Surface Adsorption Behavior Research Articles

Unveiling the Influence of Antimony Substitution on the Surface Properties and Adsorption Behavior of Ferrihydrite: From Molecular Mechanisms to Environmental Implications.

Antimony(V) substitution is common in secondary ferrihydrite, especially in mining areas and tailings. However, its impact on the adsorption behavior of ferrihydrite is still unclear. Therefore, this study investigated the influential mechanisms of Sb(V) substitution on the lattice structure and surface properties of Sb-substituted ferrihydrite (SbFh), and its adsorption of coexisting Sb(OH)6-. Antimony(V) is substituted at Fe1 sites and is primarily distributed on the surface. Substitution has opposing effects on the outer- and inner-sphere complexation of Sb(OH)6-. On one hand, substituted-Sb(V) transfers more positive charges to ≡FeOH, reducing the number of H bonds. Subsequently, the charge saturation of ≡FeOH decreases, surface charge increases, and outer-sphere complexation is promoted. On the other hand, the elevated bond valence of Sb-O increases charge saturation of ≡FeOH, reducing the charge capacity that ≡FeOH can accommodate from inner-sphere complexes. Thus, inner-sphere complexation is inhibited. Inner-sphere complexation plays a more important role, and Sb(OH)6- adsorption is inhibited. Additionally, the primary complexation modes of Sb(OH)6- transform from bidentate to monodentate complexation. This research has important implications for understanding the environmental behavior of ferrihydrite, as well as the fate and bioavailability of antimony in mining areas and tailings.

Polyacrylate modified Cu electrode for selective electrochemical CO2 reduction towards multicarbon products

Highly selective production of value-added multicarbon (C2+) products via electrochemical CO2 reduction reaction (eCO2RR) on polycrystalline copper (Cu) remains challenging. Herein, the facile surface modification using poly (α-ethyl cyanoacrylate) (PECA) is presented to greatly enhance the C2+ selectivity for eCO2RR over polycrystalline Cu, with Faradaic efficiency (FE) towards C2+ products increased from 30.1% for the Cu electrode to 72.6% for the obtained Cu-PECA electrode at −1.1 V vs. reversible hydrogen electrode (RHE). Given the well-determined FEs towards C2+ products, the partial current densities for C2+ production could be estimated to be −145.4 mA cm−2 for the Cu-PECA electrode at −0.9 V vs. RHE in a homemade flow cell. In-situ spectral characterizations and theoretical calculations reveal that PECA featured with electron-accepting −C≡N and −COOR groups decorated onto the Cu electrode could inhibit the adsorption of *H intermediates and stabilize the *CO intermediates, given the redistributed interfacial electron density and the raised energy level of d-band center (Ed) of Cu active sites, thus facilitating the C–C coupling and then the C2+ selective production. This study is believed to be guidable to the modification of electrocatalysts and electrodes with polymers to steer the surface adsorption behaviors of reaction intermediates to realize practical eCO2RR towards value-added C2+ products with high activity and selectivity.

Exploration of surface tension measurement methods for pharmaceutical excipients

Surface tension is a crucial functional indicator for various classes of pharmaceutical excipients, as highlighted in both the Pharmacopoeia of the People’s Republic of China (ChP) < 9601 Guidelines for Functionality-related Characteristics of Pharmaceutical Excipients > and the United States Pharmacopoeia (USP) < 1059 Excipient Performance >. However, there are few systematic studies on surface tension measurement of pharmaceutical excipients, resulting in a lack of stable parameter support in practical applications. In this study, we aim to fill this gap by exploring three different methods for measuring surface tension. These methods were carefully developed taking into account the actual measurement process and statistical theory, thus ensuring their applicability and reliability. Through comparative analyses, we have identified the most suitable measurement methods for different classes of pharmaceutical excipients. In addition, this paper describes the surface adsorption behavior of various excipients. Therefore, this study provides valuable guidance for the determination of surface tension and the study of surface adsorption behavior, which lays the foundation for further comprehensive research in the field of surface tension of pharmaceutical excipients and the improvement of general pharmacopoeia specification.

Enrichment-Sensing All-in-One Strategy Integrated in the La(OH)3-Au@AgNPs Substrate for Rapid Surface-Enhanced Raman Spectroscopy Analysis of Purine Components.

Improving the speediness of complex sample analysis has attracted much research interest in analytical science. In this work, an enrichment-sensing all-in-one strategy was presented for rapid surface-enhanced Raman spectroscopy (SERS) analysis of purine components by using the La(OH)3-Au@AgNPs nanocomposite. Two-dimensional (2D) La(OH)3 nanosheets with nanothickness and accessible active sites not only acted as efficient media for the rapid enrichment of analytes but also provided flat planes for the intensive decoration of Au@AgNPs nanoparticles to amplify the SERS signals of adsorbed analytes. The nanocomposite could realize the rapid enrichment-sensing of purine components in 1 min, including mercaptopurine, thioguanine, adenine, and purine. Subsequently, the surface adsorption behaviors were explored by density functional theory and the enhancement mechanisms were simulated by the finite-difference time-domain method. Moreover, the nanocomposite also exhibited good SERS performances with relative standard deviations (RSDs) of uniformity less than 6.5% (n = 23), RSDs of batch-to-batch stability less than 7.3% (n = 9), and long-term stability over 9 weeks with RSDs within 6.6%. Finally, the enrichment-sensing strategy was applied for the rapid SERS analysis of two projects: mercaptopurine in tablets and adenine in beers with detection limits of 6.0 and 0.76 μg/L and spiked recoveries of 90.9-100 and 84.2-101%, respectively. Benefiting from the high-performance enrichment medium and closely packed plasmonic nanoparticles, the enrichment-sensing all-in-one strategy possesses great potential for rapid on-site detection in food safety and pharmaceutical analysis.

Research on the evolution of adsorption behavior of asphalt and aggregate surface and its influencing factors

The adsorption between asphalt and aggregate surfaces is a crucial factor in the formation of the asphalt mixture structure, directly affecting the strength, stability, and aging rate of the mixture. This study aims to explore the physical-chemical bonding process between asphalt and aggregates and establish a reliable expression for asphalt adsorption on aggregate surfaces. The optimal wavelength and concentration of asphalt-toluene solutions were determined through Strategic Highway Research Program (SHRP) net adsorption tests. Then the aggregates' composition, shape, and texture properties were evaluated using a scanning electron microscope (SEM), needle-like content, and gray-level co-occurrence matrix. Finally, the impact of temperature, asphalt type, aggregate grain size, and surface texture on the adsorption evolution was studied based on the SHRP net adsorption test. Results showed significant differences in surface morphology among the four types of aggregates. Quartz exhibited the highest smoothness, while albite showed a high degree of roughness despite its complex surface morphology. Increasing temperature led to a decrease in the total adsorption capacity of the aggregates, especially for quartz and elpidite. The inflection points of the adsorption amount of calcite and albite shifted backward with 90# asphalt compared to 70# asphalt, indicating both physical and chemical adsorption. Additionally, changes in specific surface area had a more pronounced effect on the adsorption amount. The presence of a rich texture structure significantly increased the pre-sorption rate of the aggregates and ultimately influenced the adsorption amount. The research findings provide insights to more fully understand the evolution of adsorption behavior between asphalt and aggregate surfaces.

A cage-on-MOF strategy to coordinatively functionalize mesoporous MOFs for manipulating selectivity in adsorption and catalysis

Functionalizing porous materials with capping agents generates hybrid materials with enhanced properties, while the challenge is how to improve the selectivity and maintain the porosity of the parent framework. Herein, we developed a “Cage-on-MOF” strategy to tune the recognition and catalytic properties of MOFs without impairing their porosity. Two types of porous coordination cages (PCCs) of opposite charges containing secondary binding groups were developed to coordinatively functionalize two distinct porous MOFs, namely MOF@PCC nanocomposites. We demonstrated that the surface-capped PCCs can act as “modulators” to effectively tune the surface charge, stability, and adsorption behavior of different host MOF particles. More importantly, the MOF@PCCs can serve as selective heterogeneous catalysts for condensation reactions to achieve reversed product selectivity and excellent recyclability. This work sets the foundation for using molecular cages as porous surface-capping agents to functionalize and manipulate another porous material, without affecting the intrinsic properties of the parent framework.

New insights into mechanisms of pyrite flotation enhancement by hydrodynamic cavitation nanobubbles

Although it is well known that cavitation nanobubbles significantly improve the flotation performance of mineral particles, the effects of nanobubbles on sulfide mineral surface oxidation and reagent adsorption have not been studied sufficiently. The present study was conducted to investigate the effects of cavitation nanobubbles on oxidation characteristics and xanthate adsorption behavior of pyrite surface by means of micro-flotation tests, UV–visible spectroscopy, X-ray photoelectron spectroscopy (XPS) and zeta potential measurements. The experimental results have shown that the presence of cavitation nanobubbles in the pyrite flotation pulp enhanced the floatability and flotation kinetics of pyrite and improved the adsorption capacity of sodium amyl xanthate (SAX) and dixanthogen on pyrite surface as a result of stronger hydrophobic interactions. The reactive species generated by nanobubbles were identified to be dissolved oxygen (DO) and ·OH by quenching experiments. In addition, the zeta potential measurements have demonstrated that the rapid formation of cavitation nanobubbles on pyrite reduced the oxidation of pyrite surface. The results from this study have revealed important new mechanisms of cavitation nanobubbles enhancing sulfide mineral flotation from the perspectives of mineral surface oxidation and collector adsorption capacity and their synergistic effects that originate from unique characteristics of cavitation nanobubbles.

Understanding the impact of polyacrylamide molecular weight on the workability of cement paste

The impact of polymer admixtures on the performance of cementitious materials is certainly dependent on their molecular structures. This paper aims to elucidate the influence and mechanism of polyacrylamide (PAM) molecular weight on the workability of cement paste. The surface charge property and adsorption behavior of modified cement paste were quantified. Additionally, the assembly morphology of three molecular weight PAMs and the viscoelasticity of their solutions were monitored, so as to provide new insights into the underlying mechanisms. The findings indicate that the growth of PAM molecular weight causes a significant drop in fluidity and an improvement in plastic viscosity of modified cement paste. PAM with higher molecular weight can be adsorbed as a larger size of assembly aggregates on the cement particles, thus promoting the bridging effect. Besides, after the incorporation of PAM, the electrostatic repulsion between cement particles is decreased, whereas a higher PAM molecular weight causes a greater drop. Therefore, it is important to consider not only the dosage of PAM but also its molecular weight in practical engineering.

Shape and surface property effects on displacement enhancement by nanoparticles

This work studies the mechanisms of shape and surface property effects on multiphase displacement enhancement by nanoparticle suspensions in porous media. Three representative nanoparticles with promising industry applications, namely silica nanoparticles, graphene oxide and hydroxylated carbon nanotubes have been considered comprehensively. The correspondence between particle shape and surface property, interfacial adsorption behaviors, and displacement patterns has been analyzed systematically. Significant differences in adsorption tendencies and consequences are revealed via adsorption characterizations with theoretical derivations and microscopic modeling. For liquid–liquid interfacial adsorption, sheet-like and fibrous shapes with amphiphilicity are more beneficial to adsorption and retention at interface, which promotes dynamic interfacial tension reduction and emulsion stabilization. For solid surface adsorption, spherical and fibrous shapes with hydrophilicity are more favorable for formation of nanoscale rough structures, which induces the development and maintenance of wetting films. Visualization and quantification of multiphase displacement in complex structures via microfluidic experiments enable us to evaluate the relative performances and unravel displacement enhancement modes. Hydroxylated carbon nanotubes exhibit optimal performance, followed by graphene oxide and then silica nanoparticles, with clear distinction in interfacial phenomena. Enhanced liquid–liquid interfacial adsorption behaviors result in the invasion into un-swept regions with sweeping efficiency enhancement, whereas enhanced solid surface adsorption behaviors drive the detachment of defending phase in the form of isolated ganglia.

Orbital hybridization manipulated by doped Cu+ in NbC for boosting hydrogen evolution

Surface adsorption behavior and electron transfer determine the catalytic activity in hydrogen evolution reaction (HER). However, the inevitable surface oxidation of NbC hinders electron transfer and hydrogen conversion. The surface adsorption behavior and electron transfer of NbC are optimized by doping Cu+ as well as modifying the orbital hybridizations. Benefiting from the introduced electron interaction of Cu+, the lower p-d hybridization between Nb and O reduces the Nb-O bond and affords the Cu-NbC thinner surface oxidation layer. The reduced surface oxidation degree favors electron transfer. Further, the electron orbital hybridization modulates the electron states and optimizes the hydrogen adsorption behavior of Cu-NbC for efficient hydrogen conversion. As the electrochemical results, the obtained Cu-NbC demands 271 mV to drive 10 mA cm−2, which is 50 times higher than that of NbC (only 0.2 mA cm−2 at the same overpotential). Hence, we believe the orbital hybridization manipulation strategy renders a valuable solution for designing efficient HER catalysts.

Inhibition Mechanism of MgO Addition on High‐Temperature Oxidation of Magnetite: Density Functional Theory and Ab Initio Molecular Dynamics Methods Joint Research and Experimental Verification

In order to investigate and analyze the effect of MgO gangue on the surface adsorption and oxidation behavior of magnetite, the physicochemical properties of substances in the magnetite oxidation process are investigated in this study by using thermogravimetric experiments, density functional theory, and ab initio molecular dynamics methods (AIMD) methods. The oxidation mechanism of magnetite and the inhibition mechanism of magnesium oxide on the oxidation properties of magnetite are elucidated. The results of the thermogravimetric experimental study show that the initial oxidation temperature of magnetite tends to increase with the increase of MgO content. At the same time, the presence of MgO leads to the migration of oxidation reactions to the high‐temperature region. AIMD study shows that the presence of the gangue element Mg prolongs the adsorption and dissociation time of O2 molecules on the surface and reduces the interfacial chemical reaction rate of Fe3O4. Moreover, the chemical bonds formed in the system after doping Mg atom are more stable, which is not conducive to the migration of oxygen atoms between Fe3O4 crystal structures, thus affecting the comprehensive oxidation performance of minerals.

Sub PPM Detection of NO2 Using Strontium Doped Bismuth Ferrite Nanostructures.

The present work investigates the NO2 sensing properties of acceptor-doped ferrite perovskite nanostructures. The Sr-doped BiFeO3 nanostructures were synthesized by a salt precursor-based modified pechini method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The synthesized materials were drop coated to fabricate chemoresistive gas sensors, delivering a maximum sensitivity of 5.2 towards 2 ppm NO2 at 260 °C. The recorded values of response and recovery time are 95 s and 280 s, respectively. The sensor based on Bi0.8Sr0.2FeO3-δ (BSFO) that was operated was shown to have a LOD (limit of detection) as low as 200 ppb. The sensor proved to be promising for repeatability and selectivity measurements, indicating that the Sr doping Bismuth ferrite could be a potentially competitive material for sensing applications. A relevant gas-sensing mechanism is also proposed based on the surface adsorption and reaction behavior of the material.

Adsorption behavior and mechanism analysis of siloxane thickener for CO2 fracturing fluid on shallow shale soil

Reducing the adsorption of CO2 thickeners in soil particles of shallow shale is a pathway to protect the shale environment and water cycle. In this work, we first synthesized a siloxane-based thickener named AOB based on ring-opening polymerization and hydrosilylation reaction and discussed the influence of geological factors (including contents, pressure, temperature and shear rate) on the adsorption capacity of this thickener. The soil surface adsorption behavior of AOB was characterized by a self-assembled high-pressure soil adsorption device and the adsorption capacity was analyzed by Attenuated Total Reflectance Infrared Spectroscopy (ATR-FTIR). The results showed that AOB molecule belongs to the monolayer adsorption type on the soil surface by measuring the contents. Moreover, an inverse relationship was showed between pressure and adsorption capacity for AOB, while the significantly proportional relationship was presented for temperature and shear rate, respectively. It is found that the combined force formed by soil repulsion (originated from aromatic groups in AOB) and grid drag weakens the adsorption of AOB on the soil surface, resulting in a much lower adsorption capacity than the commercial PDMS. This work not only paves a new avenue for synthesizing siloxane-based polymer as CO2 thickener, but also provides an efficient measure to reduce the adsorption of thickener on the shallow soil.

First-principles study for self-limiting growth of GaN layers on AlN(0001) surface

The GaN thickness dependence of surface structural stability and adsorption behavior of Ga adatom in GaN layers on a AlN(0001) surface are investigated on the basis of first-principles calculations to clarify the self-limiting growth on AlN(0001) surface during metal-organic vapor phase epitaxy. The calculations demonstrate that the stability of reconstructed GaN layers on a AlN(0001) surface is similar to that of a GaN(0001) surface irrespective of the GaN film thickness. Furthermore, we find that the adsorption of a Ga adatom on the AlN(0001) surface easily occurs compared with that on AlN(0001) surface with GaN layers. The difference in the adsorption behavior implies that the growth of GaN layers on a AlN(0001) surface is suppressed. The calculated results provide theoretical guidance for understanding the self-limiting growth of GaN layers, resulting in the formation mechanism of GaN quantum wells.

Reasonable intrinsic microstructure of microcrystalline graphite for high-rate and long-life potassium-ion batteries

Carbon materials, including non-graphite carbon and graphite have been extensively studied as anode materials for Potassium-ion batteries (PIBs). However, due to the slow kinetics of potassiation, it is still challenging to obtain anode materials with rate capability, good stability and low price. Microcrystalline graphite (MG) possesses ordered graphene layers and abundant interparticle voids and correspondingly undergoes a surface adsorption behavior at first and then the intercalation of K+ at low potential, which is conductive to high energy density. In addition, the larger interplanar spacing of MG with suitable crystalline size can stand for the fluctuation of interlaminar spacing caused by repeated K+ bombardment because strain in such structure can be relaxed due to sufficiently available free space. When used as anode material of PIBs, microcrystalline graphite can deliver a high reversible capacity of 249 mAh g−1 at 100 mA g−1 after 100 cycles in a readily-available electrolyte of 0.8 M KPF6 in EC/DEC (1:1 vol%), which offer a significant cost-saving opportunity. Furthermore, compared to flake graphite and soft carbon, MG exhibits the highest capacity of 139 mAh g−1 at 500 mA g−1 after 500 cycles. Our investigations will greatly promote the MG's industrial development in China.

Differential Surface Interactions and Surface Templating of Nucleotides (dGMP, dCMP, dAMP, and dTMP) on Oxide Particle Surfaces.

The fate of biomolecules in the environment depends in part on understanding the surface chemistry occurring at the biological-geochemical (bio-geo) interface. Little is known about how environmental DNA (eDNA) or smaller components, like nucleotides and oligonucleotides, persist in aquatic environments and the role of surface interactions. This study aims to probe surface interactions and adsorption behavior of nucleotides on oxide surfaces. We have investigated the interactions of individual nucleotides (dGMP, dCMP, dAMP, and dTMP) on TiO2 particle surfaces as a function of pH and in the presence of complementary and noncomplementary base pairs. Using attenuated total reflectance-Fourier transform infrared spectroscopy, there is an increased number of adsorbed nucleotides at lower pH with a preferential interaction of the phosphate group with the oxide surface. Additionally, differential adsorption behavior is seen where purine nucleotides are preferentially adsorbed, with higher surface saturation coverage, over their pyrimidine derivatives. These differences may be a result of intermolecular interactions between coadsorbed nucleotides. When the TiO2 surface was exposed to two-component solutions of nucleotides, there was preferential adsorption of dGMP compared to dCMP and dTMP, and dAMP compared to dTMP and dCMP. Complementary nucleotide base pairs showed hydrogen-bond interactions between a strongly adsorbed purine nucleotide layer and a weaker interacting hydrogen-bonded pyrimidine second layer. Noncomplementary base pairs did not form a second layer. These results highlight several important findings: (i) there is differential adsorption of nucleotides; (ii) complementary coadsorbed nucleotides show base pairing with a second layer, and the stability depends on the strength of the hydrogen bonding interactions and; (iii) the first layer coverage strongly depends on pH. Overall, the importance of surface interactions in the adsorption of nucleotides and the templating of specific interactions between nucleotides are discussed.

Platinum enrichment in marine ferromanganese oxides: Constraints from surface adsorption behavior on synthetic feroxyhyte (δ-FeOOH)

Several recent studies have reported a strong association between Pt and iron-bearing minerals in marine ferromanganese oxides. However, due to the low Pt abundance (hundreds of ppb) in these ferromanganese oxides, the mechanism and controlling factors of Pt enrichment in ferromanganese oxides are not clear. Feroxyhyte is an important constituent of marine ferromanganese oxides and is thought to play an important role in Pt enrichment. Here, we used feroxyhyte as the representative of Fe minerals in the marine ferromanganese oxides to study the adsorption behavior and molecular scale adsorption mechanisms of Pt at the water-feroxyhyte interface. The study employed a combination of Pt adsorption/desorption experiments with the participation of various ionic salts, and X-ray absorption fine structure (XAFS) analyses. The adsorption/desorption experimental results showed that the presence of phosphate, ammonium and low pH environment would inhibit Pt enrichment on feroxyhyte. Pt LIII-edge XAFS analysis shows that Pt is oxidized on the feroxyhyte surface, transforming Pt (II) to Pt (IV) (OH)62−. According to the experiment results, this study proposed a hypothesis of the mechanism of Pt enrichment by feroxyhyte. Pt (II) Cl42−is considered to be the main form of Pt in seawater. [PtCln(OH)4−n]2− produced by the hydrolysis of [PtCl4]2− is adsorbed to the feroxyhyte surface through dehydration condensation, and then oxidized to Pt (IV) (OH)62−. Our results clarify the molecular-scale mechanism of Pt adsorption and fixation on feroxyhyte, and provide insights on the geochemical behavior of Pt.

Deep dewatering of bauxite residue via the synergy of surfactant, coagulant, and flocculant: Effect of surfactants on dewatering and settling properties

Complex surface properties and high fineness of bauxite residue (BR) make it hard to compact and settle, which reduces the solid content of the BR cake and solid–liquid separation efficiency. The proposed three-step procedure involving surface wettability adjustment, charge neutralization, and flocculation through the synergy of surfactants, lime, and polyacrylamide (PAM) was carried out. Polycarboxylate superplasticizer (PCE) significantly improved BR dewaterability and decreased the water content from 45.85% to 36.71% (2%) compared with the original BR cake. But the solid recovery also reduced from 93.29% to 89.28% (2%), and the BR slurry was still a stable suspension. The synergy of PCE (0.5%), lime, and PAM effectively coagulated and flocculated the BR particles, and improved BR dewaterability. The average BR particle sizes enlarged from about 10 µm to 22 µm, and the solid recovery and settling rate elevated to 99.35% and 1.596 m/h. The water content of the BR cake reduced from 52.33% to 47.18% compared without PCE addition. The surface behavior and adsorption behavior analysis showed that PCE neutralized the surface charge and decreased the surface tension of BR particles with the adsorption of PCE on its surface. The study gave a feasible suggestion for the efficient dewatering and fast settling of BR.

Surface adsorption and anticorrosive behavior of benzimidazolium inhibitor in acid medium for carbon steel corrosion

Surface adsorption and anticorrosive behavior of benzimidazolium inhibitor in acid medium for carbon steel corrosion

Incorporating hard-soft acid-base theory in multi-aspect analysis of the adsorption mechanism of aqueous heavy metals by graphene oxide

Water contamination by heavy metals is a serious environmental concern. To unravel the “species resolved” interaction mechanism of heavy metals with graphene oxide (GO), a multi-aspects analyses incorporating metal species distribution, GO surface charge, adsorption behavior and fitting, hard-soft acid-base (HSAB) theory, Fourier transformation infrared spectroscopy and X-ray photoelectron spectroscopy were performed. For pH 7 and T = 25 °C, adsorptions of aqueous Cd(Ⅱ) and Pb(Ⅱ) with equal initial concentrations of 300 mg L−1 by GO at 500 mg L−1 equilibrated in 15 min. The corresponding adsorption percentage and quantity for Cd(Ⅱ) were 98.04% and 588.22 mg g−1 and those for Pb(Ⅱ) were 92.10% and 552.56 mg g−1. When pH ≤ 7, bare Cd2+ and Pb2+ were the dominant metal species adsorbed by GO via ion exchange and chemical complexation. When pH ≥ 7, hydroxyl-complexed species were the dominant ones adsorbed by GO via precipitation, ion exchange, and chemical complexation. Electron transfer and energy lowering induced by the GO–heavy metal interaction, calculated based on HSAB theory, illuminated two points: (1) OH had a stronger binding affinity than COOH toward either Cd(Ⅱ) or Pb(Ⅱ) and (2) either OH or COOH had a stronger binding affinity toward Cd(Ⅱ) than Pb(Ⅱ). Explorations of this work may provide guidance in developing efficient graphene-based adsorbents for wastewater remediation.