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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]

Peroxymonosulfate (PMS) addition into a MnO x system is generally believed to be an effective way for expediting organics removal. Whereas in this work, we found single MnO x with a micro-current got an even better oxidation performance comparing that with PMS addition. The carbon paper electrodeposited by amorphous MnO x (AMO) was used as cathode, and the micro-current (55 µA/cm2) increased the methylene blue (MB) degradation rate by 6.1 times through enhancing the AMO oxidative ability in acidic media. At the same pH, the MB degradation rate in AMO (AMO-MC) system was close to that in AMO system with PMS addition (AMO-MC-PMS). More importantly, the MB mineralization in AMO-MC was about 1.6 times higher than that in AMO-MC-PMS. Similar phenomena were also investigated when using tetracycline (TC) as organic pollutant. The mechanisms of AMO-MC and AMO-MC-PMS for MB removal were comprehensively studied and compared. It was found that the micro-current prompted the Mn valence converting from high to low. Conversely, the PMS addition hindered this converting and impeded the direct oxidation of AMO. The GC-MS analysis indicated that the presence of PMS induced the formation of sulfoxide-containing intermediates (SCIs) which were difficult to be further degraded and resulted in the suppression of MB mineralization. Density functional theory (DFT) calculation indicated that the intermediates from AMO-MC were more facile to be attacked in an electrophilic way and adsorbed on the cathode than the SCIs. It proposed that the AMO with micro-current had the potential to remove organics efficiently, and blind PMS addition should be avoided. [Display omitted] • Amorphous MnO x (AMO) system can remove MB efficiently with the aid of a cathodic micro-current. • The micro-current can improve the activity of AMO system better than peroxymonosulfate (PMS). • Single AMO system got mineralization of 30% higher than the AMO-MC-PMS system. • Refractory intermediates were generated in the AMO-MC-PMS system. • PMS may not always play a positive role and blind addition should be avoided. [ABSTRACT FROM AUTHOR]

[Display omitted] • The paper introduces a novel two-dimensional inorganic inorganic graphenylene based on indium nitride (IGP-InN). • The material demonstrates dynamic and thermal stability at elevated temperatures (700 K) and exhibits competitive cohesive energy compared to its hexagonal InN counterpart. • An indirect band gap transition with energy (E gap) of 2.49 eV was noted, making IGP-InN suitable for optoelectronic applications in the UV visible. • An accentuated decrease in the E gap can be noted for tensile strains, with a variation of 1.19 eV. • A transition to a planar structure at tensile strains higher than 4% was observed, and a new symmetry (P 6/ m) was found. This paper reveals the structural, electronic and mechanical properties of a novel inorganic graphenylene based on indium nitride (IGP-InN). The IGP-InN was characterized via density functional theory (DFT) simulations. The phonon dispersion shows the dynamic stability of IGP-InN, and molecular dynamics simulations confirm its thermal stability up to 700 K. Besides the electronic properties, the indirect band gap transition with energy (E gap) of 2.49 eV makes IGP-InN suitable for optoelectronic applications under UV–visible. Also, the E gap tunability with mechanical strain was analyzed, with a decrease of 1.19 eV in the E gap for tensile strains. The structural buckling plays an important role, with a transition to a planar structure for tensile strains. This work reveals a new class of 2D materials, buckled inorganic graphenylenes, and provides valuable insights into designing and optimizing graphenylene-like materials. [ABSTRACT FROM AUTHOR]

Thermally Activated Delayed Fluorescent (TADF) molecules with Donor (D) -Acceptor (A) –Donor-Acceptor π-Conjugated Macrocycle structures have broad application potential in organic light-emitting diodes. In this paper, three D−A line type and one D−A−D−A π‑Conjugated Macrocycle molecules with same donor and acceptor groups are investigated using polarizable continuum model (PCM) combined with density functional theory (DFT) and time-dependent functional theory (TD-DFT) in solvent and film. It is found that the macrocyclic structure has a smaller energy gap (ΔEST) between the first singlet excited state (S1) and the first triplet excited state (T1) than the linear structure. The TADF property is also analyzed based on the calculation of spin–orbit coupling (SOC) and the (reverse) intersystem crossing (RISC) rates between S1 and T1. The macrocyclic molecules have larger SOC and faster RISC rates, which also well explains the experimental predictions and results. [Display omitted] • The macrocyclic structure has smaller △ES1-T1 as compared to the linear structure. • The macrocyclic molecules have larger SOC and faster RISC rates, which also well explains the experimental predictions and results. • Compared to the linear structure, the macrocyclic structure has a smaller reorganization energy and H-R factor. Thermally Activated Delayed Fluorescent (TADF) molecules with Donor (D) -Acceptor (A) –Donor-Acceptor π-Conjugated Macrocycle structures have broad application potential in organic light-emitting diodes. In this paper, three D − A line type and one D − A − D − A π‑Conjugated Macrocycle molecules with same donor and acceptor groups are investigated using polarizable continuum model (PCM) combined with density functional theory (DFT) and time-dependent functional theory (TD-DFT) in solvent and film. It is found that the macrocyclic structure has a smaller energy gap (ΔE ST) between the first singlet excited state (S 1) and the first triplet excited state (T 1) than the linear structure. The TADF efficiency is also analyzed based on the calculation of spin–orbit coupling (SOC) and the (reverse) intersystem crossing (RISC) rates between S 1 and T 1. The macrocyclic molecules have larger SOC and faster RISC rates, which also well explains the experimental predictions and results. [ABSTRACT FROM AUTHOR]

The effect of Cl content on total energies of W-Cl system. [Display omitted] • The monoclinic WCl 5 and the trigonal WCl 3 are the more stable phases. • WCl 6 phase may be present in two crystal forms, such as the hexagonal (P -3 m1, 164) β-WCl 6 and the hexagonal (R -3, 148) α-WCl 6. • The obtained bond distance in α-WCl 6 and β-WCl 6 are significantly longer than the mean bond distances in WCl 4 and WCl 5. • Direct Γ-Γ band gap for WCl 3 (1.78 eV), WCl 5 (0.08 eV), β-WCl 6 (1.746 eV) and α-WCl 6 (1.803 eV), while WCl 4 has the metallic character. • The atomic geometry of monoclinic WCl 4 and WCl 5 contain an ordered arrangement of W vacancies. • The PDOS profile of W and Cl are similar throughout the whole energy region, indicating the presence of hybridization between W and Cl electrons. • One shares the charge density at each point between atoms in proportion to the free atomic density, so that the distribution of bound and localized atoms resembles the molecular density. The molecular structures of WCl 6 , WCl 5 , WCl 4 , WCl 3 have been optimized by density functional theory calculations. We report the stability of the phases in the ground state, the total energies and the optoelectronic properties of the W-Cl system. We find that the material having a low tungsten concentration shows a low DOS at the Fermi level, which implies a high resistivity. Both polymorphs of WCl 6 are crystalline solids at room temperature and show the (α- WCl 6) and (β- WCl 6) phases of space group R -3 and P -3 m1 observed at 228 °C. The change in temperature influences the structural, electronic and optical properties. The object of this paper does not concern only the study of all phases, but also one controls the physical states of the molecular materials when they are subjected to polymorphic changes. Calculations on the molecular structure under symmetry indicated an orbitally degenerate ground state with bond distances in good agreement with experiment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The polar ZnO (0001) surface exhibits excellent adsorption and activation properties for SF 6. • The O vacancies on ZnO (10 1 ¯ 0) surfaces promote SF 6 activation and bond breaking. • The Zn vacancies on ZnO surfaces impair the adsorption capabilities of SF 6. • Hydroxylation enhances ZnO (10 1 ¯ 0) surfaces' chemical activation and decomposition capabilities towards SF 6. The emission of SF 6 is a worldwide concern. ZnO-based catalysts, featuring high specific surface area and abundant active sites, are potential catalysts for converting waste SF 6. This study, based on density functional theory (DFT), investigates the adsorption behavior of SF 6 on clean and modified ZnO surfaces with different polarities. The results show that polar ZnO (0001) exhibits better adsorption and activation of SF 6. The O vacancy on ZnO (10 1 ¯ 0) surfaces promotes SF 6 activation and bond breaking, while the Zn vacancy inhibits SF 6 adsorption on both ZnO facets. Among various modification treatments, hydroxylated ZnO surfaces exhibit the most significant SF 6 adsorption and activation properties. Due to the orbital hybridization between F-2p and Zn-3d, the hydroxylated ZnO (10 1 ¯ 0) surface demonstrates 46 times higher average adsorption energy and 30 times higher average charge transfer of SF 6 compared to clean surfaces. This paper elucidates the key role of ZnO hydroxylated surfaces in SF 6 activation and decomposition. [ABSTRACT FROM AUTHOR]

This paper introduces the adsorption of four harmful gases (CH 4 , HCHO, SO 2 , NO 2) on MoTe 2 monolayer and transition metal (V, Cr, Mn) decorated MoTe 2. Based on the density functional calculation (DFT), the adsorption energy, charge transfer, density of state, deformation charge density, and molecular orbitals are analyzed. It was found that transition metal decoration significantly promoted the adsorption ability of MoTe 2. [Display omitted] • Adsorption properties of pristine MoTe 2 decorated with V, Cr, Mn monolayers towards CH 4 , HCHO, SO 2 , NO 2 gases were discussed. • V-MoTe 2 had the highest adsorption energy, making it a better gas removal material. • Sensor response and recovery time were evaluated. For the detection and removal of four hazardous gases (CH 4 , HCHO, SO 2 , NO 2), we used density functional theory to investigate the properties of the pristine MoTe 2 and MoTe 2 decorated with V, Cr, and Mn atoms. By examining the density of state, adsorption energy, and charge transfer of four gases adsorbed on the surface, it was showed that the adsorption capability of MoTe 2 was significantly enhanced after the decorating of transition metals. V-MoTe 2 had the highest adsorption energies (−0.527, −2.574, −1.480, −3.363 eV) of the four gas molecules, making it a better gas removal material. The adsorption energies on Cr-MoTe 2 and Mn-MoTe 2 were lower than that of V-MoTe 2 , and their desorption time were shorter, making them more suitable for the application of gas sensors. This study revealed that V, Cr, and Mn-decorated MoTe 2 were potential materials for the detection or removal of CH 4 , HCHO, SO 2 and NO 2 gases, V-MoTe 2 was more suitable for the removal, while Cr and Mn-MoTe 2 were more suitable for the detection of harmful gases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nb/Ta doping makes the lattice of ZrCoH x (x = 1–3) shrink and the E f decreases. • Nb/Ta doping can improve the diffusion performance of H in ZrCo. • Nb/Ta doping can enhance the anti-poisoning performance of ZrCo. • Nb/Ta doping can improve the disproportionation resistance of ZrCo. The ZrCo alloy has demonstrated significant potential in the storage of hydrogen and its isotopes, but there are still some issues such as insufficient dynamic properties. In this paper, the impact of Nb/Ta doping on the hydride stability of ZrCo was examined based on the density functional theory, and the improvement of H diffusion through Nb/Ta doping was investigated. The focal point lies in exploring the influence of Nb/Ta doping on the alloy's resistance to poisoning and disproportionation. The results demonstrate that the crystal lattice maintains mechanical and thermodynamic stability even after Nb/Ta doping. Nb/Ta doping induces lattice contraction in ZrCo-H x (x = 1.0–3.0) and reduce the enthalpy of formation, thereby facilitating cyclic hydrogen storage. Additionally, Nb/Ta doping enhances the diffusion performance of H atoms within O-containing lattice, improving the alloy's resistance to poisoning. Furthermore, Nb/Ta doping lowers the energy barrier of H atoms escape from 8e sites, promoting anti-disproportionation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Drug delivery performance of bare and X-doped ZnO nanotubes toward TG is studied. • The solvent effects on the complex were evaluated by measuring the adsorption energy in an aqueous medium. • X-doped ZnO nanotubes (particularly In-doped ZnO nanotubes) are promising DDSs for the TG drug. Extensive research has been reported on the efficiency of nanomaterials for the targeted delivery of anticancer drugs. This paper exploited density functional theory (DFT) to assess the drug carrier performance of bare and X-doped ZnO nanotubes (X = In, Al, and Ge) toward the thioguanine (TG) anticancer drug. Bare ZnO nanotubes were found to be inefficient for the delivery of TG molecules. The In, Al, and Ge dopants, however, increased the adsorption energy of the ZnO nanotubes from −7.8 to –33.6, −28.5, and −30.8 kcal/mol, respectively. The natural bond orbital (NBO) analysis revealed that the charge transfer was remarkable from the adsorbate to the doped adsorbents. The solvent effects on the adsorption energy were studied in an aqueous medium. The adsorption energy of the In-doped ZnO nanotubes declined from –33.6 to −21.4 kcal/mol. It was concluded that X-doped ZnO nanotubes are promising carriers of TG drug molecules. [ABSTRACT FROM AUTHOR]

This paper evaluated the degree of reduction in graphene oxide, leveraging deep learning and machine learning models on over 15,000 Raman scattering spectra along with validation using density functional theory calculations. We addressed the limitations of previous studies, such as the consideration of an insufficient number of spectra as well as the lack of a comprehensive analysis of the contribution of individual Raman modes, by introducing machine learning and deep learning. Moreover, our models succeeded in predicting the carbon-to-oxygen ratio and classifying the reduction temperatures using the Raman scattering spectra as input. Employing the partial dependence plot and the feature importance, we interpreted the models and obtained consistent results on the significance of D* mode in graphene oxide. The intensity of the D* mode stands out by not only displaying the highest feature importance value for the reduction temperatures but also by correlating proportionally with the widest range of carbon-to-oxygen ratios among the various Raman modes in graphene oxide. Finally, we validated our findings through quantum mechanical calculations and confirmed the significance of the D* mode. Our study presents a comprehensive insight into the role of Raman modes in the degree of reduction as well as a precise methodology for evaluating the carbon-to-oxygen ratio of graphene oxide, a step towards its further industrial applications. [Display omitted] • Assessing graphene oxide degree of reduction by deep learning on over 15,000 spectra. • Predicting C/O ratios and reduction temperatures using deep learning models. • Unveiling the significance of the D* mode in degree of reduction through XAI. • Calculating density functional theory to validate correlation of D* mode. [ABSTRACT FROM AUTHOR]

In summary, changes in coverage have a significant impact on O H and C H bond broken, especially on the energy barrier of C H bond broken. When the coverage is 1/6, the reaction of CH 3 OH → CH 2 O* is the most advantageous in dynamics. [Display omitted] • It is found that the adsorption energy of CH 3 OH, CH 3 O and CH 2 O on Pt(1 1 1) increased with the increase of coverage. • 1/6 coverage is the optimal reaction choice for the dehydrogenation of CH 3 OH to CH 2 O. Platinum metal exhibits excellent catalytic activity and selectivity in many important chemical reactions. In this paper, density functional theory is used to study the adsorption configurations of oxygen in methanol on Pt(1 1 1) surface and dehydrogenation reaction (CH 3 OH → CH 2 O) at different coverage. It is found that methanol molecules prefer to adsorb at the top position of Pt(1 1 1) at various coverage levels. With the coverage increases, the adsorption capacity of methanol decreases rapidly, and then tends to flatten until the coverage reaches 1/6. The product of CH 2 O is formed by two-step dehydrogenation process. The energy barrier for both dehydrogenations increase first and then decreases with increasing coverage. The lowest energy barrier for both dehydrogenations occurs on the Pt(1 1 1) surface with coverage of 1/6 (E a, O H = 0.66 eV, E a, C H = 0.16 eV). Therefore, coverage of 1/6 is the optimal coverage for CH 3 OH generating CH 2 O on the Pt(1 1 1) surface. [ABSTRACT FROM AUTHOR]

In this paper, we employed Density Functional Theory (DFT) to study structural and mechanical stability, electric, magnetic and electronic properties of cubic Co-based new quaternary half-Heusler alloys CoZrCrZ (Z = Al, Ga, In) using WIEN2k. Volume optimisation suggests that these alloys are stable in the Y1 structure and show ferromagnetic behavioTAur. Generalised Gradient approximation calculations confirm the half-metallic nature of the reported alloys, which show metallic nature, and semiconducting band gaps exist in spin-up and spin-down channels, respectively. From the calculated cubic elastic constants, the reported Heusler alloys shows ductile nature. The calculated spin-magnetic moments of CoZrCrZ (Z = Al, Ga, In) are consistent with the Slater-Pauling rule. The very fine narrow band gap in the spin-down channel enhances the thermoelectric properties. The reported ferromagnetic half-metals with good thermoelectric parameters suggests that these alloys have possible applications in spin-based electronics and green energy technology. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, the bifunctional Ir cluster-decorated carbon Composite (Ir/C-1) electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are synthesized through simple in-situ growth of bimetallic Zn-Ir-MOF, followed by Zn reduction and evaporation for creating pore structure and uniform particle distribution. The prepared catalyst of Ir/C-1 with Ir cluster (d = 3 ± 0.1 nm) highly dispersed and closely attached to pore carbon through Ir-O-C bonds shows both excellent OER and HER performance. At a current density of 10 mA cm-2, the catalyst shows overpotentials of only 50.4 mV for HER and 359 mV for OER in 0.5 M H2SO4, respectively, which are better than commercial Ir/C and Pt/C catalysts. Density functional theory (DFT) calculations further revealed that the exposure of Ir (110) in Ir/C-1 can facilitate the thermodynamic process of HER and OER. This paper also gives a detailed discussion about the enhancement mechanism. To validate the catalyst, a single electrolysis cell is assembled using the prepared Ir/C-1 catalyst as both the anode and cathode catalysts. The result shows that the cell only needs a cell voltage of 1.653 V to obtain a current density of 10 mA cm-2, which is better than commercial Ir/C and Pt/C catalysts. [ABSTRACT FROM AUTHOR]

Photosensitizer systems play a crucial role in light absorption and charge transfer processes. Designing and selecting dye molecules with exceptional photoelectric features remains a significant scientific challenge in the realm of solar cell research. The paper explores the photovoltaic properties of two D-A'-π-A dyes (CS-70 and CS-72) both individually and after co-sensitization with chlorophyll derivatives, utilizing density functional theory (DFT) and time-dependent density-functional theory (TD-DFT) methods. The monomeric dye molecules share the same donor and conjugated bridge but differ in their auxiliary receptors (benzothiadiazole and naphthobisthiadiazole). Firstly, the study investigates the impact of various auxiliary acceptors on the properties of the dye molecules by analyzing their geometrical structure, frontier molecular orbitals, spectral properties, chemical reaction parameters, intramolecular charge transfer, electron injection, density of projected states, and dye regeneration. A detailed explanation for the superior performance of CS-72 is provided. Furthermore, a solar cell evaluation model was developed for the short circuit current density (Jsc), open circuit voltage (Voc), and photoelectric conversion efficiency (PCE) of the single dye molecule. Subsequently, simulations of the co-sensitized molecules with chlorophyll are performed, focusing on structure, excited state properties and charge transfer, suggesting that co-sensitization enhances spectral properties, light-trapping, and regeneration abilities, and long-range charge transfer between the dye molecules and chlorophyll can be found. The results also demonstrate that the Jsc of the co-sensitized molecules were improved, which facilitates the realization of a higher PCE. This study provides theoretical support for the potential of co-sensitizing dye molecules with chlorophyll to enhance solar cell efficiency, offering valuable insights for the future development of green, cost-effective, and efficient solar cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Transition metal-decorated MgO Nanocages for safer Chlormethine use. • Ni-MgO shows electronic changes upon ClM adsorption. • Pd-MgO works as Φ-type ClM sensor. This paper presents a study on the potential use of transition metal (TM)-decorated MgO nanocages, namely Ni, Pd, and Pt, in improving the efficacy and safety of chlormethine (ClM). The research employs density functional theory calculations to explore the electronic properties and adsorption behavior of ClM on the surface of TM-MgO nanocages. The study also investigates the most reactive sites of ClM and TM-MgO nanocages through molecular electrostatic potential plots. The findings reveal that Ni-MgO causes significant changes in electronic properties upon ClM adsorption, with a decrease in the energy gap of frontier molecular orbitals and an increase in electrical conductivity. Meanwhile, Pd-MgO is a suitable Φ-type sensor for ClM detection. The results suggest that TM-decorated MgO nanocages could enhance the effectiveness and safety of ClM and have the potential to be used as a drug delivery system, thus warranting further investigation. [ABSTRACT FROM AUTHOR]

[Display omitted] • XGBoost emerged as the best predictor. • ML approach shows high CIE values for Triazole compounds. • DFT calculations assume a pivotal role within the QSPR model. This paper endeavors to present an in-depth investigation into the corrosion inhibition efficiency (CIE) of novel triazole derivatives serving as corrosion inhibitors. Among the array of models considered, the extreme gradient boosting (XGBoost) model emerged as the most adept predictor in forecasting the CIE of N -heterocyclic organic compounds. This resolute preference for the XGBoost model was consistently upheld when employed in the prediction of the CIE for three newly synthesized triazole derivatives, namely, 2-[5-Phenyl-1-(2′-furanylmethylene)imino-(1,3,4)homotriazole]thio-N-(2′-furanyl)hypomethylacetylhydrazine, 2-[5-(3′-Methyl)Phenyl-1-(2′-furanylidine)imino-(1,3,4)homotriazole]thio-N-(2′-furanylidine) acetylhydrazine, and 2-[5-(4′-Methyl)Phenyl-1-(2′-furanylidine)imino-(1,3,4)homotriazole]thio-N-(2′-furanylidine) acetylhydrazine. Remarkably, this application of the XGBoost model yielded notably elevated CIE values, spanning from 88.35 % to 93.41 %. Supplementary density functional theory (DFT) calculations for these derivative compounds further substantiated the predictive trends observed through machine learning and experimental predictions. These calculations revealed robust adsorption energies falling within the range of −17.95 to −19.76 eV, in alignment with the CIE trends established through the machine learning framework. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pd atom tends to dope in the T Mo site of a MoTe 2 monolayer and the energy band gap of the doped monolayer decreases. • Both NO 2 and CO are able to stably and efficiently adsorbed on the Pd-MoTe 2 monolayer. The Pd-MoTe 2 monolayer exhibits better CO adsorption performance compared to NO 2. However, the decrease in resistance value of Pd-MoTe 2 monolayer is more significant after absorbing NO 2 than CO gas. • Pd-MoTe 2 monolayer shows promise as a resistive gas sensor. Detecting characteristic decomposition components has become a popular method for assessing the operational stability of air-insulated switchgear. This paper investigates the adsorption and sensing properties of a Pd-modified MoTe2 (Pd-MoTe2) for two common defective gases, namely, NO2 and CO, in air-insulated switchgear and employs the first-principles density functional theory (DFT) to conduct the analysis. According to the findings, Pd has a preference for doping in the TMo site on the MoTe2 monolayer, with a binding energy (Eb) of −2.240 eV. The Pd-MoTe2 monolayer exhibits effective adsorption of NO2 and CO, with both molecules chemisorbed. The adsorption energies (Ead) for NO2 and CO are −1.307 eV and −1.550 eV, respectively. Furthermore, there is an evident reduction of the band gap for the Pd-MoTe2 upon adsorbing NO2, decreasing the resistance value. In short, the Pd-MoTe2 monolayer has shown great promise as a gas sensor, laying the groundwork for improving power system stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • This paper introduces four two-dimensional inorganic biphenylene-like structures based on ZnS and CdS. • Phonon dispersion and ab initio molecular dynamics (AIMD) simulations were used to demonstrate the dynamical and thermal stabilities. • All evaluated structures are ultra-wideband gap semiconductors, with band gap energy values from 3.59 to 5.34 eV. • p-BPN-ZnS demonstrated the highest Young modulus (Y x /Y y = 25.295/34.874 N/m), followed by p-BPN-CdS (Y x /Y y = 15.286/21.339 N/m). • Notably, b-BPN-ZnS displayed a particular characteristic, a negative Poisson ratio (ν x /ν y = -0.008/-0.030), being an auxetic material. This study presents four novel inorganic structures based on the biphenylene network (BPN): planar BPN-ZnS (p-BPN-ZnS) and BPN-CdS (p-BPN-CdS) and buckled BPN-ZnS (b-BPN-ZnS) and BPN-CdS (b-BPN-CdS). Cohesive energy analyses reveal that structural buckling enhances stability, and a perturbation is necessary to obtain planar lattices. Phonon dispersion and ab initio molecular dynamics (AIMD) simulations demonstrated the dynamical and thermal stabilities. ZnS-based structures exhibited more pronounced charge accumulation and depletion than CdS. All evaluated structures are ultra-wideband gap semiconductors, with band gap energy values of 4.33, 5.34, 3.59, and 4.30 eV (at HSE06 level) for p-BPN-ZnS, b-BPN-ZnS, p-BPN-CdS, and b-BPN-CdS, respectively. p-BPN-ZnS demonstrated the highest Young modulus (Y x /Y y = 25.295/34.874 N/m), followed by p-BPN-CdS (Y x /Y y = 15.286/21.339 N/m). On the other hand, b-BPN-ZnS and b-BPN-CdS exhibit lower Young Modulus, Y x /Y y = 4.135/14.709 and 11.842/8.218 N/m, respectively. Notably, b-BPN-ZnS displayed a particular characteristic, a negative Poisson ratio (ν x /ν y = -0.008/-0.030), being an auxetic material. This report is expected to stimulate both theoretical and experimental researchers in the prediction and development of new inorganic materials based on the biphenylene network. [ABSTRACT FROM AUTHOR]

[Display omitted] • The results of this paper reveal the fact that the crystal XAlO 3 (X = Sm, Eu, Gd) is promising for energy-devices applications. • The hundred percent polarization due to their half metallic natures make candidate materials for spintronic devices. • These materials show best response to the ultraviolet-region which is clear for their dielectric functions, refractive index, absorption coefficient, extinction coefficient, optical conductivity, reflectivity, and energy loss function. • They also show outstanding thermoelectric properties. First-principles method based on density functional theory calculations are employed for investigating the electronic, optical and thermoelectric properties of XAlO 3 (X = Sm, Eu, Gd) for energy-devices applications. The spin-polarized electronic spectra of XAlO 3 depicts their half metallic nature since mere the spin up channel crosses the fermi level. Further, the optical features for instance; the dielectric functions, refractive index, absorption coefficient, extinction coefficient, optical conductivity, reflectivity, and energy loss function are studied which predict that these compounds are supposed to be better materials for the ultraviolet-region based optoelectronic and energy devices. Thermoelectric properties in terms of electrical and thermal conductivity, and figure of merit show higher values of thermoelectric characters which is extremely significant for optoelectronic devices. Interestingly, the positive value of Seebeck coefficient indirectly depict that XAlO 3 is a p-type materials. [ABSTRACT FROM AUTHOR]

A green and sustainable three-dimensional particle electrodes system with nickel-iron layered double hydroxide mixing activated carbon particles (NiFe-LDH/AC) as particle electrodes is used in this work. Its employment in degradation of N-Nitrosodiethylamine (NDEA), A type of nitrosamines disinfection byproducts (NAs) widely present in water bodies, exhibiting significant degradation efficiency at close to neutral pH. Response surface methodology (RSM) is used to analyze the interaction effects and predict optimal conditions of four operating parameters (influent water flow, electrolyte concentration, current density and initial concentration) on the NDEA degradation efficiency. Calculated coefficients of determination (R2) are higher than 0.997 for all responses according to analysis of variance. At optimum conditions, a maximum degradation efficiency of 71.88% is achieved for NDEA. The results of electron paramagnetic resonance (EPR) and free radical quenching experiments indicate that the degradation of NDEA in the 3D AER system is dominated by •OH. Furthermore, based on the recognition of main reaction intermediates by GC-MS and density functional theory (DFT), possible degradation pathway is proposed and toxicological evaluation of degradation products is made. Our research provides a promising alternative method for the efficient and environmentally friendly removal of NAs from water. • One of the few papers that use a three-electrode system for NAs degradation. • The NiFe LDH/AC particle electrodes are cost effective and have good stability. • Used RSM to optimize operating parameters and predict optimal conditions. • NDEA degradation Mechanism Probed by EPR and free radical Quenching. • Degradation path is discussed by a combination of DFT calculations and GC-MS. [ABSTRACT FROM AUTHOR]

The novel dual S-scheme WO 3 /ZnIn 2 S 4 /CoWO 4 heterojunction was formed by loading WO 3 and CoWO 4 onto ZnIn 2 S 4 (ZIS) using a simple two-step hydrothermal method. Sparfloxacin (SPX) degradation rate constant of WO 3 /ZnIn 2 S 4 /CoWO 4 heterojunction reached 0.0312 min−1, which was nearly 26-, 8.4–34.7-, and 1.6- fold greater than those of WO 3 , ZIS, CoWO 4 , and WO 3 /ZIS, respectively. The multi-charge transfer and separation mechanism of dual S-scheme heterojunction photocatalysts is deeply explored by experiments and density functional theory: the carriers moved in reverse contributed to an interfacial heterotropic built-in electric field, which accelerated the photogenerated carriers' separation and interfacial transfer ability and lifetime. Further, no recombined electrons and holes with higher reducing and oxidizing properties produced more •O 2 −, h+ and •OH, which could attack the active atoms of SPX with a high Fukui index. By combining with liquid chromatography mass spectrometry-ion trap-time of flight, plausible SPX degradation intermediates, pathways and mechanisms were presented. SPX was degraded into humic acid-like intermediates, and its environmental risk was significantly reduced. This paper offers insight into developing a novel ZIS-based dual S-scheme heterojunction strategy for solving environmental issues. [Display omitted] • A brand-novel dual S-scheme WO 3 /ZnIn 2 S 4 /CoWO 4 heterojunction was constructed. • The dual S-scheme heterojunction favors carriers' separation and lifetime extension. • The charge transfer pathway of dual S-scheme was discussed in depth. • The SPX degradation pathway was identified in theory and experiments. [ABSTRACT FROM AUTHOR]

Polychlorinated naphthalenes (PCNs) are ubiquitous in the environment and have received extensive public concern due to their dioxin-like properties. 1,2,3,4,5,6,7-heptachloronaphthalene (1,2,3,4,5,6,7-HpCN) is one of the most toxic and detected PCNs. The chlorophenoxy radical (CPR) was demonstrated as a crucial intermediate specie for PCN formation in thermal and combustion conditions. In this study, the homogeneous gas-phase formations of PCNs from the self-condensation of 2,3,4,5-terachlorophenoxy radicals (2,3,4,5-TeCPRs) and the cross-condensation of pentachlorophenoxy radical (PCPR) with 2,3,4,5-TeCPR were researched by using the direct density functional theory (DFT) kinetic calculation. The possible formation mechanisms were investigated at the MPWB1K/6–311+G(3df,2p)//MPWB1K/6–31+G(d,p) level. The rate constants and their temperature dependence of key elementary reactions were deduced over the temperature range of 600–1200 K. This study reveals that pathways concluding with Cl elimination are energetically favored over those ending with H elimination. 1,2,3,4,5,6,7-HpCN is the main PCN product from the self-condensation of 2,3,4,5-TeCPRs, whereas 1,2,3,4,5,6,7-HpCN and 1,2,3,4,5,6,8-HpCN are the major PCN products from the cross-condensation of PCPR and 2,3,4,5-TeCPR. 1,2,3,4,5,6,7-HpCN is preferentially formed from self-condensation of 2,3,4,5-TeCPRs. Multi-chlorine substitutions suppress the PCN formations. The findings discussed in this paper aim to provide detailed insights into the formation mechanism of highly chlorinated PCNs from chlorophenol precursors under thermal and combustion conditions. [Display omitted] • The PCN formation mechanism from 2,3,4,5-TeCP and PCP as precursors. • The rate constants have been calculated for the key elementary reactions. • 1,2,3,4,5,6,7-HpCN is preferentially formed from dimerization of 2,3,4,5-TeCPRs. • Multichlorine substitutions suppress the PCN formations. [ABSTRACT FROM AUTHOR]

Kitchen waste incineration technology is one of the effective technologies for achieving waste resource utilization with heat recovery and large-scale volume reduction. Pyrolysis is the most fundamental and important stage in the incineration process. Hence, this paper selects glutarimide and succinimide are abundant initial products during kitchen waste pyrolysis. Glutarimide and succinimide are the main N-containing heterocycles (33.55 wt%) in soybean protein pyrolysis from kitchen waste. The pyrolysis mechanism of glutarimide/ succinimide and the reaction pathways of NO x precursors (NH 3 , HCN, and HNCO) are studied by using density functional theory (DFT) calculation. The possible pathways of NO x precursors formation from cleavage of C-N/C-C bond caused by H-transfer and homolysis of C-N/C-C bond are proposed. The favorable pathways for the formation of HNCO have low energy barrier (430.9 kJ/mol，418.5 kJ/mol) and high reaction rate constant throughout the entire temperature range. At the same time, the hydrogenation and decomposition of HNCO have explained the trend of NH 3 and HCN formation under low temperature condition in pyrolysis experiment. Finally, this study theoretically proves that the yield of NH 3 is higher than that of HCN. This finely explains the phenomenon that NH 3 release is greater than HCN release in the experiment. In addition, this study found that the yield of NO x precursor formed by glutarimide cracking is higher, and the structure of the five membered ring succinimide (minimum energy barrier value of an open loop，334.3 kJ/mol) is more stable than that of the six membered ring glutarimide (347.0 kJ/mol). [Display omitted] • The formation mechanism of NO x precursors in glutarimide and succinimide pyrolysis is studied in-depth. • NO x precursors are formed through H-transfer cleavage and homolysis. • HNCO hydrogenation decomposition is more inclined towards the NH 3 conversion pathway. • Comparison of structural stability between glutarimide and succinimide from a thermodynamic perspective. [ABSTRACT FROM AUTHOR]

• The geometric, electronic and elastic properties of Fe 3 SnC are calculated in detail for the first time. • The results show that Fe 3 SnC is a magnetic metal. • The large elastic modulus indicates that Fe 3 SnC is a potential cermet. In this paper, the structural, electronic, and elastic properties of Fe 3 SnC were calculated based on local density approximation (LDA) and generalized gradient approximation (GGA) in density functional theory (DFT). Compared with GGA, LDA underestimates lattice constants and overestimates binding energy and elastic constants. The calculated lattice constants are 3.76 Å (LDA) and 3.83 Å (GGA), respectively, and the latter is closer to the experimental values. With U correction in GGA and LDA, the magnetic properties of the system are shown in the band structure. The GGA calculation results are more accurate, and the calculated magnetic moment of Fe 3 SnC is 5.74μ B. The band structure indicates that Fe 3 SnC is a metallic compound. The elastic constants show that Fe 3 SnC has a large elastic constant and bulk modulus, in which the C 11 calculated by GGA is as high as 463.81GPa, and the Young's modulus is as high as 350.72GPa. This indicates that Fe 3 SnC is a potential cermet due to a strong deformation resistance. At the same time, with the minimum thermal conductivity of 1.65 W/mK calculated by the Cahill model. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photoabsorption and relaxation of 12 phenylurea compounds studied in the gas phase using time-dependent density functional theory. • Two primary classes of phenylurea compounds identified based on ground state structures. • Vertical and adiabatic excitation energies computed. • Four types of excited state minima discussed. Phenylurea herbicides are widely used to control unwanted plant growth, but can linger in the environment. Photodegradation is a key mechanism by which these compounds can be transformed. This paper investigates the direct photoabsorption and relaxation of twelve phenylurea compounds (chlorbromuron, chlortoluron, diuron, fenuron, fluometuron, isoproturon, linuron, methiuron, metobromuron, metoxuron, monolinuron, monuron) using density functional theory. Ground state structures are optimized at the B3LYP-D3/def2-SVP level of theory and excited states are computed using CAM-B3LYP-D3/def2-SVPD. These molecules are found to be mostly planar and structurally similar in the ground state, with the exception of methiuron which has a significant distortion. The vertical excitation energies are affected by the presence of halogen substituents, and trends in the relaxation of these states are observed. Specifically, halogenated compounds generally have a local excited state minimum corresponding to a stretched carbon-halogen bond, phenylureas containing a methoxy group on the nitrogen have a local minimum corresponding to a twisted urea group and/or a minimum corresponding to the breaking of the nitrogen–oxygen bond between the urea and the methoxy group. The results are discussed in the context of known photodegradation mechanisms for this class of compounds. [ABSTRACT FROM AUTHOR]

• Optical, and thermoelectric properties of CsPbI 3-y Br y compounds are investigated. • The increase in Br concentration improved the stability of studied perovskites. • A high and tunable optical conductivity proved brilliant optoelectronic properties. • A positive value of the seebeck coefficient revealed a p-type semiconductor nature. • Substitution of halide I atoms by Br can improve the thermoelectric properties. Among photovoltaic materials, halide-based perovskites, such as CsPbI 3 , have been the subject of many research papers due to their suitable and direct bandgap, very good optical properties, and remarkable thermoelectric properties. Enhancing optoelectronic and thermoelectric properties can be achieved by combining halide atoms intelligently. The purpose of this article is to examine the physical properties of Br substitution at different concentrations in CsPbI 3 perovskite. The structural, electrical, and optical properties of CsPbI 3-y Br y (y = 0.5, 1.5, 2.5) compounds have been investigated by using the QUANTUM-ESPRESSO/PWSCF computational package which is based on the density functional theory and the pseudo-potential technique. The thermoelectric properties of CsPbI 3-y Br y perovskites were calculated by solving the Boltzmann transport equations within the constant relaxation time approximation as employed in the BoltzTraP package. The structural investigation reveals that when the I atom is substituted by Br, the lattice constant decreases, increasing the bulk modulus and stiffness of compounds. The calculated negative formation energy confirmed the thermodynamic stability of CsPbI 3-y Br y compounds, and the stability improved with an increase in Br concentration. The electronic investigation indicates the semiconductor nature of compounds with a direct band gap, with a slight increase in electronic band gap as Br concentration increases. The noticeable optical absorption coefficient in the visible range of the electromagnetic spectrum, along with high and tunable optical conductivity, confirms the capability of the compounds for use in optoelectronic devices. The positive value of the Seebeck coefficient revealed the p-type semiconducting nature of CsPbI 3-y Br y perovskites. Lattice thermal conductivity calculation reveals that this quantity is decreased because of the increase in phonon-phonon interaction due to rising temperature. Thermoelectric investigation indicates that a precise mixture of halide I and Br atoms significantly enhances the electrical and thermal conductivity of perovskites. Also, the substitution of halide I atoms by Br can improve the figure of merit (ZT). The maximum value of ZT at room temperature is equal to 0.99, justifying the brilliant thermoelectric properties of the studied compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The Pt's position relies on its binding with B atoms, having fewer valence electrons. • Decorated Pt atoms impact hydrogen adsorption by altering nearby electrostatics. • The adsorption energy of the Pt atom for the H 2 complex exceeds physical adsorption. • CGL-B1-Pt substrate meets the requirements of rapid adsorption and desorption. The conical cup-stacked carbon nanotubes (CSCNTs) are stacked by individual conical graphene layers (CGL) with a large number of active C atoms on their walls, making them an effective hydrogen storage material. In this paper, the structural properties of the loaded Pt atom and its hydrogen storage properties were investigated using density functional theory (DFT) with and without substitution of B atoms on the edges of the CGL. It was found that the loaded Pt atoms could adsorb 3 H 2 and up to 7 H 2 without replacing the C atoms with B atoms as well as replacing the C atoms at the edges of the CGL with B atoms at different positions, respectively. Therefore, we conclude that the position of the substituted B atom at the edge of the CGL has an important effect on the position of the loaded Pt atom and its hydrogen adsorption and storage properties. [ABSTRACT FROM AUTHOR]

In the battery industry, the performance of lithium-ion batteries operating at a high voltage is enhanced by utilizing functional additives in electrolytes to achieve higher energy densities and longer lifetimes. These additives chemically stabilize the electrolyte and aid in the formation of a stable cathode electrolyte interphase (CEI). In this paper, the investigation of oxidative potentials of more than 100 additives, using density functional theory calculations to determine the best candidates for CEI formation, is reported. The method was validated by comparing the calculated oxidation potentials and the experimental data obtained using linear sweep voltammetry based on the evaluation of 18 candidates. Further electrochemical studies (AC impedance and cycling stability) on six selected additives were conducted. Among the tested additives, the addition of quinacridone at 0.03% weight concentration resulted in the formation of a less resistive surface film on the cathode in Li/Ni0.5Mn0.3Co0.2O2 coin cells. Moreover, the capacity retention in Gr/Ni0.5Mn0.3Co0.2O coin cells increased from 62% to 77% after 200 cycles at 1C and approximately 4.4 V. The derived results suggest that the combination of the oxidation potential prediction with impedance study could be used as a powerful tool to properly and efficiently select CEI-forming additive candidates for improved battery performance. [ABSTRACT FROM AUTHOR]

Three-dimensionally (3D) architectured carbon supports have received great attention for fuel cell catalysts. However, the complicated structure makes the assessment of catalytic properties difficult using the conventional rotating disk electrode (RDE) method. This paper reports a systematic study on oxygen reduction reaction (ORR) with ion-beam sputtered Pt catalyst (at Pt loadings of 6.5–43 μg cm−2 ) on a vertically aligned carbon nanofiber (VACNF) array, consisting of conically stacked graphitic microstructures. The RDE studies reveal that thick 3D architecture of VACNFs exhibits enhanced limiting current density that deviates from the Levich equation for conventional thin-film catalysts. Nevertheless, useful information can be derived from RDE experiments with such systems. Molecular models representing VACNFs have been constructed to explore their capacity as catalyst supports for ORR. Platinum atoms form strong bonds at the open graphitic edges in VACNF, corroborating the role of VACNF in stabilizing Pt. Density Functional Theory (DFT) calculations further elucidate the two-electron and four-electron ORR pathways on the bare VACNF and Pt/VACNF catalysts, respectively. Furthermore, the Pt/VACNF catalysts show enhanced tolerance to methanol oxidation and a higher ability to recover from carbon monoxide poisoning in comparison to the benchmark Pt/C catalysts. These results provide critical insights for developing future high-performance electrocatalyst supports. [ABSTRACT FROM AUTHOR]

The knowledge of atmospheric chemistry has explained several reactions that occur in atmosphere regarding volatile organic compounds (VOCs). In this original paper, computational kinetic study was carried out on atmospheric oxidation reaction mechanism of 1-fluoro-2-methoxypropane (CH 3 CH(OCH 3)CFH 2) with OH/ClO radicals using DFT/M06-2X/6–311++G∗∗ method. To improve the results, DFT/M06-2X/6–311++G(2df,2p) single-point calculations were performed on the reacting species involved. The Monte Carlo search on the investigating hydrofluoroether (H 3 CCH(OCH 3)CFH 2) showed nine conformers with the lowest global minimum conformer being considered for this study. The reaction proceeded via four (4) reaction routes which led to dehydrogenation in each cases of the radical (OH/ClO) used. The total rate for dehydrogenation reaction of H 3 CCH(OCH 3)CFH 2 with OH/ClO radicals is 9.13 ∗ 103 s−1 and 1.23 ∗ 106 s−1 at 298 K which is in agreement with the available experimental rates recorded by Healthfield et al. (1998), Kazuaki Tokuhashi et al. (2000). Also, in each radical cases, thermodynamics parameters, the major and minor products' heat of formation were computed with potential energy surfaces (PES) for the reactions constructed at absolute temperature of 298 K. [ABSTRACT FROM AUTHOR]

This paper combines density functional theory calculations and electrochemical testing to study activity differences among iridium (Ir) surfaces in the oxygen evolution reaction. Ir metal/hydroxide is significantly more active than Ir oxide, which may be due to oxide skins at the surface weakening O-binding relative to pure metal or oxide surfaces. Here we report a disparity in activity between Ir and Ir oxide in half-cells not observed in single-cells. Extended operation at elevated temperature and potential were found to result in oxide growth, limiting how surface differences affect electrolyzer performance. Comparisons of half- and single-cell testing were used to assess how well rotating disk electrode testing predicts membrane electrode assembly performance and durability. Although oxygen evolution activities in half-cells can translate to single-cells, standard rotating disk electrode test procedures can exaggerate the activity benefit of a metal/hydroxide surface relative to membrane electrode assembly performance under typical operating conditions; it also appears that a half-cell test cannot reasonably accelerate activity loss from continual operation. While a variety of novel catalyst approaches, including alloying, faceting, morphology, and supports can improve oxygen evolution kinetics, these results suggest that Ir surfaces at different oxide states may struggle to improve performance at the device level. [ABSTRACT FROM AUTHOR]

This paper studies molecular level interaction mechanisms involved in surface activation of rubber particles when exposed to a newly developed bio-modifier and microwave irradiation. It further examines how surface activation of rubber promotes its interaction with asphalt molecules to reduce phase separation in rubberized asphalt-binder. Using quantum-based calculations, chain reactions between an amide-rich bio-modifier and irradiated molecules of rubber is examined. The density functional theory (DFT)-based molecular modeling was performed on amide-type molecules as representatives for the bio-modifier. Comparing interactions of amidyl radical (RCO-N•H) of bio-modifier with sulfur-centered and carbon-centered radicals of rubber showed that amidyl radicals have higher affinity to bind to carbon-centered radicals than to sulfur-centered radicals. While the spine triplet state for ‒N...S‒ reaction coordinates encounters the obstacle of spin block and activation barrier, no spin block is observed on the ‒N...C‒ reaction pathway. The latter reaction was further observed via FTIR spectra where a new peak appeared at 1040 cm−1 indicating formation of C N bonds. Aforementioned reactions led to grafting highly polar molecules of bio-modifier onto the surface of rubber increasing rubber's surface polarity. This was evidenced by the increase in acid-base component of rubber's surface energy from 2.9 mJ/m2 in control rubber to 14.6 mJ/m2 in treated rubber. The increased polarity increased the interactions of rubber with asphalt molecules reducing the phase separation commonly known as segregation in rubberized asphalt. The latter was reflected in reduction of differences in complex modulus (G*) between top and bottom parts of rubberized asphalt specimens from 53.69% to 0.05%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Adsorption characteristics of dimetridazole on TiO 2 crystal surface have been studied by DFT. • We found that the possibility of degradation of dimetridazole on the surface of TiO 2. • Our results show that TiO 2 (1 0 1) crystal surface can effectively use visible light under acidic and alkaline conditions. Abstract In this paper, the adsorption characteristics of dimetridazole on anatase TiO 2 (1 0 1) and (0 0 1) crystal surfaces has been studied by using density functional theory. Adsorption structures of dimetridazole on anatase TiO 2 (1 0 1) and (0 0 1) crystal surfaces have been optimized under vacuum, water, acidic and alkaline conditions, respectively. The optimum adsorption site, adsorption energy and the electronic structure of the stable adsorption model were calculated. By analyzing the optimal adsorption site, we found that the possibility of degradation of dimetridazole on the surface of TiO 2 and reaction site of degradation were the opening ring of C N bond on the imidazole ring. By comparing the adsorption characteristics of dimetridazole on two different crystal planes of TiO 2 under acidic and alkaline conditions, we found that the adsorption wavelengths of electron transition between conduction bands and valence bands of dimetridazole on anatase TiO 2 (1 0 1) crystal plane are within the range of visible wavelength. The results show that TiO 2 (1 0 1) can effectively utilize visible light and catalyze the adsorption and degradation reaction of dimetridazole on TiO 2 (1 0 1) surface. Our results show that TiO 2 (1 0 1) crystal surface can effectively use visible light under acidic and alkaline conditions. Our conclusion can explain the experimental result that the use of visible light on TiO 2 (0 0 1) face is greatly affected by the environment. [ABSTRACT FROM AUTHOR]

Abstract In perovskite solar cells (PSCs), the state-of-art Spiro-OMeTAD, which used as a hole-transporting material (HTM), suffered from complicated multistep synthesis and difficult purification that make this material cost ineffective, in addition to it being UV-unstable. Thus, new, cost-effective and easy to synthesize small organic molecules is still required. As reported, a carbazole-based compound (R01) was synthesized using a simple two steps method from low-cost commercially available compounds and used as an HTM. R01 exhibited higher conductivity and hole-mobility compared to that of the Spiro-OMeTAD. PSCs fabricated with R01 produced a power conversion efficiency of 12.03%, equivalent to that obtained in devices where Spiro-OMeTAD was the HTM. These findings highlighted R01 as a highly promising HTM with high performance, facile synthesis, and low cost. From a structural perspective, methoxy groups (–OCH 3) in the HTM structure are controlling the HOMO level of the compound, apart from the critical role they play in anchoring the material onto the core perovskite layer. In this paper, we report a systematic study of the electronic structures and photophysical properties of twelve designed derivatives of R01. R01 was modified by substituting some hydrogen in the carbazole rings by two, four and six methoxy groups at different positions. The ground and excited state geometries are optimized by applying density functional theory (DFT) and its time-dependent functional (TDDFT), respectively. Detailed investigation of two factors: (i) the number and (ii) position of methoxy groups on the frontier molecular orbitals (FMOs), absorption and emission wavelengths, ionization potential, electron affinity, reorganization energies and charge mobility are examined and discussed. The electro-optical and nonlinear optical (NLO) properties are finely tuned in the R01 derivatives. By incorporating methoxy substituents into this carbazole-based compound, systematic design of potential materials for PSCs can be feasible. [ABSTRACT FROM AUTHOR]

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The thermal processes of materials containing decabromodiphenyl ether (BDE-209) normally result in the exposure of BDE-209 to high-temperature environments, generating a series of hazardous compounds. However, the evolution mechanisms of BDE-209 during oxidative thermal processes remain unclear. Thus, this paper presents a detailed investigation on the oxidative thermal decomposition mechanism of BDE-209 by utilizing density functional theory methods at the M06/cc-pVDZ theoretical level. The results show that the barrierless fission of the ether linkage dominates the initial degradation of BDE-209 at all temperatures, with branching ratio over 80%. The decomposition of BDE-209 in oxidative thermal processes is mainly along BDE-209 → pentabromophenyl and pentabromophenoxy radicals → pentabromocyclopentadienyl radicals → brominated aliphatic products. Additionally, the study results on the formation mechanisms of several hazardous pollutants indicate that the ortho -phenyl-type radicals created by ortho -C-Br bond fission (branching ratio reached 15.1% at 1600 K) can easily be converted into octabrominated dibenzo- p -dioxin and furan, which require overcoming the energy barriers of 99.0 and 48.2 kJ/mol, respectively. The O/ ortho -C coupling of two pentabromophenoxy radicals also acts as a non-negligible pathway for the formation of octabrominated dibenzo- p -dioxin. The synthesis of octabromonaphthalene involves the self-condensation of pentabromocyclopentadienyl radicals, followed by an intricately intramolecular evolution. Results presented in this study can enhance our understanding of the transformation mechanism of BDE-209 in thermal processes, and offer an insight into controlling the emissions of hazardous pollutants. [Display omitted] • Ether linkage fission dominates the initial oxidative decomposition of BDE-209. • BDE-209.→penta-BPhx/BPhy → cyc -C 5 Br 5 →brominated aliphatic products is the main path • Ortho -C-Br bond fission, followed by a ring-closure, leads to the formation of OBDF. • The O/ ortho -C coupling of two penta-BPhx radicals controls the formation of OBDD. • The synthesis of OBN results from the self-condensation of two cyc-C 5 Br 5 radicals. [ABSTRACT FROM AUTHOR]

• Elastic, electronic, thermo-physical, and optical properties of CsV 3 Sb 5 Kagome compound are investigated. • Pressure dependent physical properties are explored. • There are strong indications that the hexagonal CsV 3 Sb 5 becomes elastically/structurally unstable at a pressure ∼ 18 GPa. • Fermi surface topology of CsV 3 Sb 5 shows strong pressure dependence. • Various optical features of CsV 3 Sb 5 are suitable for optoelectronic applications. In this paper, we have presented a comprehensive study of the physical properties of Kagome superconductor CsV 3 Sb 5 using the density functional theory (DFT) methodology. The structural, mechanical, electronic properties (band structure, electronic energy density of states, Fermi surface, and charge density distribution), atomic bonding, hardness, thermodynamics, optical properties, and their pressure dependences have been investigated systematically at different pressures. The calculated ground state lattice parameters and volume are in excellent agreement with available experimental results. The estimated single-crystal elastic constants ensured the mechanical stability of the compound, whereas phonon spectra endorse dynamical stability at zero pressure. The electronic band structure, density of states, and optical properties confirmed the metallic feature. The Pugh ratio and Poisson's ratio of the compound under study revealed the softness/ductility. The hardness of CsV 3 Sb 5 , estimated using several formulae, is quite low while the machinability index predicted good machinability with excellent lubricating properties. The compound shows tendency towards structural instability at a pressure around 18 GPa. The optical constants have also been studied to correlate them with electronic properties (band structure) and predict the possible applications of this compound. Both the mechanical and optical properties show directional anisotropy. CsV 3 Sb 5 is predicted to be an efficient absorber of ultraviolet radiation. The compound is also an efficient reflector of visible light. The superconducting transition in CsV 3 Sb 5 has been revisited following prior studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rh-doping on the MoTe 2 monolayer facilitates its adsorption on the gas molecules. • The adsorption performance of Rh-MoTe 2 monolayer on CO molecule is more optimal than that on H 2 and CH 4 molecules. • The Rh-MoTe 2 monolayer can be used as a resistance-type sensor for the detection of CO and H 2 , while CH 4 is not suitable for detection. Oil-immersed transformer plays a significant role in power systems, whose insulation failure will threaten the stable operation of the system, thus the requirements for its operational stability are higher. In this paper, the Rh-doped MoTe 2 (Rh-MoTe 2) monolayer is proposed for the detection of several typically dissolved gas molecules (CO, H 2 and CH 4) based on the first-principles density functional theory (DFT). It is found that the Rh dopant preferred to be adsorbed through the T Mo site with maximum binding energy (E b) of −3.43 eV. Then, the adsorption of Rh-MoTe 2 on CO, H 2 and CH 4 molecules is investigated with adsorption energy (E ad). Furthermore, the band gaps of CO and H 2 systems have significantly reduced, showing their excellent potential as resistance-type gas sensors; while CH 4 is not suitable for detection due to the weak interaction. This study illustrates the physicochemical properties of Rh-MoTe 2 monolayer and reveals its promising applications in dissolved gas analysis (DGA). [ABSTRACT FROM AUTHOR]

Alcoholysis of urea is an attractive methodology for the synthesis of organic acyclic carbonates. It has low environmental impact and represents an indirect way of using CO 2 . ZnO, known to have interesting performances, is reported in the literature to behave as a homogeneous catalyst in the form of Zn(NCO) 2 (NH 3 ) 2 in the methanolyis of urea. In this paper, theoretical and experimental studies are described aimed at shading light on the reaction mechanism of ethanol with urea under transition-metal ( T M ) catalysis. The reaction of ethanolysis of urea proceeds in two steps: i) formation of ethylcarbamate (EC) also in absence of catalysts; ii) co-ordination of EC, via the carbonylic group, to a T M centre and alcoholysis to afford diethylcarbonate (DEC). The adduct T M -EC has been isolated using several T M s (Zn, Sc, La) and characterized. It has been shown to react with ethanol to afford DEC. The energetics (free Gibbs energy) of the non-catalyzed and catalyzed ethanolysis of EC have been compared, highlighting the role of the T M as catalyst. The same reaction mechanism has been shown to hold for methanol, also if the energy of the TSs differs from EtOH. The reaction mechanism demonstrated in this paper for the ethanol(methanol)–urea reaction is dissimilar from that reported in the literature for the methanol–urea system, most probably due to both: i) higher level of DFT calculations used in this work that most carefully reveals the energetics of the TSs, and ii) use of Gibbs Free Energy instead of Enthalpy used by other authors. [ABSTRACT FROM AUTHOR]

In this paper a study of the temperature dependence of the vacancy formation energy in bulk fcc 4d-transition metals Ag and Pd using DFT was presented. Peculiarity of this work is the use of experimental values of the lattice parameters for the respective temperatures. This paper discusses the various contributions to the vacancy formation energy and shows that they can play an important role. It was shown that thermal excitation has a significant impact on the vacancy formation energy at high temperatures. The possibility of the existence of the compensation effect, i.e. the simultaneous changes in the contributions of the free energy and the vacancy formation energy in the fcc 4d-transition metals Ag and Pd, which were investigated from first principles. Taking in to account free oscillation energy and electronic thermal excitation depending on the temperature allows obtaining a qualitative picture of the effect of thermal expansion. The vacancy formation energy is in good agreement with previous theoretical and experimental studies. The effect of mutual compensation of different contributions to the vacancy formation energy can explain the constant value of the vacancy formation energy at any temperature and justifies the neglect of the temperature dependence of the simulation properties. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Deepening carbon hollows enhances their hydrogen storage ability. • Calculated Ea for carbon hollows lies in the range from −12.55 to −20.56 kJ/mol. • In the present study the dispersion term dominates the intermolecular interaction. Abstract Understanding the interaction of hydrogen molecules with hollow materials is crucial in the fields of hydrogen storage, sensors, catalysis, and fuel cells. In this paper, we studied hydrogen adsorption on single-walled carbon hollows by means of DFT-D3 calculations. These structures adsorb H 2 molecules significantly stronger (adsorption energy, E a , of −12.55 to −20.56 kJ/mol) than coronene (−4.15 kJ/mol), the representative of graphene, and corannulene (−7.83 kJ/mol), a slightly bent polyaromatic molecule. The reduced density gradient analysis was involved to visualize interacting regions between hydrogen and a series of adsorbents. Energy decomposition analysis was used to divide the total interaction energy into constituents. It is founded that the dispersion term is dominating in all studied cases. The present results should broaden our understanding of the mechanisms of hydrogen storage using carbon hollows. [ABSTRACT FROM AUTHOR]

LiBH 4 is among a few chemicals with the highest hydrogen storage capacities. In this paper, the crystal structure, electronic structure and dehydrogenation properties of both pure and transition metal (TM = Fe, Co, Ni, Cu and Ti)-modified LiBH 4 were investigated by using first-principles calculations based on density functional theory. According to the computing results, the occupation energies of TM-doped LiBH 4 suggest that the metal atoms prefer to occupy interstitial sites rather than substitute a Li atom site. Meanwhile, the calculation results show that the TM-modified LiBH 4 could have decreased stability and that all the TM substitutions may kinetically favour H-desorption, due to the decrease in hydrogen removal energy during the H atom release process from the bulk. The electronic structure further proves that the TM modification tends to weaken the B H bonding interaction, and that Ti-doped LiBH 4 has a good dehydrogenation performance, which is also confirmed by the reported experimental results. [ABSTRACT FROM AUTHOR]

The understanding of intermolecular interactions holds the key for many applications of organic semiconductor materials, such as azabenzenes, since they govern molecular configurations and the electron transfer rate. While the high-level quantum mechanics (QM) method can supply accurate interaction energies, it is most often time-consuming, which limits its large-scale applications. To address this issue, the approach using the polarizable force field (e.g. AMOEBA) has been recently developed. The quality of the polarizable force field is largely determined by its anisotropic atomic multipole potential (AMP). In this paper, AMPs of azabenzenes are first derived by fitting the QM-based electrostatic potentials using various exchange–correlation functionals of the density functional theory (DFT). The performance of the derived AMPs on the computations of the intermolecular interactions between azabenzenes is systematically evaluated. The findings of this study demonstrate that the both DFT-derived and MP2-derived AMPs can reproduce intermolecular electrostatic interactions in terms of that from the golden standard CCSD(T)/CBS computations. Our findings, therefore, demonstrate the feasibility to use relatively cheap QM method to derive AMPs for azabenzenes. [ABSTRACT FROM AUTHOR]