Search

Direct air capture (DAC) is a sustainable technology to alleviate the greenhouse effect and a reliable pathway to acquire inexhaustible CO2 for the production of costly chemicals and energy products. Current DAC technologies with amine‐related sorbents rely on chemisorption, while they consume intensive energy for CO2 release and sorbent regeneration by heating. Developing new DAC processes with weak, reversible adsorption can substantially reduce the regeneration energies. Herein, the design of CO2 breathing paper (CBP) is demonstrated toward spontaneous CO2 extraction from ambient air and solar‐driven regeneration. The CBP is fabricated by coupling 2‐ethyl‐4‐methylimidazole to carbon nanotube paper on the basis of density functional theory calculations. At ambient conditions, CBP spontaneously captures atmospheric CO2 with a capacity of 0.14–1.75 mmol g–1 at 0–35 °C through non‐covalent electrostatic interaction. Upon exposure to sunlight, all adsorbed CO2 can be released and converted to concentrated gas for storage. Attractively, the efficiency of solar‐driven CO2 release is much higher than the traditional temperature‐swing method owing to the IR sensitivity of CO2. Besides the reversibility, the mild conditions also ensure the durability of CBP. These findings suggest that the CBP is a promising candidate for cost‐effective DAC. [ABSTRACT FROM AUTHOR]

The sulfuric acid-doping polyaniline (H-PANI-HSO4) are applied to conduct the electrochemical measurement and simulation calculation to investigate the capacitance, electronic structure and energy band properties. The H-PANI-HSO4 growing on graphite carbon paper (H-PANI-HSO4/GCP) is applied as an electroactive electrode to investigate electrochemical properties. The Faradaic capacitance of H-PANI-HSO4/GCP electrode is ascribed to the reversible redox reaction of bisulfate anion doping/dedoping protonated PANI (H-PANI). Cyclic voltammetry measurement at a scan rate of 5mVs−1 determines an equivalent mean response current of 0.64Ag−1 and a capacitance of 128.35Fg−1. Galvanostatic charge–discharge measurement determines specific capacitance from 129.06 to 116.88Fg−1 at current densities from 0.5 to 2.5Ag−1. Cyclic voltammetry-based capacitance at equivalent current density of 0.64Ag−1 is in accordance with galvanostatic charge–discharge-based capacitance at the current density of 0.57Ag−1. Electrochemical impedance spectrum measurements indicate that H-PANI-HSO4/GCP exhibits lower charge-transfer resistance, much lower Warburg resistance, higher quasicapacitance than H-PANI-HSO4 to approaching ideal capacitor. Density functional theory calculations indicate that H-PANI-HSO4 has a higher density of states (10.6 electron/eV) and lower bandgap energy (0.481eV) than H-PANI (5.24 electron/eV, 1.449eV), indicating its enhanced electronic conductivity. The electronic bandgap energy is accordingly decreased from 0.263eV for H-PANI-HSO4/GCP to 0 for H-PANI-HSO4/GCP. Electrochemical measurement and simulation calculation investigation proves that H-PANI-HSO4/GCP electrode with anion-doped and protonated state exhibits higher electronic conductivity and capacitance performance to act as superior electroactive material. [ABSTRACT FROM AUTHOR]

Non-enzymatic electrochemical blood glucose sensors often suffer from issues such as requiring an alkaline environment, limited monitoring range, and poor anti-interference properties. Carbon substrates have been demonstrated to improve the performance of non-enzymatic sensors, but complex and energy-consuming manufacturing processes restrict their use. Herein, a simple and green approach for the preparation of 3D porous Au/Au-Pt networks (PAAPNs) is proposed using tissue paper for recycling as the nanomaterial substrate to deposit Au-Pt bimetallic nanoparticles. The unique structure of the PAAPNs sensor allows for low-potential operation (-1.0 V) with a wide monitoring range (-0.25 to 36 mM) in a neutral environment. Moreover, the sensor exhibited excellent selectivity (<10% response of interference) even without the use of an anti-interference outer membrane. Further investigation using density functional theory (DFT) simulation revealed the synergistic effect between Au and Pt in promoting glucose oxidation. Overall, this work provides a simple and low-carbon footprint method for creating carbon substrates from tissue paper for recycling, offering new opportunities for fabricating novel value-added nanomaterials for medical sensing applications. [ABSTRACT FROM AUTHOR]

In this paper, the thermo-electric, phonon, electronic, and optical properties of the C3N monolayer have been investigated using the Wien2K computational code based on first principles calculations in the framework of the density functional theory. The study of electronic properties shows the behavior of non-magnetic semiconductors with an indirect gap with a value of 0.5 electron volts for this two-dimensional structure. Also, optical properties such as dielectric function, reflection, energy loss function, absorption coefficient, and optical conductivity are calculated. C3N monolayer is optically anisotropic in z and x direction, which according to the refractive index diagram leads to birefringence, which is a key parameter for this compound's linear optical performance. The results provide a fundamental understanding of the design of composite structures used in nanodevices based on two-dimensional advanced materials. The linear response approach along the symmetric points calculates the phonon dispersion diagram. The results indicate the absence of negative modes in the phonon spectrum, indicating that the structure is dynamically stable. Investigating the thermoelectric properties of the C3N monolayer using the semi-classical Boltzmann theory shows that this monolayer has a value coefficient (ZT) close to one at room temperature and temperatures lower than room temperature. As a result, it can be proposed as a candidate for thermoelectric applications.

In this study, the optical and electronic properties of bulk and nano-layer of zinc selenide (ZnSe) and zinc sulfide (ZnS) are investigated. The calculations for solving the many-body Schrodinger equations are performed in the framework of density functional theory using the WIEN2K computational package. The Engel-Vosko and gradient generalized approximation (GGA) treat the exchange-correlation potential. To investigate the electronic and optical properties of zinc selenide and zinc sulfide nano layers, the electronic band structure and the real and imaginary parts of complex dielectric function for the bulk and nano-layer with different thicknesses are calculated and compared. The results of electronic band structures show that the energy band gap of zinc selenide and zinc sulfide nano-layers with various thicknesses decreases to zero and are metal. In contrast, the bulk of zinc selenide and zinc sulfide compounds are semiconductors. The results also show that for each compounds the static dielectric function for the perpendicular and parallel direction to the nano-layer surface is different from the bulk static dielectric function. Comparison between the real parts of complex dielectric function for the bulk and nano-layer shows that absorption of electromagnetic radiation for the ZnSe and ZnS nano-layer in comparison to corresponding bulk results occur in lower energies.

Weyl semimetals show special quantum states of matter, which have nontrivial topological features and very interesting and unique applications in the spintronics industry. One method of making these materials is the use of alloying method. In this paper, the alloys are constructed using the first-principles methods. After study of their stability, their structural, electronic, and topological properties have been studied. To study the structural and electronic properties of the alloys, the Wien2k package, based on density functional theory, has been used. Furthermore, the topological properties of the alloys have been calculated using the Wanniertools packages, based on the tight-binding method. Calculations show that the alloys, in the absence of spin-orbit coupling, have crossing points with fourfold degeneracy and band inversion. Therefore, they are topological Dirac semimetal. Considering the spin-orbit coupling, it is seen that alloys with concentrations of x = 0, 0.25, 0.5, 0.75 change to the normal semimetal by opening the band gap; but, the alloy with x = 1 concentration changes to the topological Weyl semimetal with 16 Weyl fermions couple. The full area of the first Brillouin zone (FBZ) was scanned to find the positions of the Weyl points. The results show that the Weyl points, with chirality of either +1 or -1, were scattered in the FBZ with the central symmetry, but all of them are far from the high-symmetry paths of FBZ. Furthermore, the surface state properties, like Fermi arcs, were calculated and studied for the NbSb Weyl semimetal using the Wanniertools computational packages.

In this paper, the optical properties of GaP in different phases have been investigated. The calculations were performed by using pseudopotential in the framework of density functional theory and using the PWscf code. The pseudopotentials applied here are generated using norm-conserving conditions within GGA for the exchange-correlation function. The optical properties of the Zincblend and Cinnabar phases reveal the conformity between the band structure and the imaginary part of the dielectric function, and the band gap and optical gap are almost equal. The refractive index obtained from the real part of the dielectric function in Zincblend is 3.306 and in the Cinnabar phase is 4.235 and 3.808 in the x and z directions, respectively.

In this research, the effect of hydrostatic pressure on the electronic structure and optical properties of GaAs compound has been investigated. The calculations have been done based on the density functional theory (DFT) using WIEN2K computational package. This computational package solves Kohn-Sham equations by the full-potential linearized augmented plane wave (FP-LAPW) method self-consistently. The exchange-correlation potential is calculated by the Generalized gradient approximation (GGA) and a combination of modified Becke — Johnson plus local-density approximation (mBJ-LDA) functional. All the electronic and optical properties calculations have been done in the presence of spin-orbit interaction. In the case of electronic structure calculations, using the band structure calculations at different pressures, the pressure dependence of band gap energy is calculated. The results of calculations show that by increasing the pressure the band gap energy increases linearly. Regarding the optical properties, the effect of hydrostatic pressure on the real and imaginary parts of the dielectric function ε(ω) is calculated. The results show that by increasing pressure the absorption edge and the major peaks in the imaginary part of the dielectric function are shifted towards higher energies whereas by decreasing the pressure they are shifted towards lower energies. The results also show that by increasing the pressure, the static dielectric function decreases linearly. Using the results of the real and imaginary dielectric function calculations, the optical gap and the static refractive index at different pressures are also calculated.

Given its superior structure, the abundance of surface functional groups, and low cost, cotton fiber filtration paper can be used as the support for hydrogen evolution reaction (HER) and oxygen evolution reaction catalysts (OER) instead of copper foam (CF), nickel foam (NF), or carbon cloth (CC). Herein, the chemical plating method was used to create thin self-supporting electrodes based on cotton fiber filtration paper (FP). The Co-Ni-P amorphous nanospheres can be uniformly dispersed on the self-supporting FP due to its porous structure and oxygen functional groups. The Co-Ni-P/FP electrode has an overpotential as low as 125 mV for HER and 320 mV for OER at the current density of 10 mA cm−2. Additionally, according to density functional theory (DFT) calculations, the Co atom added to the Ni-P nanosphere can lead to considerably more charge accumulation around the Co and Ni active sites, which greatly encourages the HER and OER processes. The novel porous support, FP, provides a fresh way the preparation of self-supporting electrodes. [Display omitted] • Filter paper is used to prepare the self-supporting electrode as the substrate. • The preparation method is simple and the properties are stable. • Rich oxygen-containing functional groups of FP promote deposition and dispersion. • Explore the excellent electrochemical performance of amorphous Co-Ni-P/FP by DFT. [ABSTRACT FROM AUTHOR]

In this paper, structural properties such as structure parameters, energy band structure, the density of state, and charge density of LaGaO3 are calculated from the cubic phase. The calculations have been performed using the pseudopotential and a plane wave method in the framework of density functional theory (DFT) with generalized gradient approximation (GGA) by the Quantum Espresso package. The results are in good agreement with the results of others.

[Display omitted] • Paper mill sludge ash (pm SA) was used as catalysts to activate PMS. • Aerobic calcination was conducive to the exposure/formation of octahedral FeIII. • The O O bond fracture was the root pathway for FeIV O production. • The release of solid calcium in pm SA could inhibit the active decay of FeIV O. • The pm SA could effectively degrade similar pollutants in near-neutral water. The excellent performance of high-valent iron-oxo species (FeIV O) in the degradation of pollutants by activating peroxymonosulfate (PMS) had attracted much attention. However, the generation and reaction mechanisms were still unclear. In this study, iron-rich paper mill sludge was used as a raw material for the first time to prepare iron-based catalysts with abundant octahedral FeIII sites (Fe oct III). The results showed that the highest content of Fe oct III was found in the paper mill sludge ash obtained by aerobic calcination at 800 °C (pm SA800), and the pm SA800 could exhibit excellent catalytic activity (0.4785 min−1) and stability during the oxytetracycline (OTC) degradation process. The characterization and density functional theory (DFT) calculations further indicated that the Fe oct III was the dominant active site for FeIV O production. PMS tended to be adsorbed on two adjacent Fe oct III sites to form a [Fe oct III-OSO 2 OO(H)-Fe oct III] complex with a two-site adsorption configuration. Subsequently, the O O and O H bonds in [Fe oct III-OSO 2 OO(H)-Fe oct III] broken by absorbing energy, generating FeIV O. It's worth noting that the Ca species of pm SA800 effectively stabilized the pH of the reaction solution, which ensured the stable and continuous production of FeIV O. This work provides a new idea and insight for preparing catalysts that could produce FeIV O active species. [ABSTRACT FROM AUTHOR]

In this work, the structural, electronic, and optical properties of bulk and monolayer of Iron dichalcogenides FeX2 (X= S, Se, Te) have been investigated using the full potential linearized augmented plane wave (FP-LAPW) in the framework of density functional theory (DFT) with Wien2k simulation package. The calculated results show that FeX2 compounds in the bulk structure are non-magnetic semiconductors with a direct gap at the Γ point, while the monolayer compounds are ferromagnetic with metallic character. The band structure and energy gap of bulk and monolayer structures of FeX2 are calculated using GGA-PBE and GGA-mbj approximations that Becke-Johnson functional gives us better results for band gaps. All-optical properties such as real and imaginary parts of the dielectric function, absorption and reflection coefficients, refractive and extinction index, conductivity, and electron energy loss spectrum have been calculated and analyzed for bulk and monolayer. The High amplitude and wide absorption coefficient in the visible and ultraviolet region make these compounds a good candidate for use in photoelectric instruments and solar cells. Since monolayer compounds show magnetic properties, all calculations for monolayer compounds are performed in the spin-polarized form.

It is significant to develop low-cost and highly efficient electrocatalysts for the hydrogen evolution reaction (HER) via electrochemical water splitting. Herein, we constructed P-doped NiCo2S4 nanowire arrays on carbon fiber paper (NiCo2S4−xPx/CFP) as a HER electrocatalyst in both acidic and alkaline media. Benefitting from P doping into NiCo2S4, the as-prepared NiCo2S4−xPx/CFP exhibits low HER overpotentials of 80 and 132 mV in acidic and alkaline media at a cathodic current density of 10 mA cm−2, respectively, which are far superior to counterparts of NiCo2S4 nanowire arrays on the carbon fiber paper (NiCo2S4/CFP). Meanwhile, the NiCo2S4−xPx/CFP presents excellent HER stability of 20 hours in acidic and alkaline media. From the results of density functional theory calculations, P doping can not only optimize the hydrogen adsorption energetics on each kind of atomic site of catalysts, but also strengthen the H2O molecule binding ability on the catalyst surface for the alkaline HER and favor kinetics of hydrogen adsorption and H2 formation on the catalyst surface for the acidic HER, eventually improving overall HER performances. The investigation of the HER mechanism modulated by P doping in our work offers novel inspiration to develop highly efficient ternary metal sulfides for the HER. [ABSTRACT FROM AUTHOR]

A new fluorescent probe (T2) containing pyrene-hydrazone furan moieties was developed and synthesized through a two-step process and then coated onto filter paper to form a paper-based sensor for TNT detection. The T2 sensor uses photoinduced electron transfer (PET) induced fluorescence quenching to detect TNT. The sensor properties were studied using fluorescence spectra, 1H-NMR titration and density functional theory (DFT) calculations. The reaction time of the T2 paper-based sensor for TNT detection was only five minutes. A smartphone was used as an alternative instrument to detect fluorescence signals and a typical image J-processing application was employed to evaluate the grayscale values of the smartphone-captured photographs. The sensor showed a linear concentration range for TNT detection of between 30–500 μM and a detection limit of 30 μM. The T2 paper-based sensor was found to have high selectivity and sensitivity, and it can successfully detect and image TNT in actual samples. This research demonstrates that a T2 paper-based sensor is a promising alternative for TNT detection owing to its short reaction time, high selectivity, sensitivity, and easy applicability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic properties of MoS 2 in presence of glucose has been studied using DFT. • Molecular level substrate-analyte interaction has been studied through NCI plot. • Mos 2 functionalized paper based electrochemical sensor for glucose has been developed. • The paper based electrochemical sensor shows good accuracy and selectivity. • The ML-driven smart app, GluQuantify, shows enhanced accuracy and resolution. A paper-based electrochemical sensor utilizing MoS 2 as sensing material is developed to quantitatively estimate glucose in a complex extracellular fluid matrix. The contribution of MoS 2 as sensing material is substantiated in the context of density functional theory formalism. The molecular modelling of MoS 2 and glucose interaction is elucidated through the theoretical estimation of non-covalent interactions and charge density difference plots. The charge transfer phenomenon during the oxidation of glucose molecule in electrochemical experiments is verified through electronic band structure analysis and frontier orbital theory. The electrochemical responses indicate that the sensor exhibits an average accuracy of nearly 96%, with a quantification limit of 100 nM. Furthermore, the chronoamperometric measurements highlight the superior sensitivity of the device in presence of various perturbing molecules. The obtained DPV responses were integrated with a robust machine learning-driven standalone app GluQuantify. This app precisely predicts the glucose concentrations in serum samples. The utilization of GluQuantify substantially elevates the overall accuracy of the sensing platform to 99% and automates the detection process. The application also enhances the resolution of the sensor to 0.01 µM, which mitigates the sensor resolution-related issues in manual estimation. [ABSTRACT FROM AUTHOR]

[Display omitted] • N-BPQD was synthesized through a solvothermal method using formamide as N source and solvent. • The N-BPQD exhibit a bright blue fluorescence with high quantum yield of 73.7%. • N-BPQD on fPAD was used as a visual fluorescent sensing platform for detection of bilirubin. • The fluorescent sensor shows high sensitivity and selectivity to bilirubin. • N-BPQD was a good fluorescent probe for cellular imaging. A facile top down producing approach for synthesis and doping of a nitrogen doped black phosphorus quantum dots (N-BPQD) in one-pot was developed by solvothermal method with formamide as a nitrogen source and solvent. The nitrogen atoms had introduced into BPQD structure and exhibit a bright blue photoluminescent with a high quantum yield of 73.7 %. The morphology and chemical structure of N-BPQD was characterized by transmission electron microscopy, Raman spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. A fluorescent paper analysis device (fPAD) was applied in rapid and cost-effective detection of biomarker bilirubin with naked eyes. The fPAD sensor present a high selectivity, stability and sensitive response to bilirubin in a wide linear range of 10 to 150 µM with a limit of detection limit as 26 nM (S/N = 3) and limit of quantitation as 86 nM (S/N = 10). The principles-based density functional theory, calculations on doping and binding energy of N-BPQD were analyzed via the density functional theory (DFT) simulations. Moreover, N-BPQD showed extremely low cytotoxicity, which is a promising as a good fluorescent probe for stem cell imaging application. This work provide a new platform for diagnosis of jaundice disease. [ABSTRACT FROM AUTHOR]

Herein, we demonstrate a microwave-assisted chemical reduction technique to exfoliate a few layers of graphene from the natural waste material, ‘coconut shell’. The microwave irradiation coconut shell is subjected to structural, morphological and functional groups characterization methods including SEM, Raman, FTIR and XPS spectroscopic analyses. The formation of biomass reduced graphene (BRG) has been confirmed through Raman and FTIR spectroscopic analyzes with the presence of D, G and 2D and other functional spectral bands, respectively. The surface topography of the BRG exhibits two-dimensional mat structures with wrinkle topography, imaged by electron microscopic techniques. The metallic behaviour of the BRG is evaluated by band structure calculation using density functional theory. The synthesized nanostructure has been evaluated for exhaled diabetic breath sensing application by fabricating sensor device on the paper-based substrate by roll-to-roll coating technique. The BRG sensor exhibited enhanced sensing response at a very lower concentration of diabetic biomarker with long term stability and rapid response/recovery time of 1.11 s/41.25 s, respectively. Based on our findings, the microwave-assisted BRG is a potential candidate for fabricating highly scalable, inherently safe, economically viable and excellent sensing performance to detect exhaled diabetic breath at room temperature. [ABSTRACT FROM AUTHOR]

Peroxidase‐mimicking nanozymes have been extensively studied, however, their application is limited by the requirement for an acidic pH. Herein, the development of Co‐doped mesoporous cerium oxide (Co‐m‐ceria) is reported, which operates optimally at a near‐neutral pH and exhibits a peroxidase‐like catalytic efficiency that is 600‐times higher than that of pristine m‐ceria. Density functional theory (DFT) calculations for the application of pristine and various metal‐doped m‐ceria in peroxidase‐like reactions under different pH environments are conducted to select Co as the appropriate dopant. The high peroxidase‐like activity of Co‐m‐ceria under neutral conditions and its mesoporous nature enable its application in a one‐pot cascade reaction system, wherein biomarkers of oxidative enzymes can be detected without altering the pH. Five different oxidative enzymes are immobilized in the pores of Co‐m‐ceria at high loadings, followed by incorporation of the enzyme‐containing Co‐m‐ceria in paper microfluidic devices for the convenient and simultaneous detection of multiple biomarkers. The Co‐m‐ceria‐incorporated paper microfluidic device enables the selective and sensitive determination of multiple biomarkers using a smartphone‐acquired image. This study demonstrates the potential of the rational design of nanozymes and their application in paper microfluidic devices, laying the groundwork for future applications of nanozymes in point‐of‐care testing environments. [ABSTRACT FROM AUTHOR]

Despite much efforts to stabilize sodium metal anodes for promoting their commercial applications, achieving a safe cycling process without intrinsic dendrite growth remains difficult owing to the unstable reaction interface and irregular sodium metal propagation. Herein, fluorine‐superdoped carbon nanotubes with a fluorine content of 14.38 at% are achieved using a new oxidation‐assisted plasma strategy, and then alternately assembled with cellulose nanofibrils to form periodical conductive/dielectric composite paper with outstanding mechanical properties. The superdoping of fluorine facilitates the construction of a NaF‐dominated solid electrolyte interphase layer, while the periodical conductive/dielectric network re‐homogenizes electric field distribution around irregular sodium protrusions, realizing a "bottom‐up" sodium orientation deposition and the "self‐correction" functionality during sodium plating/stripping process. Density functional theory calculations reveal that the specific oxygen species (CO/CO) and fluorine species (semi‐ionic CF/covalent CF2) on the surface of carbon matrix, could remarkably trap active fluorine fragments and generate NaF with sodium metal, respectively, which promotes the superdoping of fluorine and forms dendrite‐free sodium anodes. This delicate structure renders the sodium anodes a low nucleation overpotential of ≈7 mV, high Coulombic efficiency of 99.5% over 300 cycles at 3 mA cm−2, stable operation for up to 2100 h under ≈16 mV, and excellent full battery performance. [ABSTRACT FROM AUTHOR]

The terahertz spectrum of paper has been measured from room temperature to cryogenic temperatures. As the paper is cooled, the main absorption lines move to higher frequencies. The same behaviour is observed for two types of paper. The spectrum at base temperature provides the most direct comparison yet with calculations made using density functional theory, which assume the studied material to be at absolute zero temperature. These unique experiments should spur the development of better theoretical models of cellulose and cognate materials. [ABSTRACT FROM AUTHOR]

Sluggish CO2 reduction reaction (CO2RR) and evolution reaction (CO2ER) kinetics at cathodes seriously hamper the applications of Li-CO2 batteries, which have attracted vast attention as one kind of promising carbon-neutral technology. Two-dimensional transition metal dichalcogenides (TMDs) have shown great potential as the bidirectional catalysts for CO2 redox, but how to achieve a high exposure of dual active sites of TMDs with CO2RR/CO2ER activities remains a challenge. Herein, a bidirectional catalyst that vertically growing MoS2 on Co9S8 supported by carbon paper (V-MoS2/Co9S8@CP) has been designed with abundant edge as active sites for both CO2RR and CO2ER, improves the interfacial conductivity, and modulates the electron transportation pathway along the basal planes. As evidenced by the outstanding energy efficiency of 81.2% and ultra-small voltage gap of 0.68 V at 20 µA cm-2, Li-CO2 batteries with V-MoS2/Co9S8@CP show superior performance compared with horizontally growing MoS2 on Co9S8 (H-MoS2/Co9S8@CP), MoS2@CP, and Co9S8@CP. Density functional theory calculations help reveal the relationship between performance and structure and demonstrate the synergistic effect between MoS2 edge sites and Co9S8. This work provides an avenue to understand and realize rationally designed electronic contact of TMDs with specified crystal facets, but more importantly, provides a feasible guide for the design of high-performance cathodic catalyst materials in Li-CO2 batteries. [ABSTRACT FROM AUTHOR]

Platinum (Pt)‐based electrocatalysts are the benchmark catalysts for hydrogen evolution reaction (HER); however, they are limited by the scarcity and high price. Introducing an adequate substrate to disperse and anchor Pt‐based species is a feasible pathway to improve the utilization efficiency. Herein, a quick and continuous spray drying route is proposed to fabricate 3D crumpled Ti3C2Tx MXene loaded with sub‐nanometer platinum clusters (Pt/MXene). The 3D crumpled structure inhibits the restacking of layered MXene nanosheets and guarantees the fully exposure of Pt clusters. The as‐prepared catalyst exhibits excellent HER performances comparable to commercial Pt/C, including a low overpotential of 34 mV to reach a current density of 10 mA cm−2, a superior mass activity (1847 mA mgPt−1), a small Tafel slope (29.7 mV dec−1), and a high turnover frequency (10.66 H2 s−1). The improved activity of Pt/MXene can be attributed to the charge transfer from Pt clusters to MXene, which weakens the hydrogen adsorption, as evidenced by the density functional theory calculations. The present contribution proposes a novel strategy to anchor low‐mass‐loading sub‐nanometer precious metal clusters on crumpled MXene with fully exposed active sites for catalysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of two-armed indole appended Schiff base conjoined 1,2,3-Triazole based click derived bis-organosilane and bis-organosilatrane is synthesized. • The designed Schiff bases are developed as colorimetric, fluorescent and paper-based selective sensors for Al(III). • The binding capabilities are in sighted by using absorption and emission titrations that determine the 4 and 5 high sensitivity and ultratrace low detection limits of 1.41 × 10−9 M and 0.17 × 10−9 M. • The insights into the optical signal changes are discussed. Metal ions have significant roles in diagnosis, industry, human health, and the environment. To design and develop new lucid molecular receptors for the selective detection of metal ions is important for environmental and medical applications. In the present work, two-armed indole appended Schiff bases conjoined with 1,2,3-Triazole bis-organosilane and bis-organosilatrane skelton sensors for naked eye colorimetric and fluorescent detection sensors for Al(III) are developed. The introduction of Al(III) in sensor 4 and 5 show red shift in UV–visible spectra, changes in fluorescence spectra and immediate color change from colorless to dark yellow. Furthermore, the pH and time response studies were explored for both sensors 4 & 5. The sensors 4 and 5 exhibited significantly low detection limit (LOD) in nano-molar range 1.41 × 10−9 M and 0.17 × 10−9 M respectively from emission titration. The LOD form absorption titration was found to be 0.6 × 10−7 M for sensor 4 and 0.22 × 10−7 M for sensor 5. In addition, the sensing model is developed as paper based sensor for its practical applicability. The theoretical calculations were performed on Gaussian 03 program by relaxing the structures using Density functional theory. [ABSTRACT FROM AUTHOR]

Designing photochromic systems that exhibit tunable print/erase responses is seldom studied but critical to the implementation of rewritable paper. Previous systems printed information with photocatalysts limited to specific wavelengths and light sources and rarely considered how polymers used in film formation affect erasing of information. Herein, different visible/UV light responses are achieved by engineering the formation of oxygen vacancy defects in titanium dioxide/reduced graphene oxide composite photocatalysts. Defects are manipulated during synthesis by controlling the water concentration in a mixed solvent system, which leads to tunable photochromic response of redox dyes. Furthermore, because the accessibility of ambient oxygen directly impacts the kinetics of recoloration, tailoring the oxygen barrier properties of polyvinyl alcohol via modulating inherent polymer structure as well as the external environment, the recoloration can be further tuned to meet various application purposes. The resulting insight will assist fellow researchers in tailoring defects in photocatalyst systems for superior functional design. [ABSTRACT FROM AUTHOR]

The waste cooking oil is upcycled into N-doped carbon nanosheets, enabling fast Na+/K+ storage by means of surface charge modulation. [Display omitted] • Waste cooking oil was selected as precursor to prepare hard carbon anode materials. • NWCOC650 takes on a porous nanosheet structure with turbo layers. • NWCOC650 has a coexistence storage mechanism of adsorption/intercalation-filling. • Head group (–NH 2) can produce a synergistic effect with N-5/6/Q and graphene. • NWCOC650 exhibits excellent performances for sodium/potassium-ion batteries. Hard carbons are significant in sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, the structural defects of hard carbons lead to poor rate performance and cycling stability, which need further improvement. The waste cooking oil was used as the precursor to synthesize 3D carbon nanosheets (NWCOC) with amino nitrogen functional groups, multi-layered pores, and expanded interlayer spacing. The excellent electrochemical properties of NWCOC were investigated and it was demonstrated that NWCOC can significantly improve the adsorption of Na+/K+ on hard carbons, substantially enhancing the embedding/de-embedding of Na+/K+, reducing the diffusion distance of ions and electrons, and improving their adaptability to volume changes. In situ XRD and Raman characterization reveal that the Na storage mechanism of NWCOC is mainly based on adsorption/intercalation-filling. Combined with density functional theory, it is shown that the porous structures doped with nitrogen have a greater propensity for ion adsorption, resulting in increased ion capture and storage. As expected, NWCOC650 exhibits high capacities of 489.4 and 388.3 mAh/g in SIBs and PIBs. NWCOC650 displays superior performance in the Na 3 V 2 (PO 4) 3 /NWCOC650 full cell, achieving a capacity of 107.84 mAh/g. This work presents a new perspective on the synthesis and mechanisms of high-performance anodes for SIBs and PIBs. [ABSTRACT FROM AUTHOR]

• Electrochemically modified graphite paper is used as electrode substrate. • Molecular interactions of 3-MCPD on polymer was computationally analyzed. • The sensor surface shows a uniform coating Pt@PB Nanoparticles. • MIP/Pt@PB/EM-GP has important application prospects in future detection research. In this study, a molecularly imprinted polymer (MIP) electrochemical sensor based on electrochemically modified graphite paper (EM-GP) was developed for the detection of 3-MCPD for the first time. To this end, Prussian blue (PB) was electrodeposited on EM-GP to yield uniformly distributed PtNPs. The successful preparation of Pt@PB/EM-GP was verified by SEM, Raman spectroscopy, XRD, XPS, and EDS. MIP was then prepared by CV electropolymerization with template molecules (3-MCPD), and density functional theory (DFT) at M06-2X/6–31 + g (d,p) level was used to calculate the molecular-level interaction between 3-MCPD and MIP. Under the optimum conditions, the dynamic linear range of the sensing platform varied from 1 × 10-8 mol/L to 5 × 10-5 mol/L with a detection limit estimated to 5 × 10-9 mol/L (S/N = 3). Overall, these findings look promising for the construction of selective and quick detection platforms of 3-MCPD in food samples. [ABSTRACT FROM AUTHOR]

Electrochemical reduction of NO not only offers an attractive alternative to the Haber–Bosch process for ambient NH3 production but mitigates the human‐caused unbalance of nitrogen cycle. Herein, we report that MoS2 nanosheet on graphite felt (MoS2/GF) acts as an efficient and robust 3D electrocatalyst for NO‐to‐NH3 conversion. In acidic electrolyte, such MoS2/GF attains a maximal Faradaic efficiency of 76.6 % and a large NH3 yield of up to 99.6 μmol cm−2 h−1. Using MoS2 nanosheet‐loaded carbon paper as the cathode, a proof‐of‐concept device of Zn‐NO battery was assembled to deliver a discharge power density of 1.04 mW cm−2 and an NH3 yield of 411.8 μg h−1 mgcat.−1. Calculations reveal that the positively charged Mo‐edge sites facilitate NO adsorption/activation via an acceptance–donation mechanism and disfavor the binding of protons and the coupling of N−N bond. [ABSTRACT FROM AUTHOR]

The synthesis of a novel spirooxazine (1-benzyl-3,3-dimethylspiro[indoline-2,3′-naphtho [2,1-b] [1,4] oxazine, BSP-SP) was developed as a colorimetric probe for the quantitative analysis of Fe2+ and Pb2+ in water samples. The device is based on a microfluidic paper-based analytical device (μPAD). BSP-SP was characterized by various techniques, e.g. single-crystal X-ray diffraction (SC-XRD) and time-dependent density functional theory (TD-DFT). In addition, the density functional theory (DFT) allowed us to understand better the adsorption of Fe2+ and Pb2+ over other cations adsorption on the BSP-MO structure. The structural isomerization of BSP-SP occurs as an open-form merooxazine (BSP-MO), which acts as a ligand to form Fe2+/BSP-MO and Pb2+/BSP-MO complexes. We observed these complexes under UV irradiation as having a light blue coloration. The μPADs were also proposed as detection platforms to maintain photostability and photochromic efficiency and extend the lifetime of the spirooxazine. Under optimal conditions, the developed μPAD enables rapid and sensitive quantitative analysis of Fe2+ at pH 6 and Pb2+ at pH 11. The limits of detection (LOD) were 0.036 mg L−1 for Fe2+ and 0.152 mg L−1 Pb2+. Overall, the developed sensors, particularly the μPADs, promise the practical analysis of Fe2+ and Pb2+ in water samples. [Display omitted] • Our novel spirooxazine (BSP) was successfully synthesized as colorimetric probe. • BSP-coated μPAD was illustrated to enhance photochromic efficiency. • This method features selectivity toward Fe2+ and Pb2+ determination. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbohydrate-based fluorometric sensors 1 and 2 have been used to detect picric acid in the aqueous medium. • The detection limits of 1 and 2 for PA were calculated to be 0.094 µM and 0.013 µM, respectively. • The DFT-supported charge transfer and µ-µ interactions explained the fluorescence quenching mechanism. • The sugar moiety plays a role in developing interaction between the sensor and PA in aqueous medium. • Both the sensors were used as naked-eye colorimetric sensors for PA in the test trips. Triazole-linked pyrene-appended inexpensive sensors 1 and 2 were synthesized from carbohydrates to instantly recognize picric acid (PA) based on a charge-transfer mechanism in the semi-water medium. Both sensors showed good selectivity and sensitivity towards PA over a wide variation of nitroaromatics in the absorbance and fluorescence methods. Moreover, sensors 1 and 2 were used for quick finding of picric acids using test strips. Interestingly, it was found that the sensitivity of 2 (LOD: 0.012 µM) is higher than 1 (LOD: 0.093 µM) might be explained by the close intramolecular space of the triazole/sugar residue and pyrene in sensor 2. The fluorescence quenching and structural features of the complexes (1-PA, 2-PA) were supported by density functional theory (DFT) calculations and spectroscopic studies. [ABSTRACT FROM AUTHOR]

The design of ultralow-platinum electrocatalyst with a superior performance is of great interest for hydrogen evolution reaction (HER). Herein, we developed a facile approach of electrochemical deposition that is applicable to construct ultralow-Pt supported polyaniline-Ti3C2Tx MXene electrocatalyst (denoted as Pt/PANI-Ti3C2Tx). It is found that the aniline monomers and Ti3C2Tx nanoflakes were simultaneously electrodeposited on the surface of carbon paper and formed ordered nanostructures, which efficiently immobilizes more Pt species and promotes the H* conversion. The Pt loadings in the as-designed electrocatalyst is determined to be 2.2 µg cm-2, which is around two-order of magnification lower than that in the state-of-the-art Pt/C catalyst. While it exhibits excellent HER performance with low applied overpotential of 52 mV at a current density of 10 mA cm-2, a high turnover frequency of 14.13 H2 s-1 and high mass activity of 14 A mgPt -1, as well as excellent long-term durability. Additionally, density functional theory calculations reveal more favorable H adsorption-desorption by the synergistic effect between Pt and PANI-Ti3C2Tx facilitating hydrogen production. [ABSTRACT FROM AUTHOR]

The present study employs density functional theory-based first principle calculation to investigate the electron transport properties of polyaniline following exposure to acidic and alkaline pH. In-situ deposited polyaniline-based paper device maintains emeraldine salt form while it is exposed to acidic pH and converts to emeraldine base when it is subjected to alkaline pH solutions. These structural changes at acidic and alkaline pH are validated experimentally by Raman spectra. Furthermore, the Raman spectra computed from density functional theory are validated with the experimental spectra. The changes in the theoretical energy band gap of polyaniline obtained from first principle calculations were correlated with the changes in the experimental impedimetric response of the sensor after exposure to acidic and alkaline solutions. Finally, the impedimetric responses were used to predict urine pH through a machine learning based smart and interactive web application. Different machine learning based regression models were implemented to acquire the best possible outcome. Gradient Boosting Regressor with least square loss model was selected as it showed lowest mean square, mean absolute, and root mean square error than other models. The smart sensing platform successfully predicts the unknown pH of urine samples with an average accuracy of more than 98%. The locally deployed smart web app can be accessed within a local area network by the end-user, which holds promise towards effective detection of urinary pH. [Display omitted] [ABSTRACT FROM AUTHOR]

To advance our understanding of the molecular biochemistry of fungi which impact cultural heritage in libraries, museums and archives we investigated the diagnostic capacity of Raman spectroscopy to identify the composition of colored chromophores of fungi on paper. In this study we explored the diagnostic capacity of resonant Raman to distinguish chromophores in fungal filaments stimulated to grow on paper under high humidity with a focus on characterizing chromophores of Alternaria group species. To facilitate molecular analysis, we conducted quantum chemistry calculations of representative metabolites having optical absorption in the ultraviolet–visible spectral range. Comparing theory and experiment we show that fonsecin, erythroglaucin and aurasperone type chromophores occur in mature hyphal filaments with β-carotene dominant in yeast depositions on paper surfaces. Resonant Raman of mature filaments suggests a further contribution of carotenes longer than β-carotene to the spectral signature. Using microscopic resolution, we distinguish rich sets of Raman signatures that we assign to lignin, flavoglaucin, riboflavin, cycloleucomelon(e) and asperyellone molecular components in the spatial regions where filaments initiate from yeast depositions. In such regions, where filament microstructures stimulate development of a mature three-dimensional scaffold, the diversity of Raman resonances confirms a rich biochemistry of the developing structures. The library of computed optical and spectroscopic responses of characteristic fungal chromophores and metabolites presented here is essential for understanding the effect of fungi on a wide range of objects made from paper including books, prints, drawings, watercolors, engravings and even sculptures as well as designing next generation materials based on fungal hyphal mats. • Non-invasive Raman spectroscopy can be used to identify pigments in fungi. • Quantum chemistry (DFT) combined with Raman for quantitative measure of chromophores. • Computed optical responses of fungal chromophores and metabolites. • Raman spectroscopy combined with Quantum chemistry as tools for cultural heritage. • Alternaria sp. generates specific pigments when grown on paper. [ABSTRACT FROM AUTHOR]

With an increasing number of new scientific papers being released, it becomes harder for researchers to be aware of recent articles in their field of study. Accurately classifying papers is a first step in the direction of personalized catering and easy access to research of interest. The field of Density Functional Theory (DFT) in particular is a good example of a methodology used in very different studies, and interconnected disciplines, which has a very strong community publishing many research articles. We devise a new unsupervised method for classifying publications, based on topic modeling, and use a DFT-related selection of documents as a use case. We first create topics from word analysis and clustering of the abstracts from the publications, then attribute each publication/paper to a topic based on word similarity. We then make interesting observations by analyzing connections between the topics and publishers, journals, country or year of publication. The proposed approach is general, and can be applied to analyze publication and citation trends in other areas of study, beyond the field of Density Function Theory. [ABSTRACT FROM AUTHOR]

This paper explores the findings on the structures and physicochemical properties of titanium-oxo complexes (TOCs) stabilized by 9-hydroxy-9-fluorenecarboxylate ligands. Two complexes, with the overall formulas [Ti4O(OiPr)10(O3C14H8)2] (1) and [Ti6O4(OiPr)2(O3C14H8)4(O2CEt)6] (2), have been synthesized. The structures of the isolated crystals (1 and 2) were determined using single-crystal X-ray diffraction. Molecular structure analysis of the crystals also employed vibrational spectroscopic techniques (IR and Raman), UV--Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and powder X-ray diffraction (XRD). Density functional theory (DFT) was utilized to elucidate the electronic structures of these complexes. Furthermore, the theoretical charge distribution in 1 and 2 and their reactivity were calculated. The results of these investigations suggest that the reactivity of 2 is significantly greater than that of 1. [ABSTRACT FROM AUTHOR]

In this paper, the geometric configuration, electronic properties, and optical characteristics of an InS/GaTe heterojunction have been computed using the foundational principles of density functional theory. The analysis indicates that when the interlayer distance is 3.88 Å, the binding energy is the most negative, indicating that the structure is the most stable. The bandgap of the two monolayers is larger than that of the heterojunction, which makes the photogenerated electrons of the heterojunction more easily excited. The InS/GaTe heterojunction is a type-II heterojunction that enhances the efficient dissociation of electron–hole pairs. In addition, the InS/GaTe heterojunction demonstrates strong absorption of ultraviolet light, rendering it suitable for applications in ultraviolet detectors and related fields. Furthermore, the bandgap electron transfer direction of the InS/GaTe heterojunction can be controlled by applying electrical force and mechanical pressure. The optical absorption coefficient of the InS/GaTe heterojunction can be adjusted to modify its optical properties. Finally, the possible future applications of the InS/GaTe heterojunction are discussed. [ABSTRACT FROM AUTHOR]

This research paper investigates the electrocatalytic mechanisms and ultra-trace detection abilities of uranyl ions (UO22+) using palladium nanoparticles (PdNPs) electrodeposited in deep eutectic solvents (DESs). The unique properties of DESs, such as their adjustable viscosity and ionic conductivity, offer an advantageous and environmentally friendly medium for Pd nanoparticle electrodeposition, resulting in highly active and stable electrocatalysts. Various characterization techniques, including scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), were used to examine the morphology, size distribution, and crystallographic structure of the Pd nanoparticles. Electrochemical tests revealed that the Pd-modified electrodes show exceptional electrocatalytic activity and current sensitivity towards uranyl ions, with detection limits as low as 3.4 nM. Density functional theory (DFT) calculations were conducted to elucidate the mechanism of the electrocatalytic reduction of UO22+ by the PdNPs, providing a plausible explanation for the high sensitivity of PdNPs in detecting uranyl ions based on the calculated structural parameters and reaction energetics. This study underscores the potential of Pd nanoparticles electrodeposited in DESs as a promising method for sensitive uranyl ion detection, contributing to advancements in environmental monitoring and nuclear safety. [ABSTRACT FROM AUTHOR]

In this paper, three different Zn(II) complexes with (E)-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL2](BF4)2, while complexes 2 [ZnL(NCO)2] and 3 [ZnL(N3)2] form penta-coordinated geometry. Density functional theory (DFT) calculations were performed to enhance our understanding of the structures of the synthesized complexes and the cytotoxic activity of the complexes was tested against five human cancer cell lines (HeLa, A549, MDA-MB-231, K562, LS 174T) and normal human fibroblasts MRC-5. Additionally, antibacterial and antifungal activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two fungal strains, and a yeast strain. It is noteworthy that all three complexes show selective antifungal activity comparable to that of amphotericin B. Molecular docking analysis predicted that geranylgeranyl pyrophosphate synthase, an enzyme essential for sterol biosynthesis, is the most likely target for inhibition by the tested complexes. [ABSTRACT FROM AUTHOR]

This paper evaluates the effect of different synthesis conditions on the structural properties of the porous metal–organic frameworks MIL-53(Al) produced by the microwave method at different reaction temperatures (120, 150, and 180 °C) and times (30, 180 min). The morphologies, chemical contents and crystal structures of the synthesized samples were determined by the SEM-EDS and XRD methods, respectively. The structural properties of MIL-53(Al)s were analysed according to isotherm data obtained from nitrogen gas adsorption by applying the Brunauer–Emmett–Teller (BET), Langmuir, Dubinin–Radushkevich (DR), t-plot, Barrett–Joyner–Halenda (BJH) and quenched solid density functional theory (QSDFT) methods, as well as the new numerical clustering-based adsorption analysis (LBET) method, which is a unique numerical method that provides advanced assessment for porous structures. The LBET analysis showed that the MIL-53(Al) sample at a reaction temperature of 180 °C for 30 min has the best adsorption properties, with the highest volume of the first adsorbed layer and the highest value of the energy parameter for higher layers. Due the LBET method, it was possible to evaluate the porous structure of the MIL-53(Al) samples with high precision and reliability, and thus to determine the precise influence of the conditions of their preparation on the formation of their structure. In turn, based on the shapes of the pore size distributions (PSD), the materials analysed have very similar PSD, with only the MIL-35(AL)S1 sample having a significantly lower PSD height. In conclusion, attention was paid to the necessity of complex evaluation of adsorbent properties, taking into account not only their adsorption properties but also their mechanical and functional properties, as well as production costs and the impact of adsorbent production and utilization on the environment. [ABSTRACT FROM AUTHOR]

Although possessing well‐defined nanostructures and excellent multi‐electron redox properties, polyoxometalate clusters have poor intrinsic electrical conductivity and are prone to aggregation due to large surface energy, which makes them difficult to be fully utilized when applying as electrode materials for lithium‐ion batteries. In this paper, monodisperse K7MnV13O38 (MnV13) clusters are achieved by rationally utilizing nano‐sized high conductive carbon dots (CDs) as stabilizers. Benefiting from the fully exposed redox sites of MnV13 clusters (high utilization rate) and sufficient interfaces with carbon dots (extra interfacial energy storage), the optimized MnV13/10CDs anode delivers a high discharge capacity up to 1348 mAh g−1 at a current density of 0.1 A g−1 and exhibits superb rate/cycling capabilities. Density functional theory (DFT) calculations verify that ionic archway channels are formed between MnV13 and CDs, eliminating the bandgap and greatly improving the electron/ion conductivity of MnV13 and CDs. This paper paves a brand‐new way for synthesis of monodisperse clusters and maximization of extra interfacial energy storage. [ABSTRACT FROM AUTHOR]

The primary objective of this work is to delve into the intricacies of allylic fluorination reactions through the application of density functional theory (DFT) calculations. These reactions hold significant importance in the realm of synthesizing organofluorine compounds. The specific focus lies on comprehending the interaction mechanisms when styrenes, a class of organic molecules, come in contact with an electrophilic fluorinating reagent known as Selectfluor. Notably, this interaction pathway demonstrates remarkable efficiency in yielding allylic fluoride products. The proposed mechanism for this transformation involves a sequential process. To unveil the microcosmic intricacies governing this reaction between the alkene substrate and Selectfluor, advanced computational methodologies are employed. The paper systematically outlines the computational strategies harnessed to probe the minute details of the reaction mechanism. The outcomes of these computations are subsequently subjected to thorough analysis, encompassing crucial facets such as transition states and energy barriers. This analytical depth enhances the fundamental understanding of the reaction mechanism and sheds light on the underlying factors influencing its feasibility and efficiency. In a broader context, the insights garnered from this study carry significant utility. They provide pivotal guidance for the optimization of reaction conditions, facilitating the fine-tuning of experimental setups. Moreover, the elucidated mechanism serves as a platform for the design of even more efficient and selective allylic fluorination reactions. This paper, by amalgamating theoretical insights with practical synthetic objectives, contributes to the broader advancement of organofluorine compound synthesis and allied fields. [ABSTRACT FROM AUTHOR]

This paper deals with the synergy between Nuclear Magnetic Resonance (NMR) spectroscopic investigations and DFT calculations, mainly of NMR parameters. Both the liquid and the solid states are discussed here. This text is a mix of published results supplemented with new findings. This paper deals with examples in which useful results could not have been obtained without combining NMR measurements and DFT calculations. Examples of such cases are tautomeric systems in which NMR data are calculated for the tautomers; hydrogen-bonded systems in which better XH bond lengths can be determined; cage compounds for which assignment cannot be made based on NMR data alone; revison of already published structures; ionic compounds for which reference data are not available; assignment of solid-state spectra and crystal forms; and the creation of libraries for biological molecules. In addition to these literature cases, a revision of a cage structure and substituent effects on pyrroles is also discussed. [ABSTRACT FROM AUTHOR]

The strong metal–support interactions (SMSI) between metal and its support have been regarded as a valid approach to enhance the catalytic performance; however, the extent to which exploration of electronic state regulation affects catalytic performance of alcohol oxidation reactions (AOR) has been rarely reported. In this paper, PdAg nanoparticles loaded on a N-doped carbon substrate with controlled nitrogen content (PdAg@NxC, x representing the nitrogen contents) was synthesized through a seeded synthesis strategy for alkaline AOR. Results show that the electronic state of PdAg nanoparticles was significantly modified after nitrogen doping in the carbon support. Experimental and theoretical results indicate that with increasing nitrogen content, the degree of electronic state regulation becomes increasingly significant. Density functional theory (DFT) calculations suggest that the increased degree of SMSI promotes OH* adsorption on the PdAg surface and weakens the binding between catalyst and CO*. As a result, the PdAg@N15.3C with the highest N content exhibits excellent AOR performance, achieving a MA/SA of 10.8 A mgPd−1/13.2 mA cm−2 and 3.8 A mgPd−1/4.7 mA cm−2 on the EOR and MOR, respectively. Moreover, due to the changes in the adsorption energy of key intermediates on PdAg nanoparticles, the onset oxidation potential of PdAg@N15.3C shows a negative shift of 180 mV compared to PdAg@C as revealed by CO stripping analysis, signifying an increase in the CO tolerance. Our study demonstrates the influence of the SMSI effect between the active center and the support on the catalytic performance for AOR and presents a pathway to achieve high AOR performance through SMSI engineering. [ABSTRACT FROM AUTHOR]

In this paper, we explore the potential of LiMF3 (Lithium Metal Trifluoride) materials as electrode candidates by using density functional theory (DFT) calculations. We investigate their structural, electrochemical, and electrical properties and compare them with each other and some way with the most popular Li electrode materials. The structural properties of this kind of materials are interesting due to their 3D framework and somehow their openness of the diffusion channels, causing facile Li diffusion through the structure. We find that LiMnF3 has the best properties among the LiMF3 materials, with high structural stability (endurance of the lattice after Li ion extraction), low band-gap, suitable cell voltage, and high electrical rate-capability. LiMnF3 is especially favorable due to its environmental and toxicity advantages. After that, LiCoF3 shows appropriate properties. We also discuss the advantages and disadvantages of the other LiMF3 materials, namely LiNiF3, LiVF3, and LiFeF3, which they are also considerable electrodes. The voltage of the materials estimated to be 2, 2.6, 2.6, 3.4, and 3.1 V for M = Co, Fe, Ni, Mn, and V, respectively. This study provides a comprehensive evaluation of LiMF3 materials and suggests that they are promising candidates as Li-ion battery electrodes. This paper opens a new landscape for future investigations about these promising intercalation electrode materials. [ABSTRACT FROM AUTHOR]

We present in this paper the stability of SWCNT hybrid systems with Py molecules. vdW type interactions are therefore the main interaction mechanism between encapsulated molecules and nanotubes, and the simplest model to describe these interactions is the Lennard-Jones potential. We have therefore performed energy minimization calculations on hybrid SWCNTs in a very wide range of diameters and of all chirality using the Lennard-Jones potential. The structure of the carbon nanotube is obtained from the winding of graphene on itself to form a hollow cylinder described by the pair of integers (n, m) entirely determining its structural characteristics, while the optimization of the geometry of the Py molecule is obtained by SIESTA using the exchange–correlation functional LDA. After minimisation, an approach that combines density functional theory, molecular mechanics, bond polarizability model, and spectral moment's method has been used to compute Raman spectra. Two types of vibration modes of SWCNTs attract our attention. Initially, the modifications of the modes of Py after encapsulation will be analyzed. In the following discussion, we examine how the vibrational properties of single-walled carbon nanotubes (SWCNTs) are affected by encapsulation, specifically in relation to the RBM and tangential modes. Our analysis of the Raman active modes supports the notion that the structural integrity of the SWCNTs remains intact and indicates the occurrence of a charge transfer between the Py molecules and SWCNTs. This charge transfer depends on the geometric position of Py in the SWCNT. [ABSTRACT FROM AUTHOR]

The structural, mechanical, and thermoelectric characteristics of layered transition metal dichalcogenides MX 2 (M = Zr, Hf; X = S, Se) have been studied using density functional theory along with van der Waals correction. The exchange-correlation functional, enhanced with corrections for van der Waals interactions, has been evaluated for the hexagonal bulk structures of these materials. The analysis of elastic properties reveals that these compounds exhibit brittleness at zero pressure and conform to Born's criteria for mechanical stability. Examination of elastic constants and moduli suggests that the compounds possess reasonable machinability, moderate hardness, and anisotropy in terms of sound velocity. Transport properties, including the Seebeck coefficient, electrical conductivity, thermal conductivity, and power factor, have been computed using the semi-classical Boltzmann theory implemented in the BoltzTraP code. All investigated compounds exhibit excellent thermoelectric performance at high temperatures. This result suggests that our compounds are highly promising candidate for practical utilization in the thermoelectric scope., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The synthesis of two pyrazolone derivative compounds, PYR-I(4-Acetyl-1-(4-chlorophenyl)-3-isopropyl-1H-pyrazol-5(4H)-one) and PYR-II1-(4-Chlorophenyl))-3-isopropyl-5-oxo-4,5-5-dihydro-1H-pyrazole-4-carbaldehyde, their characterization by FT-IR, NMR, UV-Vis and GC-MS techniques, and the evaluation of the keto-enol tautomerization process of the structures along with the DFT approach and spectral data were reported in this paper. Spectral findings indicated that PYR-I was stable at the keto state. The IR spectrum recorded in solid form showed that the PYR-II structure was stable in the enol state, while the NMR spectrum in the solution medium showed that it was stable in the keto state. DFT-based analyses were realized with the B3LYP hybrid functional and the 6-311++G(d,p) basis set. The modelled keto, transition and enol state molecular geometries of structures were optimized in the gas phase and different solvent media and the total energy and dipole moment values were investigated at the specified theoretical level. The possible keto-enol tautomerism mechanism of the structures was evaluated through some thermodynamic parameters such as the difference in free Gibbs energy (ΔG), enthalpy (ΔH), entropy (ΔS), and predictive tautomeric equilibrium constants (K eq ), acidity constants (pK a ) and percentages of tautomers at 298.15 K and 1 atm pressure. The results of these analyses based on the DFT approach indicated that the keto-enol tautomer equilibrium heavily favours the keto form for PYR-I and the enol form for PYR-II in all cases. Moreover, natural bond orbital (NBO) analysis was performed for the tautomers, and the chemical reactivity profiles of the most stable tautomers were examined with the values of frontier molecular orbital energy and some reactivity descriptors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The binding affinities and interactions between eight drug candidates, both commercially available (candesartan; losartan; losartan carboxylic acid; nirmatrelvir; telmisartan) and newly synthesized benzimidazole-N-biphenyltetrazole (ACC519T), benzimidazole bis-N,N'-biphenyltetrazole (ACC519T(2) and 4-butyl-N,N-bis([2-(2H-tetrazol-5-yl)biphenyl-4-yl]) methyl (BV6), and the active site of angiotensin-converting enzyme-2 (ACE2) were evaluated for their potential as inhibitors against SARS-CoV-2 and regulators of ACE2 function through Density Functional Theory methodology and enzyme activity assays, respectively. Notably, telmisartan and ACC519T(2) exhibited pronounced binding affinities, forming strong interactions with ACE2's active center, favorably accepting proton from the guanidinium group of arginine273. The ordering of candidates by binding affinity and reactivity descriptors, emerged as telmisartan > ACC519T(2) > candesartan > ACC519T > losartan carboxylic acid > BV6 > losartan > nirmatrelvir. Proton transfers among the active center amino acids revealed their interconnectedness, highlighting a chain-like proton transfer involving tyrosine, phenylalanine, and histidine. Furthermore, these candidates revealed their potential antiviral abilities by influencing proton transfer within the ACE2 active site. Furthermore, through an in vitro pharmacological assays we determined that candesartan and the BV6 derivative, 4-butyl-N,N0-bis[20-2Htetrazol-5-yl)bipheyl-4-yl]methyl)imidazolium bromide (BV6(K + ) 2 ) also contain the capacity to increase ACE2 functional activity. This comprehensive analysis collectively underscores the promise of these compounds as potential therapeutic agents against SARS-CoV-2 by targeting crucial protein interactions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)