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Saturated packing is a random packing state of particles widely applied in investigating the physicochemical properties of granular materials. Optimizing particle shape to maximize packing density is a crucial challenge in saturated packing research. The known optimal three-dimensional shape is an ellipsoid with a saturated packing density of 0.437 72(51). In this work, we generate saturated packings of three-dimensional asymmetric shapes, including spherocylinders, cones, and tetrahedra, via the random sequential adsorption algorithm and investigate their packing properties. Results show that the optimal shape of asymmetric spherocylinders gives the maximum density of 0.4338(9), while cones achieve a higher value of 0.4398(10). Interestingly, tetrahedra exhibit two distinct optimal shapes with significantly high densities of 0.4789(19) and 0.4769(18), which surpass all previous results in saturated packing. The study of adsorption kinetics reveals that the two optimal shapes of tetrahedra demonstrate notably higher degrees of freedom and faster growth rates of the particle number. The analysis of packing structures via the density pair-correlation function shows that the two optimal shapes of tetrahedra possess faster transitions from local to global packing densities. [ABSTRACT FROM AUTHOR]

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]

Nanomaterials have excellent adsorption performance due to nano-effect and have been widely used in many fields. The adsorption performance of nanomaterials depends on their adsorption thermodynamics and kinetics. Here, the thermodynamic and kinetic equations of adsorption for spherical nanoparticles are first derived in theory. The mechanisms and regularities of influences of nano-effect on thermodynamics and kinetics, using nano-CdS adsorption of methylene blue as a probe, were investigated. The results show that there are significant influences of nano-effect (i.e., interface area effect and interface tension effect) on the thermodynamics and kinetics of nanoparticle adsorption. When the particle radius is larger and beyond the nanometer scale (∼100 nm), the nano-effect can be neglected. When the radius of the nanoparticle is within 10–50 nm, the nano-effect of adsorption is mainly the interface area effect. When the radius is less than 10 nm, the influences of both the interface area effect and the interface tension effect on adsorption thermodynamics and kinetics become more significant. The theoretic equations and experimental insights in the present work could provide a significant basis and reference for improving and perfecting the adsorption theory involving nanomaterials and provide guidelines for the explanations of adsorption mechanisms as well as the selection of adsorbents. [ABSTRACT FROM AUTHOR]

[Display omitted] • ETTA-DFP@TCBP-HOF in situ one-spot preparation of ETTA-DFP COF to TCBP-HOF. • ETTA-DFP@TCBP-HOF for both monitoring and adsorbing 4-nitrophenol (4-NP) and metamitron (MET) • ETTA-DFP@TCBP-HOF with dual-emission for sensing 4-NP and MET with different response modes. • ETTA-DFP@TCBP-HOF with desirable specific surface area for efficient removal of 4-NP and MET. A multifunctional COF@HOF (ETTA-DFP@TCBP-HOF) composite is prepared by adding red-fluorescent ETTA-DFP COF to the blue-fluorescent TCBP-HOF preparation system through molecular hydrogen bonding or π − π stacking interactions in situ one-pot synthesis. ETTA-DFP@TCBP-HOF is a multifunctional material for the quantitative detection and simultaneous adsorption of 4-nitrophenol (4-NP) and metamitron (MET) in aqueous solution. As a dual-emission fluorescent sensor, the ETTA-DFP@TCBP-HOF has both fluorescence of TCBP-HOF at 474 nm and ETTA-DFP COF at 592 nm, which shows a ratiometric response to 4-NP and MET with high selectivity, good sensitivity, good anti-interference performance and fast response. As a adsorbent, ETTA-DFP@TCBP-HOF displays rapid adsorption kinetics, and acceptable adsorption capacity for 4-NP and MET. In conclusion, this work constructs a novel multifunctional hybrid material with dual-emission center of HOF and COF, which can not only be used as a ratiometric fluorescent probe for detection, but also for removal of hazardous pollutants, suggesting a new strategy for environmental remediation and human health. [ABSTRACT FROM AUTHOR]

This study investigates silver adsorption on biochar produced from pyrolysis of spent coffee grounds (SCGs). Biochars were produced from SCGs at temperatures between 500 and 1000 °C. SCG-derived biochars were then characterised by different analytical methods, such as Brunauer-Emmet-Teller (BET), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and investigated for silver removal. The results revealed that the biochar produced at 500 °C offered a maximum surface area of 40.1 m2/g with a yield of 23.48% biochar and the highest silver adsorption capacity of 49.0 mg/g with 99.9% silver removal efficiency. The morphology of adsorbed silver on biochar was determined using scanning electron microscopy–energy-dispersive spectrometry (SEM–EDS), and XRD analyses, which showed an even distribution of silver on the biochar surface. Furthermore, X-ray photoelectron spectroscopy (XPS) confirmed that part of the silver ions was reduced to form metallic silver (Ag0)/silver nanoparticles (Ag NPs) during adsorption. The kinetics and isothermal evaluation suggested that silver adsorption was dominated by the pseudo-second-order model and Langmuir isotherm, which means that silver adsorption was mainly dominated by chemisorption and monolayer on biochar surface. Overall, this study suggests that 500 °C was the most feasible pyrolysis temperature to produce SCG-derived biochar with suitable physicochemical properties that can efficiently adsorb silver species from wastewater. [ABSTRACT FROM AUTHOR]

This study focuses on the development of eco-friendly biobased adsorbents through a sustainable hydrothermal and freeze-drying synthesis process, utilizing cost-effective bio-sourced materials to minimize energy consumption and waste. The biobased adsorbents were elaborated using hydroxyethyl cellulose-ionic liquids and bentonite clay. The elaborated biocomposites were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy/attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA), and electron microscopy-energy dispersive X-ray (SEM–EDX), Brunauer–Emmett–Teller (BET) and zeta potential (ZP). Structural analysis confirms the intercalation and incorporation of HEC-ILs polymeric chains into Be-Na matrix and the formation of biocomposites. The [HEC-ILs/Be-Na] composite was subsequently employed for solid-phase extraction of Co(II) by investigating the effect of pH, initial Co(II) concentrations, time, temperature, and the presence of co-existing ions (Na(I), Li(I), Mn(II), Ni(II), and Al(III)). The adsorption kinetics of Co(II) metal ions were suitably characterized using the pseudo-second-order model (with R2 > 0.99). Furthermore, the adsorption isotherms conformed to the Langmuir model (with R2 > 0.97), suggesting a chemisorption process with an adsorption capacity of 69.8 mg/g. The thermodynamic study reveals that the adsorption process exhibits characteristics of spontaneity and endothermicity (ΔH° = 74.197 kJ mol−1, ΔG° < 0 kJ mol−1). The proposed mechanism for Co(II) adsorption on the developed biocomposite involves electrostatic interactions, ion exchange, and anion-π interactions. The biobased composite exhibited remarkable selectivity for Co(II) and demonstrated great potential as an adsorbent for industrial applications. [ABSTRACT FROM AUTHOR]

Adsorption-based atmospheric water harvesting (AWH) has the potential to address water scarcity in arid regions. However, developing adsorbents that effectively capture water at a low relative humidity (RH < 30%) and release it with minimal energy consumption remains a challenge. Herein, we report a fluorophenyl oligomer (FO)-incorporated metal-organic framework (MOF), HKUST-1 (FO@HK), which exhibits fast adsorption kinetics at low RH levels and facile desorption by sunlight. The incorporated fluorophenyl undergoes vapor-phase polymerization at the metal center to generate fluorophenyl oligomers that enhance the hydrolytic stability of FO@HK while preserving its characteristic water sorption behavior. The FO@HK exhibited vapor sorption rates of 8.04 and 11.76 L kg−1MOF h−1 at 20 and 30% RH, respectively, which are better than the state-of-the-art AWH sorbents. Outdoor tests using a solar-driven large-scale AWH device demonstrate that the sorbent can harvest 264.8 mL of water at a rate of 2.62 L kg−1MOF per day. This study provides a ubiquitous strategy for transforming water-sensitive MOFs into AWH sorbents. In arid regions, effective atmospheric water harvesting (AWH) is essential. The fluorophenyl oligomer (FO)-incorporated HKUST-1 (FO@HK) shows impressive performance. F3@HK achieves up to 11.76 L kg−1MOF h−1 at 30% RH and can harvest 2.62 L kg−1MOF of water daily with solar energy. [ABSTRACT FROM AUTHOR]

The rising presence of drug-related contaminants in water sources is a major environmental and public health concern. Several studies have addressed the hazardous influence of these pollutants on the lives of over 400 million people worldwide. In this study, we used molecular dynamics simulations to evaluate the efficacy of two promising composite materials for the removal of pharmaceutical contaminants by using the adsorption technique. Graphitic carbon nitride/graphene (g-C3N4/graphene) and metal-organic framework (MIL-101(Fe))/graphene have been simulated for the first time for the removal of three of the most common pollutants (acetaminophen (AC), caffeine (CAF), and sulfamethoxazole (SMZ)). The nanocomposite structure has been created and optimized using the geometry optimization task in the DFTB Modules in the Amsterdam Modeling Suite. We summarized the condition of the essential parameters (Temperature, pressure, and density) of the simulation box during the MD-simulation to ensure the accuracy of our MD-simulation results. The adsorption process, van der Waals interactions, and the adsorption capacity have been calculated by using the Reactive Forcefield (ReaxFF) software. We found that the combination of MIL-101(Fe)/graphene had a higher adsorption capacity for the removal of pharmaceutical contaminants than g-C3N4/graphene. At 40 Picosecond (Ps), 80 molecules of each pharmaceutical contaminants (AC, CAF and SMZ) have been adsorbed by MIL-101(Fe)/graphene with higher exothermic energy equated to (−1174, −1630, and − 2347) MJ/mol respectively. While for g-C3N4/graphene at 40 Ps, 70 molecules of each pharmaceutical contaminants have been adsorbed with exothermic energy equated to (−924, −966, and − 1268) MJ/mol respectively. Also, our results showed that the combination of g-C₃N₄/graphene and MIL-101(Fe)/graphene both have remarkable properties that make them effective at resisting surface clogging. Finally, the results showed that the adsorption kinetics followed a pseudo-first order model, while the adsorption isotherms for AC, CAF and SMZ adhered to Freundlich model. [ABSTRACT FROM AUTHOR]

This work investigates the efficiency of green-synthesized WO3 nanoflakes for the removal of methylene blue dye. The synthesis of WO3 nanoflakes using Hyphaene thebaica fruit extract results in a material with a specific surface area of 13 m2/g and an average pore size of 19.3 nm. A combined theoretical and experimental study exhibits a complete understanding of the MB adsorption mechanism onto WO3 nanoflakes. Adsorption studies revealed a maximum methylene blue adsorption capacity of 78.14 mg/g. The pseudo-second-order model was the best to describe the adsorption kinetics with a correlation coefficient (R2) of 0.99, suggesting chemisorption. The intra-particle diffusion study supported a two-stage process involving surface adsorption and intra-particle diffusion. Molecular dynamic simulations confirmes the electrostatic attraction mechanism between MB and the (002) WO3 surface, with the most favorable adsorption energy calculated as -0.68 eV. The electrokinetic study confirmed that the WO3 nanoflakes have a strongly negative zeta potential of -31.5 mV and a uniform particle size of around 510 nm. The analysis of adsorption isotherms exhibits a complex adsorption mechanism between WO3 and MB, involving both electrostatic attraction and physical adsorption. The WO3 nanoflakes maintained 90% of their adsorption efficiency after five cycles, according to the reusability tests. [ABSTRACT FROM AUTHOR]

N-(1,3-Dimethylbutyl)-N′-phenyl-1,4-benzenediamine (6PPD) is a common additive in tires. 6PPD protects rubber from oxidative damage by ozone. Leaching of 6PPD in the environment leads to the formation of harmful byproducts such as 6PPD quinone. In this work we provide the fundamental basis for the detection of 6PPD by electrochemical techniques. We use cyclic voltammetry to study the adsorption of 6PPD on glassy carbon. We show that adsorbed 6PPD can be reversibly oxidized and reduced without disturbing the adsorption process. This result enables repeated electrochemical titrations. We determine, in neutral condition at 22 °C, an adsorption constant of Kads = 1.2 ± 0.5 μM−1 and kinetics of adsorption kads∈[0.74–5.60] × 104 L mol−1 s−1. Based on this knowledge we demonstrate the lowest concentration of 6PPD ever detected electrochemically, 10 nM. We also identify current challenges for electrochemical sensing of 6PPD. Multiple layers are formed at concentrations above 4.6 μM and the slow kinetics of adsorption requires long (hour) measurement time to reach maximum sensitivity. [ABSTRACT FROM AUTHOR]

A formulated photocurable poly(ethylene glycol) diacrylate (PEGDA) and 2‐hydroxylethyl methacrylate (HEMA) polymer matrix (PEGDA:HEMA) was developed for constructing an adsorptive 3D cubic monolith using masked stereolithography (MSLA) 3D‐printing technique. A pure PEGDA formulation served as a control in comparative studies. Additionally, two structural designs (solid cube and cubic lattice) were also quantitatively compared to determine the adsorption performance for Rhodamine B (RhB) dye removal. Results indicated that the cubic lattice formulated with hydrophilic PEGDA:HEMA (θ~47.20°) was more effective at removing RhB dye. Additionally, the preliminary study identified pH 9 as the optimal level for RhB dye removal using 3D cubic monolith for both formulations. A Taguchi orthogonal array of L9 (33) was used to concurrently vary three parameters: adsorbent dosage (0.65 ± 0.02 g per cubic lattice), operating temperature (30°C, 40°C, and 50°C), and initial RhB concentration (20, 60, and 100 ppm). The highest mean of the signal‐to‐noise (S/N) ratio was chosen to obtain the highest adsorption performance. The removal efficiency (R%) of RhB dye ranged from 44.48% to 94.86%, and the adsorption capacity (K) ranged from 0.59 to 3.73 (mg/g) after 5 h. Seven adsorption isotherms and five adsorption kinetics modelling were performed. Adsorption isotherm data fitted well with the Redlich–Peterson model for both linear (R2 = 0.998) and nonlinear (R2 = 1). Besides that, the pseudo‐second‐order model (PSO) accurately described adsorption kinetics (R2 = 0.995). The separation factor (RL) confirmed favourable adsorption (0 < RL < 1). Thermodynamic parameters indicated that the adsorption process was endothermic and at higher temperatures, entropy increased. Also, the 3D–printed PEGDA:HEMA cubic lattice exhibited good mechanical stability. Furthermore, the 3D PEGA: HEMA lattice has the ability to be used in several adsorption cycles of degrading RhB dye. Ultimately, the present work demonstrates the viability of 3D printing photocurable PEGDA:HEMA resin and utilizes statistical tools to optimize process parameters, enhancing predictability for wastewater management. [ABSTRACT FROM AUTHOR]

The application of a synthesized carbon xerogel (RFX) for the adsorptive removal from water of ciprofloxacin (CPX), a widely used fluoroquinolones-group antibiotic for humans and animals, has been reported in this work. The carbon xerogel was characterized by N2 adsorption–desorption isotherms, FTIR, Raman spectroscopy, TPD studies, elemental analysis, determination of isoelectric point (pHIEP) and scanning electron microscopy (SEM). CPX adsorption experiments were conducted in batch mode, using results obtained with F400 commercial activated carbon for comparison purposes. CPX adsorption kinetics were well-described by the pseudo-second-order model for both adsorbents and by the Elovich model in the case of F400 activated carbon. Therefore, CPX equilibrium adsorption capacity values were of 457 and 72 mg g−1 for RFX xerogel and F400 activated carbon, respectively. This significant difference can be attributed to the higher specific surface area and micropores volume values of F400 carbon; in this sense, this material led to a slower CPX kinetic adsorption. Also, the Dual-site Langmuir model best-described the experimental CPX adsorption isotherms in both cases. By the adsorption studies at different solution pH, it could be concluded that several mechanisms, e.g., hydrophobic and π-π interactions, and electrostatic forces highly influenced CPX adsorption capacity. Furthermore, adsorption tests using several environmentally relevant aqueous matrices have been accomplished. In this case, a competitive effect between the natural organic matter (NOM) and the target pollutant occurred in all the tested real matrices, decreasing CPX adsorption capacity, especially remarkable for F400 activated carbon. Finally, Density Functional Theory (DFT) has been used to elucidate the interactions between CPX and adsorbents, finding a high relevance of the π-π electron donor–acceptor interactions in which CPX acts as an acceptor. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are promising high‐performance capacitive deionization (CDI) materials. Strategies to optimize CDI performance of COFs focus largely on hybridization with conductive substrates, to improve their their intrinsically poor conductivity. A new structure‐function relationship between COFs and their substrates is proposed here based on substrate‐induced surface curvature. Graphene (zero‐curvature) and carbon nanotubes (CNT, curved) are selected as COF growthsubstrates to assess the effect of curvature engineering effect on CDI performance of TpPa‐SO3H‐COF. Ultrahigh ion (Na+) adsorption capacity (58.74 mg g−1) is achieved by CNT‐COF hybrid (cf. compared to graphene‐COF hybrid 34.20 mg g−1), demonstrating the significance of curvature engineering. Notably, the corresponding salt (NaCl) adsorption capacity of CNT‐COF hybrid reaches 149.25 mg g−1 in 1000 ppm at 1.2 V, representing state‐of‐the‐art CDI performance, and the highest value among organic CDI electrodes. X‐ray photoelectron spectroscopy and theoretical calculations subsequently reveal that substrate curvature can induce local strain, which regulates charge distribution within the COF skeleton, causing a lower binding energy state for Na+ adsorption. Electrochemical quartz crystal microbalance measurements revealed faster Na+ adsorption kinetics of CNT‐COF due to regulated charge distribution within COF skeleton induced by substrate curvature. This work gives new insight into design of COF materials based on curvature engineering. [ABSTRACT FROM AUTHOR]

Dye wastewater is becoming one of the most significant sources of water pollution, and its impact on human survival is immeasurable. In this study, we successfully synthesized a nanofiber membrane with environmentally friendly and efficient properties using electrospinning of a mixture of sodium alginate (SA) and copper oxide (CuO) nanoparticles, aimed at effective dye removal. The adsorption performance of the SA/CuO nanofiber membrane was evaluated using the cationic dye methylene blue (MB). The maximum adsorption capacity of the nanofiber membrane was increased significantly with the addition of CuO nanoparticles, reaching a maximum value of 1633.4 mg g−1, almost twice as much as that of pure SA membrane. The adsorption kinetics follows the pseudo‐second‐order model, where chemisorption acts as the rate‐limiting step. The adsorption isotherm data indicate that the adsorption is monolayer. The nanofibrous membranes showed better dye removal under an alkaline environment. After four cycles of adsorption/desorption, the MB removal efficiency remained at 70.1% of the original adsorption capacity. The addition of CuO nanoparticles facilitated the adsorption of MB dyes, while the form of the nanofibrous membrane is easily recoverable and reusable. Therefore, the as‐prepared SA/CuO nanofibrous composite membrane is a potentially favorable adsorbent material for wastewater treatment applications. [ABSTRACT FROM AUTHOR]

That long-term consumption of water with arsenic concentrations greater than 10 μg L−1 induces renal, hepatic, and cardiovascular diseases, in addition, the effective adsorbents for removing arsenic are limited by their harsh synthesis conditions, slow adsorption kinetics, low adsorption capacities and hard solid-liquid separation. Herein, a hierarchical cauliflower-like γ -Fe 2 O 3 /H- γ -AlOOH magnetic composites for the treatment of As(V)-contaminated wastewater is firstly proposed to avoid the complex centrifugation and filtration process, and achieve the purpose of simplifying operation. A series of physicochemical characterization tools reveal the successful synthesis of hierarchical cauliflower-like γ -Fe 2 O 3 /H- γ -AlOOH magnetic composite adsorbent with a large specific surface area (S BET) of 131.82 m2 g 1, high Zeta potential of +17.22 mV, and magnetic saturation (Ms) of 26.1 emu g−1, which synergistically improves the adsorption performance and achieve the purpose of simplifying operation. The related adsorption experimental data demonstrates that the saturated adsorption capacity for As(V) reaches 130.17 mg g−1 and decreases by only 17.6 % after six adsorption-desorption experiments, and the whole adsorption process conforms to Pseudo-second order model and the Langmuir model, which proves it is more inclined to be monolayer adsorption and there is no chemical reaction between As(V) and adsorbent. In addition, the adsorption of As(V) onto the cauliflower-like γ -Fe 2 O 3 /H- γ -AlOOH magnetic composites is assigned to a spontaneous, endothermic and entropy increased process. The main adsorption mechanism is that, combined with X-ray photoelectron spectroscopy (XPS) analysis, all components of the composite are involved in the adsorption of As(V), with the predominance of metal hydroxyl groups. The synthetic route of a novel and highly effective adsorbent, the hierarchical cauliflower-like γ -Fe 2 O 3 /H- γ -AlOOH magnetic composite material, provides a more promising alternative candidate for the As(V) treatment, from the perspective of aquatic ecosystem protection and solid-liquid separation. The synthetic route of a novel and highly effective adsorbent, the hierarchical cauliflower-like γ -Fe 2 O 3 /H- γ -AlOOH magnetic composite material, provides a more promising alternative candidate for the As(V) treatment, from the perspective of aquatic ecosystem protection and solid-liquid separation. [Display omitted] [ABSTRACT FROM AUTHOR]

Metal–organic frameworks (MOFs) have great potential for the adsorption of minor molecular alcohols in the vapor phase. However, the drawbacks of powdered MOFs, including low recyclability and problematic separation, limit their application in fermented wine. Chitosan (CS) is a low‐cost, eco‐friendly, moldable matrix used in the food industry. In this study, a novel CS@ZIF‐8 adsorbent with excellent microporous surface area was successfully synthesized by incorporating hydrophobic ZIF‐8 into CS. The results showed that CS@ZIF‐8 beads had a high adsorption affinity for methanol at a Zn2+/2‐methylimidazole molar ratio of 1:5. The adsorption mechanism of methanol on CS@ZIF‐8 beads was systematically studied by X‐ray photoelectron spectroscopy, isotherms, and kinetics. The Langmuir model calculated the maximum adsorption of methanol to 56.8 mg/g. Adsorption kinetics are consistent with pseudo‐second‐order models. Furthermore, CS@ZIF‐8 beads presented excellent recyclability for removing methanol for five consecutive cycles. It could treat 60 bed volumes of Chinese yellow wine in column filtration experiments to make the concentration below 50 mg/L. In summary, the highly efficient CS@ZIF‐8 adsorbent has great potential for methanol adsorption from fermented wines. Practical Application: Methanol will exhibit adverse symptoms such as weakness and headaches after it is ingested. Therefore, methanol control is an important safety factor in the production of fermented wine. The adsorption method is recognized as a widely used technique due to its high efficiency and selectivity. The CS@ZIF‐8 adsorbent synthesized in this paper provides a new idea for methanol removal. [ABSTRACT FROM AUTHOR]

Ball milling is a feasible and promising method of biochar modification that can significantly increase its adsorption ability to methylene blue (MB). This study synthesized nine biochars derived from water hyacinth under different pyrolysis temperatures and modified with ball milling and Fe3O4. The structural properties of the pristine and ball-milled magnetic biochars were investigated and employed to adsorb MB. The results showed that ball milling significantly enhanced the specific surface area, total pore volume, and C-, N-, and O-containing groups of biochars, especially in low-temperature pyrolysis biochars. The Langmuir isotherm and the pseudo-secondary kinetic model fitted well with the MB adsorption process on biochars. After ball-milled magnetic modification, the adsorption capacity of biochar at 350 °C for MB was increased to 244.6 mg g−1 (8-fold increase), owing to an increase in accessible functional groups. MB removal efficiencies by low-temperature pyrolysis biochars were easily affected by pH, whereas high-temperature pyrolysis biochars could effectively remove MB in a wide pH range. WQM1, with the high adsorption capacity and stability, provided the potential to serve as an adsorbent for MB removal. Based on DFT calculations, the chemisorption and electrostatic interactions were the primary mechanism for enhancing MB removal with ball-milled magnetic biochar at low-temperature pyrolysis, followed by H-bonding, π–π interaction, hydrophobic interaction, and pore filling. [ABSTRACT FROM AUTHOR]

A modified loess/chitosan composite (ML@CS) was prepared via solution. The microstructure and physicochemical properties of ML@CS were characterised via scanning electron microscope (SEM), Zeta potential, X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR), and thermogravimetric analysis (TGA). An aqueous solution of methyl orange (MO) was used as simulated wastewater from which the influence of the initial concentration and pH of MO, the dosage amount and regeneration performance of ML@CS, adsorption temperature, and time on the adsorption effect of MO were systematically investigated. The adsorption kinetics, isothermal adsorption, and adsorption mechanism were also analysed. The results indicate that ML@CS had a good adsorption effect on MO. When the initial concentration of MO was 200 mg/L, pH was 5.0, and ML@CS dosage was 1.0 g/L, the adsorption equilibrium could be reached within 180 min at room temperature, and the equilibrium adsorption capacity and removal rate reached 199.52 mg/g and 99.75%, respectively. After five adsorption–desorption cycles, the MO removal rate remained above 82%. The adsorption behaviour of ML@CS for MO conforms to the pseudo–second–order kinetic model and the Langmuir isotherm adsorption model. The spontaneous exothermic process was mainly controlled by monolayer chemical adsorption and the physical adsorption only played an auxiliary role. ML@CS efficiently adsorbed MO in water and can be used as a high-efficiency, low-cost adsorbent for printing and dyeing wastewater treatment. [ABSTRACT FROM AUTHOR]

Ensuring clean water sources is pivotal for sustainable development and the well-being of communities worldwide. This study represents a pioneering effort in water purification, exploring an innovative approach utilizing modified reduced graphene oxide (rGO) aerogels. These advanced materials promise to revolutionize environmental remediation efforts, specifically removing organic contaminants from aqueous solutions. The study investigates the exceptional adsorption properties of rGO-aerogel, enhanced with cysteamine, to understand its efficacy in addressing water pollution challenges. The characterization methods utilized encompass various analytical techniques, including FE-SEM, BET, FTIR, TGA, DSC, XPS, NMR, and elemental analysis. These analyses provide valuable insights into the material's structural modifications and surface chemistry. The research comprehensively explores the intricacies of adsorption kinetics, equilibrium, and isothermal study to unravel the underlying mechanisms governing contaminant removal. MO and Ni2+ exhibited adsorption of 542.6 and 150.6 mg g−1, respectively, at 25 °C. Ni2+ has unveiled the highest removal at pH 5, and MO has shown high removal in a wide pH range (pH 4–7). Both contaminants have shown fast adsorption kinetic performance on an rGO-aerogel surface. This study aims to identify the synergistic effect of cysteamine and rGO in aerogel formation to remove heavy metals and organic contaminants. These findings mark a significant stride in advancing sustainable water-treatment methods and pioneering in synthesizing innovative materials with versatile applications in environmental contexts, offering a potential solution to the global water pollution crisis. [ABSTRACT FROM AUTHOR]

The removal and detection of highly toxic mercury(II) ions (Hg2+) in water used daily is essential for human health and monitoring environmental pollution. Efficient porous organic polymers (POPs) can provide a strong adsorption capacity toward heavy metal ions, although the complex synthetic process and inconvenient phase separation steps limit their application. Hence, a combination of POPs and magnetic nanomaterials was proposed and a new magnetic porous organic polymer adsorbent was fabricated by a green and mild redox reaction in the aqueous phase with trithiocyanuric acid (TA) and its sodium salts acting as reductive monomers and iodine acting as an oxidant. In the preparation steps, no additional harmful organic solvent is required and the byproducts of sodium iodine are generally considered to be non-toxic. The resulting magnetic poly(trithiocyanuric acid) polymers (MPTAPs) are highly porous, have large surface areas, are rich in sulfhydryl groups and show easy magnetic separation ability. The experimental results show that MPTAPs exhibit good adsorption affinity toward Hg2+ with high selectivity, rapid adsorption kinetics (10 min), a large adsorption capacity (211 mg g−1) and wide adsorption applicability under various pH environments (pH 2~8). Additionally, MPTAPs can be reused for up to 10 cycles, and the magnetic separation step of MPTAPs is fast and convenient, reducing energy consumption compared to centrifugation and filtration steps required for non-magnetic adsorbents. These results demonstrate the promising capability of MPTAPs as superior adsorbents for effective adsorption and separation of Hg2+. Based on this, the prepared MPTAPs were adopted as magnetic solid-phase extraction (MSPE) materials for isolation of trace Hg2+ from aqueous samples. Under optimized conditions, the extraction and quantification of trace Hg2+ in water samples were accomplished using inductively coupled plasma mass spectrometry (ICP-MS) detection after MSPE procedures. The proposed MPTAPs-based MSPE-ICP-MS method is efficient, rapid, sensitive and selective for the determination of trace Hg2+, and was successfully employed for the accurate analysis of trace Hg2+ in tap water, wastewater, lake water and river water samples. [ABSTRACT FROM AUTHOR]

Water pollution is caused by heavy metals, minerals, and dyes. It has become a global environmental problem. There are numerous methods for removing different types of pollutants from wastewater. Adsorption is viewed as the most promising and financially viable option. Nanostructured materials are used as effective materials for adsorption techniques to extract metal ions from wastewater. Many types of nanomaterials, such as zero-valent metals, metal oxides, carbon nanomaterials, and magnetic nanocomposites, are used as adsorbents. Magnetic nanocomposites as adsorbents have magnetic properties and abundant active functional groups, and unique nanomaterials endow them with better properties than nonmagnetic materials (classic adsorbents). Nonmagnetic materials (classic adsorbents) typically have limitations such as limited adsorption capacity, adsorbent recovery, poor selective adsorption, and secondary treatment. Magnetic nanocomposites are easy to recover, have strong selectivity and high adsorption capacity, are safe and economical, and have always been a hotspot for research. A large amount of data has been collected in this review, which is based on an extensive study of the synthesis, characterization, and adsorption capacity for the elimination of ions from wastewater and their separation from water. The effects of several experimental parameters on metal ion removal, including contact duration, temperature, adsorbent dose, pH, starting ion concentration, and ionic strength, have also been investigated. In addition, a variety of illustrations are used to describe the various adsorption kinetics and adsorption isotherm models, providing insight into the adsorption process. [ABSTRACT FROM AUTHOR]

The present study investigated the capability of cassava peel (Manihot Esculenta Crantz) in Pb(II) and Cr(VI) removal. The comparative study was conducted using batch method observing some parameters. The results indicated that the optimum adsorption of Pb(II) occurred at pH 5, initial concentration of 1000 mg/L, and contact time of 50 min. On the other hand, the optimal adsorption of Cr(VI) was achieved at pH 2, initial concentration of 1200 mg/L, and contact time of 70 min. The adsorption isotherms of both metals tended to follow the Langmuir model, while the adsorption kinetics suited to pseudo-second-order model. Thermodynamic parameters indicated that the adsorption process was spontaneous (ΔG° negative), endothermic (ΔH° positive), and exhibited surface dispersion on the biosorbent (ΔS° positive). Characterization using Fourier Transform Infrared (FTIR), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Thermogravimetry (TGA) provided evidence of both physical and chemical adsorption. The adsorption capacity of cassava peel was also tested on samples collected approximately 30 m from the bay shoreline, resulting in a removal percentage of 94.67% for Pb(II) and 82.28% for Cr(VI) under optimal pH and contact time conditions. [ABSTRACT FROM AUTHOR]

Metal phosphides exhibit high energy densities as hosts for lithium/sodium storage owing to their conversion reaction mechanism. Nevertheless, they typically suffer from inferior reversibility and cyclability because of the dissolution of polyphosphides and sluggish electrochemical kinetics. Herein, a series of dual‐bond confined MXene‐MxPy‐G composites have been fabricated, in which MxPy nanoparticles are strongly bound with MXene and graphene nanosheets via Ti─P and C‐P bonds. On one hand, the dual‐bond confinement offers strong adsorption to trap polyphosphides, greatly stabilizing the conversion‐formed products during cycling. On the other hand, dual‐bond immobilization largely promotes electron transfer and ion diffusion, facilitating the reversibility of conversion reactions. As anticipated, these MXene‐MxPy‐G hybrids demonstrate superb lithium/sodium‐storage performance. Particularly, as an anode for lithium‐ion batteries, the MXene‐Sn4P3‐G delivers a high initial coulombic efficiency of 90.1% and a high reversible capacity of 1058.6 mAh g−1 at 0.2 A g−1. Even tested at high rates of 1.0/2.0 A g−1, it can still maintain high reversible capacities of 820.6/726.5 mAh g−1 after 1450 cycles. When applied in pouch full‐cells and sodium‐ion batteries, it also shows extended cyclic lifespans of 350 and 1200 cycles. This work provides new insights to improve the reversibility and cyclability of conversion‐type anodes. [ABSTRACT FROM AUTHOR]

A silica-supported copolymer loaded with bis (2-ethylhexyl) phosphate was prepared and first investigated for the separation of trace radium from natural 232Th. Results showed that the adsorbent was prepared successfully with ultrahigh selectivity and ultrafast adsorption kinetics towards thorium, making the separation easy and convenient. The chemical recovery rate to radium reached 96.7%, and the decontamination factor to thorium exceeded 105. Generally, this work demonstrated the feasibility of using this material and method to directly separate 228Ra and 224Ra from 232Th, rendering it significant in the future preparation and application of 212Pb. [ABSTRACT FROM AUTHOR]

The objective of this study was to produce hydrophobic porous wood ceramics as adsorbents for CO2 through the resin treatment of pine. The prepared samples underwent analysis using various methods to determine their structure and properties. An orthogonal experimental approach was employed to obtain adsorbents with optimal preparation process. The highest adsorption capacity was determined to be 1.36 mmol/g at a temperature of 30 ℃ and a CO2 concentration of 15 vol%. The effect of temperature on the microstructure of wood ceramics was studied by characterization. Increasing temperatures adversely affected the adsorption capacity. Nevertheless, the hydrophobic nature of wood ceramics resulted in little impact of humidity on CO2 absorption. The CO2 adsorption kinetics of wood ceramics were analyzed using kinetic studies, which demonstrated that the kinetics can be accurately fitted by both the pseudo-first-order and Avrami models. The findings of the adsorption isotherm analysis showed that the Langmuir model fit was optimal. Following 30 cycles of adsorption-desorption in the presence of simulated gas, the CO2 sorption capacity of the wood ceramics was maintained at over 90%. In terms of CO2/N2 selectivity, the wood ceramics showed a clear preference for CO2, especially at 30 °C, where the CO2/N2 selectivity ratio reached 24.50. [ABSTRACT FROM AUTHOR]

Potassium permanganate (KMnO4) and potassium ferrate (K2FeO4) were used as modifiers to modify molecular sieves, and the modification periods were 35 days (KMnO4) and 27 days (K2FeO4), respectively. About 1 mol/L NaOH was used to pretreat the molecular sieves during the modification process of K2FeO4, and the modification period was further shortened to 22 days. After modification, modified molecular sieve (MMS) could effectively and continuously remove ammonium (NH4+) and manganese ions (Mn2+) from water. The adsorption kinetics showed that the adsorption of NH4+ and Mn2+ by MMS conformed to the quasi-secondary kinetic model adsorption kinetic model, and the adsorption process was mainly chemisorption. During the modification process, SEM, EDS, BET and XPS were used to investigate the structural characteristics of MMS. In the modification mechanism of molecular sieve, lattice oxygen (referred to as Oα), Mn (II), and Mn (III) accelerated the oxidation of Mn2+ to Mn4+ and promoted the rapid formation of active manganese oxide, which played a key role in shortening the modification period of MMS. This study contributes to a better understanding of the preparation and performance of MMS through a comprehensive analysis of the optimized molecular sieve modification process and the exploration of the accelerated formation mechanism of active manganese oxide. [ABSTRACT FROM AUTHOR]

In this study, magnetic material was synthesized using iron salts, then silicon-specific material was used to gain porosity, straight-chain polyacrylamide (PAM) was modified to give the surface functional properties, and the final product synthesized Fe3O4/SiO2/PAM nanocomposite material. Heavy metal (Pb and Cd) removal studies were carried out with the synthesized composite material, considering the central composite design and response surface methodology (CCD-RSM) optimization model. The effects of various parameters, for example, the initial concentration, pH, adsorbent dose, temperature and contact time, were investigated as a part of this study. To optimize these parameters, the CCD-RSM model was applied to design the experiments. Analysis of variance (ANOVA) was applied to evaluate statistical parameters and investigate interactions of variables. In the designed experimental set, the amount of adsorbent (30 mg), pH 7.0 value, temperature (40 °C), initial concentration of Pb (80 mg/L) and Cd (20 mg/L) and 90 min contact time were determined as the optimum conditions. The high coefficient of determination of both metals showed good agreement between experimental results and predicted values (R2 0.99; 0.95). TEM, SEM, XRD, FTIR, BET and Zeta potential analyses were performed to characterize the structure and morphology of the adsorbent. In Pb2+ and Cd2+ heavy metal removal studies, maximum adsorption capacities were determined as 66.54 and 13.22 mg/g, respectively. Additionally, adsorption isotherms, adsorption kinetics and thermodynamic modeling studies were conducted. Features such as large surface area and high adsorption capacity of the synthesized nanoparticles were observed. In this study, Fe3O4/SiO2/PAM demonstrated its potential as an effective adsorbent for the removal of heavy metal ions present in simulated wastewater samples. In particular, we can say that the material has a strong selectivity, as well as a high affinity for Pb(II) ions. [ABSTRACT FROM AUTHOR]

Water pollution due to organic compounds has emerged as a global concern. Among various methods for wastewater treatment like advanced oxidation process, photodegradation, reverse osmosis, etc., adsorption is an economical and effective method. Different research scientists have focused on developing low-cost materials for the adsorption of organic pollutants from aqueous streams. The Discovery of M-xenes has led to a new and interesting vein of research. This article summarises M-xenes and M-xenes based nanocomposites for wastewater treatment. Adsorption kinetics and mechanism is also discussed in this paper. The adsorption is due to chemical attractions between pollutants and functional groups on the surface of M-xenes. Surface modified M-xenes have the potential to be excellent adsorbent materials for water remediation. Various factors affecting the adsorption capacity of M-xenes are discussed. Lastly, the future prospects for developing M-xenes as efficient, low-cost and non-toxic materials for water remediation are also addressed. [ABSTRACT FROM AUTHOR]

Adsorption is a highly effective method for wastewater quality adjustment, offering advantages such as low cost and availability of adsorbents. This study investigates the efficient removal of Anionic Actas Pink dye (AAPD), a major contributor to environmental pollution. Green adsorbents including lead oxide (PbO), zinc oxide (ZnO), cadmium oxide (CdO), and copper oxide (CuO) were synthesized via eco-friendly routes for AAPD removal. Maximum adsorption capacities (qe) were observed at pH 7 (PbO, ZnO, CdO) and pH 2 (CuO and native) with values of 83.83 mg/g at 100 ppm, 75.65 mg/g at 100 ppm, 70.50 mg/g 75 ppm, 61.21 mg/g at 150 ppm, and 52.69 mg/g at 150 ppm, respectively, using an adsorbent dose of 0.05 g/50 mL at temperature of 37°C, and 90 min contact time. Adsorption followed Langmuir isotherm for all adsorbents except native, with PbO also fitting Freundlich and Dubinin–Radushkevich isotherms. Kinetics adsorption data supported pseudo-second-order, while thermodynamic analysis indicated spontaneous and exothermic nature. Effects of electrolytes, surfactants, and desorption were also evaluated. Characterization through FTIR, SEM, and XRD confirmed the morphology and functional groups of these nano-quantum dots. Citrus limon peel-based biosynthesis offers sustainable, eco-friendly, and cost-effective alternatives, highlighting their potential for dye adsorption. Highlights: Explore cost-effective and efficient adsorption methods for wastewater treatment Discover effective adsorbents capable of efficiently removing Anionic Actas Pink Sustainable synthesis of green quantum dot was made using agricultural waste Gain insights into adsorption mechanisms through robust modeling techniques [ABSTRACT FROM AUTHOR]

In order to achieve the resource utilization of waste polyester (WPT), the WPT based activated carbon (WPT-AC) was prepared by ZnCl2 activation high-temperature pyrolysis method. The phase morphology, characteristic groups, pore structure of specific surface area and microstructure were characterized by TGA, XRD, FTIR, BET and SEM. The optimum preparation process of WPT-AC was determined by L9(34) orthogonal experiment, and the adsorption performance of WPT-AC for methylene blue (MB) was evaluated. WPT-AC showed a high specific surface area of 1037.62 m2/g, with rich pore structure, which provided the possibility for efficient adsorption. The pretreatment of ZnCl2 plays a key role in the formation of WPT-AC pore structure, and the abundant pore structure is conducive to improving the adsorption of pollutants. WPT-AC showed excellent performance in the field of organic dye adsorption, and the highest removal rate of MB reached 97.34%. The adsorption was mainly related to electrostatic attraction, hydrogen bonding and π–π conjugation. The analysis of adsorption kinetics and thermodynamics is conducive to a better understanding of the adsorption process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon nanofibrous membranes were prepared for adsorptive separation of VOCs. • The membranes showed hierarchical porous structures and functional surfaces. • The membranes possessed comparable adsorption quantities and fast kinetics. • The membranes exhibited good reusability and dynamic adsorption performance. Volatile organic compounds (VOCs) in the air pose great health risks to humans and the environment. Adsorptive separation technology has proven effective in mitigating VOC pollution, with the adsorbent being the critical component. Therefore, the development of highly efficient adsorbent materials is crucial. Carbon nanofibers, known for their physical–chemical stability and rapid adsorption kinetics, are promising candidates for removing VOCs from the air. However, the relatively simple porous structures and inert surface chemical properties of traditional carbon nanofibers present challenges in further enhancing their application performance further. Herein, a hierarchical porous carbon nanofibrous membrane was prepared using electrospinning technology and a one-step carbonization & activation method. Phenolic resin and polyacrylonitrile were used as co-precursors, with silica nanoparticles serving as the dopant. The resulting membrane exhibited a specific surface area of up to 1560.83 m2/g and surfaces rich in functional O-/N- groups. With a synergistic effect of developed micro- and meso -pores and active chemical surfaces, the carbon nanofibrous membrane demonstrated excellent adsorption separation performance for various VOCs, with comparable adsorption capacities and fast kinetics. Moreover, the membrane displayed remarkable reusability and dynamic adsorption performance for different VOCs, indicating its potential for practical applications. [ABSTRACT FROM AUTHOR]

Molecularly imprinted polymers (MIPs) are a diverse class of materials designed for selective molecular recognition. These polymers are synthesized with particular binding sites that are suited to a target molecule or a collection of structurally similar molecules through the use of a process called molecular imprinting. MIPs were synthesized in this work to specifically remove direct violet 51 from occupational leachates and aqueous solutions. Methacrylic acid functioned as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and alcohol as a porogenic solvent. To improve the dye removal effectiveness, a number of factors were optimized, including time, pH, analyte concentrations, and MIP/NIP dosages. The findings showed that MIPs had a much greater capacity for direct violet 51 adsorption than nonimprinted polymers (NIPs), with MIP adsorption capacity reaching 42.553 mg g−1 and NIP adsorption capacity reaching 7 mg g−1. The pseudo 2nd-order model described the adsorption kinetics, and the rate constant (K2) for MIPs was found to be 0.00251 mg g−1 min. Furthermore, a high rebinding efficiency of 94 % was observed when the selectivity of MIPs for direct violet 51 was assessed against structurally similar templates. [ABSTRACT FROM AUTHOR]

This review summarizes the use of film-forming amines (FFAs) for corrosion protection in water/steam industrial circuits, focusing on carbon steel. It discusses industrial feedback on FFAs' benefits and challenges, alongside experimental methods for studying their inhibition and structural properties. Key research areas include FFAs' corrosion inhibition mechanisms, adsorption kinetics, and layer structures. The review also identifies knowledge gaps and suggests future research directions to deepen the understanding of FFAs. [ABSTRACT FROM AUTHOR]

In this study, three starch hydrogels composite prepared using different ratios of starch, citric acid, acrylamide, and MgO nanoparticles (referred to as St1-g-(CA-AM), St2-g-(CA-AM), and St3-g-(CA-AM) MgO). These materials were assessed using FT-IR, SEM, and EDX. The adsorption of 134Cs(I) and 60Co (II) onto these materials studied using radiometric analysis. The investigation focused on how temperature, contact duration, initial metal ion concentration, and pH of the solution affected the sorption efficiency. It is found that a pH value of 7 optimized the adsorption reaction, reaching equilibrium after 40 minutes. The kinetics of the adsorption followed a pseudo-second order model. The Langmuir model adequately explained the sorption mechanism, supported by the analysis of isotherm models. The monolayer adsorption capacities for 60Co (II) and 134Cs (I) were 113.38 and 100.2 mg g−1, respectively. The thermodynamic study indicated that the sorption process is both endothermic and spontaneous. [ABSTRACT FROM AUTHOR]

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In this study, arsenic-contaminated groundwater is treated using a novel iron oxide/carbon composite. Raw chelating carbon materials with amidoxime functional groups were mixed with ferric chloride solution and then soaked to pH 3 solution to produce the composite. The specific surface area and adsorption volume of the iron oxide/carbon absorbent are 89.0 m2/g and 0.220 cc/g, respectively. Arsenic (1 mg/L) removal by different doses of the adsorbent (5 to 80 g/L) ranges from 49% to 79% in bath experiments. Arsenic removal increases with increasing dosage of the adsorbent. The adsorption kinetics and isotherm of arsenic removal reveal better fit for pseudo-second-order kinetic model and Langmuir isotherm, which indicates that the main mechanisms of arsenic adsorbed by the adsorbent are chemisorption and monolayer adsorption. Arsenic removal by the adsorbent within 15 to 35℃ has an insignificant difference, which indicates that the material is suitable to be applied under ambient temperature. The results of tank test show that the removal of arsenic (0.2 mg/L) by the adsorbent in the samples collected from in situ groundwater reaches 85%, demonstrating a good performance of the adsorbent for the treatment of arsenic-contaminated groundwater. The adsorbent used in this study can be applied to remediate arsenic-contaminated groundwater in the future. [ABSTRACT FROM AUTHOR]

Phase pure sodium trititanate (Na2Ti3O7) and hexatitanate (Na2Ti6O13) nanorods were controllably synthesized using sodium carbonate and titanic acid as sodium and titanium precursors by calcination at 850 °C for 12 h. The adsorption properties of trititanate and hexatitanate nanorods for the removal of heavy metal ions, Ni2+ and Pb2+ from simulated wastewaters at pH of 3‒7 and 20‒65 °C were investigated. The adsorption of Ni2+ and Pb2+ ions on sodium trititanate and hexatitanate nanorods are through ion exchange and electrostatic adsorption. The adsorption of Ni2+ and Pb2+ ions could be well fitted by the pseudo-second order adsorption kinetics and Langmuir adsorption isotherm. Based on the Langmuir adsorption isotherm, the adsorption capacities of naked sodium trititanate nanorods for Ni2+ and Pb2+ from simulated wastewaters at 20 °C and pH 7 are 104.17 and 89.85 mg∙g‒1 while the adsorption capacities of naked sodium hexatitanate nanorods are 95.69 and 76.69 mg∙g‒1, respectively. Sodium trititanate nanorods exhibit higher adsorption capacities for heavy metal ions from wastewaters than sodium hexatitanate nanorods because the former has richer Na+ ions for ion exchange with heavy metal ions than the latter. The adsorption processes of Ni2+ and Pb2+ on sodium trititanate and hexatitanate nanorods are spontaneous. The phase pure sodium titanate nanorods may have practical application for the removal and enrichment of metal ions from wastewaters. [ABSTRACT FROM AUTHOR]

The present work aimed to highlight an efficient, readily accessible, and cost-effective adsorbent derived from Dalbergia sissoo (DS) leaf powder for removing the environmentally hazardous dye "alizarin red S" (ARS) from hydrous medium. A variant of the adsorbent is activated via sulfuric acid and composited with magnetic iron oxide nanoparticles (DSMNC). Both adsorbents are thoroughly characterized using techniques such as Fourier transform infrared spectroscopy, point of zero charge, energy-dispersive X-ray spectroscopy, and scanning electron microscopy, which show that they have a porous structure rich in active sites. Different adsorption conditions are optimized with the maximum removal efficiency of 76.63% for DS and 97.89% for DSMNC. The study was highlighted via the application of various adsorption isotherms, including Freundlich, Langmuir, Temkin, and Dubinin–Radushkevich, to adsorption data. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were utilized to investigate the kinetics and mechanism of adsorption. The Freundlich model and pseudo-second-order kinetics exhibited the best fit, suggesting a combination of physical interactions, as confirmed by the D–R and Temkin models. The dominant adsorbate–adsorbent interactive interactions responsible for ARS removal were hydrogen bonding, dispersion forces, and noncovalent aromatic ring adsorbent pi-interactions. Thermodynamic parameters extracted from adsorption data indicated that the removal of the mutagenic dye "ARS" was exothermic and spontaneous on both DS and DSMNC, with DSMNC exhibiting higher removal efficiency. [ABSTRACT FROM AUTHOR]

Enzymatic recycling of polyethylene terephthalate (PET) has attracted significant attention in recent years. While the fusion of anchor peptides to PET hydrolases is believed to enhance PET hydrolytic activity, a quantitative analysis is yet lacking. Here, we construct four fusion enzymes by fusing anchor peptides (including hydrophobic LCI, LCIM1 and TA2, and hydrophilic EK4) to the C terminus of HotPETase, one of the most active PET hydrolases for high‐crystallinity PET (HC‐PET). Single‐molecule force spectroscopy (SMFS) demonstrates that hydrophobic anchor peptides promote adhesive interactions between the fusion enzymes and the PET surface. This is also validated by the adsorption kinetics and isotherms, and the saturated adsorption capacity remains unaltered compared to HotPETase. At low substrate loadings, the apparent hydrolytic activity of these fusion enzymes is positively related to the hydrophobicity of the anchor peptides. Among them, HotPETase‐LCI stands out as the most effective enzyme for HC‐PET degradation, demonstrating a 1.5‐fold increase in hydrolytic activity. At high substrate loadings, the advantages of fusion with anchor peptides diminish. We conclude that fusion enzymes only facilitate the hydrolytic rates of reactions for HC‐PET but have little effect on the final conversion extent. [ABSTRACT FROM AUTHOR]

Solid amine adsorbents represent a promising class of CO2 sorbents, but their amine efficiency is limited by the inaccessibility of peripheral amines. The surface of mesocellular silica foam (MCF) is functionalized with the mixture of short‐chain 3‐Glycidyloxypropyl) triethoxysilane (GPTES) and long‐chain Octadecyltrimethoxysilane (OTMS), forming pocket structures on the support surface, thereby exposing more amine sites and enhancing the amine efficiency of polyethylenimine (PEI). The resulting adsorbent demonstrates a high CO2 adsorption capacity (5.02 mmol g−1 at 50 °C, 10 vol.% CO2, and 50%RH), high amine efficiency (0.43 at the dry condition), outstanding cyclic stability (0.5% performance decline per cycle under the conditions of dry CO2 regeneration), and fast adsorption kinetics (15 min for adsorption saturation at 50 °C). First‐principles calculations and CO2 temperature‐programmed desorption (TPD) experiments demonstrate that the introduction of GPTES and OTMS is beneficial to decreasing adsorption energy and forming paired carbamic acid states and ammonium carbamate states. [ABSTRACT FROM AUTHOR]

Introduction: Currently, there are few investigations on the effect of a synthetic exogenous quorum sensing (QS) agonist on the bioleaching rate of Acidithiobacillus thiooxidans (A. thiooxidans). Methods: We created AHL (N-acyl-homoserine lactone) analogues and investigated their effects on A. thiooxidans biofilm formation, adsorption kinetics, bioleaching, and mechanism. Results: The findings revealed that N-(3-thiolactone)- dodecylamine (Y3) significantly increased the biofilm formation of A. thiooxidans in 96-well plates and sulfur sheets. Adsorption tests revealed that Y3 increased the adhesion rate, adsorption constant, and adsorption efficiency. Bioleaching tests indicated that Y3 boosted bioleaching efficiency, with Ni2+ and Cu2+ bioleaching rates increasing by 49.13% and 33.03%, respectively. Transcriptomic analysis revealed that Y3 increased genes associated with QS pathways and biofilm formation, particularly afeI, which was dramatically elevated 42 times. Discussion: The study laid the groundwork for a better understanding of the mechanics of A. thiooxidans biofilm formation, which could help improve the potential application of A. thiooxidans in bioleaching. [ABSTRACT FROM AUTHOR]

Herein, we firstly develop porous organic cage (POC) as an efficient platform for highly effective radioactive iodine capture under industrial operating conditions (typically ≥150 °C), ≤150 ppmv of I2). Due to the highly dispersed and readily accessible binding sites as well as sufficient accommodating space, the constructed NKPOC‐DT‐(I−) (NKPOC=Nankai porous organic cage) demonstrates a record‐high I2 uptake capacity of 48.35 wt % and extraordinary adsorption capacity of unit ionic site (~1.62) at 150 °C and 150 ppmv of I2. The I2 capacity is 3.5, 1.6, and 1.3 times higher than industrial silver‐based adsorbents Ag@MOR and benchmark materials of TGDM and 4F‐iCOF‐TpBpy‐I− under the same conditions. Furthermore, NKPOC‐DT‐(I−)Me exhibits remarkable adsorption kinetics (k1=0.013 min−1), which is 1.2 and 1.6 times higher than TGDM and 4F‐iCOF‐TpBpy‐I− under the identical conditions. NKPOC‐DT‐(I−)Me thus sets a new benchmark for industrial radioactive I2 adsorbents. This work not only provides a new insight for effectively enhancing the adsorption capacity of unit functional sites, but also advances POC as an efficient platform for radioiodine capture in industry. [ABSTRACT FROM AUTHOR]

In this study, hydrothermally synthesized magnesium oxide demonstrated effective fluoride adsorption, with a maximum capacity of 199.67 mg g−1 and equilibrium was achieved within 60 min. The morphology of magnesium oxide and the adsorption mechanism were investigated by SEM, FTIR, BET and XPS. The adsorption process conformed to the Freundlich isotherm and pseudo-second-order kinetic models. The ΔH and ΔS of fluoride adsorption by this material were 44.58 kJ mol−1 and 163.31 J mol−1 K−1, respectively, indicating surface heterogeneity and specific adsorption kinetics. Optimal fluoride removal was observed in the pH range of 4–11, with the highest adsorption capacity achieved at pH 5.0. Co-existing ions significantly influenced the adsorption performance (Cl− < NO3− < SO42− < HCO3− < PO43−). These findings underscore the potential application of magnesium oxide in water treatment and suggest avenues for further optimization of synthesis and operational parameters. [ABSTRACT FROM AUTHOR]

This work developed a novel sustainable adsorbent (PF-Aq) prepared by the amino-functionalization of palm oil fibers (PF). XPS, SEM/EDS, TGA/DSC, and FT-IR techniques proved the successful functionalization of the PF with the amino group. The PF-Aq adsorbent presents a high adsorption capacity for phosphate and Cr(VI) ions. Adsorption kinetics of the ions onto the PF-Aq followed the general-order models, with 240- and 300-min equilibrium times for phosphate and Cr(VI), respectively. The Freundlich equilibrium model can explain the adsorption of phosphate and Cr(VI) on the PF-Aq. Besides, the maximum adsorption capacities were 151.07 mg g−1 for phosphate and 206.08 mg g−1 for Cr(VI). The best pH for the adsorption of both ions on PF-Aq was 4.0. Interestingly, adsorption was exothermic for phosphate and endothermic for Cr(VI). The adsorption capacities were reduced by 16% for phosphate and 10% for Cr(VI) after 5 adsorption–desorption cycles, demonstrating the good recyclability of the PF-Aq. It can be concluded that PF-Aq is a relevant adsorbent to uptake phosphate and Cr(VI) from water due to its high adsorption capacity, low cost, recyclability, availability, and fast kinetics. Finally, the excellent adsorption potential results from inserting amino groups in the PF, allowing electrostatic interactions between adsorbent and adsorbate. [ABSTRACT FROM AUTHOR]

The oxygen reduction reaction (ORR) has gradually attracted attention recently due to its enormous potential applications in proton exchange membrane fuel cell (PEMFC). Therefore, developing effective and economical ORR electrocatalysts has become an increasingly important issue. Additionally, efficient ORR catalysts can accelerate the activation of PEMFC, facilitating industrial applications. This review focuses on the modulation of triple phase boundary (TPB), introducing the establishment of TPB, adsorption kinetics, and reaction kinetics. It also traces the ORR electrocatalytic mechanism. Importantly, the review discusses the latest advancements in ORR electrocatalyst development, including precious metal catalysts (Pt/C-based MEA registered a power density of 800 mW cm−2), non-precious metal catalyst (The power density of Fe–N/MC is up to 1.15 W cm−2), and non-metal catalysts (N, P, S tri-doped holey carbon with a peak power as high as 275.1 mW cm−2). The discussion further extends to unitary catalysts, binary catalysts, ternary catalysts, heteroatom doping, heteroatom-free doping, and defect doping. Furthermore, speculation and discussion on the prospects and challenges of ORR electrocatalysts are provided. These insights will contribute to guiding the design of ORR electrocatalysts from the TPB perspective, influencing the fast activation of fuel cells and future research. Modulating TPB is a crucial approach to change oxygen reduction catalysts. This review summarizes the latest research progress on ORR fuel cell catalysts for the fast activation of fuel cells. [Display omitted] • Classification of oxygen reduction reaction catalyst. • The method of modulating triple phase boundary of oxygen reduction reaction catalyst. • Oxygen reduction reaction catalyst is used for fast activation of PEMFC. [ABSTRACT FROM AUTHOR]

In the critical domain of wastewater treatment, the development of cost-effective, durable, and recyclable adsorbents with high adsorption capacities remains a significant challenge. This study introduces a novel magnetic bimetallic Metal–Organic Framework (MOF) adsorbent, MZIF-67-Co/Cu, doped with copper ions. The MZIF-67-Co/Cu adsorbent was successfully synthesized and structurally characterized, demonstrating remarkable selectivity for removing methyl orange (MO) from water. This high selectivity is attributed to the adsorbent's high porosity and Lewis base properties at the coordinating metal ion center. The incorporation of Cu ions significantly enhances the porous architecture and increases the number of metal adsorption sites, leading to an impressive maximum MO adsorption capacity of 39.02 mg/g under optimized conditions (0.5 g/L adsorbent concentration, pH 3.0, 250 rpm agitation speed, adsorption time > 10 min). The adsorption kinetics closely follow the pseudo-second-order model, and the isotherm data fit well with the Langmuir model. The primary adsorption mechanisms involve electrostatic attraction and mesoporous interaction. This study highlights MZIF-67-Co/Cu as a highly efficient adsorbent with magnetic recovery capabilities, positioning it as a promising candidate for addressing critical issues in wastewater treatment. [ABSTRACT FROM AUTHOR]

Global concern over arsenic contamination in drinking water necessitates innovative and sustainable remediation technologies. This study evaluates the adsorption performance of Fe–Mn binary oxide (FMBO) nanocomposites developed by coating polyethylene (PE) and polyethylene terephthalate (PET) with FMBO for the removal of As(III) and As(V) from water. Adsorption kinetics were rapid, with equilibrium achieved within 1–4 h depending on the material and pH. PET-FMBO and FMBO exhibited faster rates and higher arsenic removal (up to 96%) than PE-FMBO. Maximum As(III) adsorption capacities ranged from 4.76 to 5.75 mg/g for PE-FMBO, 7.2 to 12.0 mg/g for PET-FMBO, and up to 20.8 mg/g for FMBO, while capacities for As(V) ranged from 5.20 to 5.60 mg/g, 7.63 to 18.4 mg/g, and up to 46.2 mg/g, respectively. The results of the Dubinin–Radushkevich isotherm model, with free energy (Ea) values exceeding 16 kJ/mol, suggest chemisorption is the dominant mechanism, which is supported by the kinetics data. Given the effective removal of As(III), chemisorption likely proceeds through ligand exchange during the Mn oxide-mediated oxidation of As(III) and complexation with hydroxyl groups on the nanocomposite. These findings highlight the strong potential of Fe–Mn polymer nanocomposites, particularly PET-FMBO, for efficient arsenic removal during practical water treatment applications. [ABSTRACT FROM AUTHOR]

Among the perovskite oxide community, La‐based perovskites have garnered considerable interest due to their remarkable properties including catalytic, electrocatalytic, photocatalytic, sensing, electrical, magnetic, and optical characteristics. Herein, rhodamine‐B (RB) dye has been reported to be sono‐catalytically decomposed by an ultrasound‐assisted advanced oxidation process (AOP) using perovskite‐type LaMnO3 (LMO) nanospheres synthesized via ultrasonic approach. Several physiochemical characterizations such as XRD, FT‐IR, XPS, SEM, TEM, and SEM‐EDS investigations were used to investigate the LMO perovskite nanospheres. Then, LMO potential for adsorption and the sonocatalytic decolorization of RB dye in an aqueous solution are examined. With LMO perovskites, the adsorption and removal kinetics of RB correspond to the pseudo‐first‐order model. Furthermore, by utilizing the pseudo‐first‐order, the RB dye process is removed with improved efficacy in the following sequence: Agitation alone: 3.76×10−4 min−1

The application of low-cost biosorbent of bamboo in methylene blue (MB) removal treatment is limited by its poor adsorption performance. In this study, bamboo parenchyma cell (BP) was isolated from bamboo powder by facile method of water separation and then incorporated with natural non-toxic vermiculite (VE) to prepare bamboo parenchyma cell-vermiculite (VEBP) composites. Much more nanopores were formed and more active adsorbed sites were introduced by filling with VE in BP lumen, which is favorable for improving the MB adsorption capacity. The MB adsorption isotherm of VEBP was preferably fitted with Langmuir model, yielding the highest equilibrium MB adsorption capacity of approximately 422 mg/g. As-obtained adsorption capacity is much higher than that of BP and various kinds of biosorbents in previous researches. Besides, the adsorption kinetics was closer to the pseudo-second-order model, indicating the dominant chemisorption process. Thermodynamic parameters implied the endothermic and spontaneous as well as entropy-governed adsorption process. Based on the analysis of adsorption behavior together with characterizations of VEBP, it can be confirmed that the predominant mechanisms for MB adsorption may involve electrostatic attraction, ion exchange, hydrogen bonding, pore filling, complexation reaction, and π-π interactions. Furthermore, the VEBP exhibited excellent reusability with MB removal efficiency of more than 80% after five cycles. Therefore, this study successfully provides a facile method for preparation of bamboo-based adsorbent with efficient MB adsorption performance. [ABSTRACT FROM AUTHOR]

To enhance the physical and chemical properties and stability of magnetic MOFs, and to improve their adsorption and reuse performance, an innovative modification strategy involving hybridization with three-dimensional (3D) terminal carboxyl hyperbranched polymers was employed. A novel polymer composite material, Fe3O4@MOF/HBPC, was synthesized and its morphological characteristics were analyzed. The adsorption properties of Fe3O4@MOF/HBPC were tested by removing Malachite Green (MG) from aqueous solutions. Various influencing factors, including dosage, pH, and temperature, as well as adsorption kinetics, isotherms, and thermodynamics were investigated. The results showed that the stretching vibration peaks of Fe3O4@MOF/HBPC appeared at 1708 cm−1, 1408 cm−1, 1278 cm−1, 1112 cm−1, and 543 cm−1, corresponding to the C＝O, –COO−, O–H, C–O, and Fe–O bands, respectively. Fe3O4@MOF/HBPC exhibited a negative charge and a spherical structure. The composite material contained the elements O, C, Fe, and N, and the assembly process had a minimal impact on the crystal structure. For MG removal, the optimal reaction conditions were a dosage of 20 mg and pH 6. The adsorption process followed a pseudo-first-order kinetic model and a Langmuir isotherm model, and it was found to be endothermic and spontaneous, involving both physical and chemical adsorption. Regarding recycling and reuse, Fe3O4@MOF/HBPC demonstrated a recycling efficiency of over 90.8%, with a removing efficiency of MG of above 87.5% after three cycles, indicating excellent stability and reusability. [ABSTRACT FROM AUTHOR]