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First‐principles calculations based on density functional theory (DFT) are used to investigate the phase transition characteristics, electronic structures, and optical properties of pure and Co‐doped VO2 (M1 and R phase). Studies show that the metal‐to‐insulator phase transition temperature of VO2 is significantly reduced after Co doping, which is correlated to the decrease of bandgap value. Besides, the decrease of the energy required for electron transition of M1‐phase Co‐doped VO2 corresponds to the imaginary part of the dielectric peak moving to the low‐energy region. For both the M1‐ and R‐phase VO2, the visible light transmissivity of the Co‐doped VO2 is increased than that of pure VO2, which is beneficial to the application of VO2 film as visible windows. In addition, the absorptivity and reflectivity of Co‐doped R‐phase VO2 in the infrared light range are larger than those of M1‐phase VO2, indicating that the Co‐doped VO2 can block more infrared light at higher temperature to fulfill the purpose of lowering temperature. Overall, these results give new insights for the application of Co‐doped VO2 as a photoenergy material to regulate the room temperature. [ABSTRACT FROM AUTHOR]

First‐principles calculations based on density functional theory (DFT) are used to investigate the phase transition characteristics, electronic structures, and optical properties of pure and Co‐doped VO2 (M1 and R phase). Studies show that the metal‐to‐insulator phase transition temperature of VO2 is significantly reduced after Co doping, which is correlated to the decrease of bandgap value. Besides, the decrease of the energy required for electron transition of M1‐phase Co‐doped VO2 corresponds to the imaginary part of the dielectric peak moving to the low‐energy region. For both the M1‐ and R‐phase VO2, the visible light transmissivity of the Co‐doped VO2 is increased than that of pure VO2, which is beneficial to the application of VO2 film as visible windows. In addition, the absorptivity and reflectivity of Co‐doped R‐phase VO2 in the infrared light range are larger than those of M1‐phase VO2, indicating that the Co‐doped VO2 can block more infrared light at higher temperature to fulfill the purpose of lowering temperature. Overall, these results give new insights for the application of Co‐doped VO2 as a photoenergy material to regulate the room temperature. [ABSTRACT FROM AUTHOR]

Selecting effective corrosion inhibitors from the vast chemical space is not a trivial task, as it is essentially infinite. Fortunately, machine learning techniques have shown great potential in generating shortlists of inhibitor candidates prior to large-scale experimental testing. In this work, we used the corrosion responses of 58 small organic molecules on the magnesium alloy AZ91 and utilized molecular descriptors derived from their geometry and density functional theory calculations to encode their molecular information. Statistical methods were applied to select the most relevant features to the target property for support vector regression and kernel ridge regression models, respectively, to predict the behavior of untested compounds. The performance of the two supervised learning approaches were compared and the robustness of the data-driven models were assessed by experimental blind testing. [ABSTRACT FROM AUTHOR]

Abstract: The regioselective and enantioselective synthesis of β‐indolyl cyclopentenamides, a versatile chiral building block, by asymmetric addition of indoles to α,β‐unsaturated iminium intermediates has been achieved through chiral anion catalysis. Key to the success of this methodology is the generation of a chiral anion‐paired ketone‐type α,β‐unsaturated iminium intermediate from α‐hydroxy enamides. Preliminary mechanistic studies and DFT calculations are consistent with a mechanism involving multiple, concurrent pathways for isomerization of the initially formed azaallylcation into the key α,β‐unsaturated iminium intermediate, all mediated by the phosphoric acid catalyst. [ABSTRACT FROM AUTHOR]

Density functional theory (DFT) calculations are applied to the study of proton transport in maleimide and its homologues, succinimide and phthalimide. The calculations reproduce correctly their structural characteristics and reveal the hydrogen bonding and proton hopping properties. Specifically, the calculations show that the potential barrier for proton transfer between two maleimide molecules is about 30.60 kcal mol −1 mediated by one or two water molecules with correction of solvation effect by water, and will decrease to about 13.22 kcal mol −1 if ethylphosphonic acid molecule is used as mediator with correction of solvation effect by phosphoric acid. In addition, the calculations also show that succinimide and phthalimide possess similar characteristics compared to maleimide. Finally, it is concluded that maleimide and its homologues are building block candidates for the design of high-temperature proton exchange membranes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two efficient fluorescent probes based on 1,3,4-thiadiazole and coumarin core were successfully designed with the guidance and assistance of Density Functional Theory calculations. • Both of them displayed high selectivity and sensitivity, low detection limit, fast response time and color change after addition of TNP. • 1H NMR analysis and DFT calculations were employed to get insight into the principle and scheme of selective recognition. • LK-1 was successfully applied for the detection of TNP in real water samples and test strip experiments. Two remarkablely fluorimetric probes were developed to rapidly detect 2,4,6-trinitrophenol (TNP). With the help of density functional theory (DFT) calculations, we confirmed that using 1,3,4-thiadiazole skeleton as recognition group and coumarin unit as fluorophore would show excellent application prospects in terms of TNP detection. The probes LK-1 and LK-2 displayed green and orange emission with fluorescence quenching yield as high as 83.7% and 75.1% in solution. Further evaluation demonstrated that they display outstanding selectivity and sensitivity for rapid and visual detection of TNP. Both fluorescent color and fluorescence emission spectrum had significant changes and these phenomena could easily observe via naked-eye and analytical instrument. The detection limits of them were 97 nM and 71 nM. What's more, application in real water samples and solid phase paper tests illustrated the practical significance of detection of TNP. [ABSTRACT FROM AUTHOR]

To boost the electrocatalytic activity of metal nanoparticles, it is important to rationally design the composition and surface atomic structure, and develop efficient synthesis protocols. Herein, a facile one‐pot self‐templated method for preparing PtPdAg hollow nanodendrites (HNDs) is deployed. These HNDs possess rich atomic steps and grain boundaries, leading to evidently higher catalytic activity in methanol electrooxidation reaction than commercial Pt black and solid particles with smooth surfaces. From control experiments and density functional theory calculations, it is proven that the tri‐metallic HND has a stronger electronic coupling as compared with the PtPd and PtAg nanoparticles. As a result, the PtPdAg HNDs show high anti‐poison capability and catalytic activity for methanol oxidation reaction. This study provides a new strategy for controllable synthesis of hollow alloy nanocatalysts with high efficiency. [ABSTRACT FROM AUTHOR]

[Display omitted] • Photogenerated electrons are entirely located in BiVO 4 in CdS/BiVO 4. • CdS substrate in CdS/BiVO 4 /H 2 O can enhance hydrogen diffusing rate. • Used solvation effect can provide rational Δ G H* in HER process. • O p orbital reforms the orbital energy level and activates the HER activity. Herein, using an electrophoretic deposition strategy, a S-scheme CdS (cubic)/BiVO 4 (monoclinic) heterostructured photocatalyst is fabricated. The as-synthesized photocatalysts exhibit high carrier separation efficiency, prominent hydrogen evolution ability and high stability. The results of the detailed density functional theory (DFT) prove that the photogenerated electrons and holes are located in BiVO 4 and CdS components, respectively. Besides, an explicit solvent model based on the electron-enriched region in CdS/BiVO 4 heterojunction is designed deliberately to investigate the solid/liquid interface issues. Intriguing findings demonstrate that the surface hydrogen diffusing rate in CdS/BiVO 4 /H 2 O is faster than that of BiVO 4 /H 2 O and is highly associated with the electron-enrich effect, which has a greater capacity to promote water decomposition, the possibility of proton collision and photocatalytic hydrogen evolution. Notably, the H p orbital can participate in the electron-enrich effect during solvation, thus reforming the orbital energy level and activating the HER of the BiVO 4 component in the CdS/BiVO 4 system. [ABSTRACT FROM AUTHOR]