Chemisorption Type Research Articles

Ultrasonic-assisted adsorption of heavy copper and lead metal ions by g-C3N4, application of g-C3N4@MNPs (M: Pb, Cu) in the catalytic photoreduction of organic pollutants

In this paper, the prepared g-C3N4 was used firstly as an adsorbent of copper and lead ions by using both ultrasonic and classical methods in order to improve the adsorption of bigger metal amounts in a very good dispersion. This adsorption study was performed in-depth by evaluating the influence of contact time, the metal concentration, and the pH effect. The adsorption mechanism follows the Langmuir isotherm and the pseudo-second-order model which confirm its chemisorption type. The maximal adsorbed quantities obtained were 285.7 mg/g and 238.09 mg/g for Cu2+ and Pb2+ respectively which represent a high performance. Once the adsorption was done, the obtained nanocomposite g-C3N4@CuNPs and g-C3N4@PbNPs were used in the photocatalytic reduction of anionic and cationic dye in a simple and binary system which constitutes a recovery and recycling of heavy metals. All materials were characterized by several analyses in order to investigate the structural, thermal, textural, and morphological properties. Each nanocomposite showed an affinity for a specific material according to its surface charge. Finally, the rate constants towards methylene blue dye reached a high level up to 1.2881 min−1 and 0.6406 min−1 for the g-C3N4@CuNPs and g-C3N4@PbNPs respectively, implying a large efficiency against both organic and inorganic water pollutants.

Mechanism of inhibitory action of fruit cake extracts as a new environmentally inhibitors of carbon steel corrosion

In this study the firstly study reported on the use of plum, cherry, nectarine and apple pomace extract as corrosion inhibitors of steel in water solution. Potentiodynamic polarization study showed that extracts act as a mixed type inhibitors with dominant cathodic effect. Linear polarization resistance method (LRP) assesses the time-related effect of inhibitors during open circuit potential corrosion. The results show that the inhibitory efficiency of our extract increases with increasing time formation protective film to reach 99 % in a concentration of 500 ppm. LC - MS and FTIR spectroscopy techniques can be concluded that several water-soluble interaction products of chemical reaction in NaCl are identified namely flavanol–anthocyanin and flavanol-aldehyde adducts. Subsequently, the iron-mediated complexation and oxidation of the extract components (flvonoids) in the aqueous solution were explored using UV-spectrophotometric and HPLC methods. With the passage of time, iron-mediated oxidative degradation and coupling reactions occurred, resulting in the production of hydroxybenzoic acid derivatives. Consequently, the inhibition decreased after 24 h. The chemisorption type of interaction of the product formed in the inhibited solution forming the adsorption-polymerization layer with the steel surface is established. Based on the quantum-chemically calculated parameters of the electronic structure of flavanol–anthocyanin and flavanol-aldehyde adducts, it was established for the first time that the combination of reactive fragments in them, which are spatially located in different planes with a higher quantity of hydroxyl groups, increases their adsorption activity and, as a result, their inhibitory capacity.

Investigation of the chemical action mechanism based on reactive force field in SiC chemical–mechanical polishing process

The material removal mechanism in the chemical–mechanical polishing (CMP) process is closely related to the tribochemical reactions. In order to understand the tribochemical behaviors of diamond polishing SiC in different environments, the polishing processes in dry, pure water, and H2O2 solution are studied by the reactive force field molecular dynamics (ReaxFF-MD) simulation. Three types of chemisorption, -H, –OH, and -O-, are found on the surface of SiC in both pure water and H2O2 solution. Besides, three different material removal methods are summarized in the CMP process of SiC with diamond abrasives, namely mechanical removal, adhesive removal, and oxidative removal. Although there is oxidative removal in water and H2O2 solution, the total atoms removed will actually decrease, because the chemisorption reduces the atoms removed by adhesive removal. It is found that H2O2 solution can more effectively reduce adhesive bonds and is more conducive to oxidative removal. The reduction of adhesive bonds and changes in material removal methods result in a smaller average friction coefficient and less structural damage during polishing in H2O2 solution. This study reveals the relationship between material removal and tribochemical reactions, which can provide some guidance for the improvement of CMP process.

Facile and innovative application of surfactant-modified-zeolite from Austrian fly ash for glyphosate removal from water solution

This study highlights a pioneering approach in the development of an efficient, affordable, and economically feasible adsorbent specifically tailored for the removal of glyphosate (Gly) from contaminated water. To accomplish this objective, a low-cost and pure NaA Zeolite (NaAZ) was synthesized with 93% crystallinity from Austrian fly ash (AFA) as a precursor for the first-time. Taguchi design was employed to optimize critical parameters such as the SiO2/Al2O3 ratio, alkalinity concentration, time, and temperature. The cation exchange capacity (CEC) and external cation exchange capacity (ECEC) are determined as critical factors for the modification process. Subsequently, the pure NaAZ was modified with hexadecyl trimethyl ammonium chloride (HDTMAC), a cationic surfactant. The utilization of surfactant-modified zeolite (SMZ) for Gly removal demonstrates its innovative application in this field, highlighting its enhanced adsorption capacity and optimized surface properties. The AFA, NaAZ, and SMZ were characterized using analytical techniques including XRD, XRF, FTIR-ATR, SEM, TGA, BET, CHNSO analyzer and ICP-OES. The adsorbent exhibited effective Gly removal through its pH-dependent charge properties (pH 2–10), with an optimized pH 6 facilitating a significant electrostatic interaction between the adsorbent and Gly. SMZ demonstrated remarkable adsorption capacity and removal efficacy, surpassing most reported adsorbents with values of 769.23 mg/g and 98.92% respectively. Our study demonstrates the significant advantage of the SMZ, with a low leaching concentration of only 6 ppm after 60 days, ensuring environmental safety, long-term stability, and public health considerations. The kinetics of the adsorption process was well described by the pseudo-second order and the Freundlich isotherm. Pore diffusion and H-bonding were postulated to be involved in physisorption, whereas electrophilic interactions led to chemisorption type of adsorption. Consequently, SMZ provides a practical significance, broad applicability and promising solution for Gly removal, facilitating sustainable water treatment.

Sorption treatment of water from chromium using biochar material

Sorption treatment of wastewater from chromium compounds is a current and actively developing area of research. However, there is a lack of sorbents combining high efficiency and economic affordability with the possibility of application in industrial conditions. In this work, the sorption properties of biochar material “EcoChar,” obtained as a result of fast pyrolysis of agricultural poultry waste, were studied in relation to the removal of trivalent chromium ions, and the basic thermodynamic parameters of the process, which is the type of strong chemisorption, were determined. Based on the IR spectra of the sorbent material, the formation of chelate complexes by hydrolyzed chromium ions with the involvement of carboxylic groups and simple ether bonds is suggested. Using the Langmuir model, the values of sorption capacity of sorbent were found as, 68.8 ± 0,2 mg Cr(III)/g and 87.5 ± 0,3 mg Cr(III)/g at 298 and 318 K, respectively. These values, which are much higher than those of their corresponding waste material counterparts, make the use of this biochar as an adsorbent advantageous for the removal of Cr(III) containing compounds from acidic wastewater.

Enhancement of surface area of iron oxide modified by natural moieties towards defluoridation from water and antibacterial properties

A novel adsorbent has been developed by modifying iron oxide (Fe2O3) surface using humic acid (HA) biopolymer and reduced graphene oxide (rGO), resulting in a highly efficient composite rGO/HA-Fe2O3 with magnetic property for removal of fluoride. The surface area of the composite is found to be 455.6 m2/g which has been enhanced around five times after modification with rGO and HA. Batch adsorption experiments were conducted to determine the optimal conditions for fluoride adsorption. The study found that the maximum fluoride adsorption occurred at adsorbent dose of 0.3 g/L, pH 7, contact time of 120 min. Equilibrium adsorption study data best fitted for the freundlich isotherm model, whereas, kinetic studies follow second-order kinetics which demonstrates multilayer adsorption on a heterogeneous surface with chemisorption type interaction. The adsorption process was found to be feasible, spontaneous, endothermic in nature and also the adsorbent was capable of removing around 99% of fluoride at 100 ppm initial fluoride concentration. The composite demonstrated a fluoride removal capacity of 376.46 and 395.32 mg/g at 30 and 50 °C, respectively, at pH 7, and also exhibited antibacterial properties. The composite was successfully regenerated using a 0.1 M alkaline solution with 98% efficiency and can be reused up to four cycles with an efficiency of 83.1%. The antibacterial property of the composite was assessed using solutions of Escherichia coli in water. This study is unique in its use of humic biopolymer in fluoride adsorption studies with graphene oxide, incorporating iron oxide to maintain a neutral pH during the adsorption process. The high surface area of the rGO/HA-Fe2O3 facilitates for removal of fluoride up to a very high-level fluoride concentration broadening its practical applications in various aspects. Moreover, this adsorbent is cost-effective as the precursors are easily and abundantly available in the natural environment.

Multifunctional 2D g-C4N3/MoS2 vdW Heterostructure-Based Nanodevices: Spin Filtering and Gas Sensing Properties.

Two-dimensional (2D) magnetic materials are the key to the development of the new generation in spintronics technology and engineering multifunctional devices. Herein, the electronic, spin-resolved transmission, and gas sensing properties of the 2D g-C4N3/MoS2 van der Waals (vdW) heterostructure have been investigated by using density functional theory with non-equilibrium Green's function method. First, the g-C4N3/MoS2 vdW heterostructure demonstrates ferromagnetic half-metallicity and superior adsorption capacity for gas molecules. The spin-dependent electronic transport of the g-C4N3/MoS2-based nanodevice is obviously regulated by parallel or anti-parallel spin configuration in electrodes, leading to perfect single-spin conduction behavior with a nearly 100% spin filtering efficiency, a negative differential resistance effect, and other interesting electrical transport phenomena. Moreover, g-C4N3/MoS2 exhibits directional dependency and strong transport anisotropic behavior under bias windows, indicating that the electric current propagates more easily through the vertical direction than the horizontal direction. The physical mechanisms are revealed and analyzed by presenting the bias-dependent transmission spectra in combination with the projected local device density of states. Finally, the g-C4N3/MoS2-based gas sensor is more sensitive to CO, NO, NO2, and NH3 molecules with the chemisorption type. The strong chemical adsorption leads to the formation of electrons on the local scattering center and ultimately affects the transport properties, resulting in the maximum gas sensitivity reaching 6.45 for NO at the bias of 0.8 V. This work not only reveals that the g-C4N3/MoS2 vdW heterostructure with high anisotropy, perfect spin filtering, and outstanding gas sensitivity is a promising 2D material but also provides an insight into the further application in futuristic electronic nanodevices.

Corrosion Inhibition Data and Statistical Analysis of the Performance of Rosemary Oil Extract on High Carbon Steel in Dilute Electrolyte Solutions

Application of plant extracts for the corrosion protection of engineering materials is an ongoing research to replace the conventional toxic, costly and unsustainable chemical derivatives. Data on the corrosion inhibition performance of rosemary oil extracts on high carbon steel in 0.5 M C6H8O7, 0.5 M H2SO4 and 3.5 wt.% NaCl solution was studied and the inhibition efficiency data statistically analysed. The oil extract performed poorly in C6H8O7 solution with optimal inhibition efficiency of 49.21% at 1.5% extract concentration. However, the extract performed effectively in H2SO4 and NaCl solution with optimal inhibition efficiency of 78.45% at 2.5% extract concentration and 97.87% at 1.5% extract concentration. Inhibition efficiency varied significantly with exposure time and concentration. The oil extract exhibited chemisorption type adsorption mechanism in all the solutions in consonance with Langmuir, Frumkin and Freundlich adsorption isotherms. Statistical data on standard deviation showed the variation of extract inhibition efficiency with respect to mean inhibition value and exposure time was relatively significant in C6H8O7 solution due to instability of inhibitor molecules, compared to the relatively low values obtained in H2SO4 and NaCl solution. Data from numerical variation showed extract concentration is the dominant statistically relevant inducing inhibition performance of rosemary oil extract in C6H8O7 and NaCl solution with statistical relevance factor of 63.40% and 70.36% compared to the corresponding values obtained in H2SO4 solution were extract concentration and exposure time were statistically relevant. Data showed 30%, 19% and 90% of inhibition efficiency data in C6H8O7, H2SO4 and NaCl solution are above 70% inhibition value at margin of error of +0.09, +0.077 and +0.059.

Fe-Mn-Al metal oxides/oxyhydroxides as As(III) oxidant under visible light and adsorption of total arsenic in the groundwater environment

Arsenite (As(III)) and arsenate (As(V)) species are responsible for arsenic toxicity in groundwater. Anoxic groundwater condition makes it concentrate with highly toxic As(III) compared to As(V). Commercial arsenic adsorbents are mainly effective to adsorb As(V), thus a costly oxidation step needs before an adsorption step. An adsorbent with strong As(III) oxidation capability at visible light and the capability to effectively adsorb As(V) from water is warranted. Ternary metal oxides/oxyhydroxides were prepared by mixing Fe, Al, and Mn-salt precursors and hydrolyzed simultaneously up to an optimized pH. The formation of oxyhydroxides Fe, Al, & Mn, specifically Mn(IV) oxidation state, can quickly oxidize the As(III) species in water; simultaneously, arsenic species get adsorbed on other (Fe, Al oxides/hydroxides) adsorption sites. The manganese compound’s energy bandgap (1.29 eV) is accountable for showing the oxidation capability of the adsorbent even under visible light irradiation. Hence, the maximum Langmuir adsorption capacity obtained was 34.34 mg/g and 21.22 mg/g for the As(III) and As(V), respectively. The Elovich kinetics concluded the chemisorption type of adsorption of arsenic species in the groundwater environment. XPS analysis confirms the oxidation of As(III) species into the As(V) species and reveals the inner sphere arsenic complexation mechanism through surface hydroxyls. As(III) removal through oxidation followed by adsorption was almost identical under visible light conditions and UV exposure. Thus, the study proposes using this adsorbent as indoor household filter media for arsenic removal without the requirement of UV irradiation.

First-principles investigation of Hydroxycarbamide anticancer drug delivery by X12N12 (X = B, Al, Ga) fullerene nanostructures: A DFT, NBO and QTAIM analysis

The group-III nitride fullerenes (B12N12, Al12N12 and Ga12N12) are noncytotoxic and chemically stabile for human and are the perfect carriers for the delivery of drugs. This present study has computed the the different properties to explore the interaction among Hydroxycarbamide (HU) and X12N12 (B12N12, Al12N12 and Ga12N12) nanocages using DFT method both in gas and water phase. Our investigation exhibits that Al12N12 and Ga12N12 can be smart drug carrier for the delivery of HU drug as confirmation from the adsorption study. The energy of adsorption of all the complexes shows chemisorption type adsorption, indicating the interaction between the HU and Al12N12 and Ga12N12. The change of Eg of our studied structures indicates the sensitivity of the nanocages towards HU drug molecule. Therefore, it is predicted that HU drug onto the Al12N12 and Ga12N12 nanocages might be good delivery vehicle which will be helpful to which will benefit from saving human.

Enhanced gas molecules adsorption on γ-graphyne doped with Fe atom: A first- principles study

The adsorption behaviors of gas molecules O2, CO, NO, NO2 and SO2 on the surface of γ-graphyne doped with Fe atom were explored in detailed by first principles calculations. It is found that dopant Fe atoms could be embedded stability into the γ-graphyne plane with the lower binding energy, the modified surface could significantly enhance the adsorption capacity for free gas molecules. Gas molecules are anchored firmly at the surfaces through the formation of chemical bonds with Fe dopant atoms, the typical chemisorption behaviors can be confirmed by the analysis of electronic properties. The OO bond is elongated to 1.412 Å because of the chemical interaction between adsorbed O2 and dopant surface, the production of activated oxygen radicals maybe used for elimination of toxic gases. The sensing mechanism of GY-Fe was discussed by desorption properties of gas and band structure analysis, we obtained the recovery time about 7.89 s for SO2 at 398 K. Therefore, this study, maybe provide some helpful informations for the design of graphyne-based gas sensors and catalysts.

Novel bipolar magnetic semiconductor materials formed by adsorption of methyl or halomethyles on the graphene: A spin-polarized density functional theory study

Exploring magnetic materials with electrically controlled spin polarization and room temperature magnetic ordering is of particular importance for applications in spintronic devices. In this study, we present a detailed theoretical study on the structural, electronic, and magnetic features of pristine graphene on which methyl(CH3) or a halomethyl (CH2F, CH2Cl, CH2Br, or CH2I) radical has been adsorbed. The framework of our calculations is dispersion-corrected density functional theory with due account of the spin degree of freedom within the Quantum-ESPRESSO package. The investigation starts with a complete discussion of the geometrical characteristics, followed by a thorough study of the manner of charge transfer and redistribution, electronic band structures, and density of states. The calculated adsorption energies and distances demonstrate the adsorption process to be of the chemisorption type. The adsorption of each radical on graphene is accompanied by a net charge transfer, changing the work function of the resulting compounds and modulating the electronic and magnetization characteristics of pristine graphene. Considerations of the calculated spin-distinct electronic band structure and density of states support the latter conclusion. The presence of unequal band gaps in the up and down spin channels also corroborates the aforementioned compounds' bipolar magnetic semiconductor nature.

Effect of magnetization on the adsorptive removal of an emerging contaminant ciprofloxacin by magnetic acid activated carbon

Magnetic acid activated carbons (MAAC) were prepared from the shells of Sterculia villosa Roxb by activating the biomass and magnetizing it using the co-precipitation technique. Characterization of MAAC prior and post adsorption was performed using various microscopic and spectroscopic analytical techniques, and they verified the formation of magnetic aggregates over porous activated carbon surface. Vibrating Sample Magnetometer (VSM) analysis confirmed the superparamagnetic behaviour of the adsorbent with saturation magnetization (Ms) value of 18.2 emu/g, causing an easy and rapid recovery from the adsorption setup in the presence of an external magnetic field. Langmuir isotherm and pseudo-second-order kinetic model best fit the experimental data with theoretical Langmuir maximum adsorption capacity as 81.97 mg/g and verifying chemisorption type of adsorption process, respectively. Thermodynamic analysis verified the interaction among adsorbate and adsorbent as endothermic, spontaneous, and thermodynamically favourable. Co-existing metal cations showed a significant reduction in ciprofloxacin removal efficiency; co-existing anions, though, showed a negligible influence on the adsorption efficiency of MAAC. Recyclability studies verified that the adsorption efficiency fell from 98% in the first cycle to 43% in the fifth cycle. The Ms value fell to 7.6 emu/g (after five adsorption cycles), affecting the adsorbent's recovery. The Phyto-toxicological assessment was performed to evaluate the environmental risk to human and aquatic life using Vigna mungo seeds. MAAC proved to be an effective and magnetically separable adsorbent for removing antibiotics.

Removal of rhodamine B from aqueous solution by adsorption on corn cobs activated carbon

<p>In the present study, adsorption experiments were carried out to investigate the removal of rhodamine B from an aqueous solution using chemically activated carbon from corn cobs, a cheaper adsorbent. The characteristics of carbon were determined using X-ray diffraction, SEM, iodine number, pHpzc, and the Boehm titration method. The results show that the prepared activated carbon is amorphous, microporous, and generally acidic on the surface. The kinetic study of the adsorption of rhodamine B on this carbon was carried out, and the rate of sorption was found to conform to pseudo-second-order kinetics with 80 min as equilibrium time. The equilibrium adsorption revealed that the experimental data fitted better to the Langmuir isotherm model for removing rhodamine B. The interaction rhodamine B-activated carbon is mainly chemisorption type. The optimal conditions of rhodamine B removal onto the carbon of this study are mass of carbon = 0.3 g and pH = 3.15. The maximum monolayer adsorption capacity for rhodamine B removal was found to be 5.92 mg.g<sup>-1</sup>. This study has shown that the prepared activated carbon makes it possible to effectively clean up wastewater contaminated by rhodamine B with a removal efficiency of up to 99.60% for 300 mg of AC in 25 mL of the rhodamine B solution (5 mg.L<sup>-1</sup>).</p>

Arsenic(V) removal on the lanthanum-modified ion exchanger with quaternary ammonium groups based on iron oxide

In this study, the commercially available iron oxide sorbent with quaternary ammonium groups was modified with lanthanum(III) ions for removing arsenate(V) from water. Several analyses, such as SEM, N2 adsorption–desorption method, FTIR and XPS, were employed to characterize the ion exchanger and explore the adsorption of As(V) ions on Ferrix A33E-La(III) (in the abbreviated form A33E-La(III)). The experimental results revealed much better sorption properties of A33E-La(III) than those of unmodified A33E. After the modification, the maximum sorption capacity of the ion exchanger increased by 55% and the percentage removal at various initial As(V) concentrations was higher. According to the results, the As(V) removal was spontaneous and of the exothermic chemisorption type which proceeded due to the formation of monodentate and bidentate inner-sphere complexes as well as lanthanum arsenate by precipitation. Even after 3 cycles of adsorption–desorption A33E-La(III) could be used for arsenic(V) removal with almost the same initial efficiency. It was found that the presence of lanthanum on the surface of the ion exchanger plays a great role in the adsorption of As(V) from the contaminated water due to changing the mechanism of the process.

Fe-Phthalocyanine on Cu(111) and Ag(111): A DFT+vdWs investigation

Starting from dyes in the industrial domain, Metal-Phthalocyanine (MPc), a macrocyclic planar organo-metallic molecule, can nowadays be used in various applications at low cost in several areas such as oncology, sensors, catalysts, spintronic devices, to name a few. Some applications require the deposition of these molecules on metallic surfaces, whereas sometimes the bulk molecular system is used. In this work, we study both the bulk system of iron-Phthalocyanine (FePc) and its adsorption on Cu(111) and Ag(111). We investigate the structural, electronic, and magnetic properties of these materials using Density Functional Theory (DFT) taking into consideration van der Waals effects to further reflect the importance of the involved interactions on the properties. We found that the FePc bulk system displays a magnetic state resulting from the metallic central Fe atom. However, the adsorbed FePc partially loses its magnetization when it is deposited on a transition metal surface of Cu(111) or Ag(111). Additionally, both C4 symmetry and C2 symmetry were observed with STM images for FePc/Ag(111) and FePc/Cu(111), respectively. The adsorption is found to be of a strong chemisorption type with relatively large binding energy (∼x223C 5 eV/molecule) and charge transfer (∼x223C 0.7e−) from the metal surface to the molecule.

Superior removal of methylene blue using green fabricated pomegranate peel/nano-hematite composite: reusability, isotherm and kinetics study

Green hematite nanoparticles were synthesized using pomegranate peel extract of different concentrations (2 g, 4 g, and 6 g) and in the presence of the peel residuals. The obtained products defined as PP/GNH (I), PP/GNH (II), and PP/GNH (III) referring to the hematite nanoparticles at different concentrations compositing with pomegranate peel residuals. The products were addressed as green adsorbents for methylene blue dye contaminants in water. They exhibit superior adsorption properties with theoretical qmax of 666, 1111, and 909 mg/g for PP/GNH (I), PP/GNH (II), and PP/GNH (III), respectively. The equilibration times were attained after 480 min for the three products. The isotherm and kinetic studies indicate that the adsorption systems for the synthetic materials are of chemisorption type. The adsorption behaviors of these systems can be demonstrated according to Pseudo-second order as well as Elovich kinetic model. Furthermore, the adsorption results reflected a mono-layer uptake form which was more suitable for the Langmuir model than other investigated models. The products also showed high performances when it comes to remove the dyes investigated such as methylene blue Congo red, safranin, methyl orange, and crystal violet. Finally, green fabricated nano hematite/pomegranate peel composites are of high stability and can be reused for five cycles. Communicated by Ramaswamy H. Sarma

Dithiocarbamate modified glucose as a novel eco-friendly corrosion inhibitor for copper in sodium chloride media

A novel eco-friendly corrosion inhibitor named dithiocarbamate modified glucose (DTCG) was synthesized from glucose by amination and nucleophilic addition reaction. The anti-corrosion behavior of DTCG for copper in 3 wt% NaCl solution was studied by experimental and theoretical methods. The results show that its maximum inhibitive efficiency can exceed 96% using different technology assessments. DTCG as a mixed-type inhibitor is firmly adsorbed on the copper surface and presents typical chemisorption. DTCG shows significant anti-corrosion performance compared with other glucose-based inhibitors. The DFT calculation results confirms the experimental conclusions.

Assembly of cerium impregnated pectin/silica–gel biopolymeric material for effective utilization for fluoride adsorption studies

The current global concern related to ground water contamination especially fluoride (F- contamination has ascended in an increased exigence for effective adsorbents. In this study, we have used a surface altered pectin biopolymer with silica–gel (SG), and incorporation of cerium oxide (Ce@SG-Pec) for the application of F- adsorption studies from the aqueous systems. The temperature, contact time, absorbent dosage, pH, coexisting anions, and initial F- concentration are discussed. The isothermal and kinetic data were fitted to Temkin and pseudo-second-order model, respectively. Analysis of adsorptive thermodynamics showed that the adsorption process was endothermic, spontaneous, feasible, and chemisorption type of adsorption mechanism. The good adsorption is attributed to chemical adsorption through strong surface complexation of cerium and silicon with F- as well as the special structure of adsorbent. The surface analyses (BET and FESEM) had shown the decrease in pore size after the F- adsorption. Additionally, FTIR analyses supported the substantial role of ion–exchange and electrostatic interaction in the adsorption mechanism.

Interaction studies of glycine, acetate and methylamine on β-tellurene nanoribbon – A first-principles analysis

We investigated the structural stability of β-tellurene nanoribbon (β-TeNR) and explored the adsorption behaviour of glycine, acetate, and methylamine malodorous molecules on β-TeNR based on ab-initio calculations. Besides, β-TeNR exhibits semiconducting behaviour with a direct energy gap (Eg) of 1.657 eV. In the beginning, the dynamical solidity and geometrical firmness were confirmed with regard to the phonon band spectrum and negative cohesive energy (−3.406 eV/atom), respectively. With the support of band structure and PDOS (projected-density of states), the electronic characteristics of β-TeNR are explored. Provocatively, two dissimilar superior adsorption sites (top &hollow-sites) of chief malodorous on β-TeNR were demonstrated with regard to the average band gap variation (Ega), Bader charge transfer (Q), and binding energy (EB). The calculated EB of preferential interaction sites is found to be in the scope of −0.190 to −1.751 eV referring to mixed physisorption and chemisorption type of interaction upon β-TeNR. The outcomes recommend that β-TeNR can be positively utilised as a chemi-resistor to sense the glycine, acetate, and methylamine molecules in an unpleasant atmosphere.