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Metal organic frameworks (MOFs) are crystalline, three-dimensional structures with high surface areas and tunable porosities. Made from metal nodes connected by organic linkers, the exact properties of a given MOF are determined by node and linker choice. MOFs hold promise for numerous applications, including gas capture and storage. M2(4,4′-dioxidobiphenyl-3,3′-dicarboxylate)—henceforth simply M2(dobpdc), with M = Mg, Mn, Fe, Co, Ni, Cu, or Zn—is regarded as one of the most promising structures for CO2 capture applications. Further modification of the MOF with diamines or tetramines can significantly boost gas species selectivity, a necessity for the ultra-dilute CO2 concentrations in the direct-air capture of CO2. There are countless potential diamines and tetramines, paving the way for a vast number of potential sorbents to be probed for CO2 adsorption properties. The number of amines and their configuration in the MOF pore are key drivers of CO2 adsorption capacity and kinetics, and so a validation of computational prediction of these quantities is required to suitably use computational methods in the discovery and screening of amine-functionalized sorbents. In this work, we study the predictive accuracy of density functional theory and related calculations on amine loading and configuration for one diamine and two tetramines. In particular, we explore the Perdew–Burke–Ernzerhof (PBE) functional and its formulation for solids (PBEsol) with and without the Grimme-D2 and Grimme-D3 pairwise corrections (PBE+D2/3 and PBEsol+D2/3), two revised PBE functionals with the Grimme-D2 and Grimme-D3 pairwise corrections (RPBE+D2/3 and revPBE+D2/3), and the nonlocal van der Waals correlation (vdW-DF2) functional. We also investigate a universal graph deep learning interatomic potential's (M3GNet) predictive accuracy for loading and configuration. These results allow us to identify a useful screening procedure for configuration prediction that has a coarse component for quick evaluation and a higher accuracy component for detailed analysis. Our general observation is that the neural network-based potential can be used as a high-level and rapid screening tool, whereas PBEsol+D3 gives a completely qualitatively predictive picture across all systems studied, and can thus be used for high accuracy motif predictions. We close by briefly exploring the predictions of relative thermal stability for the different functionals and dispersion corrections. [ABSTRACT FROM AUTHOR]

This study employs grand canonical Monte Carlo (GCMC) simulations to investigate the impact of functional group modifications (CH3, OH, NH2, and OLi) on the adsorption performance of CH4/N2 on Ni‐MOF‐74. The results revealed that functional group modifications significantly increased the adsorption capacity of Ni‐MOF‐74 for both CH4 and N2. The packed methyl groups in CH3‐Ni‐MOF‐74 create an environment conducive to CH4, leading to the highest CH4 adsorption capacity. The electrostatic potential distribution indicates that the strong electron‐donating effect introduced by the alkali metal Li results in the highest electrostatic potential gradient in Li‐O‐Ni‐MOF‐74, leading to the strongest adsorption of N2, this is unfavorable for CH4/N2 separation. At 1500 kPa the selectivity order of adsorbents for mixed gases was as follows: CH3‐Ni‐MOF‐74 > NH2‐Ni‐MOF‐74 > OH‐Ni‐MOF‐74 > Ni‐MOF‐74 > Li‐O‐Ni‐MOF‐74. This study highlights that CH3‐Ni‐MOF‐74 possesses optimal CH4 selectivity and adsorption performance. Given the current lack of research on functionalized MOF‐74 for the separation of CH4 and N2, the findings of this study will serve as a theoretical guide and provide references for the applications of CH4 adsorption and CH4/N2 separation. [ABSTRACT FROM AUTHOR]

Separation of the mixture of ethylene (C2H4) and ethane (C2H6) to produce polymer-grade C2H4 is of prime importance in the petrochemical industry. In this context, metal–organic frameworks (MOFs) featuring tunable pore metrics and surface chemistry, especially those with inverse C2H6/C2H4 adsorption selectivity, hold great promise in energy-effective purification of C2H4 by adsorptive separation, but often encounter the well-known trade-off between adsorption selectivity and capacity. In this work, we report two new MOFs by deploying the pore-space-partition (PSP) strategy for the purpose of reducing the pore aperture size while retaining the gas-accessible pore volume. As a result, Ni-bodc-tpt (bodc = bicyclo[2.2.2]octane-1,4-dicarboxylic acid, tpt = 2,4,6-tri(4-pyridyl)-1,3,5-triazine) by combining optimal pore size, large cage pore volume, and rich C–H binding sites exhibits concurrently high C2H6 adsorption capacity (131.65 cm3 g−1) and C2H6/C2H4 selectivity (1.8) at 298 K and 1 bar, which is superior or comparable to many benchmark C2H6-selective MOFs. A dynamic breakthrough experiment demonstrates that high-purity C2H4 (>99.9%) can be harvested in one step from a binary mixture of C2H6/C2H4 (50/50, v/v), attesting to the feasibility of this new MOF as a prospective C2H4 purification agent. [ABSTRACT FROM AUTHOR]

Electrocatalytic carbonylation of CO and CH3OH to dimethyl carbonate (DMC) on metallic palladium (Pd) electrode offers a promising strategy for C1 valorization at the anode. However, its broader application is limited by the high working potential and the low DMC selectivity accompanied with severe methanol self‐oxidation. Herein, our theoretical analysis of the intermediate adsorption interactions on both Pd0 and Pd4+ surfaces revealed that inevitable reconstruction of Pd surface under strongly oxidative potential diminishes its CO adsorption capacity, thus damaging the DMC formation. Further theoretical modeling indicates that doping Pd with Cu not only stabilizes low‐valence Pd in oxidative environments but also lowers the overall energy barrier for DMC formation. Guided by this insight, we developed a facile two‐step thermal shock method to prepare PdCu alloy electrocatalysts for DMC. Remarkably, the predicted Pd3Cu demonstrated the highest DMC selectivity among existing Pd‐based electrocatalysts, reaching a peaked DMC selectivity of 93 % at 1.0 V versus Ag/AgCl electrode. (Quasi) in situ spectra investigations further confirmed the predicted dual role of Cu dopant in promoting Pd‐catalyzed DMC formation. [ABSTRACT FROM AUTHOR]

Electrocatalytic carbonylation of CO and CH3OH to dimethyl carbonate (DMC) on metallic palladium (Pd) electrode offers a promising strategy for C1 valorization at the anode. However, its broader application is limited by the high working potential and the low DMC selectivity accompanied with severe methanol self‐oxidation. Herein, our theoretical analysis of the intermediate adsorption interactions on both Pd0 and Pd4+ surfaces revealed that inevitable reconstruction of Pd surface under strongly oxidative potential diminishes its CO adsorption capacity, thus damaging the DMC formation. Further theoretical modeling indicates that doping Pd with Cu not only stabilizes low‐valence Pd in oxidative environments but also lowers the overall energy barrier for DMC formation. Guided by this insight, we developed a facile two‐step thermal shock method to prepare PdCu alloy electrocatalysts for DMC. Remarkably, the predicted Pd3Cu demonstrated the highest DMC selectivity among existing Pd‐based electrocatalysts, reaching a peaked DMC selectivity of 93 % at 1.0 V versus Ag/AgCl electrode. (Quasi) in situ spectra investigations further confirmed the predicted dual role of Cu dopant in promoting Pd‐catalyzed DMC formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Eco-design of a highly efficient Cr(VI) adsorbent with bimodal micro-/mesoporous structure. • Green synthesis approach utilizing Sorghum waste as a sustainable silica source for the adsorbent. • A one-pot synthesis method led to homogeneously distributed adsorption sites on the MI-Cl-FDU-12. • MI-Cl-FDU-12 demonstrated a high adsorption capacity of 416.9 mg g-1 at 313 K for Cr(VI) • MI-Cl-FDU-12 adsorbent revealed excellent regeneration performance by six consecutive cycles. This paper presents an eco-design approach to the synthesis of a highly efficient Cr(VI) adsorbent, utilizing a positively charged surface mesoporous FDU-12 material (designated as MI-Cl-FDU-12) for the first time. The MI-Cl-FDU-12 anion-exchange adsorbent was synthesized via a facile one-pot synthesis approach using sodium silicate extracted from sorghum waste as a green silica source, 1-methyl-3-(triethoxysilylpropyl) imidazolium chloride as a functionalization agent, triblock copolymer F127 as a templating or pore-directing agent, trimethyl benzene as a swelling agent, KCl as an additive, and water as a solvent. The synthesis method offers a sustainable and environmentally friendly approach to the production of a so-called "green" adsorbent with a bimodal micro-/mesoporous structure and a high surface area comparable with the previous reports regarding FDU-12 synthesis. MI-Cl-FDU-12 was applied as an anion exchanger for the adsorption of toxic Cr(VI) oxyanions from aqueous media and various kinetic and isotherm models were fitted to experimental data to propose the adsorption behavior of Cr(VI) on the adsorbent. Langmuir model revealed the best fit to the experimental data at four different temperatures, indicating a homogeneous surface site affinity. The theoretical maximum adsorption capacities of the adsorbent were found to be 363.5, 385.5, 409.0, and 416.9 mg g−1 at 298, 303, 308, and 313 K, respectively; at optimal conditions (pH=2, adsorbent dose=3.0 mg, and contact time of 30 min), surpassing that of most previously reported Cr(VI) adsorbents in the literature. A regeneration study revealed that this adsorbent possesses outstanding performance even after six consecutive recycling. [ABSTRACT FROM AUTHOR]

A novel S-scheme ZnO-Zn 2 SnO 4 -based heterojunction with oxygen vacancies is in situ prepared. The synergistic effect of oxygen vacancies and S-scheme heterojunction not only generates rich active species but also activates small molecules, thereby greatly enhancing the deep oxidation efficiency of nitric oxide to nitrate under visible light irradiation. [Display omitted] The generation of hazardous intermediates during the process of photocatalytic nitric oxide (NO) oxidation presents a tough issue. Herein, a one-step microwave strategy was employed to introduce oxygen vacancies (OVs) into zinc oxide-zinc stannate (ZnO-Zn 2 SnO 4) heterojunction, resulting in an improvement in the photocatalytic efficiency for NO removal. The construction ZnO-Zn 2 SnO 4 heterojunction with the OVs (ZSO-3) owns a significant contribution towards highly efficient electron transfer efficiency (99.7%), which renders ZSO-3 to exert a deep oxidation of NO-to-nitrate (NO 3 −) rather than NO-to-nitrite (NO 2 −) or NO-to-nitrogen dioxide (NO 2). Based on the solid supports of experimental and simulated calculations, it can be found that OVs play an irreplaceable role in activating small molecules such as NO and O 2. Moreover, the enhanced adsorption capacity of small molecules, which guarantees the high yield of active radical due to the formation of S-scheme heterojunction. This work illuminates a novel viewpoint on one-step in-situ route to prepare Zn 2 SnO 4 -based heterojunction photocatalyst with deep oxidation ability of NO-to-NO 3 −. [ABSTRACT FROM AUTHOR]

The discharge of colored effluent into water bodies is a big concern; hence, the current work was designed to fabricate a superior nanocomposite (NBM) using the Newbouldia laevis husk (NB) and functionalized multiwalled carbon nanotubes (f-MWCNTs) for the adsorption of malachite green oxalate (MGO). Brunauer–Emmett–Teller (BET) surface analysis was used to assess the specific surface area of NB (0.7699 m2 g−1) and NBM (94.006 m2 g−1). Fourier transform infrared spectroscopy (FTIR) was employed to determine the chemical moieties on the surface of the adsorbent. Field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA) were used to analyze the surface morphology and the thermal behavior of the adsorbents. Essential factors of the adsorption process were investigated, and it was revealed that pH 6.0, adsorbent dose of 0.05 g, contact time 80 min, concentration of 100 mg dm−3 and maximum adsorption capacity of 35.78 mg g−1 (NB) and 69.97 mg g−1 (NBM) were the optimal parameters. The NB and NBM adsorption processes followed a pseudo-first-order kinetic model. The exothermic and endothermic adsorptive processes were noticed to be the best descriptions of MGO elimination by NB and NBM, respectively. The uptake of MGO by NB and NBM was best described by models of Freundlich and Langmuir isotherms. Besides, NBM demonstrated uptake efficiency that is >80% after the fourth adsorption/desorption cycle. As a result, NBM has a wide range of possible uses in environmental remediation. The husk of Newbouldia laevis is a frequent waste that must be managed properly. This paper describes the application of Newbouldia laevis husk as a value-added material for the design of a water treatment agent. The use of carbon nanotube in the modification of Newbouldia laevis husk would have a synergistic effect on the overall property of the nanocomposite. Nanocomposite synthesized from multiwalled carbon nanotubes (MWCNTs) and Newbouldia laevis husk were characterized and used for the sequestration of malachite green oxalate from contaminated water. Our primary goal is to optimize the nanocomposite by varying factors of adsorption such as solution pH, equilibrium, kinetic, thermodynamic, and regeneration studies. We believe that this study will contribute to the existing knowledge of Newbouldia laevis husk. Owing to the exceptional potential of the nanocomposite, this adsorbent can be extended to possible field applications. [ABSTRACT FROM AUTHOR]

Our study aims to investigate the response of the unicellular alga, Haematococcus pluvialis, to the toxicity of lead and propose a low-cost, highly efficient biological adsorbent for the purification of wastewater and lead-contaminated water. The first part examines the effects of lead toxicity on certain physiological indicators of this alga. In the second part, the potential of this alga in lead removal and its adsorption capacity was assessed. The alga was cultivated in a BG11 medium and treated with lead nitrate concentrations of 10, 50, and 200 mg/L during its exponential growth. The results showed that with an increase in lead concentration up to 200 mg/L, the growth rate, chlorophyll a, chlorophyll b, carotenoid and total protein content decreased, while malondialdehyde (MDA) content increased. The astaxanthin content slightly increased at the 10 mg/L but decreased at the 200 mg/L treatment. Maximum lead adsorption was observed at 98.69% under optimal conditions, including a pH of 6, an adsorbent dose of 1 g/L, a lead concentration of 25 mg/L, a temperature of 25 °C, and an exposure time of 120 min. The results of this study demonstrate that Haematococcus pluvialis has the potential for effective lead removal from aquatic environments. While the influence of heavy metals on certain algae species has been explored, research on the impact of lead on Haematococcus pluvialis—a microalga of significant interest for astaxanthin production—remains uncharted territory. Therefore, understanding the impact of this heavy metal and the alga's metal absorption capabilities has profound implications for biotechnology and bioremediation applications. This study promotes H. pluvialis as an economically viable lead absorbent suitable for both industrial and domestic purposes. [ABSTRACT FROM AUTHOR]

In this study, pineapple crown (PC) feedstock residues were utilized as a potential precursor toward producing activated carbon (PCAC) via pyrolysis induced with ZnCl2 activation. The PCAC has a surface area (457.8 m2/g) and a mesoporous structure with an average pore diameter of 3.35 nm, according to the Brunauer–Emmett–Teller estimate. The removal of cationic dye (Fuchsin basic; FB) was used for investigating the adsorption parameters of PCAC. The optimization of significant adsorption variables (A: PCAC dose (0.02–0.1 g/100 mL); B: pH (4–10); C: time (10–90); and D: initial FB concentration (10–50 mg/L) was conducted using the Box-Behnken design (BBD). The pseudo-second-order (PSO) model characterized the dye adsorption kinetic profile, whereas the Freundlich model reflected the equilibrium adsorption profile. The maximum adsorption capacity (qmax) of PCAC for FB dye was determined to be 171.5 mg/g. Numerous factors contribute to the FB dye adsorption mechanism onto the surface of PCAC, which include electrostatic attraction, H-bonding, pore diffusion, and π–π stacking. This study illustrates the utilization of PC biomass feedstock for the fabrication of PCAC and its successful application in wastewater remediation. [ABSTRACT FROM AUTHOR]

Mesoporous silica/polyaniline (PANI) composite nanofibers with a full interpenetrating structure were synthesized via a controlled sol–gel process and in situ polymerization route from anodic alumina oxide (AAO) membranes. In the synthetic process, AAO membranes act as a template for the preparation of PANI/silica composite fibers. After removal of the AAO templates by hydrochloric acid (HCl) dissolution, the as-prepared mesoporous silica/PANI composite fibers possess a uniform fiber morphology and full interpenetrating structure, resulting in a continuous conductive PANI network with high porosity and large specific surface area. SEM images of mesoporous silica/PANI composite fibers shows that the diameter of the silica fibers has not been changed before and after PANI deposition, proving that PANI is well filled in the channel. The nitrogen (N2) absorption/desorption experiments suggest that the average pore size and the surface area of silica/PANI composite fibers are 5.7 nm and 147 m2/g respectively. The profile of isotherms is similar to that of blank silica nanofibers with lower adsorption capacity and relative pressure, which demonstrates that aniline can polymerize in the pore channel. The results of four-probe method show that the conductivity of the mesoporous silica/PANI composite fibers is 2.6 × 10–4 S/cm. This synthetic strategy is also suitable for fabricating various nanostructured composite nanofibers of PANI and other inorganic materials. [ABSTRACT FROM AUTHOR]

The abundant tunable functional groups and room-temperature sensing properties of MXenes have garnered increasing interest in the field of gas sensing. However, the majority of research has exclusively focused on the combined impact of external substances with MXenes functional groups, with limited exploration into the modulation of MXenes' intrinsic functional groups. In this work, we successfully produced molten salt-modified Ti 3 C 2 T x MXene (M-Ti 3 C 2 T x) with tunable oxygen-functionalized surfaces using the molten salt immersion method and employed it as a chemical resistive gas sensor to detect NO 2 at room temperature (RT). Using diverse analytical techniques, we propose the O−addition effect on the surface titanium atoms and the O−substitution effect on the edge carbon atoms, refining the existence form of –O functional groups as well as realizing the effective regulation of the intrinsic functional groups. With a high response (∼25.87%−100 ppm NO 2 , whose response value is five times higher than that of pristine Ti 3 C 2 T x), relatively rapid response speed (∼99 s−25 ppm NO 2), high sensitivity (∼0.29 ppm−1), low detection limits (theoretical LoD is 3.3 ppm), good selectivity and long-term stability (maintain stable within 28 days) at RT, the sensor based on M-Ti 3 C 2 T x demonstrates excellent NO 2 sensing performance. To understand the sensing mechanism, density functional theory (DFT) calculations were conducted to explore adsorption behaviors. Theoretical analysis validates that M-Ti 3 C 2 T x has a stronger adsorption capacity for NO 2 (E ad = −1.149 eV) owing to the formation of covalent bond between the –O functional group and the nitrogen atom of NO 2. The application of the molten salt can effectively modulate the intrinsic functional groups of MXenes, expanding the scope of MXenes surface modification engineering and creating new opportunities for enhancing the gas sensing capabilities of MXenes. [ABSTRACT FROM AUTHOR]

Hollow SiO 2 microspheres have become attractive materials for nanotechnology applications owing to their biological inertness and high functionality. In this study, hydrophobic spherical hollow cages were formed using the soft stencil method with Pluronic F127 and cetyltrimethylammonium bromide (CTAB) as the structure-directing agent, and hollow nanoporous SiO 2 microspheres (FHMS) were prepared using the soft template method. Various of amine functionalization modes were further employed to demonstrate the complexity of the relationship between pore structure/amidation mode/amine content and adsorption capacity. The hollow morphology of the porous silica was revealed using field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and its porous properties were revealed using nitrogen adsorption-desorption isotherm measurements. Experiments on the fixed-bed dynamic adsorption process at 15% CO 2 showed that the high specific surface area, high pore volume and amine content of the carriers had a positive effect on the adsorption performance. However, the accessibility of the adsorption centre was affected at high loadings, and the amine efficiency and adsorption capacity were reduced. The dual amine functionalized FHMS-G-I60 maintained the integrity and order of the hollow mesoporous carrier structure, and overcame the dilemma of easy loss in the cycle process of the impregnation method and the low adsorption capacity of the grafting method. It possessed an adsorption capacity of 3.62 mmol/g, high adsorption cycling stability (more than 99.5% adsorption maintained after 10 cycles) and high amine efficiency (0.2852 mmol CO 2 /mmol N). CO 2 -TPD analysis (Thermal Programmed Desorption) further showed that FHMS-G-I60 had a faster desorption rate and lower regeneration energy consumption. In general, such structure-directed prepared matrices and functionalized with different amines are promising and low-cost adsorbents that can be used to capture CO 2 from ambient air and flue gases under different demands. [ABSTRACT FROM AUTHOR]

This study introduces UiO-66-PO3, a novel functionalized metal–organic framework (MOF) tailored for efficient thorium separation and enrichment from wastewater. UiO-66-PO3 was synthesized by amination reaction between UiO-66-NH2 and 2-carboxyethylphosphonic acid. Comprehensive characterization techniques confirmed its successful synthesis and revealed its unique properties. UiO-66-PO3 exhibited a remarkable theoretical maximum adsorption capacity of 320.0 mg g−1 for Th(IV) under optimized conditions. Its exceptional hydrophilicity significantly enhanced the adsorption capacity compared to UiO-66-NH2. Furthermore, UiO-66-PO3 retained over 89% of its initial adsorption capacity for Th(IV) after five adsorption–desorption cycles, highlighting excellent regeneration capabilities. UiO-66-PO3 emerges as a promising adsorbent for thorium separation due to its high adsorption capacity, regeneration performance, and tunable properties. [ABSTRACT FROM AUTHOR]

This study prepared epoxy resin reinforced porous beads (CERBs) by crosslinking a water-soluble epoxy monomer, 1,4-butanediol diglycidyl ether (BDE), with chitosan (CS) using isophorone diamine (IPD) as a crosslinking agent. CERBs are prepared by a one-step method under atmospheric pressure and used for the adsorption of Congo Red (CR). The Sips isotherm model indicates that the maximum adsorption capacity of CERBs for Congo Red is 2289.2 mg g−1. CERBs have a three-dimensional network structure and strong mechanical properties, and can be reused more than 5 times maintaining a high adsorption capacity. Therefore, this material can be produced on a large scale and has great potential for commercial applications. [ABSTRACT FROM AUTHOR]

The preparation of efficient and cheap adsorbents is important for the removal of chlorinated volatile organic compounds, which are carcinogenic, teratogenic, and mutagenic to human health. In this study, ethylenediamine and ZnCl2 were introduced simultaneously into Camellia oleifera shell-based biochar by the impregnation method. A series of nitrogen doped porous carbons (ANOC-x) were prepared by adjusting the ethylenediamine impregnation ratio combined with NaOH activation. Among them, the chlorobenzene adsorption capacity of ANOC-1.5 reached 1187 mg g−1, which was 1.4 times that of undoped porous carbon. This was attributed to that ANOC-1.5 had the maximum specific surface area (2685 m2 g−1) and a hierarchical porous structure, which provided abundant adsorption sites and mass transfer channels for chlorobenzene adsorption. In addition, the chlorobenzene adsorption performance of porous carbon was highly correlated with surface defects, which was attributed to the fact that the surface of ANOC-1.5 (0.615 at%) contains more pyrrole heterocycles than AOC (0.258 at%), forming more π-electron rich defect sites. These defect sites had strong π–π interactions with chlorobenzene molecules, which could easily bind with the aromatic rings of chlorobenzene, thus improving the adsorption capacity of chlorobenzene. Moreover, ANOC-1.5 had high thermal stability and excellent regeneration performance, and its adsorption capacity for chlorobenzene remained above 90% after five regeneration tests, which exhibited potential for industrial applications. [ABSTRACT FROM AUTHOR]

The ascribed work suggests a fabrication pathway of carbon aerogel material from the rose apple (Syzygium jambos) fruit (RACA), in which a hydrothermal step, followed by a calcination process under various temperatures from 600 to 900 °C was carried out. RACA were characterized via multiple methods to briefly determine the optimal calcination temperature for the application, revealing that the temperature of 700 °C provided an intermediate deconstruction effect to form the amorphous structure and amplified the surface area. Whence, the materials were assessed for the adsorption capacities towards diesel oil which provided a capacity of approximately 35 g/g, although the adsorption capacity decreased slightly after 5 cycles of recovery and reuse. Furthermore, RACA‐700 exhibits high adsorption capacity of organic solvents (toluene, cyclohexane, butanol, hexane, and chloroform) and the ciprofloxacin antibiotic. Besides, the utilization of the fabricated carbon aerogel in the supercapacitor was also investigated. The obtained results elucidate the highest specific capacitance of 61.20 F/g, corresponding with the lowest resistance of 195.6 Ω, which indicates the ability to maintain capacitance after 5000 cycles and still retain 60 % efficiency, thereby signifying the potential application of carbon aerogel in sustainable material construction. [ABSTRACT FROM AUTHOR]

Developing candidate materials which possess the ability of both selective detection and efficient capture of precious metal gold is highly desirable for environment and economy. However, most of reported materials only focus on single function, which seriously restricts their practical application as probes or adsorbents. Herein, a two dimensional (2D) acridine‐based covalent organic framework (TpDa‐COF) is prepared via the linkage of imine bonds for gold detection and adsorption. The synthesized COF can achieve both fluorescence and colorimetric dual sensing for Au3+ in a low concentration range (0.1–1.5 ppm) with the limit of detection (LOD) of 0.036 ppm. Impressively, the selectivity of TpDa‐COF for the detection of Au3+ is admirable (Fe3+, Fe2+ and Cu2+ for negligible influence on its fluorescence). In addition, TpDa‐COF exhibits ultrahigh adsorption capacity of 982.5 mg ⋅ g−1 for gold at pH=4, which is attributed the synergistic effect of both selective coordination and reductive process of Au(III) to Au(0). Meanwhile, both positive entropy change (ΔS=76.07 J ⋅ mol−1 ⋅ K−1) and high distribution coefficient (Kd=12484.8 mL ⋅ g−1) confirm the good affinity between TpDa‐COF framework and gold. This work gives us a new insight to prepare COF with pyridine nitrogen sites for gold detection and adsorption. [ABSTRACT FROM AUTHOR]

Developing candidate materials which possess the ability of both selective detection and efficient capture of precious metal gold is highly desirable for environment and economy. However, most of reported materials only focus on single function, which seriously restricts their practical application as probes or adsorbents. Herein, a two dimensional (2D) acridine‐based covalent organic framework (TpDa‐COF) is prepared via the linkage of imine bonds for gold detection and adsorption. The synthesized COF can achieve both fluorescence and colorimetric dual sensing for Au3+ in a low concentration range (0.1–1.5 ppm) with the limit of detection (LOD) of 0.036 ppm. Impressively, the selectivity of TpDa‐COF for the detection of Au3+ is admirable (Fe3+, Fe2+ and Cu2+ for negligible influence on its fluorescence). In addition, TpDa‐COF exhibits ultrahigh adsorption capacity of 982.5 mg ⋅ g−1 for gold at pH=4, which is attributed the synergistic effect of both selective coordination and reductive process of Au(III) to Au(0). Meanwhile, both positive entropy change (ΔS=76.07 J ⋅ mol−1 ⋅ K−1) and high distribution coefficient (Kd=12484.8 mL ⋅ g−1) confirm the good affinity between TpDa‐COF framework and gold. This work gives us a new insight to prepare COF with pyridine nitrogen sites for gold detection and adsorption. [ABSTRACT FROM AUTHOR]

The rational construction of electrocatalysts has sparked a growing interest in accelerating redox kinetics of polysulfide and effectively restricting the "shuttle effect" in Li‐S batteries. In this work, a novel MXene‐supported ultrasmall Co3Fe7 bimetallic alloy hybrids are fabricated via a one‐pot molten salt etching strategy. The Ti3AlC2 precursor can be directly converted to Co3Fe7‐MXene using this environmentally friendly approach, eliminating the need for acid/alkaline treatments and complex procedures. Meanwhile, the ultrasmall Co3Fe7 alloy particles are in situ formed and tightly anchored on the MXene substrate. By simple coating, Co3Fe7‐MXene modified separator functions as a barrier to effectively inhibit the shuttle effect. Furthermore, electrochemical tests and theoretical calculations demonstrate that Co3Fe7‐MXene exhibits exceptional adsorption capacity and remarkable catalytic ability toward polysulfides, owing to the synergistic effect of bimetallic alloy. Consequently, Li‐S cells assembled with Co3Fe7‐MXene modified separator achieve a high capacity, excellent rate performance, and superior cycle stability. This study provides a comprehensive insight into the design of MXene with bimetallic alloys as efficient electrocatalysts for LiPSs in high‐performance and long‐life Li‐S batteries. [ABSTRACT FROM AUTHOR]

Magnetic solid phase adsorption separation (MSPA) technology is an efficient and convenient separation method, which can simplify the separation step and shorten the separation time. It has wide application value in the purification of antibiotic pollutants in water. In this study, a novel magnetic biochar adsorbent (DES1@MnFe2O4‐BBC) with strong selectivity and high adsorption capacity was synthesized. It was composed of banana peel as the biochar source, Mn/Fe bimetallic oxide as the magnetic source and deep eutectic solvent (DES) as the functional monomer. The physicochemical properties of DES1@MnFe2O4‐BBC were systematically characterized by nitrogen adsorption–desorption, synchronous thermal analyzer, vibrating sample magnetometer, X‐ray diffractometer, X‐ray photoelectron spectroscopy, and field emission electron microscopy. The adsorption conditions were optimized by the single‐factor optimization method. Also, under the optimal adsorption conditions, the maximum adsorption capacity of DES1@MnFe2O4‐BBC for ceftiofur sodium was 75.01 mg·g−1. The test of adsorption thermodynamics and kinetics illustrated that the Langmuir isotherm adsorption model and pseudo‐second‐order kinetic equation were suitable well with the adsorption system established in this article. Adsorbent regeneration cycle experiment revealed that the DES1@MnFe2O4‐BBC was an efficient and reusable adsorbent. In the end, all research proves the novel magnetic adsorbent synthesized in this study can provide a new idea for the removal of antibiotics in water. [ABSTRACT FROM AUTHOR]

The high demand for lithium (Li) relates to clean, renewable storage devices and the advent of electric vehicles (EVs). The extraction of Li ions from aqueous media calls for efficient adsorbent materials with various characteristics, such as good adsorption capacity, good selectivity, easy isolation of the Li-loaded adsorbents, and good recovery of the adsorbed Li ions. The widespread use of metal-based adsorbent materials for Li ions extraction relates to various factors: (i) the ease of preparation via inexpensive and facile templation techniques, (ii) excellent selectivity for Li ions in a matrix, (iii) high recovery of the adsorbed ions, and (iv) good cycling performance of the adsorbents. However, the use of nano-sized metal-based Lithium-ion sieves (LISs) is limited due to challenges associated with isolating the loaded adsorbent material from the aqueous media. The adsorbent granulation process employing various binding agents (e.g., biopolymers, synthetic polymers, and inorganic materials) affords composite functional particles with modified morphological and surface properties that support easy isolation from the aqueous phase upon adsorption of Li ions. Biomaterials (e.g., chitosan, cellulose, alginate, and agar) are of particular interest because their structural diversity renders them amenable to coordination interactions with metal-based LISs to form three-dimensional bio-composite materials. The current review highlights recent progress in the use of biopolymer binding agents for the granulation of metal-based LISs, along with various crosslinking strategies employed to improve the mechanical stability of the granules. The study reviews the effects of granulation and crosslinking on adsorption capacity, selectivity, isolation, recovery, cycling performance, and the stability of the LISs. Adsorbent granulation using biopolymer binders has been reported to modify the uptake properties of the resulting composite materials to varying degrees in accordance with the surface and textural properties of the binding agent. The review further highlights the importance of granulation and crosslinking for improving the extraction process of Li ions from aqueous media. This review contributes to manifold areas related to industrial application of LISs, as follows: (1) to highlight recent progress in the granulation and crosslinking of metal-based adsorbents for Li ions recovery, (2) to highlight the advantages, challenges, and knowledge gaps of using biopolymer-based binders for granulation of LISs, and finally, (3) to catalyze further research interest into the use of biopolymer binders and various crosslinking strategies to engineer functional composite materials for application in Li extraction industry. Properly engineered extractants for Li ions are expected to offer various cost benefits in terms of capital expenditure, percent Li recovery, and reduced environmental footprint. [ABSTRACT FROM AUTHOR]

The development of the nuclear industry has stimulated research in uranium extraction from seawater (UES) by adsorption. However, in practical applications, it's hard to equip various ion concentration measurement instruments for real‐time characterizing uranium adsorption capacity. Given the radioactive property of uranium, if only a Geiger counter is possessed, how it can be utilized to rapidly evaluate uranium adsorption in the adsorbent? This study proposes the Geiger‐Uranium‐Distance model, which establishes correlations among Geiger counter readings, uranium adsorption capacity, and distance, thereby offering a viable approach. While maintaining a constant radius for the adsorbent stack point, during the laboratory phase, the average molecular mass (MA) and the kGg(z) values of the original adsorbent are determined. In practical applications, the surrounding radiation background GE (µSv h−1) is detected. Subsequently, the Geiger counter is vertically positioned above the stacked point of adsorbent after uranium adsorption. Utilizing the measured radiation intensity value G (µSv h−1), and employing the equation G=kGg(z)Qe1+MAQe+GE$G\ = {k}_G\ g(z)\frac{{{Q}_e}}{{1 + {M}_A{Q}_e}} + {G}_E$, the uranium adsorption capacity Qe can be obtained. [ABSTRACT FROM AUTHOR]

In the current study, sol gel and hydrothermal methods were used to synthesis pure TiO2 (TO) and its composite with multiwalled carbon nanotubes (TO–C), respectively. The prepared materials were subjected to surface and structural characterization using XRD, RAMAN, FESEM and EDX. The batch mode experiments were carried out systematically to obtained the adsorption data which were further analysed using various isotherm, kinetic, and thermodynamic models, in order to determine the adsorptive potential of TO and TO–C for the remediation of U(VI). The thermodynamic characteristics showed the endothermic and spontaneous nature of adsorption. The isotherm studies revealed the maximum Langmuir adsorption capacity (mg/g) of 65.74 and 41.97 exhibited by TO–C and TO, respectively for U(VI). The study proposed that U(VI) extraction from water is primarily caused by п-electron density of MWCNTs and monolayer chemisorption through coordination complex formation. These results confirm the prospective use of TO–C as packing material for column units in water purifiers. [ABSTRACT FROM AUTHOR]

Fluoride contamination in groundwater may pose serious health issues. Among all the technologies, adsorption is considered to be highly efficient and is widely used for remediation in environment. In the present study, copper oxide nanoparticles (CuO) were synthesized by chemical precipitation method and used as adsorbent. The study intends to examine copper oxide nanoparticles behaviour when fluoride ions are present in an aqueous solution. The batch mode experiment demonstrated a substantial ability of the copper oxide nanoparticles for adsorption of fluoride with an adsorption capacity of 69.9 mg/g at a pH of 6, temp 298 K and adsorbent dose of 0.5 g/L. [ABSTRACT FROM AUTHOR]

Low-quality cotton fibers are a low-value waste material within the cotton industry. Upcycling and transforming into high-value materials are highly desired. This study investigates upcycling fibers into hydrogel biosorbents and assesses their efficacy in dye adsorption. An effective gelation approach was employed via simply dropping droplets of suspension mixture of sodium alginate and fibers into acidic bath. Resulting composite hydrogel beads were utilized for dye removal. Composite beads successfully immobilized less than 70 wt% of fibers and achieved a significant improvement in thermal stability. Composite beads with 50 wt% fibers and alginate showed no decrease in methylene blue adsorption capacity. This outcome was unexpected considering the lower dye adsorption capacity of fibers than alginate, particularly notable since it indicated that reduced quantities of the more costly sodium alginate were sufficient to achieve comparable dye adsorption capacity. Mechanistic study unveiled that both the loose crosslinking structure and the electrostatic forces were responsible for the unexpected high adsorption capacity of 50% fiber-alginate. This study reports a promising, innovative and effective upcycle strategy for the first time that can transform fibers into high-value biosorbents without compromising dye adsorption capability. [ABSTRACT FROM AUTHOR]

[Display omitted] As a noble metal with extremely high economic benefits, the recovery of silver ions has attracted a particular deal of attention. However, it is a challenge to recover silver ions efficiently and selectively from aqueous solutions. In this research, the novel metal–organic frameworks (MOFs) adsorbent (Zr-DPHT) is prepared for the highly efficient and selective recovery of silver ions from wastewater. Experimental findings reveal that Zr-DPHT's adsorption of Ag(I) constitutes an endothermic process, with an optimal pH of 5 and exhibits a maximum adsorption capacity of 268.3 mg·g−1. Isotherm studies show that the adsorption of Ag(I) by Zr-DPHT is mainly monolayer chemical adsorption. Kinetic studies indicate that the internal diffusion of Ag(I) in Zr-DPHT may be the rate-limiting step. The mechanism for Ag(I) adsorption on Zr-DPHT involves electrostatic interactions and chelation. In competitive adsorption, Ag(I) has the largest partition coefficient (9.64 mL·mg−1), indicating a strong interaction between Zr-DPHT and Ag(I). It is proven in the adsorption–desorption cycle experiments that Zr-DPHT has good regeneration performance. The research results indicate that Zr-DPHT can serve as a potential adsorbent for efficiently and selectively capturing Ag(I), providing a new direction for MOFs in the recycling field of precious metals. [ABSTRACT FROM AUTHOR]

The removal of uranium from radioactive wastewater is an important step in nuclear waste management. In this study, a solid adsorbent was developed utilizing mesoporous alumina encapsulated within polyethersulfone (PES) beads for effective uranium extraction. The encapsulation process enhances the stability and selectivity of the material, while the mesoporous structure of alumina enables controlled mass transfer and optimal uranium adsorption. These composite beads were synthesized and thoroughly characterized, and their performance was evaluated for uranium removal from simulated radioactive wastewater. The synthesized materials have been characterized by FTIR, TGA–DSC, SEM, EDX and BET surface area analysis techniques to get complete insight into morphology, functionality and topography of materials. Batch adsorption experiments revealed rapid uranium uptake, reaching equilibrium within a short time frame. The maximum adsorption capacity was found to be ~18 mg g−1. These findings establish the potential of mesoporous alumina-encapsulated PES beads as a promising candidate for uranium extraction, offering a valuable contribution to the advancement of radioactive waste treatment technologies. [ABSTRACT FROM AUTHOR]

Rose Bengal (RB) is a halogen-containing water-soluble dye that is frequently used for therapeutic purposes. The dye, on the other hand, is poisonous and may cause inflammation, stinging and other adverse reactions in eyes and skin of living beings as it comes in water resources with medical waste. As a reason, it is thought to be desirable to propose a systematic approach for removing or minimising the effect of RB dye via adsorption. Here in this work, a novel CeO2/Fe3O4/g-C3N4 (CFC) nanocomposite has been synthesised by the co-precipitation-assisted hydrothermal method. The morphological and structural properties were studied by powder HRTEM, XRD, EDAX, FTIR and XPS, and also, the surface area of the CFC was measured by BET. UV-DRS was employed for the band gap calculation. This nanocomposite showed excellent adsorption properties for Rose Bengal (RB). The synthesised nanostructure exhibited a maximum adsorption capacity of 83.05 mgg−1 for RB dye. Furthermore, the nanocomposite has shown adsorption efficiency close to 99% after being regenerated and reused up to five times. It followed pseudo-second-order kinetics and an isotherm best fit with the Langmuir model. Based on the adsorption studies and FTIR studies, it is confirmed that the hydrogen bonding and electrostatic interactions are the predominating factors for the adsorption process. [ABSTRACT FROM AUTHOR]

Ionic liquid functionalised egg residues were tested for their biosorption ability towards water soluble anionic 'orange G' dye. Egg residues after ionic liquid treatment were characterised via FTIR, SEM and TGA. Adsorption process was optimised by evaluating different experimental parameters including effect of adsorbent dose, contact time, agitation speed, temperature and pH. Modified egg shell membrane (MESM) exhibited higher efficiency for orange G dye adsorption followed by unmodified egg shell membrane (ESM) and powdered egg shell (PES). Equilibrium states were achieved in 1 hour for the different studied initial dye concentrations at acidic pH, 120 rpm and 30°C. Under optimum conditions >95% dye is removed with 27 mg/g adsorption capacity of MESM for 80 ppm dye solution. Study was further extended to find the best-fitted kinetic and isothermal model. It was found that the process follows pseudo-second-order kinetics and Langmuir isothermal model. Adsorbent was regenerated and reused without significant loss of efficiency. This research work presented that ionic liquid modified egg shell membrane is highly efficient with regard to its ecological perspective and cost effectiveness for the removal of toxic dye from wastewater. [ABSTRACT FROM AUTHOR]

Exploring efficient adsorbents still remains an important challenge due to the poor efficiency of the reported adsorbents for the adsorption of antibiotics. Herein, we design and prepare a novel nanosheets-like hollow TiO 2 (NHT) adsorbent by using hollow TiO 2 as a precursor through alkaline hydrothermal treatment. Adsorption results show that NHT exhibits a high adsorption percentage (98.05%) within 20 min and a maximum adsorption uptake of 24.51 mg/g for Levofloxacin (LVOF) pollutant (10 mg/L, 50 mL), which is 17 times higher than that (1.4 mg/g) of pristine hollow TiO 2 (HT). Notably, NHT realizes >91% of the adsorption percentage for LVOF pollutant after the tenth run only through photo-regeneration without extra post-treatments, effectively overcoming the disadvantages of harsh regeneration procedures for most of the existed adsorbents. Adsorption data and the performance characterizations present deep insights into adsorption mechanism, which reveals that pore filling effect, hydrogen-bond interactions, and electrostatic attraction are the key parameters for the excellent adsorption of LVOF by NHT. Therefore, the present study can provide a promising direction for the fabrication of efficient adsorptive photocatalyst by using low-cost TiO 2 as a precursor. [Display omitted] • Novel nanosheets-like hollow TiO 2 (NHT) adsorbent was prepared via a facile alkaline hydrothermal treatment. • NHT adsorbent exhibited higher adsorption capacity of LVOF and faster adsorption kinetics than the present materials. • NHT manifested efficient adsorption of LVOF in ambient factors and real water matrices. • Exceptional levofloxacin adsorption/photo-regeneration cycles were realized by NHT adsorptive photocatalyst. • The efficient adsorption mechanism was ascribed to pore-filling effect, hydrogen bonding, and electrostatic interactions. [ABSTRACT FROM AUTHOR]

This study presents the synthesis and characterization of a copper-based layered double hydroxide (Cu-LDH) composite via the coprecipitation method. The composite material aimed to effectively remove the anionic dye "Coomassie Brilliant Blue" (CBB) and exhibit antibacterial properties against both gram-positive and gram-negative bacteria. The synthesized nanocomposites were characterized using various techniques. The adsorption of CBB dye was investigated by studying various physicochemical variables, including contact time, pH of the dye solution, and initial dye concentration. The optimal dosage and contact time for efficient CBB dye removal were determined as 0.07 g and 10 min, respectively. The results showed that Cu-LDHs exhibited a high adsorption capacity for CBB dye, with a maximum removal efficiency of 85% which could be achieved within 10 min, and the Cu-LDHs improved an experimental adsorption capacity at equilibrium qmax = 80 mg/g. The adsorption process followed a pseudo-second-order kinetic model. The Langmuir isotherm model provided a good fit to the equilibrium data, indicating monolayer adsorption. Furthermore, the antibacterial activity of Cu-LDHs was assessed against various bacterial strains using a diffusion method. The results demonstrated the inhibitory effects of Cu-LDHs and CBB-Cu-LDHs on bacterial growth at a dosage of 10 mg, indicating the potential of Cu-LDHs as antibacterial agents. The underlying mechanisms responsible for dye adsorption and antibacterial activity were discussed. [ABSTRACT FROM AUTHOR]

The current work assessed the corrosion inhibitory efficacy of three ligands, namely methyl 2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate(MDN), 1-((3,4-dimethylphenyl)diazenyl)naphthalen-2-ol (DDN), and 3-((2-hydroxynaphthalen-1-yl)diazenyl)benzonitrile (HDN). Electrochemical and quantum methodologies, along with UV–Vis, SEM, and EDX, were employed. The anticorrosion process was comprehensively investigated. Potentiodynamic polarization validated the mixed type nature of inhibitors by demonstrating a drop in the cathodic hydrogen evolution reaction and the anodic metal dissolution, resulting to a significant decrease in corrosion current densities. Enhanced rates of effectiveness are achieved with higher inhibitor doses. Electrochemical impedance spectroscopy investigations confirmed the formation of a protective layer at the metal/solution interface, demonstrating that charge transfer was the primary cause of mild steel corrosion. The inhibitory potencies of the studied inhibitors at 10−3 M were 94.65, 94.56, and 93.63% for MDN, DDN, and HDN, respectively. The presence of several attributes in the molecular skeleton, such as nitrogen heteroatoms, aromatic rings, and the ester substituent group (CO2CH3), enhanced the availability of non-bonded and π-electrons and created stable covalent bonds by donating electrons to the iron surface. The inhibitory efficiency was better than 89% across all temperature ranges, suggesting the potential benefits of inhibitors at elevated temperatures. Adsorption trials revealed high effectiveness in corrosion control on mild steel, with Langmuir-based physisorption and chemisorption. The impact of electronegative O and N atoms, along with aromatic rings, in forming protective coatings was demonstrated by quantum chemistry computations which linked molecular structure and charge density patterns to the inhibition potency of MDN, DDN, and HDN, highlighting MDN's strong adsorption capacity. [ABSTRACT FROM AUTHOR]

A novel cross-linked network structure of MnO2 nanotubes@Co3O4 polyhedron composite had been successfully prepared. Cobalt metal–organic framework (ZIF-67) in-situ grew on the open end of MnO2 nanotubes. Via a thermal treatment, MnO2@ZIF-67 was transformed into MnO2@Co3O4. When the Mn/Co molar ratio was 4:5, MnO2@Co3O4-45 showed excellent catalytic performance and water-resistance, which could obtain 100% HCHO conversion at 60 °C. The superior catalytic performance was mainly contributed to the strong synergistic interaction originated from the coupled interface between MnO2 and Co3O4. Moreover, the high percentage of Mn4+ and Co3+, plenty surface active oxygen species and well low-temperature reducibility played important roles for the enhancement of catalytic activity. DFT simulations showed that MnO2@Co3O4 exhibited the moderate adsorption capacity for HCHO, O2 and H2O, facilitating desorption of products and then continuing to the next catalytic reaction. Reaction pathways were also proposed under different atmosphere by in situ DRIFTS analysis. [ABSTRACT FROM AUTHOR]

We studied the impact of dopants Al, Ga and In atoms on the dacarbazine (DAC) drug delivery performance of a BC3 nanosheet (BCNS) using the density functionals τ-HCTHhyb, M06-2X and B3LYP. It was found that the pristine BCNS is not a good choice for this drug delivery. Doping of the Al, Ga and In atoms into the BCNS surface raised the energy of adsorption of DAC from −6.7 to −26.4, −27.8 and −32.1 kcal / mol, respectively. According to the analysis of the partial density of states, the dopant atoms considerably contributed to the generation of virtual orbitals of doped BCNS. This showed that the dopants are more suitable for nucleophilic attack than the B atoms. Finally, the adsorption performance and capacity of the DAC are increased by dopants, making the nanosheet more favourable for drug delivery. A drug release mechanism was introduced in cancerous tissues, showing substantial protonation of the DAC in cancerous cells with low pH, leading to the separation of DAC from the sheet surface. The reaction mechanism of DAC with the BCNS changed from covalent bonding in the natural environment to H-bonding in the acidic environment of the cancer tissues. [ABSTRACT FROM AUTHOR]

Storage capacity and differential molar enthalpy of adsorption (or isosteric heat of adsorption) are important parameters to understand the characteristic of heterogeneous materials and catalysts for chemical and energy industry applications. Langmuir isotherm and other single site, dual site, and multilayer isotherms are developed for the prediction of adsorption and enthalpy, with a main assumption of constant isosteric heat of adsorption. However, some experimental and simulation data showed some inconsistencies in terms of heat of adsorption. Exploiting molecular simulation, we provide a first principle estimate of gas hosting capacity and associated thermodynamic properties of nanopores as present in type IID kerogen. The adsorption capacity and enthalpy of adsorption of the organic matter was computed using the grand canonical ensemble combined with the fluctuation method. The data obtained were utilized to assess the predictive power of industry standard models such as the Langmuir isotherm and other single site, dual site, and multilayer isotherms with respect to adsorption and enthalpy. The obtained results suggest that the sorption and thermodynamic properties of kerogen nanostructures are best described by monolayer-multisite isotherms rather than multilayer models. In short, for an adsorption theory to be physically consistent, it should capture both adsorption and isosteric heat. [ABSTRACT FROM AUTHOR]

Although tin mining activities in the southern part of Thailand have been abandoned for more than 40 years, arsenic contamination in old tin-mining areas continues to pose a health risk. Fortunately, natural adsorption of arsenic by sediment has reduced the arsenic concentration in water to the maximum allowable level within a 10-kilometre radius of the mine sources. This article attempts to characterize the arsenic adsorption properties of sediment along a water creek which passes through the old tin-mine areas in Ron Phibun district, Nakhon Si Thammarat province, Thailand, where the contamination has been most severe. It was found that Fe tends to be associated with the adsorption capacity of arsenic in sediment. However, pH 4 and pH 7 did not associate with adsorption capacity. At pH 12, the solubility of arsenic increases, making it less likely to be adsorbed into the sediment and more likely to dissolve in water. For the adsorption isotherms of the sediment, the so-called '2-step Langmuir/Freundlich models', with the advance of switching functions (Logistic or Arctan functions), were proposed. Then, based on the principle of parsimony, a stepwise model reduction approach was used to choose the optimal models. It was found that the isotherms were used successfully to describe the historical arsenic-contamination data of the past 14 years (2005 - 2019) and to predict future trends qualitatively. [ABSTRACT FROM AUTHOR]

Adsorption is now recognized as an effective and economic method for wastewater treatment. Thus, in recent years, development of low cost adsorbent for dye loaded wastewater remediation has become an important area of research. Algerian phosphate was tested as an effective adsorbent for the removal of cationic dye methylene Blue (MB) as well as the anionic dye blue bezaktiv S-GLD 150 (BB) from synthetic wastewater. The phosphate was characterized by XRD, FT-IR, TGA, SEM, EDX and BET analysis. pHPZC analysis was performed to determine pH sensitive adsorptive removal of cationic and anionic dyes. Batch adsorption experiments of the dyes from aqueous solution were conducted, taking into account the influence of initial dye concentration (10–500 mg/L), adsorbent dosage (1–6 g/L), contact time (5–120 min) and solution pH ((2–12) ± 0.2). The experimental results show that, the adsorption was pH dependent with a high adsorption capacity of MB in basic range and high adsorption of BB in the acidic range. Experimental adsorption data were modeled by different equilibrium isotherms such as Langmuir, Freundlich, Redlich Peterson and Sips. The adsorption process fitted well to pseudo-second-order kinetics and the Langmuir model. The calculated maximum adsorbed quantity qmax of MB and BB were found 30.61 (mg/g) and 20.78 (mg/g) successively. The adsorption process was found to be exothermic in nature in the case of the MB and endothermic for BB. Accordingly; the phosphate has been shown to be a very efficient and low-cost adsorbent, and a promising alternative for eliminating dyes from industrial wastewater. [ABSTRACT FROM AUTHOR]

The difference in floatability between smithsonite and dolomite is small m the system with dodecyllamine as collector, and it Is difficult to separate by flotaiion. The effects of sodium tripolyphosphate,sodium pyrophosphate and sodium hmetaphosphate on the f1otation of smithsonite and dolomite were studied by single mineral f1otation experiment. The resuits show that when the dosage of soduum tripolyphosphate ss 30 mg/L,it has a strong nnhibitory effect on dolomite and a weaker inhibitory effect on smithsonite, achieving selective inhibition of dolomite. The actual ore test resuits show that using 600 g/t sodium tripolyphosphate as a dolomite inhibitor, znc concentrate with znc grade of 36. 49% and recovery of 75. 49% can be obtained by flotation separation, and the effective separation of smithsonite and dolomite can be reaiized. The inhibition mechanism of sodium tripolyphosphate on dolomite was dsscussed by Zeta potential test and adsorption capacity tes. The resuits show that sodium tripolyphosphate can signiiicanlly affect the adsorption of the collector dodecyllamine on the surface of dolomite,but has iittie effect on the adsorption of smithsonite, which increases the adsorption difference of the collector on the surface of smithsonite and dolomite,resuiting n the difference in the f1oatability between smithsonite and dolomite. [ABSTRACT FROM AUTHOR]

Based on the problem of nickel remove from ferrous sulphate solution with low nickel content, it was Investigated by on exchange process in this paper. Different factors, including resin tilting capacity, pH, time, initial nickel content and so on, were investigated to explore the performance of nickel remove from ferrous sulphate solution by designed experiments. The resutts indicate that priority se1ectivity for nickel ss presented in ferrous sulphate solution after resin adsorption and the operating capacity of CH-90 resin for nickel ss 15 mg/g. After resin adsorption,Fe/Ni molar ratio ss increased from 17 : 1 to 93 : 1 and removal rate on nickel reached 87%. Additiona11y,nickel content ss reduced to 0. 3 g/L. In other words,nickel ss removed effectually from ferrous sulphate solution. The adsorption isotherms and adsorption kinetics were evaluated by changing the initial content and adsorption reaction time. It was found that the resin was in tine with the Langmuir adsorption ssotherm,and met the quasi-second-order kinetic equation. Furthermore,adsorption process was mainly controlled by on exchange. [ABSTRACT FROM AUTHOR]

Porous carbon nanotubes can not only provide a large surface area for anchoring sulfur and restraining polysulfides, but also provide continuous conductive networks to facilitate ion transport in lithium-sulfur batteries (LSBs). In order to improve the performance of LSBs, surface-modified groups can be exploited to restrict the shuttle effect of polysulfides. Therefore, thin-walled porous carbon nanotubes with low cost and high yield were successfully prepared from polymer nanotubes. Sulfonic groups were modified on the walls of the thin-walled porous carbon nanotubes by reacting with concentrated sulfuric acid. The sulfonic group-modified thin-walled porous carbon nanotubes were utilized as a sulfur-deposited cathode matrix for LSBs, and the discharge capacity of 617.7 mA h g−1 is obtained after 100 cycles at 0.5 C, showing a good rate performance. Based on DFT calculation, sulfonic groups can enhance the binding energy between porous carbon nanotubes and sulfur, and strengthen the adsorption capacity of porous carbon nanotubes for polysulfides as well, which further proves the effectiveness of the system in optimizing the performance of LSBs. [ABSTRACT FROM AUTHOR]

In the present study, we report the synthesis, characterization and assessment of the carbon dioxide adsorption capacity of a composite made of boron nitride and carbon. The material is obtained through a two-step process. In the initial step, ammonia borane is introduced into the pores of a zeolitic imidazolate framework (ZIF-8) using a novel one-pot synthesis method. The ZIF-8 is formed in situ around the ammonia borane molecules, eliminating the need for an infiltration step. The successful confinement of ammonia borane within the ZIF-8 structure is verified through different characterization techniques (IR, XRD, TGA-DSC, and 11B MAS NMR). In the second step, ZIF-8 containing confined ammonia borane is pyrolyzed. Ammonia borane acts as a precursor of boron nitride and the process results in a composite comprising carbon, boron and nitrogen. The composite was subsequently characterized and evaluated as a potential adsorbent for carbon dioxide. With a specific surface area of 56 m2 g−1, the composite demonstrates a CO2 uptake of 1.94 mmol g−1 (or 85.4 mg g−1) when exposed to 1.5 bar of CO2 at 30 °C. This value surpasses reported capacities of other boron nitride-based materials as CO2 adsorbents. When comparing the CO2 adsorption capacity in terms of the specific surface area, a significant enhancement is observed (34 × 10−3 mmol m−2). This suggests that the material provides more active sites for CO2 adsorption, such as polarized B–C, B–N, and C–N bonds. This key factor may be even more important than having a large specific surface area. Therefore, the potential for developing new boron-based materials with enhanced CO2 adsorption capacities lies in increasing both specific surface area and active sites. [ABSTRACT FROM AUTHOR]

MOF-74 or M2(dhtp) (M = metal ions, dhtp = 2,5-dihydroxyterephthalic acid), as a typical class of metal–organic frameworks (MOF), have garnered considerable interest due to their abundant unsaturated metal sites. However, environmental and economic limitations caused by the extensive use of organic solvents in traditional syntheses hinder their industrial applications. Although water as a green solvent is considered to be the best candidate solvent, water-based MOFs often have poor crystallinity and long synthesis time, and controlling the particle size is difficult. Herein, a water-based strategy is proposed to synthesize high-quality MOF-74–Co with controllable particle sizes in a rotating packed bed (RPB) reactor using high-gravity technology. MOF-74–Co could be rapidly prepared in the RPB, and shows a smaller and more uniform particle size, higher crystallinity, and larger specific surface area, as compared to the counterpart prepared in a traditional stirred tank reactor. Further adopting acetic acid as a modulator, the as-prepared MOF-74–Co has the highest BET surface area (1599 m2 g−1) in the reported literature so far and simultaneously possesses a high space–time yield (293 kg m−3 day−1). High-quality MOF-74–Zn and MOF-74–Ni can also be prepared, proving the generality of this strategy. Furthermore, the small-sized MOF-74–Co-78 nm exhibits a faster adsorption rate and a larger saturation adsorption capacity (298 mg g−1) for CO2 compared with large-sized samples. This study not only advances the field of green synthesis of MOFs but also paves the way for efficient manufacturing processes in MOF-74 synthesis for CO2 adsorption. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption behavior of intrinsic black phosphorus (BP) and BP doped with five atoms of O, Si, S, Cu and Zn on Pb 2 + in aqueous solution was investigated by using the first principle of nature. The formation energy was calculated to be the smallest for Si-doped BP at 2.608 eV, indicating the best structural stability. The adsorption energy was calculated and showed that the doped BP is more capable of adsorbing Pb 2 + than the intrinsic BP, with the S-doped BP having the strongest adsorption capacity of 0.151 eV. The density of states was calculated and showed that the bandgaps of the doped BP are all smaller than the 1.3 eV of the intrinsic BP, indicating that the doping can improve electrical conductivity of the adsorption system. The charge transfer was calculated and showed that S doping, O doping, Cu doping and Zn doping enhanced the ionic bonding between BP surface atoms and Pb 2 + , while Si doping weakened the ionic bonding. The charge transfer of S doping was the largest at 1.371 e, indicating that S-doped BP had the strongest ability to adsorb Pb 2 + . [ABSTRACT FROM AUTHOR]

The surface characteristics of nanoparticles have a huge impact on adsorption effects. In this paper, thiol‐functional mesoporous silica nanospheres (MSNs−SH) are successfully prepared through simple one‐step hydrolysis and co‐condensation of tetraethyl orthosilicate and (3‐mercaptopropyl) triethoxysilane with hexadecyltrimethylammonium bromide and sulfobetaine 12 as dual‐template. The obtained MSNs−SH have high surface area (1260 m2 g−1), accessible mesopores (2.2 nm), great pore volume (1.7 cm3 g−1), and uniform adjustable diameter (90 nm). Furthermore, the diameter and pore‐size of MSNs−SH can be controlled via adjusting the ethanol content in the synthesis system. MSNs−SH exhibit a fast adsorption kinetics, marked adsorption capacity of cationic rhodamine B (RB 534.2 mg g−1), and remarkable selective adsorption for cationic dyes. Theoretical analysis reveals the adsorption behavior of RB on MSNs−SH follows the Langmuir isotherm models and pseudo‐second‐order kinetic. Additionally, the thermodynamic results indicate that the adsorption process is a spontaneous process driven by temperature. The results demonstrate that MSNs−SH are greatly potential for effectively removing cationic dyes from wastewater, with the advantages of simple preparation, high adsorption performance and perfect selectivity. [ABSTRACT FROM AUTHOR]

[Display omitted] Metal-organic frameworks (MOFs) have been widely studied for Cr(VI) adsorption in water. Theoretically, numerous MOFs can be synthesised by assembling diverse metals and ligands. However, the traditional manual experimentation for screening high-performance MOFs is resource-intensive and inefficient. A screening strategy for MOFs based on machine learning was proposed for the adsorption and removal of Cr(VI) from water. By collecting the characteristics of MOFs and the experimental parameters of Cr(VI) adsorption from the literature, a dataset was constructed to predict the adsorption performance. Among the six regression models, the model trained by the extreme gradient boosted tree algorithm had the best performance and was used to simulate the adsorption and screen potential high-performance adsorbents. Structure-property analysis indicated that prepared MOF adsorbents with properties of 0.37 < largest cavity diameter < 0.71 nm, 0.18 < pore volume < 0.57 cm3/g, 412 < specific surface area < 1588 m2/g, 0.43 < void fraction < 0.62 will achieve enhanced adsorption of Cr(VI) in water. High-performance adsorbents were successfully screened using a combination of machine-learning prediction and analysis. Experiments were conducted to verify the exceptional adsorption capacity of UiO-66 and MOF-801. This method effectively identified adsorbents and accelerated the development of new MOF adsorbents for contaminant removal, providing a novel approach for the discovery of superior adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] The utilization of Na 2 MnSiO 4 as a Faraday electrode in hybrid capacitive deionization (HCDI) is investigated to achieve efficient desalination. The Na 2 MnSiO 4 /C (NMSO) materials were fabricated via a simple sol–gel method, in which the synthesis process was modulated by adjusting the volume ratio of ethanol to water. When maintaining the volume ratio of water to ethanol at 3:1, the resultant NMSO-3/1 exhibited expected salt adsorption capacity of 31.06 mg g−1 and salt adsorption rate of 20.43 mg g−1 min−1. This distinguished desalination performance was mainly attributed to its inherent multiple redox pairs, as well as the integration of ethanol, which enhanced both specific capacitance and hydrophilicity of the material. This study opens a new perspective for the development of highly efficient materials in HCDI. [ABSTRACT FROM AUTHOR]