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Overuse of fossil fuels and anthropogenic activities have led to excessive emissions of carbon dioxide, leading to global warming, and measures to reduce atmospheric carbon dioxide concentrations are needed to overcome this global challenge. Therefore, exploring an environmentally friendly strategy for capturing airborne CO2 and converting it into high‐value‐added chemicals offers a promising pathway toward “carbon neutrality”. In recent years, porous organic polymers have attracted much attention for carbon capture and the catalytic conversion of carbon dioxide because of their high specific surface area, high chemical stability, nanoscale porosity, and structural versatility, which make them easy to functionalize. In this review, we introduce the preparation methods for various POPs, the types of POPs adsorbed during carbon dioxide capture, and the progress in the use of POPs for the photocatalytic and chemicatalytic conversion of carbon dioxide, with a special discussion on the influence of adsorption type on the efficiency of catalytic conversion. Finally, we propose a prospective direction for the subsequent development of this field. [ABSTRACT FROM AUTHOR]

Organosulfur compounds are regarded as a kind of prospective cathode materials for lithium batteries due to their high theoretical specific capacity. However, they still suffer from the issues of sluggish redox kinetics and low utilization. The rational design of the cathode host for effectively confining active materials and accelerating the sluggish sulfur kinetics is an effective strategy. Herein, the study synthesizes an atomic‐scale single‐atom cobalt catalyst and interweave it with CNTs to fabricate an ideal host material (donated as CoSANC@CNTs) for the cathode in Li–PTS batteries. Electrochemical measurements reveal that CoSANC not only efficiently accelerates the redox kinetics in the whole reaction process but also shows excellent adsorption capacity, which is corroborated by the theoretical calculation results as well. As excepted, the Li–PTS battery equipped with CoSANC@CNTs electrode delivers an outstanding long cycling stability with a high initial specific capacity of 550.2 mAh g−1 and a slow capacity decay rate of 0.05% per cycle over 700 cycles at 1 C. Even under a high PTS loading of 8.6 mg cm−2, the PTS/CoSANC@CNTs cathode is still maintained with an excellent capacity retention of 91.1% at 0.1 C after 50 cycles. [ABSTRACT FROM AUTHOR]

Copyright of Iraqi Journal of Chemical & Petroleum Engineering is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Gas adsorption on solid surfaces can be categorized into two types: physical adsorption and chemical adsorption. By applying knowledge of surface chemistry, this study aims to simulate and analyze experimental results in the resistive gas sensing process. The objective is to investigate the adsorption behavior and utilize it as research material for undergraduate innovation and entrepreneurship projects and undergraduate thesis designs. This research will enhance students’ understanding of gas-solid adsorption principles, improve their ability to apply theory to practice, and cultivate their scientific research skills. [ABSTRACT FROM AUTHOR]

The purpose of this study is to reveal the adsorption mechanism of oxygen molecules on gold clusters. density functional theory is employed to investigate the low-energy structure of multiple O2 adsorption on the Au10+ cluster and findings are compared with IR spectra. The nature of bonding of the O2 molecule and Au10+ cluster has been characterised through several metrics like binding energy, dissociation energy, bond length, and vibrational frequencies. The result shows that the lowest-energy structures are prism-shaped rather than tetrahedron-shaped, where only one O2 is chemically adsorbed while others are physically adsorbed. Chemically adsorbed η2-O2 behaves like free O2–, forming a single electron π bond with Au10+, while physically adsorbed η1-O2 does not result in an effective chemical bond and behaves like free O2. This study provides insights into the mechanism of oxygen molecule adsorption on gold clusters and can contribute to further research on the catalytic mechanism of gold clusters. Highlights Lowest energy structures are prism-shaped rather than tetrahedron-shaped, which is supported by IR spectrum and chemical hardness. Chemically adsorbed O2 is activated and displays structural and spectral features of free O2–, while physically adsorbed O2 is close to free O2 in vibrational frequency and bond length. Chemical adsorption is equivalent to a single electron π bond while physical adsorption forms no effective chemical bond due to the lack of electronic pairing between Au10+ and O2. [ABSTRACT FROM AUTHOR]

A novel hierarchically nanostructured magnetite (Fe3O4) was manufactured using microwave-assisted reflux method without surfactants. The nanostructured Fe3O4 is formed via the co-precipitation of Fe(III) and Fe(II), followed by a nanocrystal aggregation-based mechanism. Moreover, the effects of solution pH, contact time, initial Sb concentration, coexisting anions, and recycle numbers on the adsorption of nanostructured Fe3O4 toward Sb were extensively examined in the batch adsorption tests. The results demonstrated that the obtained Fe3O4 exhibited excellent adsorption ability toward Sb with the maximum adsorption capacities of 154.2 and 161.1 mg.g−1 for Sb(III) and Sb(V), respectively. The prepared Fe3O4 could be easily regenerated and reused for adsorption/desorption studies multiple times without compromising the Sb adsorption ability. Further exploration indicated that the oxidation or reduction reactions infrequently occurred during Sb adsorption processes. The proposed hierarchically nanostructured Fe3O4 thus could be potentially used for sustainable and efficient antimony removal. [ABSTRACT FROM AUTHOR]

As the heavy metal ion in aqueous solutions, Pb2+ has certain harm to the surrounding natural and ecological environment. To eliminate the pollution of Pb2+ in aqueous solution, Na-type zeolite was prepared from the coal gasification slag by alkaline activation technology, and then the hydrodynamic of fluidized bed with Na-type zeolite granules was studied to achieve fluidization stability. Finally, the adsorption process and mechanism of Pb2+ in aqueous solutions using Na-type zeolite were studied by multiple adsorption experiments in stable fluidized bed. The results showed that: The removal process of Pb2+ using Na-type zeolite is a single-layer adsorption dominated by chemical adsorption, companying with surface electrostatic interaction and ionic exchange processes in the interlayer. Fluidized adsorption process of Pb2+ by Na-type zeolite is mainly affected by rising-water velocity, original concentration of Pb2+, and bed material quantity in fluidized bed. The order of influence significance was as below: Original concentration (c o) > Bed material quantity (m o) > Rising-water velocity (v t). Under optimal opera t ing conditions (c o =200 mg/L, v t =0.053 m/s, m o =72 g), t he fluidized bed have higher adsorption saturation (q s =0.649 g/g) than that of fixed bed (q s =0.501 g/g), promoting the adsorption process of Pb2+ by Na-type zeolite. This research provided a new method for the efficient removal of Pb2+ from aqueous solution. [Display omitted] [ABSTRACT FROM AUTHOR]

The industrial production processes often produce different concentrations and types of odorous pollutants. Most odors have a low odor threshold, and the human sense of smell can still have a strong, unpleasant odor even at low ppb concentrations. The main challenges in low ppm concentration odor purification are short contact time, high air volume, low equilibrium adsorption capacity, and easy physical desorption. For the first time, this work reviews the technical paths how to purify four typical types of low concentrations of odors such as H 2 S, NH 3 , CH 3 SH, and CH 3 SCH 3 from low ppm concentration levels to low ppb, with the view of the odor sources, the development of treatment technology, international permissible emission standards, and the recent status of adsorbent materials. To begin, Citespace software is employed to analyze the progress, hotspots, and technology trends in the field of odor pollutant research over the past 28 years and the factors that affect removal efficiency of low-concentration odorous pollutants are discussed in detail. Then, taking activated carbon, molecular sieve, and metal-organic frameworks as target adsorbents, how to strengthen the integrated ways of physical adsorption and chemical adsorption of these adsorbents are suggested starting from the synergistic effects of modifications for pore structure, surface chemical functional groups, and complexation and redox reactions of metal ions. As a practice, the application cases of purifying low-concentration odorous pollutants by the adsorption are briefly introduced. Finally, the challenges of developing novel adsorption materials and technologies to purify low-concentration odorous pollutants toward lower than odor threshold are presented. [Display omitted] ● Deep deodorization of odor from several ppm levels to lower than odor threshold. ● Progress analysis with Citespace and limitation of tradition treating technologies. ● Intensify physical and chemical adsorption by modifying adsorbate microstructure. ● Path and challenge for opening technical bottlenecks for satisfying odor threshold. [ABSTRACT FROM AUTHOR]

In this study, a solid waste cementitious material was developed using phosphogypsum (PG) and coal-fired slag (CS), effectively promoting the resource utilization of PG waste. PG contains significant amounts of harmful substances such as phosphate ions (PO 4 3-), and fluoride ions (F-), which cause serious environmental risks and limit the practical application of PG. The porous structure of CS was utilized to adsorb PO 4 3- and F-. The mechanical properties, hydration products leaching characteristics and adsorption behavior were thoroughly examined. The results demonstrated that the incorporation of CS played a crucial role in the practical application of PG, significantly enhancing the softening coefficient from 0.49 to 0.93 and boosting the compressive strength from 6.9 MPa to 28.3 MPa after curing 28 days. CS effectively adsorbed PO 4 3- and F- from PG filtrate, with adsorption capacities of 0.77 mg/g and 0.17 mg/g, respectively. The adsorption enthalpy values indicated that the adsorption of PO 4 3- onto CS was an endothermic process, while the adsorption of F⁻ was exothermic. CS reduced the leaching of PO 4 3- and F- from PG slurry by 63.36 % and 54.75 % of, respectively. This approach, which utilizes porous CS for adsorption, offers a promising solution for the safe disposal and effective utilization of PG. • Coal-fired slag (CS) successfully adsorbed phosphate of 63.36 % and fluoride of 54.75 % from Phosphogypsum (PG). • The addition of CS improved the compressive strength from 6.9 MPa to 28.3 MPa of PG, increasing the softening coefficient from 0.49 to 0.93. • The developed PG-CS composite offers a viable solution for the safe disposal and effective utilization of PG waste. [ABSTRACT FROM AUTHOR]

In this study, the fluorescent probe M1 for specifically recognizing H 2 S was designed and synthesized via the introduction of 2-chloro-5-nitrobenzoic acid into the oxanthracene moiety of DCF-MPYM. The fluorescence titration and selectivity results demonstrated that probe M1 could selectively detect H 2 S, and its detection limit for H 2 S was calculated to be 45.31 μM. The reaction mechanism of the probe can be explained the nucleophilic addition of HS- induced the cleavage of ester bond and subsequently restored the spectral properties of DCF-MPYM. To facilitate practical applications, the fluorescent aerogel CMC-M1 that can absorb and remove H 2 S in water was constructed. The adsorption capacity and removal efficiency of CMC-M1 for H 2 S were 0.626 mg·g−1 and 99.36%, respectively. The results of adsorption kinetic indicate that the adsorption effect of CMC-M1 on Na 2 S was mainly chemical adsorption. Furthermore, the fluorescent aerogel CMC-M1 can be utilized for qualitative, quantitative detection and effective removal of H 2 S in simulated textile dyeing and finishing wastewater. [Display omitted] • Fluorescent probe M1 for specifically and selectively recognizing H 2 S was synthesized. • Fluorescent aerogel CMC-M1 that can absorb and remove H 2 S in water was constructed. • Constructing fluorescent aerogel will contribute to the detection and effective removal of H 2 S. The dyeing, wastewater acidification and anaerobic treatment processes in the textile always produce a large amount of hydrogen sulfide (H 2 S), which will be harmful to the human beings. The fluorescent detection of H 2 S with highly specific and sensitive probe is of significance. Here, using the 2, 7-dichlorofluorescein (DCF) derivative DCF-MPYM as the fluorophore, a fluorescent probe M1 for specifically recognizing H 2 S was designed and synthesized by introducing 2-chloro-5-nitrobenzoic acid into the oxanthracene moiety of DCF-MPYM. The introduction of 2-chloro-5-nitrobenzoic acid results in DCF-MPYM being in a closed-loop state, thus, the fluorescence quantum yield (Φ) of the probe M1 was low. The characteristic of weak fluorescence plays an important role in the use of a fluorescent probe. The fluorescence titration and selectivity results demonstrated that the probe M1 could selectively detect H 2 S, and its detection limit for H 2 S was calculated to be 45.31 μM. The reaction mechanism of the probe was verified by the high-resolution mass spectrometry (HRMS) and liquid chromatography as the nucleophilic addition of H 2 S to the probe M1 , which induced the cleavage of ester bond and subsequently restored the spectral properties of DCF-MPYM. To bring the probe M1 into practical application, the fluorescent aerogel CMC-M1 was constructed by mixing the probe M1 and carboxymethyl cellulose sodium (CMC-Na) aerogel, and the fluorescent aerogel can be applied in absorbing and removing H 2 S in water. The adsorption capacity and removal efficiency of CMC-M1 for H 2 S were 0.626 mg·g−1 and 99.36 %. The investigation of adsorption kinetic showed that the adsorption effect of CMC-M1 towards Na 2 S was mainly chemical adsorption. In addition, the fluorescent aerogel CMC-M1 can be applied for qualitative, quantitative detection and effective removal of H 2 S in dyeing and finishing wastewater. [ABSTRACT FROM AUTHOR]

We developed and evaluated an anodized-aluminum pressure-sensitive paint (AA-PSP) with new formulations of free-base porphyrin, H 2 TCPP , as an optical unsteady pressure sensor. The luminophore H 2 TCPP has quite a short fluorescent lifetime (2.4 ns on the condition of the AA-PSP). The fluorescence spectroscopy result shows that the excitation wavelength of H 2 TCPP corresponds to violet-colored (425 nm) and green-colored (longer than 520 nm) lights. The pressure sensitivity is sufficiently high for the pressure sensor (0.33–0.51%/kPa) and the temperature sensitivity is very low (0.07–1.46%/K). The photodegradation of the AA-PSPs is not severe in both excitation light sources of the green LED and the Nd:YAG laser. The resonance tube experiment result shows the cut-off frequency of the AA-PSPs is over 9.0 kHz, and the results of the shock tube experiment show the 10 µs order time constant of the normal shock wave. [ABSTRACT FROM AUTHOR]

The elucidation of interfacial physicochemical mechanisms between asphalt and mineral aggregates is vital for comprehending the interface formation in asphalt mixtures and enhancing their performance. To this end, multiscale evaluation methods were used to investigate the mechanisms and influencing factors of interfacial physicochemical interactions between asphalt and mineral aggregates (IPIAMA). Initially, the dynamic shear rheometer (DSR) was used to measure the complex shear modulus (G*) of various asphalt mastics. Subsequently, the interface film thickness was calculated using G* in conjunction with the Hashin and Mori-Tanaka (MT) micromechanical models. This indicator facilitated quantitative assessments and the analysis of influencing factors. The results indicated that the MT model underestimated the interface film thickness by approximately 0.08–0.29 % compared to the Hashin model, a discrepancy attributable to assumptions regarding aggregate particle interlocking. Moreover, the interface film thickness systematically varied with factors such as aggregate content, type of aggregate, and type of asphalt, ranging from 0.24 to 0.53 μm. To further elucidate the IPIAMA mechanisms behind these variations, the fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and the ultraviolet test (UV) testing were conducted. FTIR tests demonstrated that the primary components of mineral aggregates—dolomite, calcite, and quartz—contributed to the physical adsorption increments on asphalt functional groups by 0.0185, 0.0509, and 0.004, respectively. SEM images revealed that dolomite and calcite possessed more surface fissures and pores than quartz. XPS tests showed that calcium carbonate and magnesium carbonate chemically reacted with asphalt, resulting in electron shifts of 0.9 eV and 1.1 eV, respectively, while silicon oxide only exhibited electron shifts when combined with a silane coupling agent-modified asphalt. UV tests demonstrated that lighter asphalt fractions were preferentially absorbed into the pores and micro-cracks of mineral aggregates. Consequently, the complex IPIAMA involved physical adsorption, chemical reactions, and selective absorption, strongly correlating with factors such as mineral composition, surface morphology, and asphalt type. • Calculated asphalt-mineral interface film thickness via micromechanical models and analyzed key influencing factors. • Investigated physical and chemical adsorption between asphalt and mineral aggregates using FTIR, SEM, and XPS methods. • Verified selective adsorption behavior between asphalt and minerals through ultraviolet analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Above 92% 131I removal efficiency within alkaline pH range of 8–11. • Adjustable silver content in adsorbent through synthesis to regulate iodine capture capacity. • Higher 131I removal efficiency in real seawater than that of commercial resins. • Ion exchange and complexation mechanisms occurring at specific binding sites ensure selectivity. For the efficient removal of radioactive iodide ions from medium and low radioactive contaminated water, an Ag-doped adsorbent was designed via radiation grafting method and chemical modification and applied based on the solid–liquid adsorption method. The silver loading content in the adsorbents could be flexibly decided by adjusting the sulfhydryl content. SEM/EDS, ATR, XPS, and XRD characterization methods were used to determine the features of the new adsorbents. With the silver content 67.9 mg/g and 125.6 mg/g in the adsorbents PGM25%-Ag+ and PGM220%-Ag+ respectively, the maximum I− adsorption capacities were varied at 29.92 mg/g and 100.82 mg/g. In wide pH conditions (pH7-11), PGM25%-Ag+ was sufficient to achieve 131I removal efficiency of over 92 %, and the removal efficiency was almost unaffected in the coexistence of high concentration (10 mmol/L) of anions and complex real contaminated seawater, highlighting the applicability and selectivity of the adsorbent. The adsorption behavior conformed to the Langmuir isothermal model and pseudo-second-order kinetics model. XPS analysis confirmed that excellent adsorption capacity and selectivity were attributed to the chemical adsorption mechanism of ion exchange and complexation occurs between I− and Ag on the solid–liquid interface, where AgI precipitation formed. In addition, the Ag+-doping adsorbent withstood the harsh conditions of 200 kGy irradiation by observing the ATR structure, thermal stability, and 131I removal property. This study provides a feasible solution for the treatment of low and medium-radioactive contaminated seawater. [ABSTRACT FROM AUTHOR]

Schematic diagrams illustrating the principle of improving batteries performance by modifying separator with NSC/PP and MS@NSC/PP. [Display omitted] • Expanding aids in distributing metal sulfides uniformly via impregnation. • Carbon material covers large pores and improves interface impedance. • Composite separators anchor polysulfides and enhancing reaction kinetics. Lithium-sulfur (Li-S) batteries, renowned for high energy density and abundant sulfur reserves, are recognized as a research hotspot. However, the commercial implementing of Li-S batteries is confronted with scientific and technical challenges, including the shuttle effect resulting in low active material utilization, and slow reaction kinetics leading to poor cycle stability. To optimize the structure and composition of carbon composite materials based to meet the application requirements for long cycle life and high utilization of active substances has become the focus and difficulty. In this study, a composite separator MS@NSC/PP by coting nanosheet carbon (NSC) material loaded with amounts of metal sulfide (MS) was prepared via expansion technology and sulfurization impregnation. The combination of two processes greatly increases interaction area between MS@NSC and polysulfides and achieves uniform loading of MS, fully enhancing the mitigation of shuttle effect through strong chemical adsorption, and further hastening the conversion reaction of polysulfides deposited on the surface. Compared with NSC/PP and NiS 2 @NSC/PP separators, the batteries with CoS 2 @NSC/PP separator display a high initial discharge capacity of 1135 mAh g−1 at 0.2C, maintaining more improved cycle stability at 2C. [ABSTRACT FROM AUTHOR]

Copyright of Jornal of Biotechnology Research Center is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND The adsorption resins have been successfully used for the treatment of various types of industrial wastewater due to their excellent advantages of high degree of harmlessness, wonderful resource utilization effect, and adjustable material structure. However, the adsorption capacity of traditional resin to the high polarity aniline has been limited since the adsorption mainly relies on hydrophobic adsorption. RESULTS: In this study, novel oxygen‐containing resins were prepared by modifying a benzene skeleton through chemical functional groups screening and physical structure regulation. The influences of functional groups to the precursor resins were thoroughly studied and the adsorption capacity of the dihydrofuran‐2,5‐dione modified resins was 7.9% higher than the precursor resins, exhibiting the unparalleled adsorption activity to p‐aminobenzoic acid (PABA). Subsequently, a series of dihydrofuran‐2,5‐dione modified crosslinking resins named FSG1‐5 were prepared with various physical structures. The resin FSG‐2 exhibited the best adsorption property, as the adsorption capacity to p‐aminobenzoic acid was 28.3% higher than H‐103 (a commercial hyper‐cross‐linked resin). CONCLUSION: On the basis of the comparison of kinetics, thermodynamics, and resin's physicochemical structure, FSG‐2 could achieve efficient adsorption to aniline compounds by physical adsorption, such as π‐π conjugation, molecular size effect, and chemical adsorption, including hydrogen bonding and acid–base effect enhanced the adsorption interaction, which laid a theoretical foundation for the design and preparation of new materials. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Efficient strategies in enhancing sensitivity are pivotal to ultrasensitive detection of tumor markers. In this work, based on the strategy of label-assisted chemical adsorption triggered conversion of electroactivity of sensing interface, a Ag/AgCl process was achieved to enhance sensitivity of the constructed sandwich-type amperometric immunosensor for ultrasensitive detection of carbohydrate antigen 19–9 (CA19-9). Briefly, polydopamine-Ag nanoparticles (PDA-Ag NPs), as signal precursor, combined with labeling antibody were served as labels and graphene oxide-melamine (GO-MA) substrate with chemical absorption capacity was applied as smart sensing interface. After successfully incubating labels, there was primitively no current response due to the poor conductivity between labels and electrode. However, in the presence of H 2 O 2 , Ag NPs from labels can be etched into Ag ions, which were adsorbed by GO-MA to form GO-MA-Ag as electroactive substrate. Then, the substrate exhibited a sharp and stable electrochemistry peak of solid-state Ag/AgCl process in the buffer containing KCl. The sensitivity toward detection of CA19-9 was notably enhanced based on the appearance of sharp peak. Under optimum conditions, the designed immunosensor demonstrated a wide working range from 0.0001 to 100 U mL−1 and an ultralow detection limit 0.032 mU mL−1. Thus, utilizing this strategy to construct immunosensor was highly promising in clinical diagnosis for ultrasensitive detection of tumor makers. Image 1 • GO-MA composite for chemosorption of Ag+ was used as smart sensing interface. • Ag/AgCl electrochemical process was realized via label-assisted chemosorption. • The immunosensor showed ultralow limit of detection 0.032 mU mL−1 for CA19-9. [ABSTRACT FROM AUTHOR]

Bi 2 Se 3 is one of the most promising topological insulators, but it suffers from intrinsic n-doping due to Se-vacancies, which shifts the Fermi level into the bulk conduction band, leading to topologically trivial carriers. Recently it was shown that this Fermi-level shift can be compensated by a locally controlled surface p-doping process, through water adsorption and XUV irradiation. Here, the microscopic mechanism of this surface doping is studied by means of density functional theory (DFT) focusing on the adsorption of H 2 O, OH, O, C and CH on Bi 2 Se 3. We find that water adsorption has a negligible doping effect while hydroxyl groups lead to n-doping. Carbon adsorption on Se vacancies gives rise to p-doping but it also strongly modifies the electronic band structure around the Dirac point. Only if the Se vacancies are filled with atomic oxygen, the experimentally observed p-doping without change of the topological surface bands is reproduced. Based on the DFT results, we propose a reaction path where photon absorption gives rise to water splitting and the produced O atoms fill the Se vacancies. Adsorbed OH groups appear as intermediate states and carbon impurities may have a catalytic effect in agreement with experimental observations. [Display omitted] • Adsorption of water, oxygen, carbon, OH and CH on Bi 2 Se 3 is studied by DFT. • Carrier doping due to chemisorption at Se vacancies is elucidated. • A chemical reaction is proposed for photo-induced p-doping of H 2 O/Bi 2 Se 3. [ABSTRACT FROM AUTHOR]

The adsorption phenomenon has been used extensively to achieve and explain solid-state reactions, control contamination, and purify liquids and gases. This process implies the use of a porous medium or a material with specific adsorption centers where the interactions with the reagents occur. Determination of the properties of adsorbent or catalyst materials that do not contain specific adsorption sites by physical gas adsorption is a well-established procedure in most research and quality-control laboratories. However, characterizing the specific centers by selective adsorption—chemisorption—remains an open question for discussion and study. The specific centers involved are often acidic/basic and metallic; in most cases, reagents are adsorbed and desorbed in these centers, whose determination allows controlling the processes and comparing the materials. The techniques and procedures presented herein facilitate the evaluation and the qualitative and quantitative determination of the surface properties of the materials using chemisorption processes for metallic and acidic/basic sites. The aim of this work is to review these techniques and procedures, including the updates published by several researchers, who mostly strive to explain the results of bifunctional metallic and acid–base catalytic behavior. [Display omitted] • Adsorption phenomenon can explain reactions and separation processes. • Characterization of the specific centers by selective adsorption—chemisorption. • Determination of the surface properties using chemisorption processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • LaMnO x catalysts absorbed microwave by first dielectric loss and secondary magnetic loss. • The adsorption capacity of Mn to toluene was much stronger than that of La. • LaMnO 3 perovskite and oxygen vacancies ensured the high activity of the La 1 Mn 1 O x catalyst. • Toluene oxidation follows the L-H and the MvK mechanisms simultaneously. To verify the catalytic activity of La m Mn n O x (m,n = 1,2; x = 2.5 ∼ 5.5) catalyst in microwave catalytic combustion of volatile organic compounds (VOCs), monolithic La m Mn n O x catalysts were prepared and applied in toluene oxidation in this study. The research demonstrated that the La m Mn n O x catalysts had strong microwave-absorbing properties due to first dielectric loss and secondary magnetic loss. The bed temperature rose rapidly due to the formation of hotspots under microwave irradiation. Furthermore, La m Mn n O x catalysts chiefly adsorbed toluene by chemical adsorption, and the adsorption capacity of Mn was much stronger than that of La. Based on the activity tests, La 1 Mn 1 O x (x = 2.5 ∼ 3.5) catalyst exhibited the highest catalytic activity among the four catalysts, and toluene was converted and mineralized completely at 259 ℃ and 315 ℃, respectively, under the conditions of an initial toluene concentration of 1000 mg/m3, bed height of 150 mm, and gas velocity of 2.5 L/min. Highly active LaMnO 3 perovskite, uniform distribution of active particles, and abundant oxygen vacancies ensured the high activity of the La 1 Mn 1 O x catalyst. Hence, the La 1 Mn 1 O x catalyst was stable after a total of 600 min of activity test. According to electron transfers on the active Mn surface, the adsorption and activation of gaseous oxygen, and the transformation of O ads to O latt on the oxygen vacancies, toluene oxidation speculates to follow the Langmuir-Hinshelwood and the Mars-van Krevelen mechanisms simultaneously. Therefore, this work provides further technological support for applying La m Mn n O x catalysts in microwave catalytic combustion of industrial VOCs waste gas. [ABSTRACT FROM AUTHOR]

Abstract The practical applications of lithium-sulfur (Li S) batteries remains remote because of low utilization of sulfur and short cycle life caused by low conductivity of sulfur, shuttle effect of lithium polysulfides and severe volume expansion. It is therefore exigent to rationally design an effective sulfur host. Here a novel sulfur host material--alpha molybdenum trioxide (α-MoO 3) spheres are introduced into Li S battery cathode acting as lithium polysulfides absorbent and efficient matric of sulfur. The abundant oxygen atoms on the surface of α-MoO 3 , making it form chemical binding interactions with lithium polysulfides, which can effectively alleviate the dissolution of lithium polysulfides. Moreover, α-MoO 3 as the matric of sulfur alleviates volume expansion of active sulfur and enhanced the utilization of sulfur, which results in improving the battery performances. As a result, S/α-MoO 3 electrode with the sulfur content of 68 wt.% shows an initial discharge capacity of 1086.2 mAh g−1 and good capacity retention is obtained with 912.8 mAh g−1 after 400 cycles at 0.5 C. After 50 cycles at rates ranging from 0.1 to 2 C, the cell still returns a high specific capacity of 916.5 mAh g−1 at 0.5 C. The results demonstrate α-MoO 3 was a promising sulfur host material for promoting the performances of Li S batteries with high sulfur content cathode. Graphical abstract Image 1 Highlights • The mechanism that α-MoO 3 adsorbs lithium polysulfides is proposed clearly. • The sulfur content reaches 68 wt.% in S/α-MoO 3 electrode. • The cell shows excellent cycling stability, rate performance and discharge capacity. [ABSTRACT FROM AUTHOR]

Lithium sulfur batteries are one of the most potential rechargeable energy storage devices due to its high energy density and low cost. Nevertheless, the practical applications are heavily hindered by polysulfide shuttle effect, which would cause fast capacity fading. Polysulfide adsorption has been proved to be an effective strategy via chemical bonding or physical constraint. Here, a fresh Li x La y TiO 3 and acetylene black hybrid coated separator was constructed to suppress the migration of polysulfides and served as an upper current collector to fully utilize the active material. The acetylene black embellished separator and the pristine one were used as reference. Comprehensive and systematic results proved that the hybrid coated separator could not only effectively trap polysulfides, but also promote the conversion of polysulfides, which would improve the rate and cycle performance. The as-prepared sample with 1.0% Li x La y TiO 3 addition showed the best electrochemical performance with a high capacity of 890 mA h g -1 at 1600 mA g −1 . An enhanced cycling performance with 716 mA h g -1 retained after 100 cycles at 800 mA g −1 was observed, corresponding to a capacity retention of 81.2%. In summary, this study provides a simple, low cost and effective approach to promote the development of lithium sulfur batteries. [ABSTRACT FROM AUTHOR]

Mixed Cu and Mg oxides on nitrogen-rich activated carbon (AC) from Nypha fruticans biomass were characterized and their CO adsorption performance was measured. Highly dispersed CuO and MgO nanoparticles on AC was obtained using an ultrasonic-assisted impregnation method. The optimum adsorbent is 5%CuO-25%MgO/AC having good surface properties of high surface area, pores volume and low particles agglomeration. The higher content of MgO of 5%CuO-25%MgO/AC adsorbent contributes to less metal carbide formation which increases their porosity, surface area and surface basicity. XPS analysis showed some amount of nitrogen content on the surface of the adsorbent which increased their surface basicity towards selective CO adsorption. The presence of moisture accelerated the CO chemisorption to form a hydroxyl layer on the surfaces. The 5%CuO-25%MgO/AC adsorbent successfully adsorbed CO via physisorption and chemisorption of 14.8 and 36.2 wt%, respectively. It was significantly higher than fresh AC with better selectivity to CO. [ABSTRACT FROM AUTHOR]

This work attempted to explore the feasibility of using iron-contaminated graphite concentrate as an effective adsorbent for Cr(VI) removal from polluted water. Adsorption isotherm and kinetics were conducted to investigate the Cr(VI) removal capacity by the iron-contaminated amorphous graphite concentrates. In addition, SEM-EDS, XPS were carried out to further examine the solid samples. The results showed that amorphous graphite concentrate had a 1.52 mg/g adsorption capacity of Cr(VI), with the adsorption being fitted well with the pseudo-second-order kinetics model. In addition, chemical adsorption of Cr(V) on iron-contaminated graphite concentrate due to the formation of ≡Fe-O4HCr and Fe2-(CrO4)3 complexes was proposed. This study revealed that iron-contaminated amorphous graphite concentrate would be a cheap and good adsorbent for the removal of Cr(VI) from contaminated water. [ABSTRACT FROM AUTHOR]

In the previous studies, adsorption and corrosion inhibition of various anions and an organic cation inhibitor, tetrabutylammonium ion (C4H9)4N+ (TBA+), on the surface of Fe in deaerated 1 M HClO4 were discussed on the basis of the hard and soft acids and bases principle. The present investigation deals with adsorption behaviors of adsorptive anions Cl-, I-, and SH- and also the anions plus TBA+ on the Fe surface in 1 M HClO4. The values of the surface coverage θ for the anions and/or TBA+ were obtained from the electric double layer capacitances determined by impedance measurements. TBA+, which has no unshared electron pair, was adsorbed on the surface by electrostatic interaction. The anions which hold unshared electrons are chemisorbed rather than electrostatically adsorbed on the surface by the formation of a stable soft acid and soft base interaction. The highest values of θ for I- and SH-, classified as soft bases, were observed at potentials near the zero-charge potential Epzc because the Fe surface at Epzc behaves as the softest acid. TBA+ was adsorbed on the anion-chemisorbed Fe surface by electrostatic interaction, resulting in high θ values. [ABSTRACT FROM AUTHOR]

• Graphene oxide was modified by polyaluminium chloride; • HAO@GO exhibited an excellent adsorption capacity towards fluoride; • Chemical adsorption and ligand exchange are responsible for the adsorption of fluoride onto HAO@GO. Adsorption methods have garnered significant attention for fluoride removal from water bodies owing to their superior selectivity, simple operations, and wider applicability. However, the development of adsorbents with higher adsorption performances requires significant attention. Here, graphene oxide is endowed with excellent affinity towards fluoride by doping polyhydroxy complexes onto its surface structure and regulating the potential charge. Multiple detection measurements involving scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction (XRD), and transmission electron microscopy (TEM) were employed to demonstrate the textural properties of graphene oxide (GO) modified by polyaluminium chloride (HAO@GO). Conversely, the effects of parameters including the preparation conditions, co-existing competitive ions, recyclability, contact time, and initial concentration on the adsorption behaviors were systematically determined. The adsorption experimental data were fitted well by the Langmuir isotherm model and pseudo-first-order model. The calculated maximum adsorption capacity was 129.23 mg/g at room temperature (25 °C) and a pH of 7.00, which is greater than that of most reported adsorbents. The existence of competitive anions, such as NO 3 - , SO 4 2 - , and PO 4 3 - , unavoidably interferes with fluoride adsorption. TEM, zero point of charge test, adsorption isotherm, and X-ray photoelectron spectroscopy (XPS) tests indicated that chemical adsorption and ligand exchange are responsible for the adsorption of fluoride onto HAO@GO. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successful synthesis of CeO 2 decorated Co 3 O 4 tubes supported uniform Ni nanoparticles and reached 85.3 % for CO 2 conversion at 300 °C for CO 2 methanation. • In-situ DRIFS was carried out to measure the mechanism by CO 2 adsorption and hydrogenation. • Revealing the synergistic effects among the components by DFT. CO 2 absorption and activation play key roles in the process of CO 2 methanation, but revealing the mechanism and synergistic effects are still challenges, especially in some complicated routes. Herein, an optimized hollow Ni/CeO 2 -Co 3 O 4 catalyst is shown to be capable of CO 2 absorption and activation, the performance could be attributed to the strong synergistic effects among each component. In addition, the respective role was verified that the Co 3 O 4 and CeO 2 contributed to the CO 2 adsorption and subsequently coupled with Ni for CO 2 activation. Furthermore, in-situ DRIFTS were used to demonstrate the hydrogenation mechanisms, and the promotion of CO 2 absorption and CH 4 selectivity was confirmed in Ni/CeO 2 -Co 3 O 4. The DFT results verified the synergistic effects of the established catalysts, which could also be a universal strategy for the catalysts designation. [ABSTRACT FROM AUTHOR]

Core-hell hollow TiO 2 @VP heterostructure sulfur host displays a favorable LiPS adsorption ability and excellent catalytic activity towards polysulfide conversion with a high specific capacity of ∼1430 mAh g−1 at 0.1C, and an excellent rate capacity of ∼521 mAh g−1 at 5C. Even at a very high sulfur loading of ∼7.5 mg cm−2, the h-TiO 2 @VP/S cathode-based Li-S battery delivers an exceptional areal capacity of ∼7.13 mAh cm−2. [Display omitted] • Core-shell of hollow TiO 2 spheres decorated with VP nanosheets were developed. • The combination of excellent catalytic performance and strong adsorption properties for LiPS was investigated. • The h-TiO 2 @VP/S cathode presents high capacity and outstanding long-term stability. • Li-S battery can work well under ultrahigh sulfur loading of ∼ 7.4 mg cm−2 and low E/S of ∼ 5.1 µL mg−1. Lithium-sulfur (Li-S) batteries are disclosed as prospective alternatives for next-generation energy storage technologies, due to their high theoretical energy density and cost-effectiveness. However, the shuttle effect and sluggish conversion reaction of polysulfide (LiPS) inhibit them from commercial application. To overcome these challenges, we anticipated a novel strategy to rational design a hollow titanium oxide nanosphere that is decorated with vanadium phosphide nanosheets (h-TiO 2 @VP) as an efficient sulfur host. The combination of strong chemical adsorption ability of hollow TiO 2 nanospheres and excellent LiPS conversion catalyst of VP nanosheets which help to suppress the shuttling effect. The theoretical calculation showed that the h-TiO 2 @VP-50 (ratio of 5:5) could deliver higher conductivity and better adsorption ability toward LiPS. In particular, the composite of h-TiO 2 @VP and sulfur (h-TiO 2 @VP/S) cathode reveals a high specific capacity of ∼1430 mAh g−1 at 0.1C, and an excellent rate capacity of ∼521 mAh g−1 at 5C. Even at a high sulfur loading of ∼ 7.5 mg cm−2, the h-TiO 2 @VP/S cathode-based Li-S battery delivers an exceptional areal capacity of ∼ 7.13 mAh cm−2. This study opens a new door for designing the highly efficient Li-S battery cathode which can be a promising alternation for the state-of-the-art Li-ion cell. [ABSTRACT FROM AUTHOR]

In order to improve the uptake capacity of Cu 2 O for I − anions from water, Ag loaded Cu 2 O composites have been synthesized through a facile method, characterized using SEM, XRD, XPS and applied to remove I − anions under different experimental environments. The results show that the uptake capacity of Ag@Cu 2 O increased with the increasing Ag doped amount. Meanwhile, the uptake capacity (0.20 mmol g −1 ) of 1.0%-Ag@Cu 2 O for the removal of I − anions is ten times higher than that of pure Cu 2 O (0.02 mmol g −1 ). Furthermore, a mechanism explaining the highly efficient removal of I − anions has been proposed according to characterization analyses of the composites after adsorption and subsequently been verified by adsorption under visible light experiments. 1.0%-Ag@Cu 2 O (0.5%-Ag@Cu 2 O, 0.2%-Ag@Cu 2 O) shows a high iodide uptake efficiency of 98.5% (77.6%, 37.8%) in the visible light, much higher than that under the darkness (86.3%, 69.7% and 30.8%). In addition, the adsorbent showed excellent selectivity for I − anions in the presence of large concentrations of competitive anions, eg. uptake efficiencies are 78.2%, 62.8%, 70.2% and 77.9% in the presence of the Cl − , CO 3 2− , SO 4 2− and NO 3 − competitive anions, respectively, and could work in a wide pH range of 3–11. This study is hopefully to prompt Cu 2 O to become a new and highly efficient adsorbent for iodide adsorb from solutions. [ABSTRACT FROM AUTHOR]

In order to improve the adsorption speed of iodine from water, MIL-101 with extra-large specific surface area (3054 m 2 /g) was chosen as a base material, and then, Ag was doped into MIL-101 to enhance its adsorption capacity through an incipient-wetness impregnation method. With the characterization of SEM-EDS, TEM, XRD, XPS, TGA, IR, and BET techniques, the resulting Ag was identified to be stay in the framework of MIL-101 stably in the form of Ag II (generally, Ag II cation is not stable). However, after the adsorption of I − anions, Ag II stay in the cages of MIL-101 in the form of AgI/AgI 3 . It is important to note that, all adsorbents show high adsorption speed of iodine in solution. The equilibrium adsorption time of the adsorbents were acquired by only a few minutes, which can be attributed to its large BET surface area. An interesting note is that, when the doping amount of Ag is less than 9%, the iodine anions adsorption capacity of Ag@MIL-101 is greater than its theoretical adsorption capacity. It shows that both physical adsorption and chemical adsorption are existed in the adsorption process. This study hopefully leads to a new and highly efficient Ag-based adsorbent for iodide adsorb from solutions. [ABSTRACT FROM AUTHOR]

This study aimed to quantify the adsorption affinity of neutralized 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP-N) toward hydroxyapatite (HA) and dicalcium phosphate dihydrate (DCPD) at pH 7.0 by employing the Langmuir isotherm model. Furthermore, the effects of inorganic phosphate (Pi) and fluoride (F−) ions on the adsorption of 10-MDP-N onto HA and DCPD were examined. Fixed amounts of HA and DCPD powders were suspended in different concentrations of 10-MDP-N solutions and were incubated for 18 h. Equilibrated concentrations of 10-MDP-N were measured by spectrophotometry and the adsorption affinity was estimated using the Langmuir model. Moreover, the adsorption was examined by zeta-potential analysis. The results indicated that significant Langmuir correlation was noted in both substrates, along with an increasing negative zeta-potential; however, in DCPD the correlation was less strong. The addition of 1.0 mM Pi slightly delayed the adsorption of 10-MDP-N onto both substrates, whereas 3.0 mM Pi drastically delayed adsorption onto HA but completely inhibited adsorption onto DCPD. Up to 50 ppm, F− enhanced the adsorption onto HA, and the adsorption plateaued at higher concentrations of F−, whereas no obvious influence of F− on the adsorption onto DCPD was noted. [ABSTRACT FROM AUTHOR]

An new methody for physical and chemical adsorption modeling in column apparatuses is presented. A convection-diffusion model is obtained in the approximations of the continua mechanics, where the mathematical point is equivalent to the medium elementary volume which is sufficiently small with respect to the column volume and at the same time sufficiently large with respect to the intermolecular volumes of the medium. The created convection-diffusion type model allows performing qualitative analysis of the process and obtaining the effect of the velocity radial nonuniformity in the column. An average concentration model is applied for quantitative description of physical and chemical adsorption in the column apparatus. The methods for model equation solutions and model parameter identifications are described. [ABSTRACT FROM AUTHOR]

Designing and optimizing cost-effective photocatalytic systems for the photocatalytic degradation of antibiotics remains a considerable challenge. Herein, a certain amount of copper was doped into BiOBr with a two-dimensional (2D) structure through a simple hydrothermal method to improve its capability to degrade tetracycline hydrochloride (TC) under visible light. The physicochemical properties of the prepared samples were characterized. By adjusting the CuCl 2 ·2 H 2 O amounts in the mixture, the 1 wt% Cu/BOB displayed the optimal photocatalytic TC degradation rate of 86.2% under visible light irradiation, which was 1.34 times higher than that of pure BiOBr. The DFT calculation results indicated that the Cu 3d and Cu 4 s orbitals constitute the doped energy level, which modified the band structure of the original BiOBr and effectively improved the visible light response capability. Importantly, the doped copper ions optimized the chemical adsorption capacity of TC by regulating the microenvironment around the active sites on the BiOBr and accelerated the separation of photogenerated charge carriers. This work could provide new insight into enhancing the chemical adsorption performance of 2D BiOBr by ion doping and provide a strategy for photocatalytic antibiotic degradation. [Display omitted] • Copper doped BiOBr 2D nanosheets were synthesized by a simple one-step hydrothermal method. • The TC photodegradation ability of copper-doped BiOBr increased by 1.34 times. • Cu-doping enhanced the TC chemical adsorption on BiOBr during the photodegradation process. [ABSTRACT FROM AUTHOR]

As one important component of sulfur cathodes, the carbon host plays a key role in the electrochemical performance of lithium-sulfur (Li-S) batteries. In this paper, a mesoporous nitrogen-doped carbon (MPNC)-sulfur nanocomposite is reported as a novel cathode for advanced Li-S batteries. The nitrogen doping in the MPNC material can effectively promote chemical adsorption between sulfur atoms and oxygen functional groups on the carbon, as verified by X-ray absorption near edge structure spectroscopy, and the mechanism by which nitrogen enables the behavior is further revealed by density functional theory calculations. Based on the advantages of the porous structure and nitrogen doping, the MPNC-sulfur cathodes show excellent cycling stability (95% retention within 100 cycles) at a high current density of 0.7 mAh cm-2 with a high sulfur loading (4.2 mg S cm-2) and a sulfur content (70 wt%). A high areal capacity (≈3.3 mAh cm-2) is demonstrated by using the novel cathode, which is crucial for the practical application of Li-S batteries. It is believed that the important role of nitrogen doping promoted chemical adsorption can be extended for development of other high performance carbon-sulfur composite cathodes for Li-S batteries. [ABSTRACT FROM AUTHOR]

Highlights: [•] The adsorbent is novel and can be practical. [•] Fast adsorption and high adsorption capacity for acid dyes were observed. [•] Our adsorbent can remove acid dyes of different structures. [ABSTRACT FROM AUTHOR]

This review provides an overview of recent advances that have been achieved in understanding the basic physics of friction and energy dissipation in molecularly thin adsorbed films and the associated impact on friction at microscopic and macroscopic length scales. Topics covered include a historical overview of the fundamental understanding of macroscopic friction, theoretical treatments of phononic and electronic energy dissipation mechanisms in thin films, and current experimental methods capable of probing such phenomena. Measurements performed on adsorbates sliding in unconfined geometries with the quartz crystal microbalance technique receive particular attention. The final sections review the experimental literature of how measurements of sliding friction in thin films reveal energy dissipation mechanisms and how the results can be linked to film-spreading behavior, lubrication, film phase transitions, superconductivity-dependent friction, and microelectromechanical systems applications. Materials systems reported on include adsorbed films comprised of helium, neon, argon, krypton, xenon, water, oxygen, nitrogen, carbon monoxide, ethane, ethanol, trifluoroethanol, methanol, cyclohexane, ethylene, pentanol, toluene, tricresylphosphate, t-butylphenyl phosphate, benzene, and iodobenzene. Substrates reported on include silver, gold, aluminum, copper, nickel, lead, silicon, graphite, graphene, fullerenes, C60, diamond, carbon, diamond-like carbon, and YBa2Cu3O7, and self-assembled monolayers consisting of tethered polymeric molecules. [ABSTRACT FROM PUBLISHER]

Abstract: Binder is essential in the iron ore agglomeration. Fulvic acid (FA) is one of organic active fractions of the MHA binder. A further study of the interaction between FA and iron ore surface was conducted via elemental analysis, chemical group analysis, batch adsorption experiments, X-ray photoelectron spectroscopy (XPS) investigation, zeta potential measurements and scanning electron microscope (SEM) imaging. It is found that the adsorption amount of FA onto iron ore surface obviously increases with increasing the solution pH. X-ray photoelectron spectroscopy (XPS) analysis indicates that ligand exchange (coordination) as a special chemical adsorption occurs at the interface of iron ore and FA. Zeta potential results display that the adsorption of FA onto iron ore surface can be characterized by specific ligand exchange and electrostatic forces. Scanning electron microscope (SEM) imaging shows that flocculation sedimentation is observed during the adsorption process. Ball-shaped FA–mineral colloidal complex with a diameter of 20–100μm is presented in the SEM micrograph of FA-coated mineral granules. Ligand exchange, hydrophobic interactions and electrostatic force are contributive to the adsorption, with ligand exchange and hydrophobic interactions predominant. [Copyright &y& Elsevier]

Abstract: Lithium adsorption on two dimensional graphene and armchair graphene nanoribbons is studied using advanced density functional theory calculations. The relative stability of different adsorption sites is investigated taking into account different ribbon widths, adsorbate densities, and spin states. We find the singlet spin state to be the true ground state of the systems considered. For this spin state, the binding energy increases with decreasing adatom density due to lower Coulomb repulsion between the partially charged Li atoms. At low adsorbate densities the favorable adsorption sites on the nanoribbons are found to be the hollow sites near the edges of the ribbon, whereas at higher densities, Li atoms tend to couple on next-nearest neighboring hexagons close to the ribbon''s edge. Adsorption of the metal atoms is found to significantly decrease the bandgaps of all systems studied, turning them metallic for sufficiently large adatom densities. This suggests lithium doping as a possible route for bandgap engineering of graphitic systems. [Copyright &y& Elsevier]

FTIR spectra, the static contact angles, the sliding angles, and the ellipsometric thicknesses were measured on some monolayers prepared from n-alkyltrichlorosilane by a chemical adsorption (CA) technique. The molecular arrangement in the monolayer formed by the CA technique, CA monolayer, was found to be random or bulk-like when the carbon number of the alkyl group was 4 or 5, and the CA molecules were arranged along the substrate surface when the carbon number became 3, 8, and over. The arranged CA molecules were found to stand with the tilt angle of about 28° from the normal of the substrate surface when the carbon number was 8, and the tilt angle became smaller as the carbon number was above 8. It was proved that the CA molecules stood with the tilt angle of about 20 degrees when the carbon number was 20. These tilt angles were obtained by the ellipsometric thickness of the CA monolayer and the molecular length of the all trans-zigzag CA molecular model calculated by AM1. [ABSTRACT FROM AUTHOR]

Abstract: As candidates for hydrogen storage materials, Ti-doped pyracylenes, with a carbon atom replaced with a Ti atom, have been studied with density functional theory based method. Ti-doped pyracylene III with the Ti atom lying on a pentagon is the most stable isomer with substitutional energy of 4.73 eV/mol. Up to three H2 molecules can be adsorbed on to the Ti atom through charge transfer and partially chemisorptions due to the partially filled d orbitals and positive charges on Ti. Totally seven H2 molecules can be adsorbed on Ti-doped pyracylenes with mixture of chemo- and physisorption. Charge polarization induced electrostatic attraction is one of the major driving forces for physisorption. [Copyright &y& Elsevier]

Biological units such as macromolecules, organelles, and cells are directed to a proper location by gradients of chemicals. We consider a macroscopic element with surface binding sites where chemical adsorption reactions can occur and show that a thermodynamic force generated by chemical gradients acts on the element. By assuming local equilibrium and adopting the grand potential used in thermodynamics, we derive a formula for the "chemophoresis" force, which depends on chemical potential gradients and the Langmuir isotherm. The conditions under which the formula is applicable are shown to occur in intracellular reactions. Further, the role of the chemophoresis in the partitioning of bacterial chromosomal loci/plasmids during cell division is discussed. By performing numerical simulations, we demonstrate that the chemophoresis force can contribute to the regular positioning of plasmids observed in experiments. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the physical performance (adhesion resistance, heat resistance, rubbing resistance, chemical resistance) of an extremely thin and the high durable and chemically adsorbed fluorocarbon film with a low surface energy on the metal surface (the thickness is about 1nm order) was evaluated. The demolding resistance in injection-molding can decrease without compromising the mold shape and dimensional accuracy by using a chemically adsorbed and highly durable fluorocarbon film. Consequently, this technique should be very beneficial when applied to the molding of resin materials that have difficulty with mold release, such as silicone, urethane and elastomer resins. Further, this method will be useful for the molds used for making precision components that need to be highly accurate and ultra thin, such as optical components and chemical chips, for which conventional release agents cannot be used. [Copyright &y& Elsevier]

Abstract: Hg0 adsorption experiments with different kinds of activated carbons (ACs) were conducted in nitrogen environment to study the effects of ACs with different surface characteristics on adsorption. Three kinds of ACs prepared by steam activation did not adsorb elemental mercury (Hg0) in nitrogen environment, while another kind of AC prepared by chemical activation using zinc chloride (ZnCl2) showed significant Hg0 adsorption capability in the same experimental conditions because Hg0 was oxidized by the oxidative elements on the surface of AC. ACs without oxidative elements did not adsorb Hg0 through physical adsorption in nitrogen environment. It was therefore concluded that Hg0 adsorption by AC was a chemical adsorption process. [Copyright &y& Elsevier]

Solar-energy-driven water purification is a promising technology for obtaining clean water during the current global climate crisis. Solar absorbers with high light absorption capacity and efficient energy conversion are critical components of solar-driven water evaporation and purification systems. Herein, we demonstrate that porous reduced graphene oxide (rGO)-based composite spheres facilitate efficient water evaporation and effective organic pollutant adsorption from water. Most solar light (>99% for 1 mm thick composites) is absorbed by the porous rGO-based composite spheres floating on water and is subsequently converted into heat, which is efficiently transferred to water at the air–water interface. Evaporation efficiency via energy conversion by the floating sphere composites reaches ∼74%. The increase in surface temperature of water also contributes to improving the adsorption capacity of the rGO-based composite spheres for organic pollutants. Furthermore, the composites can effectively block ultraviolet radiation, preventing the chemical reaction of water pollutants into harmful components. [Display omitted] • The floating porous rGO–agarose composites at the water-air interface effectively transferred thermal energy to water. • The increase in water temperature improved the adsorption capacity of the rGO–agarose composite spheres for organic pollutants in water. • By blocking UV, rGO–agarose composites can inhibit the formation of harmful chemicals via photochemical reactions in water. [ABSTRACT FROM AUTHOR]

Graphene is modified with weak acids: acetic and benzoic. vdW interactions stabilize the adsorption on pristine and Stone Wales defected graphene. Chemical adsorption take place in graphene with vacancies. [Display omitted] • There is physical adsorption of C 7 H 6 O 2 and CH 3 COOH on both pristine graphene and Stone Wales defected graphene. • There is chemisorption of C 7 H 6 O 2 and CH 3 COOH on graphene with vacancies. • Non Covalent Index show that both, acetic and benzoic acids, were stabilized via vdW interactions. • Pristine and Stone Wales show Dirac cone whereas a vacancy presents a metallic behavior. • Functionalization with weak acids does not modify the electronic properties of graphene. The modification of graphene with acetic acid (AA) and benzoic acid (BA) was performed through computational simulations using the density functional theory (DFT). Pristine graphene, graphene with vacancies and Stone-Wales defects were considered. Adsorption results on pristine and Stone-Wales defected grapehene show weak physical interactions with both molecules, as confirmed by the non-covalent interaction index. Functionalized graphene sheets have similar structural and electronic properties. On the other hand, by placing vacancies in its structure, graphene promotes strong molecule adsorption on the surface due to the dangling bonds in these systems. Chemical adsorption is present by having a stronger interaction between the acids and surface. Single vacancy graphene becomes metallic. However, upon functionalizing it with acetic acid and benzoic acid, the electronic properties become pristine-like, demonstrating that functionalization with weak acids does not change the electronic characteristics of graphene. [ABSTRACT FROM AUTHOR]

[Display omitted] • Density functional theory was used to study the chemical adsorption effects of Fenbendazole and AuNPs. • Explain the reason for the selective enhancement of Raman spectroscopy. • The functional groups adsorbed by fenbendazole on AuNPs were determined. • The vibration direction of the enhanced vibration mode was determined. Fenbendazole, a benzimidazole derivative with anti-tubulin polymerization properties, has been widely used in the treatment of parasitic infections. Because of its anticancer activity similar to that of many anticancer drugs, low cost and few side effects, fenbendazole has attracted wide research attention. The chemical adsorption of fenbendazole and gold nanoparticles are studied by the UV–Vis spectrophotometry, density functional method, Raman spectroscopy and surface-enhanced Raman spectroscopy. By comparing and analyzing the theoretical and experimental Raman spectra, this paper explains the reasons for the difference between the theoretical and experimental Raman spectra. Meanwhile, it is also found that the frequencies at 851 cm−1, 1222 cm−1, 1425 cm−1 and 1566 cm−1 are greatly enhanced. It is found that imidazole is adsorbed vertically to the surface of the substrate. It is concluded that Fenbendazole is vertically adsorbed on the surface of AuNPs through imidazole. [ABSTRACT FROM AUTHOR]

DFT study shows that no chemical adsorption of DTC-CTS occurs on the surface of sphalerite, but strong chemical adsorption occurs on the surface of Cu-activated sphalerite. [Display omitted] • The activation of ZnS by Cu makes DTC-CTS more easily adsorbed on mineral surface. • The interaction between DTC-CTS and ZnS (1 1 0) surface is very weak. • There is a strong chemisorption between DTC-CTS and Cu-activated ZnS (1 1 0) surface. • The activation of ZnS by Cu also has a great influence on S atoms on mineral surface. Density functional theory (DFT) was used to simulate the adsorption of dithiocarbamate chitosan (DTC-CTS) on sphalerite (1 1 0) and Cu-activated sphalerite (1 1 0) surfaces in the presence and absence of water molecules. The results show that the adsorption of DTC-CTS on sphalerite (1 1 0) and Cu-activated sphalerite (1 1 0) surfaces in the absence of water are physical adsorption and chemical adsorption, respectively. It indicates that the adsorption capacity of DTC-CTS on sphalerite surface is enhanced obviously after being activated by Cu. That's because DTC-CTS is easier to adsorb on Cu. Besides, the replacement of Zn by Cu on sphalerite (1 1 0) surface further enhanced the adsorption ability of DTC-CTS onto S of sphalerite surface. However, the presence of water molecules has little effect on the adsorption of DTC-CTS on sphalerite (1 1 0) and Cu-activated sphalerite (1 1 0) surfaces. The results of Density of states (DOS) and Mulliken population analysis also confirmed that the adsorption of DTC-CTS on Cu-activated sphalerite (1 1 0) surface is easier and more stable than that of sphalerite (1 1 0) surface. [ABSTRACT FROM AUTHOR]

• Fe single-atom catalyst was synthesized through pyrolyzing coordinated polymer (PCP) strategy. • Interaction between CS 2 and Fe atom was far stronger than that with Fe 2 O 3 cluster. • High atom utilization and strong interaction ensured the high adsorption capacity. Carbon disulfide (CS 2) is a typical organic sulfur compound emitted from many industrial processes, such as petrochemical, smelting, et al. Chemical adsorption is a promising method for CS 2 removal and Fe based adsorbents usually show excellent performance. Single-atom catalysts (SACs) always perform magical effects in various heterogeneous reactions. In this work, pyrolyzing coordinated polymer (PCP) strategy was adopted to synthesize Fe single-atom catalyst. HAADF-STEM and XAFS results show that among several support precursor (Zn, Ce, Ag and Al), single-atom Fe only appears successfully on Al coordinated catalyst Fe-C/Al 2 O 3 , which also performs the optimal adsorption efficiency. The contrast with Fe 2 O 3 -C/Al 2 O 3 catalyst shows that single-atom Fe catalyst has remarkable advantage and the agglomeration of iron atoms decreases the adsorption capacity. DFT calculation results finally reveal that the strong interaction between Fe atom and C atom (in CS 2) induces the increment of CS 2 adsorption capacity on Fe single-atom catalyst Fe-C/Al 2 O 3. [ABSTRACT FROM AUTHOR]

The structure reforming of MIL-125(Ti) plays a key role for chemical adsorption: As(III) or As(V) can successfully replace certain organic linker in MIL-125(Ti) and organic linker transform into terephthalic acid. • The microporosity of MIL-125(Ti) can be enhanced by increasing the mixing degree of the reactants in the synthesis process. • Adsorption kinetics models and characterizations manifested the chemical adsorption of arsenic on microporous MIL-125(Ti). • Mechanism of structure reforming is verified by experimental and simulation study. The adsorption behavior of arsenic on adsorbent have been researched widely, but chemical adsorption of arsenic is uncommon. In this work, a kind of microporous metal-organic framework (MIL-125(Ti)) with columnar morphology and uniform size was solvothermally synthesized, and its chemical adsorption behavior and mechanism of arsenic were firstly investigated by experimental and simulation study. Remarkably, ultra-fast adsorption behavior and excellent arsenic removal capability was achieved. It takes only 20 min to rapidly remove 5 mg L−1 arsenic with 0.2 g L−1 MIL-125(Ti), which is far superior to the previously reported materials. Both experimental and simulation study results show that the adsorption of arsenic obeys a new chemical adsorption mechanism. Both As(III) and As(V) can easily replace the terephthalic acid ligand via competitive coordination and bind to the Ti active site of MIL-125(Ti). In addition, the reaction energy barriers for ligand substitution by H 2 O, As(III) and As(V) are 0.46, 0.33 and 0.15 eV, respectively, which further confirming that structure reforming of MIL-125(Ti) plays a key role for chemical adsorption. The study solves the difficulty of removing low concentration of arsenic and provides molecular-level understanding of the chemical adsorption mechanism of arsenic on MIL-125(Ti). [ABSTRACT FROM AUTHOR]