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A high-performance Single-Atom Ni Catalyst Loaded Graphyne was screened by utilizing density functional theory calculations. [Display omitted] The electrochemical synthesis of hydrogen peroxide (H 2 O 2) provides a greener and more efficient method compared with classic catalysts containing toxic metals. Herein, we used first-principles density functional theory (DFT) calculations to investigate 174 different single-atom catalysts with graphyne substrates, and conducted a three-step screening strategy to identify the optimal noble metal-free single atom catalyst. It is found that a single Ni atom loaded on γ-graphyne with carbon vacancies (Ni@V-γ-GY) displayed remarkable thermodynamic stability, excellent selectivity, and high activity with an ultralow overpotential of 0.03 V. Furthermore, based on ab-initio molecular dynamic and DFT calculations under the H 2 O solvent, it was revealed that the catalytic performance for H 2 O 2 synthesis in aqueous phase was much better than that in gas phase condition, shedding light on the hydrogen bond network being beneficial to accelerate the transfer of protons for H 2 O 2 synthesis. [ABSTRACT FROM AUTHOR]

Two new Co(II)-coordination polymers, [Co2(L1)2(H2O)3(SO4)2](H2O)11 (1) and [Co(H2O)2(L1)(L2)](H2O)4 (2, L1 = 3,5-di(1H-imidazol-1-yl)pyridine, H2L2 = 4-sulfobenzoic acid) have been successfully prepared by the usage of the layering method. The obtained two complexes were characterized by single crystal X-ray diffraction and elemental analyses. The results show that complex 1 is a 1D v-shaped chain structure with H-bond interactions observed in its network while complex 2 is a 2D layered structure with a ttd topological net. In addition, the anti-liver cancer activity of complexes 1 and 2 was evaluated via the CCK-8 assays against the HHCC liver cancer cell lines. [ABSTRACT FROM AUTHOR]

Sugarcane, a cash crop, is easily affected by low temperature, which results in a decrease in yield and sugar production. Breeding a new variety with cold tolerance is an essential strategy to reduce loss from cold stress. The identification of germplasms and genes/proteins with cold tolerance is a vital step in breeding sugarcane varieties with cold tolerance via a conventional program and molecular technology. In this study, the physiological and biochemical indices of 22 genotypes of S. spontaneum were measured, and the membership function analysis method was used to comprehensively evaluate the cold tolerance ability of these genotypes. The physiological and biochemical indices of these S. spontaneum genotypes showed a sophisticated response to low temperature. On the basis of the physiological and chemical indices, the genotypes were classified into different cold tolerance groups. Then, the high-tolerance genotype 1027 and the low-tolerance genotype 3217 were selected for DIA-based proteomic analysis by subjecting them to low temperature. From the four comparison groups, 1123, 1341, 751, and 1693 differentially abundant proteins (DAPs) were identified, respectively. The DAPs based on genotypes or treatments participated in distinct metabolic pathways. Through detailed analysis of the DAPs, some proteins related to protein homeostasis, carbohydrate and energy metabolism, amino acid transport and metabolism, signal transduction, and the cytoskeleton may be involved in sugarcane tolerance to cold stress. Furthermore, five important proteins related to cold tolerance were discovered for the first time in this study. This work not only provides the germplasms and candidate target proteins for breeding sugarcane varieties with cold tolerance via a conventional program and molecular breeding, but also helps to accelerate the determination of the molecular mechanism underlying cold tolerance in sugarcane. [ABSTRACT FROM AUTHOR]

Significant variability issues in metal-molecule contacts, such as adsorption geometry, lead to characteristic variability in the electrical responses of individual molecules. Herein, co-assembling 1-ethylimidazole (EIM) on Au(111) has been shown to be a feasible and effective strategy for tuning the binding configurations of pyridine-linked molecular junctions in the most common aqueous environments and atmospheric environments. The single-molecule conductance measurements clearly show a transition from multiple conductance peaks to a single conductance peak with increasing EIM concentration. Raman spectroscopy and DFT calculations suggest that the thermodynamically favorable EIM adsorbate results in the vertical orientation of the bipyridine. [ABSTRACT FROM AUTHOR]

Photosynthesis in nature uses the Mn4CaO5 cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II. Herein, we demonstrate bio-inspired heterometallic LnCo3 (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of the CaMn4O5 cluster. Anchoring LnCo3 on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The NdCo3/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0% at 350 nm. Ultrafast transient absorption spectroscopy revealed the transfer of a photoexcited electron and hole into the PCN and LnCo3 for hydrogen and oxygen evolution reactions, respectively. A density functional theory (DFT) calculation showed the cooperative water activation on lanthanide and O−O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of a bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting. [ABSTRACT FROM AUTHOR]

Herein we report a facile bottom-up strategy to prepare highly dispersed supported Co 3 O 4 on N-doped Porous Carbon (NPC). Specifically, ZIF-67 (ZIF = Zeolitic Imidazolate Frameworks) microcrystals firstly grow on benzoic acid modified covalent organic framework (BFC), resulting in ZIF-67/COF composite. Subsequently, highly dispersed Co 3 O 4 /NPC was obtained via the calcination of ZIF-67/COF. Interestingly, high dispersion of supported Co 3 O 4 is dominated by homogeneous distribution of benzoic acid auchoring on nanoporous COF. More notably, largely triggered by the porosity and confining effect of COF, the resultant Co 3 O 4 /NPC features highly active crystal plane and a large specific surface area of 228.0 m 2 /g. Furthermore, the oxygen evolution reaction (OER) measurement results demonstrated that highly dispersed Co 3 O 4 /NPC features good catalytic activity (330 mV overpotential at 10 mA.cm −2 , 79 mV.dec −1 Tafel slope and mass activity of 130 A.g −1 at overpotential of 400 mV) and durable stability, superior to currently available counterparts. Moreover, Li-ion battery (LIB) tests also showed high reversible capacity (785 mA.h.g −1 at 500 mA.g −1 ) as well as excellent cycling stability and rate performance. Furthermore, Density functional theory (DFT) calculation results demonstrated that these superior OER properties can be attributed to the geometrical and electronic effects of Co 3 O 4 /NPC on activation and adsorption/desorption of reaction species. [ABSTRACT FROM AUTHOR]