Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF;RF = CF(CF3)OCF7, n = 2, 3;RF-(VM)n-RF] was applied to the preparation of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/α-, β-, ...Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF;RF = CF(CF3)OCF7, n = 2, 3;RF-(VM)n-RF] was applied to the preparation of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/α-, β-, γ-cyclodextrin polymers (α-, β-, γ-CDPs) composites [RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs] by the sol-gel reaction of the corresponding oligomer in the presence of the α-, β-, γ-CDPs under alkaline conditions. The RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs composites thus obtained were found to give a good dispersibility toward the traditional organic media except for water, and were applied to the surface modification of glass to provide a sueperoleophilic/superhydrophobic characteristic on the modified surface, although the corresponding RF-(VM-SiO2)n-RF nanocomposites can give a usual oleophobic/superhydrophobic property on the surface. These composites powders were also found to be applicable to the packing material for the column chromatography to separate the mixture of oil/water and the water in oil (W/O) emulsions. More interestingly, these composite powders were found to have a higher adsorption ability toward not only low-molecular weight aromatic compounds such as bisphenol A and bisphenol AF but also volatile organic compounds, compared to that of the pristine α-, β-, γ-CDPs.展开更多
Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization,...Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 - 4.5 meq/g and 2.5 - 6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% - 40% and 20% - 35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly.展开更多
Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread applica...Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.展开更多
Separation of ethane from ethylene is a very important but challenging process in the petrochemical industry.Finding an alternative method would reduce the energy needed to make 170 million tons of ethylene manufactur...Separation of ethane from ethylene is a very important but challenging process in the petrochemical industry.Finding an alternative method would reduce the energy needed to make 170 million tons of ethylene manufactured worldwide each year.Adsorptive separation using C2H6-selective porous materials to directly produce high-purity C2H4 is more energy-efficient.We herein report the"reversed C2H6/C2H4 adsorption"in a metal–organic framework Cr-BTC via the introduction of oxygen on its open metal sites.The oxidized Cr-BTC(O2)can bind C2H6 over C2H4 through the active Cr-superoxo sites,which was elucidated by the gas sorption isotherms and density functional theory calculations.This material thus exhibits a good performance for the separation of 50/50 C2H6/C2H4 mixtures to produce 99.99%pure C2H4 in a single separation operation.展开更多
Biochar,as an efficient,effective,and potential soil improver,has broad application prospects in the field of defluoridation.This study aimed to evaluate the defluoridation potential of iron(Fe)and manganese(Mn)co-mod...Biochar,as an efficient,effective,and potential soil improver,has broad application prospects in the field of defluoridation.This study aimed to evaluate the defluoridation potential of iron(Fe)and manganese(Mn)co-modified biochar from groundwater.The varied Fe/Mn molar ratio(2∶1 and 1∶2)modified biochar was prepared by corncob with the pyrolysis temperature of 300℃,400℃,and 500℃.Batch experiments for fluoride(F^(-))removal were performed by corncob biochar before and after Fe-Mn modified.Their composition,structure,and performance were analyzed by multiple characterization techniques to clarify F‒removal mechanisms.Our results indicated that unmodified corncob biochar produced at 400℃(BC400)exhibited the highest F‒adsorption efficiency(87.3%)among three unmodified samples,attributable to its largest specific surface area(2.55 m^(2)/g).Notably,F‒removal amounts by Fe-Mn modified BC400 were 2 times higher than BC400.The enhanced F⁻removal performance of Fe-Mn modified biochar can be attributed to several mechanisms:(1)the modification produced rougher surface textures,resulting in an increased specific surface area(about 3.50 m^(2)/g);(2)newly formed Fe-O and Mn-O bonds on the biochar surface facilitated the formation of complexes with F^(-);and(3)the adsorption results fitted well with pseudo-second-order and Freundlich models(R^(2)>0.98),indicating that the removal process involved physicochemical adsorption.These findings demonstrate that Fe-Mn modified biochar is a highly efficient and cost-effective material for F^(-)remediation and holds significant potential for application in contaminated groundwater and soil systems.展开更多
The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the...The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the form of S—P bond.The ADD adsorption on argentite and sphalerite surface in Ag^(+)system was revealed by ICP,Zeta potential and XPS analyses.It is shown that the dissolved Ag^(+)from argentite surface can be absorbed on sphalerite surface in the form of silver hydroxide,and AgOH hydrophilic colloid prevents the adsorption of ADD on sphalerite surface.The ADD adsorption on argentite and sphalerite surface in the pulp containing silver and zinc ions was revealed by adsorption capacity and surface wettability analyses.It is shown that the combined Zn(OH)_(2) and AgOH hydrophilic colloid leads to greater ADD adsorption capacity on argentite surface and stronger surface hydrophobicity than sphalerite.Flotation tests demonstrate that ADD enables efficient separation of argentite from sphalerite in the pulp containing silver and zinc ions.展开更多
The severe shuttle effect and sluggish reaction kinetics in room-temperature sodium-sulfur(RT Na-S)batteries have been major bottlenecks hindering their practical application.To overcome these challenges,a straightfor...The severe shuttle effect and sluggish reaction kinetics in room-temperature sodium-sulfur(RT Na-S)batteries have been major bottlenecks hindering their practical application.To overcome these challenges,a straightforward reduction approach was employed to design three bimetallic alloy nanoparticles(FeNi,FeCo,and NiCo)supported on multistage porous carbon substrates.Experimental and theoretical calculations reveal that the charge transfer within the alloy catalyst influences the position of its d-band center and its degree of hybridization with sodium polysulfides(NaPSs).An increased charge transfer leads to a shift of the alloy’s d-band center closer to the Fermi energy level,thereby enhancing its adsorption and catalytic capabilities.Among the three alloy compositions,the FeNi alloy exhibits the highest charge transfer.Consequently,the FeNi alloy demonstrates the superior electrochemical performance,achieving a high reversible specific capacity of 848.2 mA h g^(−1),with an average capacity degradation rate of only 0.037%per cycle over 1000 cycles at 1.2 C.The S/FeNi/NC cathode exhibits a low electrolyte-to-sulfur(E/S)ratio of 6.6µL mg^(−1),while maintaining a high reversible specific capacity of 568.1 mA h g^(−1).This offers valuable insights for the application of alloy catalysts in the S/FeNi/NC cathode of RT Na-S batteries.展开更多
The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium...The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium chloride,and magnesium sulfate)was investigated.Bovine serum albumin(BSA)was selected as the model protein.Parameters including particle size and zeta potential were assessed,while various spectroscopic techniques were utilized to elucidate the changes in BSA during its interaction with liposomes.The particle size and light intensity distribution changes indicated that the introduction of inorganic pairs,especially the metal cations,could significantly influence both the adsorption of BSA and the aggregation of particles.Furthermore,spectral characterization elucidated that BSA exhibited more extended peptide chains with enhanced exposure to hydrophobic acid amino residues upon adding ion pairs.Electrostatic adsorption and chelation insertion were proposed as metal ion binding modes and the corresponding BSA corona formation.In the electrostatic adsorption mode,sodium ions can enhance the electrostatic interactions,facilitating the“connection”between BSA and liposomes.Magnesium ions can induce stronger hydrophobic interactions through chelation,effectively“drag”BSA segments into the lipid bilayer.This work highlighted important physiological factors for protein-liposome interaction and provided rational model constructions to lay the foundation for further relevant studies.展开更多
Injecting impure CO_(2)for enhanced gas recovery(CO_(2)-EGR)offers a dual benefit by improving natural gas extraction while enabling CO_(2)sequestration.However,the interactions between CO_(2),N_(2),and CH_(4)under re...Injecting impure CO_(2)for enhanced gas recovery(CO_(2)-EGR)offers a dual benefit by improving natural gas extraction while enabling CO_(2)sequestration.However,the interactions between CO_(2),N_(2),and CH_(4)under reservoir conditions require further investigation.This study employs Grand Canonical Monte Carlo(GCMC)and Molecular Dynamics(MD)simulations to quantify the adsorption and diffusion behaviors of CO_(2),N_(2),and CH_(4)in quartz nanopores over a pressure range of 1-24 MPa under varying water saturations and gas compositions.The results indicate that:(1)CO_(2)exhibits the broadest energy distribution and the strongest adsorption stability,occupying about 20%-30%more adsorption sites than CH_(4)or N_(2)and showing the least sensitivity to water saturation,with only a 30%reduction at 50%saturation,compared to 60%for CH_(4),giving CO_(2)a clear competitive advantage.(2)The adsorption and desorption behaviors are strongly pressure dependent,as increasing pressure reduces the adsorption layer area and shifts gas distribution from adsorption dominated to free phase.Competitive adsorption analysis reveals that while CO_(2)dominates displacement at low pressures,mixtures that contain N_(2)achieve higher CH_(4)desorption efficiency above 13 MPa by mitigating diffusion resistance.(3)A higher N_(2)fraction improves CH_(4)diffusion coefficients,thereby facilitating gas mobility and ensuring superior recovery performance under high-pressure conditions.This study advances the fundamental knowledge of microscale gas behavior in tight sandstones and supports the feasibility of impure CO_(2)injection as a practical strategy for sustainable gas production.展开更多
Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphou...Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphous Al_(2)O_(3)shells(10 nm)were deposited on the surface of highly active hydrogen storage material particles(MgH_(2)-ZrTi)by atomic layer deposition to obtain MgH_(2)-ZrTi@Al_(2)O_(3),which have been demonstrated to be air stable with selective adsorption of H_(2)under a hydrogen atmosphere with different impurities(CH_(4),O_(2),N_(2),and CO_(2)).About 4.79 wt% H_(2)was adsorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)at 75℃under 10%CH_(4)+90%H_(2)atmosphere within 3 h with no kinetic or density decay after 5 cycles(~100%capacity retention).Furthermore,about 4 wt%of H_(2)was absorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)under 0.1%O_(2)+0.4%N_(2)+99.5%H_(2)and 0.1%CO_(2)+0.4%N_(2)+99.5%H_(2)atmospheres at 100℃within 0.5 h,respectively,demonstrating the selective hydrogen absorption of MgH_(2)-ZrTi@10nmAl_(2)O_(3)in both oxygen-containing and carbon dioxide-containing atmospheres hydrogen atmosphere.The absorption and desorption curves of MgH_(2)-ZrTi@10nmAl_(2)O_(3)with and without absorption in pure hydrogen and then in 21%O_(2)+79%N_(2)for 1 h were found to overlap,further confirming the successful shielding effect of Al_(2)O_(3)shells against O_(2)and N_(2).The MgH_(2)-ZrTi@10nmAl_(2)O_(3)has been demonstrated to be air stable and have excellent selective hydrogen absorption performance under the atmosphere with CH_(4),O_(2),N_(2),and CO_(2).展开更多
Adsorption is becoming an important method in water and wastewater treatment technology at low concentrations. Pb2+ adsorption at low concentration onto various solid surfaces using either nano metal oxide of MnO2, or...Adsorption is becoming an important method in water and wastewater treatment technology at low concentrations. Pb2+ adsorption at low concentration onto various solid surfaces using either nano metal oxide of MnO2, or granulated activated carbon (GAC) or agricultural by-products such as tea leaves and coffee residue are considered promising. In this adsorption study the measurements were conducted by equilibrating Lead solutions at different concentrations range 19 - 291 μmol·L-1 with various adsorbent suspensions in the concentration range 0.388 - 8.738 g·L-1. Comparing all the adsorption capacities calculated using Langmuir equation Pb2+ adsorption by MnO2 shows the highest adsorption capacity with the estimated Γm = 528.0 μmol·g–1 at a fixed equilibrium constant K = 0.0119 L·μmoL-1. In addition, the Pb2+ adsorption by coffee residue is subject to a particle concentration effect in which the adsorption density decreases as the concentration of solid adsorbent Cs is increased. The Pb2+ adsorption by tea leaves, MnO2 and GAC shows less dependency to the concentration of solid adsorbent Cs, especially at lower metal ion concentrations. In the particular case of Pb2+ adsorption on MnO2 there appears to be no dependence on Cs.展开更多
Static adsorption and dynamic damage experiments were carried out on typical 8#deep coal rock of the Carboniferous Benxi Formation in the Ordos Basin,NW China,to evaluate the adsorption capacity of hydroxypropyl guar ...Static adsorption and dynamic damage experiments were carried out on typical 8#deep coal rock of the Carboniferous Benxi Formation in the Ordos Basin,NW China,to evaluate the adsorption capacity of hydroxypropyl guar gum and polyacrylamide as fracturing fluid thickeners on deep coal rock surface and the permeability damage caused by adsorption.The adsorption morphology of the thickener was quantitatively characterized by atomic force microscopy,and the main controlling factors of the thickener adsorption were analyzed.Meanwhile,the adsorption mechanism of the thickener was revealed by Zeta potential,Fourier infrared spectroscopy and X-ray photoelectron spectroscopy.The results show that the adsorption capacity of hydroxypropyl guar gum on deep coal surface is 3.86 mg/g,and the permeability of coal rock after adsorption decreases by 35.24%–37.01%.The adsorption capacity of polyacrylamide is 3.29 mg/g,and the permeability of coal rock after adsorption decreases by 14.31%–21.93%.The thickness of the thickener adsorption layer is positively correlated with the mass fraction of thickener and negatively correlated with temperature,and a decrease in pH will reduce the thickness of the hydroxypropyl guar gum adsorption layer and make the distribution frequency of the thickness of polyacrylamide adsorption layer more concentrated.Functional group condensation and intermolecular force are chemical and physical forces for adsorbing fracturing fluid thickener in deep coal rock.Optimization of thickener mass fraction,chemical modification of thickener molecular,oxidative thermal degradation of polymer and addition of desorption agent can reduce the potential damages on micro-nano pores and cracks in coal rock.展开更多
In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanopart...In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanoparticles(HAPNPs).Surface chemical composition and morphology of the prepared membranes were systematically investigated by ATR-FTIR,XPS,XRD,FESEM,and EDS mapping analyses.The results verified that a large number of HAPNPs were successfully embedded on the modified membrane crosssections.Moreover,HAPNPs content in the casting solution is an important factor that could have profound influence on the structures and performances of PVDF/HAPNPs blend membranes.The optimal membrane M2 with 2 wt%HAPNPs exhibited excellent hydrophilicity,outstanding mechanical strength of 19.60 MPa,and high water flux of(2466±31)L·m^2·h^-1.The maximum static adsorption capacity of the optimal membrane was about 10.83 mg/g,which is 3.75 times that of the pristine PVDF membrane(2.89 mg/g).PVDF/HAPNPs membranes were not only utilized for static adsorption,but also applied to dynamic dye removal.The possible adsorption mechanism between Congo red(CR)and HAPNPs embedded on the blend membranes was firstly discussed in this work.HAPNPs interacted with CR via Lewis reaction,hydrogen bond interaction,as well as electrostatic attraction to achieve the adsorption effect.Herein,the PVDF/HAPNPs blend membranes with extraordinary hydrophilicity,mechanical strength,and dye removal efficiency possess tremendous potential for practical applications of wastewater treatment.展开更多
The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. T...The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of solution pH and initial metal concentration on adsorption capacity were examined in batch experiments. The affinity and the adsorption capacity of DTS, CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir isotherm models. The separation factor (RL) analysis suggests that the removal of metal ions onto three agricultural wastes studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39 mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The characterisation studies were carried out using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed significantly following interaction with metal ions. The primary adsorption mechanism was complexation between metal ions and binding sites of biosorbents. Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.展开更多
Adsorption and desorption mechanisms of methylene blue (MB) removal with iron-oxide coated porous ce-ramics filter (IOCPCF) were investigated in batch and column mode. The results revealed that MB removal mechanisms i...Adsorption and desorption mechanisms of methylene blue (MB) removal with iron-oxide coated porous ce-ramics filter (IOCPCF) were investigated in batch and column mode. The results revealed that MB removal mechanisms included physical adsorption and chemical adsorption, of which chemical adsorption by surface ligand complex reaction played a dominant role after infrared spectrum analysis. Recycling agents were se-lected from dilute nitric acid (pH=3), sodium hydroxide solution (pH=12) and distilled water. Among three agents, dilute metric acid (pH=3) was the best recycling agent. Regeneration rate of IOCPCF arrived at 82.56% at batch adsorption and regeneration was finished in 75min at column adsorption. Adsorp-tion-desorption cycles of IOCPCF after batch and column adsorption were four and three times, respectively. Further, compared with fresh IOCPCF, MB removal rate with these desorbed IOCPCF adsorption only slightly decreased, which suggested that IOCPCF should be used repeatedly.展开更多
Antibiotics,as an emerging pollutant due to their extensive use and difficulty in biodegradation,can cause harm to health through bioaccumulation.To address this,various photocatalysts have been developed for rapid an...Antibiotics,as an emerging pollutant due to their extensive use and difficulty in biodegradation,can cause harm to health through bioaccumulation.To address this,various photocatalysts have been developed for rapid antibiotic removal.However,their low concentrations limit mass transfer efficiency,resulting in suboptimal performance.Adsorption is crucial for enhancing photocatalytic efficiency.In this study,a series of binary heterojunction catalysts(x%BWO@STHP)were synthesized,consisting of Bi_(2)WO_(6)(BWO)grafted with sulfonated triptycene-based hypercrosslinked polymer(STHP).The high specific surface area of STHP,combined withπ-πconjugation and ionic interactions with antibiotics,significantly enhances adsorption capacity.This facilitates effective contact between low-concentration pollutants in aqueous solutions and the active sites of the catalyst.The formation of a Z-scheme heterojunction between BWO and STHP facilitates photogenerated charge separation,and further significantly improves photocatalytic degradation performance.Specifically,the 20%BWO@STHP catalyst achieved rapid adsorption equilibrium for oxytetracycline(OTC),doxycycline(DOX),and tetracycline(TC)within 2 min and completely degraded them after 15 min of irradiation.Compared to pristine BWO,the photocatalytic reaction rate constants are significantly increased,being 9.69 times higher for OTC and 13.45 times higher for DOX.The catalyst exhibits excellent reusability and holds promising potential for practical applications.展开更多
This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized...This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized by X-ray diffraction (XRD) analysis. Batch adsorption study revealed that the optimum conditions for the removal were as follows: pH 2, adsorbent dosage 80 g/L and contact time of 6 min, which resulted in 92% removal and 0.464 mg/g maximum adsorption capacity. Adsorption isotherm and kinetic studies showed that Freundlich isotherm and pseudo-second-order kinetic models fitted best to the experimental data. Column adsorption study at 5 mL/min of flow rate showed that 90% removal was obtained at 2 min of contact time which represented its breakthrough point. The column reached saturation at 30 min and the maximum column adsorption capacity recorded was 0.412 mg/g. The column adsorption behavior showed good fit with both Thomas and Yoon-Nelson kinetic models. These findings suggested that the utilization of POFA as a low-cost adsorbent to remove Cr(VI) from wastewater, either in batch or fixed bed adsorption system is not only effective, but concurrently will help to reduce wastes from the palm oil industry.展开更多
The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed ...The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed perimeter hydroxyl (OH) groups built around the edge of an indented, two-dimensional hexagonal pore. This hydroxylated pore and models of various explosive molecules were optimized using MM2 molecular mechanics parameters. Values were calculated for the molecule-surface interaction energy (binding energy), E, for 22 explosive molecules on a flat graphene bilayer and on the specially designed hydroxylated pore within the bilayer. The molecule-surface binding energy for trinitrotoluene (TNT) increased from 17.9 kcal/mol on the flat graphene bilayer to 42.3 kcal/mol on the hydroxylated pore. Due to the common functionality of nitro groups that exist on many explosive molecules, the other explosive molecules studied gave similar enhancements based on the specific hydrogen bonding interactions formed within the pore. Each of the 22 explosive adsorbate molecules showed increased molecule-surface interaction on the bilayer hydroxylated pore as compared to the flat bilayer. For the 22 molecules, the average E for the flat graphite surface was 15.8 kcal/mol and for the hydroxylated pore E was 33.8 kcal/mol. An enhancement of adsorption should make a detection device more sensitive. Nanosensors based on a modified graphene surface may be useful for detecting extremely low concentrations of explosive molecules or explosive signature molecules.展开更多
To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5...To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5), respectively were prepared and characterized, then their adsorption performance and mechanism in the absence and presence of Mg^(2+) were comparatively investigated in this study. The results showed that the Elovich, pseudo-second-order and Langmuir isotherm models correlated with the experimental data well. The adsorption mechanism involved the complexation between phosphate and zirconium. Coexisting Mg^(2+) slightly inhibited the adsorption of phosphate on ZrO_2(5.3), including the adsorption capacity and rate, but coexisting Mg^(2+) greatly increased the adsorption capacity and rate for ZrO_2(7.1)and ZrO_2(10.5). The enhanced adsorption of phosphate on ZrO_2(7.1) and ZrO_2(10.5) in the presence of Mg^(2+) was mainly due to the formation of Mg^(2+)-HPO_4^(2-) ion pair(MgHPO_4~0) in the solution and then the adsorption of MgHPO_4~0 on the adsorbent surface, forming the phosphatebridged ternary complex Zr(OPO_3H)Mg. In the absence of Mg^(2+) , the maximum phosphate adsorption capacity at pH 7 calculated from the Langmuir isotherm model decreased in the order of ZrO 2(7.1)(67.3 mg/g) > ZrO_2(5.3)(53.6 mg/g) ≈ ZrO_2(10.5)(53.1 mg/g), but it followed the order of Zr O2(7.1)(97.0 mg/g) > ZrO_2(10.5)(79.7 mg/g) > ZrO_2(5.3)(51.3 mg/g) in the presence of Mg^(2+) . The results of this work suggest that ZrO_2(7.1) is more suitable for use as an adsorbent for the effective removal of phosphate from municipal wastewater than ZrO_2(5.3) and ZrO_2(10.5),because Mg^(2+) is generally present in this wastewater.展开更多
Understanding the factors underlying the interaction of water with oxide surfaces is of high technological importance for applications ranging from nuclear fuel safety to heterogeneous catalysis.However,it is a comple...Understanding the factors underlying the interaction of water with oxide surfaces is of high technological importance for applications ranging from nuclear fuel safety to heterogeneous catalysis.However,it is a complex task as numerous different factors(related to the surface and bulk properties)are involved.In the present study,we investigated the characteristics of water adsorption(quantities adsorbed and energetics)on binary oxides of fluorite structure and their mixed oxide combinations(solid solutions).Three representative oxides were chosen,differing in lattice parameter(ionic radius)and oxidation state:ThO_(2)which has a very stable Th^(4+)cation,CeO_(2)in which the cerium cations can be easily reduced to Ce^(3+),and UO_(2)in which the uranium cations tend to further oxidize to U^(5+)and U^(6+).Based on the H_(2)O adsorption isotherms and enthalpies of adsorption versus coverage,combined with X-ray photoelectron spectroscopy(XPS)study of the oxide surface,the main factors underlying the characteristics of water adsorption on the fluorite oxides were identified.The present work points to the importance of oxygen hyper-stoichiometry(in U-containing oxides)on the interaction of water with the oxide’s surface.Furthermore,correlations between Fermi level positioning and water dissociation tendencies are established.This work advances our understanding of water-oxide interactions with implications for material design in energy and environmental systems.展开更多
文摘Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF;RF = CF(CF3)OCF7, n = 2, 3;RF-(VM)n-RF] was applied to the preparation of fluoroalkyl end-capped vinyltrimethoxysilane oligomer/α-, β-, γ-cyclodextrin polymers (α-, β-, γ-CDPs) composites [RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs] by the sol-gel reaction of the corresponding oligomer in the presence of the α-, β-, γ-CDPs under alkaline conditions. The RF-(VM-SiO2)n-RF/α-, β-, γ-CDPs composites thus obtained were found to give a good dispersibility toward the traditional organic media except for water, and were applied to the surface modification of glass to provide a sueperoleophilic/superhydrophobic characteristic on the modified surface, although the corresponding RF-(VM-SiO2)n-RF nanocomposites can give a usual oleophobic/superhydrophobic property on the surface. These composites powders were also found to be applicable to the packing material for the column chromatography to separate the mixture of oil/water and the water in oil (W/O) emulsions. More interestingly, these composite powders were found to have a higher adsorption ability toward not only low-molecular weight aromatic compounds such as bisphenol A and bisphenol AF but also volatile organic compounds, compared to that of the pristine α-, β-, γ-CDPs.
文摘Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodi-acetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 - 4.5 meq/g and 2.5 - 6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% - 40% and 20% - 35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly.
基金financially supported by the National Natural Science Foundation of China (No.52372188)Natural Science Foundation of Henan (Nos.242300421625,252300421333)+4 种基金CAS Henan Industrial Technology Innovation & Incubation Center (No.2024121)Key Scientific Research Project of Education Department of Henan Province (Nos.22A150042,23A150038,and 24A150019)2023 Introduction of studying abroad talent programthe China Postdoctoral Science Foundation (No.2019 M652546)Key Project of Science and Technology of Henan Province (No.252102240007)。
文摘Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.
基金the financial support from the National Natural Science Foundation of China(Nos.21606163 and 21878205)Coal Bed Methane Joint Foundation of Shanxi(2016012006)+2 种基金Foundation of State Key Laboratory of Coal Conversion(J18-19-610)Welch Foundation(grant AX-1730)the Distinguished Scientist Fellowship Program(DSFP)at KSU.
文摘Separation of ethane from ethylene is a very important but challenging process in the petrochemical industry.Finding an alternative method would reduce the energy needed to make 170 million tons of ethylene manufactured worldwide each year.Adsorptive separation using C2H6-selective porous materials to directly produce high-purity C2H4 is more energy-efficient.We herein report the"reversed C2H6/C2H4 adsorption"in a metal–organic framework Cr-BTC via the introduction of oxygen on its open metal sites.The oxidized Cr-BTC(O2)can bind C2H6 over C2H4 through the active Cr-superoxo sites,which was elucidated by the gas sorption isotherms and density functional theory calculations.This material thus exhibits a good performance for the separation of 50/50 C2H6/C2H4 mixtures to produce 99.99%pure C2H4 in a single separation operation.
基金financially supported by the National Natural Science Foundation of China(42007181)Chinese Academy of Geological Sciences Basal Research Fund(CSJ-2024-03)National Key Research and Development Program of China(2023YFC3709104).
文摘Biochar,as an efficient,effective,and potential soil improver,has broad application prospects in the field of defluoridation.This study aimed to evaluate the defluoridation potential of iron(Fe)and manganese(Mn)co-modified biochar from groundwater.The varied Fe/Mn molar ratio(2∶1 and 1∶2)modified biochar was prepared by corncob with the pyrolysis temperature of 300℃,400℃,and 500℃.Batch experiments for fluoride(F^(-))removal were performed by corncob biochar before and after Fe-Mn modified.Their composition,structure,and performance were analyzed by multiple characterization techniques to clarify F‒removal mechanisms.Our results indicated that unmodified corncob biochar produced at 400℃(BC400)exhibited the highest F‒adsorption efficiency(87.3%)among three unmodified samples,attributable to its largest specific surface area(2.55 m^(2)/g).Notably,F‒removal amounts by Fe-Mn modified BC400 were 2 times higher than BC400.The enhanced F⁻removal performance of Fe-Mn modified biochar can be attributed to several mechanisms:(1)the modification produced rougher surface textures,resulting in an increased specific surface area(about 3.50 m^(2)/g);(2)newly formed Fe-O and Mn-O bonds on the biochar surface facilitated the formation of complexes with F^(-);and(3)the adsorption results fitted well with pseudo-second-order and Freundlich models(R^(2)>0.98),indicating that the removal process involved physicochemical adsorption.These findings demonstrate that Fe-Mn modified biochar is a highly efficient and cost-effective material for F^(-)remediation and holds significant potential for application in contaminated groundwater and soil systems.
基金the support from the National Key Research and Development Program of China (No. 2022YFC2904504)the Science and Technology Research Project of Jiangxi Provincial Department of Education, China (No. GJJ2200864)the Gansu Provincial Key Research and Development Project, China (No. 22YF7GA073)。
文摘The flotation separation of argentite from sphalerite using ammonium dibutyl dithiophosphate(ADD)was studied.Molecular simulation(MS)calculation shows that ADD is chemisorbed on argentite and sphalerite surface in the form of S—P bond.The ADD adsorption on argentite and sphalerite surface in Ag^(+)system was revealed by ICP,Zeta potential and XPS analyses.It is shown that the dissolved Ag^(+)from argentite surface can be absorbed on sphalerite surface in the form of silver hydroxide,and AgOH hydrophilic colloid prevents the adsorption of ADD on sphalerite surface.The ADD adsorption on argentite and sphalerite surface in the pulp containing silver and zinc ions was revealed by adsorption capacity and surface wettability analyses.It is shown that the combined Zn(OH)_(2) and AgOH hydrophilic colloid leads to greater ADD adsorption capacity on argentite surface and stronger surface hydrophobicity than sphalerite.Flotation tests demonstrate that ADD enables efficient separation of argentite from sphalerite in the pulp containing silver and zinc ions.
基金supported by Shaanxi Fundamental Science Research Project for Chemistry and Biology(23JHQ011)Natural Science Foundation of Shaanxi(2024JC-YBMS-115)Natural Science Basic Research Plan in Shaanxi Province of China(2025JC-YBMS-141)。
文摘The severe shuttle effect and sluggish reaction kinetics in room-temperature sodium-sulfur(RT Na-S)batteries have been major bottlenecks hindering their practical application.To overcome these challenges,a straightforward reduction approach was employed to design three bimetallic alloy nanoparticles(FeNi,FeCo,and NiCo)supported on multistage porous carbon substrates.Experimental and theoretical calculations reveal that the charge transfer within the alloy catalyst influences the position of its d-band center and its degree of hybridization with sodium polysulfides(NaPSs).An increased charge transfer leads to a shift of the alloy’s d-band center closer to the Fermi energy level,thereby enhancing its adsorption and catalytic capabilities.Among the three alloy compositions,the FeNi alloy exhibits the highest charge transfer.Consequently,the FeNi alloy demonstrates the superior electrochemical performance,achieving a high reversible specific capacity of 848.2 mA h g^(−1),with an average capacity degradation rate of only 0.037%per cycle over 1000 cycles at 1.2 C.The S/FeNi/NC cathode exhibits a low electrolyte-to-sulfur(E/S)ratio of 6.6µL mg^(−1),while maintaining a high reversible specific capacity of 568.1 mA h g^(−1).This offers valuable insights for the application of alloy catalysts in the S/FeNi/NC cathode of RT Na-S batteries.
基金supported by the National Natural Science Foundation of China(No.82373800)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011236)Continuation"Project of Excellent Doctors,Guangzhou Basic and Applied Basic Research Foundation(No.2025A04J5082).
文摘The protein corona formation has been reported to influence the liposomes’behavioral performance in vivo.Accordingly,the effect of physiologically relevant inorganic ion pairs(sodium chloride,sodium sulfate,magnesium chloride,and magnesium sulfate)was investigated.Bovine serum albumin(BSA)was selected as the model protein.Parameters including particle size and zeta potential were assessed,while various spectroscopic techniques were utilized to elucidate the changes in BSA during its interaction with liposomes.The particle size and light intensity distribution changes indicated that the introduction of inorganic pairs,especially the metal cations,could significantly influence both the adsorption of BSA and the aggregation of particles.Furthermore,spectral characterization elucidated that BSA exhibited more extended peptide chains with enhanced exposure to hydrophobic acid amino residues upon adding ion pairs.Electrostatic adsorption and chelation insertion were proposed as metal ion binding modes and the corresponding BSA corona formation.In the electrostatic adsorption mode,sodium ions can enhance the electrostatic interactions,facilitating the“connection”between BSA and liposomes.Magnesium ions can induce stronger hydrophobic interactions through chelation,effectively“drag”BSA segments into the lipid bilayer.This work highlighted important physiological factors for protein-liposome interaction and provided rational model constructions to lay the foundation for further relevant studies.
基金supported by the National Natural Science Foundation of China(Grant No.U23A2022)the National Natural Science Foundation of China(Grant No.52474047)+2 种基金the Natural Science Foundation of Chongqing(Grant No.CSTB2024NSCQ-MSX0951)the Natural Science Foundation of Sichuan Province(Grant No.2025ZNSFSC1357)the National Science and Technology Major Project(Grant No.2025ZD1404307).
文摘Injecting impure CO_(2)for enhanced gas recovery(CO_(2)-EGR)offers a dual benefit by improving natural gas extraction while enabling CO_(2)sequestration.However,the interactions between CO_(2),N_(2),and CH_(4)under reservoir conditions require further investigation.This study employs Grand Canonical Monte Carlo(GCMC)and Molecular Dynamics(MD)simulations to quantify the adsorption and diffusion behaviors of CO_(2),N_(2),and CH_(4)in quartz nanopores over a pressure range of 1-24 MPa under varying water saturations and gas compositions.The results indicate that:(1)CO_(2)exhibits the broadest energy distribution and the strongest adsorption stability,occupying about 20%-30%more adsorption sites than CH_(4)or N_(2)and showing the least sensitivity to water saturation,with only a 30%reduction at 50%saturation,compared to 60%for CH_(4),giving CO_(2)a clear competitive advantage.(2)The adsorption and desorption behaviors are strongly pressure dependent,as increasing pressure reduces the adsorption layer area and shifts gas distribution from adsorption dominated to free phase.Competitive adsorption analysis reveals that while CO_(2)dominates displacement at low pressures,mixtures that contain N_(2)achieve higher CH_(4)desorption efficiency above 13 MPa by mitigating diffusion resistance.(3)A higher N_(2)fraction improves CH_(4)diffusion coefficients,thereby facilitating gas mobility and ensuring superior recovery performance under high-pressure conditions.This study advances the fundamental knowledge of microscale gas behavior in tight sandstones and supports the feasibility of impure CO_(2)injection as a practical strategy for sustainable gas production.
基金supported by the National Natural Science Foundation of China(22175136)the State Key Laboratory of Electrical Insulation and Power Equipment(EIPE23127)the Fundamental Research Funds for the Central Universities(xtr052024009).
文摘Metal hydrides with high hydrogen density provide promising hydrogen storage paths for hydrogen transportation.However,the requirement of highly pure H_(2)for re-hydrogenation limits its wide application.Here,amorphous Al_(2)O_(3)shells(10 nm)were deposited on the surface of highly active hydrogen storage material particles(MgH_(2)-ZrTi)by atomic layer deposition to obtain MgH_(2)-ZrTi@Al_(2)O_(3),which have been demonstrated to be air stable with selective adsorption of H_(2)under a hydrogen atmosphere with different impurities(CH_(4),O_(2),N_(2),and CO_(2)).About 4.79 wt% H_(2)was adsorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)at 75℃under 10%CH_(4)+90%H_(2)atmosphere within 3 h with no kinetic or density decay after 5 cycles(~100%capacity retention).Furthermore,about 4 wt%of H_(2)was absorbed by MgH_(2)-ZrTi@10nmAl_(2)O_(3)under 0.1%O_(2)+0.4%N_(2)+99.5%H_(2)and 0.1%CO_(2)+0.4%N_(2)+99.5%H_(2)atmospheres at 100℃within 0.5 h,respectively,demonstrating the selective hydrogen absorption of MgH_(2)-ZrTi@10nmAl_(2)O_(3)in both oxygen-containing and carbon dioxide-containing atmospheres hydrogen atmosphere.The absorption and desorption curves of MgH_(2)-ZrTi@10nmAl_(2)O_(3)with and without absorption in pure hydrogen and then in 21%O_(2)+79%N_(2)for 1 h were found to overlap,further confirming the successful shielding effect of Al_(2)O_(3)shells against O_(2)and N_(2).The MgH_(2)-ZrTi@10nmAl_(2)O_(3)has been demonstrated to be air stable and have excellent selective hydrogen absorption performance under the atmosphere with CH_(4),O_(2),N_(2),and CO_(2).
文摘Adsorption is becoming an important method in water and wastewater treatment technology at low concentrations. Pb2+ adsorption at low concentration onto various solid surfaces using either nano metal oxide of MnO2, or granulated activated carbon (GAC) or agricultural by-products such as tea leaves and coffee residue are considered promising. In this adsorption study the measurements were conducted by equilibrating Lead solutions at different concentrations range 19 - 291 μmol·L-1 with various adsorbent suspensions in the concentration range 0.388 - 8.738 g·L-1. Comparing all the adsorption capacities calculated using Langmuir equation Pb2+ adsorption by MnO2 shows the highest adsorption capacity with the estimated Γm = 528.0 μmol·g–1 at a fixed equilibrium constant K = 0.0119 L·μmoL-1. In addition, the Pb2+ adsorption by coffee residue is subject to a particle concentration effect in which the adsorption density decreases as the concentration of solid adsorbent Cs is increased. The Pb2+ adsorption by tea leaves, MnO2 and GAC shows less dependency to the concentration of solid adsorbent Cs, especially at lower metal ion concentrations. In the particular case of Pb2+ adsorption on MnO2 there appears to be no dependence on Cs.
基金Supported by National Natural Science Foundation of China(51674209)Sichuan Province Youth Science and Technology Innovation Team(2021JDTD0017).
文摘Static adsorption and dynamic damage experiments were carried out on typical 8#deep coal rock of the Carboniferous Benxi Formation in the Ordos Basin,NW China,to evaluate the adsorption capacity of hydroxypropyl guar gum and polyacrylamide as fracturing fluid thickeners on deep coal rock surface and the permeability damage caused by adsorption.The adsorption morphology of the thickener was quantitatively characterized by atomic force microscopy,and the main controlling factors of the thickener adsorption were analyzed.Meanwhile,the adsorption mechanism of the thickener was revealed by Zeta potential,Fourier infrared spectroscopy and X-ray photoelectron spectroscopy.The results show that the adsorption capacity of hydroxypropyl guar gum on deep coal surface is 3.86 mg/g,and the permeability of coal rock after adsorption decreases by 35.24%–37.01%.The adsorption capacity of polyacrylamide is 3.29 mg/g,and the permeability of coal rock after adsorption decreases by 14.31%–21.93%.The thickness of the thickener adsorption layer is positively correlated with the mass fraction of thickener and negatively correlated with temperature,and a decrease in pH will reduce the thickness of the hydroxypropyl guar gum adsorption layer and make the distribution frequency of the thickness of polyacrylamide adsorption layer more concentrated.Functional group condensation and intermolecular force are chemical and physical forces for adsorbing fracturing fluid thickener in deep coal rock.Optimization of thickener mass fraction,chemical modification of thickener molecular,oxidative thermal degradation of polymer and addition of desorption agent can reduce the potential damages on micro-nano pores and cracks in coal rock.
基金financially supported by the National Natural Science Foundation of China (Nos. 51303028, 31771893, and 31401609)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University (No. SKLPEE-KF201720)
文摘In this work,poly(vinylidene fluoride)(PVDF)membranes with hydrophilicity as well as preeminent mechanical strength and dye removal efficiency were fabricated by blending with three dimensional hydroxyapatite nanoparticles(HAPNPs).Surface chemical composition and morphology of the prepared membranes were systematically investigated by ATR-FTIR,XPS,XRD,FESEM,and EDS mapping analyses.The results verified that a large number of HAPNPs were successfully embedded on the modified membrane crosssections.Moreover,HAPNPs content in the casting solution is an important factor that could have profound influence on the structures and performances of PVDF/HAPNPs blend membranes.The optimal membrane M2 with 2 wt%HAPNPs exhibited excellent hydrophilicity,outstanding mechanical strength of 19.60 MPa,and high water flux of(2466±31)L·m^2·h^-1.The maximum static adsorption capacity of the optimal membrane was about 10.83 mg/g,which is 3.75 times that of the pristine PVDF membrane(2.89 mg/g).PVDF/HAPNPs membranes were not only utilized for static adsorption,but also applied to dynamic dye removal.The possible adsorption mechanism between Congo red(CR)and HAPNPs embedded on the blend membranes was firstly discussed in this work.HAPNPs interacted with CR via Lewis reaction,hydrogen bond interaction,as well as electrostatic attraction to achieve the adsorption effect.Herein,the PVDF/HAPNPs blend membranes with extraordinary hydrophilicity,mechanical strength,and dye removal efficiency possess tremendous potential for practical applications of wastewater treatment.
文摘The feasibility of durian tree sawdust (DTS), coconut coir (CC) and oil palm empty fruit bunch (EFB) as low-cost biosorbents for the removal of Cu(II), Pb(II) and Zn(II) ions from aqueous solutions was investigated. The effects of solution pH and initial metal concentration on adsorption capacity were examined in batch experiments. The affinity and the adsorption capacity of DTS, CC and EFB were evaluated. The adsorption behaviour of Cu(II), Pb(II) and Zn(II) ions onto DTS, CC and EFB was described using Freundlich and Langmuir isotherm models. The separation factor (RL) analysis suggests that the removal of metal ions onto three agricultural wastes studied was favourable. The maximum adsorption capacities (Q) estimated from the Langmuir isotherm model for Cu(II), Pb(II) and Zn(II) were 18.42, 20.37 and 22.78 mg/g for DTS, 18.38, 37.04 and 24.39 mg/g for CC, and 26.95, 37.59 and 21.19 mg/g for EFB, respectively. The characterisation studies were carried out using Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX) and Fourier Transform Infrared Spectrometer (FTIR). The surface morphology of the biosorbents changed significantly following interaction with metal ions. The primary adsorption mechanism was complexation between metal ions and binding sites of biosorbents. Both hydroxyl and amine groups are the main binding sites in DTS, CC and EFB.
文摘Adsorption and desorption mechanisms of methylene blue (MB) removal with iron-oxide coated porous ce-ramics filter (IOCPCF) were investigated in batch and column mode. The results revealed that MB removal mechanisms included physical adsorption and chemical adsorption, of which chemical adsorption by surface ligand complex reaction played a dominant role after infrared spectrum analysis. Recycling agents were se-lected from dilute nitric acid (pH=3), sodium hydroxide solution (pH=12) and distilled water. Among three agents, dilute metric acid (pH=3) was the best recycling agent. Regeneration rate of IOCPCF arrived at 82.56% at batch adsorption and regeneration was finished in 75min at column adsorption. Adsorp-tion-desorption cycles of IOCPCF after batch and column adsorption were four and three times, respectively. Further, compared with fresh IOCPCF, MB removal rate with these desorbed IOCPCF adsorption only slightly decreased, which suggested that IOCPCF should be used repeatedly.
基金the financial support provided by the National Natural Science Foundation of China(22478267,22438009,U24A20535)Basic Research Program of Jiangsu province(BK20243002)+1 种基金Prospective Application Research Project of Suzhou(SYC2022042)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Antibiotics,as an emerging pollutant due to their extensive use and difficulty in biodegradation,can cause harm to health through bioaccumulation.To address this,various photocatalysts have been developed for rapid antibiotic removal.However,their low concentrations limit mass transfer efficiency,resulting in suboptimal performance.Adsorption is crucial for enhancing photocatalytic efficiency.In this study,a series of binary heterojunction catalysts(x%BWO@STHP)were synthesized,consisting of Bi_(2)WO_(6)(BWO)grafted with sulfonated triptycene-based hypercrosslinked polymer(STHP).The high specific surface area of STHP,combined withπ-πconjugation and ionic interactions with antibiotics,significantly enhances adsorption capacity.This facilitates effective contact between low-concentration pollutants in aqueous solutions and the active sites of the catalyst.The formation of a Z-scheme heterojunction between BWO and STHP facilitates photogenerated charge separation,and further significantly improves photocatalytic degradation performance.Specifically,the 20%BWO@STHP catalyst achieved rapid adsorption equilibrium for oxytetracycline(OTC),doxycycline(DOX),and tetracycline(TC)within 2 min and completely degraded them after 15 min of irradiation.Compared to pristine BWO,the photocatalytic reaction rate constants are significantly increased,being 9.69 times higher for OTC and 13.45 times higher for DOX.The catalyst exhibits excellent reusability and holds promising potential for practical applications.
文摘This study investigated the removal of hexavalent chromium, Cr(VI) from aqueous solution by adsorption using palm oil fuel ash (POFA), an agricultural waste from the palm oil industry. POFA adsorbent was characterized by X-ray diffraction (XRD) analysis. Batch adsorption study revealed that the optimum conditions for the removal were as follows: pH 2, adsorbent dosage 80 g/L and contact time of 6 min, which resulted in 92% removal and 0.464 mg/g maximum adsorption capacity. Adsorption isotherm and kinetic studies showed that Freundlich isotherm and pseudo-second-order kinetic models fitted best to the experimental data. Column adsorption study at 5 mL/min of flow rate showed that 90% removal was obtained at 2 min of contact time which represented its breakthrough point. The column reached saturation at 30 min and the maximum column adsorption capacity recorded was 0.412 mg/g. The column adsorption behavior showed good fit with both Thomas and Yoon-Nelson kinetic models. These findings suggested that the utilization of POFA as a low-cost adsorbent to remove Cr(VI) from wastewater, either in batch or fixed bed adsorption system is not only effective, but concurrently will help to reduce wastes from the palm oil industry.
文摘The possibility of a graphene bilayer nanosensor for the detection of explosive molecules was modeled using computational chemistry. A pore was designed on a graphene bilayer structure with three strategically placed perimeter hydroxyl (OH) groups built around the edge of an indented, two-dimensional hexagonal pore. This hydroxylated pore and models of various explosive molecules were optimized using MM2 molecular mechanics parameters. Values were calculated for the molecule-surface interaction energy (binding energy), E, for 22 explosive molecules on a flat graphene bilayer and on the specially designed hydroxylated pore within the bilayer. The molecule-surface binding energy for trinitrotoluene (TNT) increased from 17.9 kcal/mol on the flat graphene bilayer to 42.3 kcal/mol on the hydroxylated pore. Due to the common functionality of nitro groups that exist on many explosive molecules, the other explosive molecules studied gave similar enhancements based on the specific hydrogen bonding interactions formed within the pore. Each of the 22 explosive adsorbate molecules showed increased molecule-surface interaction on the bilayer hydroxylated pore as compared to the flat bilayer. For the 22 molecules, the average E for the flat graphite surface was 15.8 kcal/mol and for the hydroxylated pore E was 33.8 kcal/mol. An enhancement of adsorption should make a detection device more sensitive. Nanosensors based on a modified graphene surface may be useful for detecting extremely low concentrations of explosive molecules or explosive signature molecules.
基金supported by the Shanghai Natural Science Foundation (No.15ZR1420700)the National Science Foundation of China (Nos.51408354 and 50908142)the Scientific Research Project of Shanghai Science and Technology Committee (No.10230502900)
文摘To understand the effect of precipitation pH and coexisting Mg^(2+) on phosphate adsorption onto zirconium oxide(ZrO_2), ZrO_2 particles precipitated at pH 5.3, 7.1 and 10.5, i.e., ZrO_2(5.3), ZrO_2(7.1)and ZrO_2(10.5), respectively were prepared and characterized, then their adsorption performance and mechanism in the absence and presence of Mg^(2+) were comparatively investigated in this study. The results showed that the Elovich, pseudo-second-order and Langmuir isotherm models correlated with the experimental data well. The adsorption mechanism involved the complexation between phosphate and zirconium. Coexisting Mg^(2+) slightly inhibited the adsorption of phosphate on ZrO_2(5.3), including the adsorption capacity and rate, but coexisting Mg^(2+) greatly increased the adsorption capacity and rate for ZrO_2(7.1)and ZrO_2(10.5). The enhanced adsorption of phosphate on ZrO_2(7.1) and ZrO_2(10.5) in the presence of Mg^(2+) was mainly due to the formation of Mg^(2+)-HPO_4^(2-) ion pair(MgHPO_4~0) in the solution and then the adsorption of MgHPO_4~0 on the adsorbent surface, forming the phosphatebridged ternary complex Zr(OPO_3H)Mg. In the absence of Mg^(2+) , the maximum phosphate adsorption capacity at pH 7 calculated from the Langmuir isotherm model decreased in the order of ZrO 2(7.1)(67.3 mg/g) > ZrO_2(5.3)(53.6 mg/g) ≈ ZrO_2(10.5)(53.1 mg/g), but it followed the order of Zr O2(7.1)(97.0 mg/g) > ZrO_2(10.5)(79.7 mg/g) > ZrO_2(5.3)(51.3 mg/g) in the presence of Mg^(2+) . The results of this work suggest that ZrO_2(7.1) is more suitable for use as an adsorbent for the effective removal of phosphate from municipal wastewater than ZrO_2(5.3) and ZrO_2(10.5),because Mg^(2+) is generally present in this wastewater.
基金Open access funding provided by Ben-Gurion University
文摘Understanding the factors underlying the interaction of water with oxide surfaces is of high technological importance for applications ranging from nuclear fuel safety to heterogeneous catalysis.However,it is a complex task as numerous different factors(related to the surface and bulk properties)are involved.In the present study,we investigated the characteristics of water adsorption(quantities adsorbed and energetics)on binary oxides of fluorite structure and their mixed oxide combinations(solid solutions).Three representative oxides were chosen,differing in lattice parameter(ionic radius)and oxidation state:ThO_(2)which has a very stable Th^(4+)cation,CeO_(2)in which the cerium cations can be easily reduced to Ce^(3+),and UO_(2)in which the uranium cations tend to further oxidize to U^(5+)and U^(6+).Based on the H_(2)O adsorption isotherms and enthalpies of adsorption versus coverage,combined with X-ray photoelectron spectroscopy(XPS)study of the oxide surface,the main factors underlying the characteristics of water adsorption on the fluorite oxides were identified.The present work points to the importance of oxygen hyper-stoichiometry(in U-containing oxides)on the interaction of water with the oxide’s surface.Furthermore,correlations between Fermi level positioning and water dissociation tendencies are established.This work advances our understanding of water-oxide interactions with implications for material design in energy and environmental systems.
