Al_edge_B 2 species is more stable than other forms for Al-BN-SAAs. • All Al-BN-SAAs have superior ADS performance than pristine h-BN. • The enhanced performance is attributed to the newly formed S Al coordination bond. A concept of single atom adsorbents (SAAs) is proposed to the fields of highly selective adsorption desulfurization from diesel. Here, SAAs with the Al atom anchoring on the surface of hexagonal boron nitride have been systematically explored by density functional theory. Firstly, all the possible doping sites have been considered and their stabilities have been discussed by the doped energy. Additionally, the activity and selectivity for the adsorptive desulfurization of these Al-based SAAs have been predicted. Results show that all the Al-based SAAs can enhance the activity and selectivity of adsorptive desulfurization due to the newly formed S-Al coordination bond. We hope this work can provide a reliable theoretical foundation for the design of SAAs with higher adsorptive activity and superior selectivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Graphdiyne-like boron nitride nanosheets were transformed into SAAs. • SAAs exhibit an enhanced adsorption capacity. • The CO 2 adsorption mechanism was evaluated in detail. • Charge transfer is the main factor in CO 2 adsorption. Developing an efficient adsorbent with optimal absorption capacity for carbon dioxide (CO 2) has always been a significant issue. Recently, single-atom adsorbents (SAAs) have been highlighted with special interest as a promising material with a wide range of applications. Nevertheless, comprehending the intricate mechanisms of gas adsorption on SAAs remains an enormous challenge. Herein, we have systematically evaluated the adsorption mechanisms over the transition metals (Fe, Co, Ni, Cu, and Zn) embedded onto the graphdiyne-like boron nitride monolayer using density functional theory calculations. Results show that SAAs exhibit a promoted capacity compared to the pristine graphdiyne-like boron nitride monolayer, mainly ascribed to the electron donation and back-donation mechanism between metal and CO 2. Further, BNene/Fe is favorable for CO 2 adsorption with the strongest interaction energy (−20.7 kcal mol−1). We hope this work will facilitate the design of SAAs in the field of gas adsorption. [ABSTRACT FROM AUTHOR]

Iron, copper oxides composite particles (Fe/Cu oxides CPs) were produced using rapid, single-step, green and sustainable pathway from biomolecules of pine needle extract and were adopted as a potential adsorbent for the removal of norfloxacin (NOR) and ofloxacin (OFLX) from aqueous solution. To understand the morphologies and properties of Fe/Cu oxides CPs, surface analysis via SEM image, EDS, TEM, XPS, BET and FTIR pattern were employed. The effects of factors such as contact time, reaction temperature, initial pH, initial concentration and ionic strength on the adsorption capacity of NOR or OFLX onto Fe/Cu oxides CPs were studied. Kinetic analysis confirmed that the kinetic data were well described by Double-constant rate equation. The experimental equilibrium data were well fitted by Redlich-Peterson, Koble-Corrigan and Dubinin-Radushkevich models and the maximum adsorption capacity of Fe/Cu oxides CPs calculated by Langmuir model for NOR and OFLX was 1.64 mmol/g and 1.26 mmol/g at 293 K, respectively. Thermodynamic parameters such as Gibbs free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were calculated and the results indicated that the NOR or OFLX adsorption onto Fe/Cu oxides CPs was spontaneous and endothermic. Adsorption mechanism of NOR and OFLX may be involved a combination of electrostatic interaction, the formation of hydrogen bonds, π-π stacking interactions, surface complexation, hydrophobic interaction. [ABSTRACT FROM AUTHOR]

Designing atomically defective adsorbents with high specific surface area has emerged as a promising approach to improve sorption properties. Herein, hierarchical porous boron nitride nanosheets with boron vacancies (Bv-BNNSs) were in-situ synthesized via a one-step ZnCl 2 -assisted strategy. Being benefitted from the dual-functional template of zinc salt, highly-active boron vacancies and abundant hierarchical pores were simultaneously generated in the Bv-BNNSs framework. By employing the boron vacancies engineering strategy, the morphological and electronic structures were controllably tuned. Meanwhile, the specific surface area was improved to as high as 1104 m2/g. Owning to the abundance of accessible surface active-sites, the sorption capacity to antibiotic tetracycline (TC) on Bv-BNNSs was boosted by 38% compared to the pristine boron nitride nanosheets (BNNSs). Detailed fitting results showed that TC sorption on Bv-BNNSs obeyed the pseudo-second order kinetic equation and the Freundlich isotherm model. The pi − pi interaction with a multi-layered stacking form was proposed as the dominated sorption mechanism. Furthermore, DFT calculations verified that the interaction energy between Bv-BNNSs and TC was enhanced. The high activity, excellent selectivity, and remarkable durability of the Bv-BNNSs nanomaterial suggest the great potential in practical wastewater treatment. [ABSTRACT FROM AUTHOR]

Novel 3D porous Cd(II) ion-imprinted polymer (Cd(II)-IIP) microspheres based on octavinyl polyhedral oligomeric silsesquioxane (OV-POSS) were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization technique combined with the synergistic effect of N-hydroxymethylacrylamide (NMA) and 1-vinylimidazole (1-VI) as bifunctional monomers. RAFT polymerization could achieve a controllable synthesis of polymer networks on OV-POSS. The structure, composition and properties of Cd(II)-IIP were systematically investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscope, water contact angle and thermogravimetric analysis. The results showed that the adsorbent, with a water contact angle of 0 ° and superhydrophilicity, has a high potential for application in aqueous phase systems. Different parameters influencing the sorption performance of Cd(II)-IIP, such as OV-POSS ratio, functional monomers ratio, adsorbent dosage, pH and adsorption time were optimized. Under optimal conditions, the maximum adsorption amount of Cd(II)-IIP for Cd(II) was 80.21 mg/g, and the adsorption equilibrium state could be reached within 40 min. The sorption kinetics proved that the sorption was chemisorption and the rate-limiting step was intraparticle diffusion. Thermodynamic studies showed that Cd(II) sorption was a spontaneous endothermic process. Importantly, XPS analysis, density functional theory (DFT) and frontier molecular orbital (FMO) theory calculations showed that the sorption of Cd(II)-IIP was attributed to the coordination of O and N atoms with Cd(II) on NMA and1-VI, respectively. Actual water sample analysis results indicated that Cd(II)-IIP was an adsorbent of great application potential. [Display omitted] • Controllable synthesis of 3D porous Cd(II)-IIP using RAFT polymerization in concert with bifunctional monomers. • Cd(II)-IIP exhibited superior hydrophilicity and excellent selectivity compared to matrix material OV-POSS. • A combination of experiments and DFT calculations elucidated the adsorption mechanism. [ABSTRACT FROM AUTHOR]

Novel 3D porous Cd(II) ion-imprinted polymer (Cd(II)-IIP) microspheres based on octavinyl polyhedral oligomeric silsesquioxane (OV-POSS) were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization technique combined with the synergistic effect of N-hydroxymethylacrylamide (NMA) and 1-vinylimidazole (1-VI) as bifunctional monomers. RAFT polymerization could achieve a controllable synthesis of polymer networks on OV-POSS. The structure, composition and properties of Cd(II)-IIP were systematically investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscope, water contact angle and thermogravimetric analysis. The results showed that the adsorbent, with a water contact angle of 0 ° and superhydrophilicity, has a high potential for application in aqueous phase systems. Different parameters influencing the sorption performance of Cd(II)-IIP, such as OV-POSS ratio, functional monomers ratio, adsorbent dosage, pH and adsorption time were optimized. Under optimal conditions, the maximum adsorption amount of Cd(II)-IIP for Cd(II) was 80.21 mg/g, and the adsorption equilibrium state could be reached within 40 min. The sorption kinetics proved that the sorption was chemisorption and the rate-limiting step was intraparticle diffusion. Thermodynamic studies showed that Cd(II) sorption was a spontaneous endothermic process. Importantly, XPS analysis, density functional theory (DFT) and frontier molecular orbital (FMO) theory calculations showed that the sorption of Cd(II)-IIP was attributed to the coordination of O and N atoms with Cd(II) on NMA and1-VI, respectively. Actual water sample analysis results indicated that Cd(II)-IIP was an adsorbent of great application potential. [Display omitted] • Controllable synthesis of 3D porous Cd(II)-IIP using RAFT polymerization in concert with bifunctional monomers. • Cd(II)-IIP exhibited superior hydrophilicity and excellent selectivity compared to matrix material OV-POSS. • A combination of experiments and DFT calculations elucidated the adsorption mechanism. [ABSTRACT FROM AUTHOR]

Dyes that are released into the environment may have negative effects on living organisms. To address this issue, a biomass-derived carbon adsorbent made from Enteromorpha was tested for its ability to remove methyl orange (MO) from wastewater. The adsorbent was found to be effective in removing MO, with a 1:4 impregnation ratio producing an adsorbent that could remove 96.34% of MO from a 200 mg/L solution using only 0.1 g of adsorbent. At higher concentrations, the adsorption capacity increased up to 269.58 mg/g. Through molecular dynamics simulations, it was discovered that after mono-layer adsorption reached saturation, the remaining MO molecules in solution formed hydrogen bonds with the adsorbed MO, which led to further aggregation on the adsorbent surface and increased adsorption capacity. Additionally, theoretical investigations revealed that the adsorption energy of anionic dyes increased with Nitrogen-doped carbon materials, with the pyrrolic-N site having the highest adsorption energy for MO. The carbon material derived from Enteromorpha showed promise in treating wastewater containing anionic dyes, thanks to its high adsorption capacity and strong electrostatic interaction with the sulfonic acid groups of MO. [Display omitted] • Bio-adsorbents have high surface area (911.44 m2/g) and pore volume (0.60 cm3/g). • High-concentration solutions underwent multistage adsorption. • Concentration and N - sites led to high adsorption capacity (269.58 mg/g). • MO has π-π interaction with the graphene's surface due to its phenyl-like structure. • The hydrogen bonding (C –H ... π, –SO 3 ... H) can enhance the adsorption energy. [ABSTRACT FROM AUTHOR]

[Display omitted] • BCN doped with Cu(I) adsorption sites have been successfully prepared. • BCN-Cu-0.04 shows remarkably enhanced ADS performance. • BCN-Cu-0.04 displays high adsorption selectivity for 4,6-DMDBT. • The main force is S-Cu coordination and π-π interaction. Boron carbon nitride (BCN) has emerged as an effective material owing to its high specific surface area, porous structure, and excellent chemical inertness. However, the existing BCN adsorbents for adsorption desulfurization (ADS) exhibit inferior adsorption capacity and selectivity. Herein, a series of novel BCN nanofibers doped with Cu(I) adsorption sites (BCN-Cu-X, X = 0.02, 0.04, 0.06, 0.08 mmol) were fabricated via a simple one-pot pyrolysis method derived from a carboxylic acid copper coordination compound. The results demonstrated that BCN-Cu-0.04 shows a remarkably increased adsorption capacity for dibenzothiophene (DBT) about 33% higher than BCN under the same conditions. It is also noteworthy to mention that BCN-Cu-0.04 presents high ADS performance even for the refractory sulfur compound 4,6-Dimethyldibenzothiophene (4,6-DMDBT, 42.2 mg S/g adsorbent). Furthermore, density functional theory (DFT) calculations proved that the enhanced performance of BCN-Cu-X in ADS is attributed to the π-π interaction and newly formed sulfur-copper (S-Cu) coordination bond, which is different from other Cu-based adsorbents. This study may inspire the development of new synthetic routes which are possible to realize high-efficiency and high-selectivity ADS. [ABSTRACT FROM AUTHOR]

With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman, UV-Vis, wide-angle XRD and N2 adsorption-desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions. The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone. [ABSTRACT FROM AUTHOR]

We have systematically explored the electronic structures and magnetic properties of metal Pd, Pt, Cu, Ag, Au and Zn adsorbed MoSe 2 monolayer by means of first-principles calculations. It reveals that stable chemical adsorption has been formed between the adatoms Pd, Pt, Cu, Ag, Au and MoSe 2 monolayer, however, weak physical interaction is found between Zn and MoSe 2 monolayer owing to the small adsorption energy. Both the framework structure and electronic property of the metal adsorbed MoSe 2 monolayer are slightly tuned by the adatoms. More importantly, magnetic character is introduced in Cu, Ag and Au systems. [ABSTRACT FROM AUTHOR]

Abstract: Adsorption of water and ethanol on wheat starch and wheat gluten has been studied in the temperature range of 60–150°C using inverse gas chromatography (IGC). From the chromatographic retention data it is able to calculate the separation factors for the two solutes and obtain values for thermodynamic parameters such as Gibbs free energy (ΔG s) and the enthalpy (ΔH s) of adsorption of water and ethanol. The results indicate that water is adsorbed more strongly than ethanol at all temperatures, and the low temperature is found to facilitate the adsorptive separation of water from ethanol. It is also shown that the starch definitely plays a crucial role for the water and ethanol separation, despite that wheat flour includes both gluten and starch. The wheat starch is seen to have potential application in biomass water–ethanol separation to obtain fuel ethanol through the preferential adsorption of water from aqueous ethanol. [Copyright &y& Elsevier]