Electrochemical properties of a cobalt(II) complex with sulfadiazine and 1,3-bis(pyridin-4-yl)propane.

catena-Poly[[bis{4-[(pyrimidin-2-ylazanidyl)sulfonyl]aniline}cobalt(II)]-bis[µ-1,3-bis(pyridin-4-yl)propane]], [Co(C10H8N4O4S2)2(C13H14N2)]n or [Co(L)2(bpp)]n, crystallizes as a one-dimensional polymeric structure which is further stabilized by intermolecular hydrogen bonding. The refined Flack parameter, -0.001 (10), indicates that the model represents the correct absolute structure. Investigation of the thermal stability shows that the complex is stable up to 543 K. The structure is of interest with respect to its electrochemical properties in the reduction reaction of H2O2 to H2O.

Synthesis, crystal structure and fluorescence spectrum of a cadmium(II) sulfaquinoxaline complex.

catena-Poly[[[4-amino-N-(quinoxalin-2-yl)benzenesulfonamidato]aquacadmium(II)]-µ-4-amino-N-(quinoxalin-2-yl)benzenesulfonamidato], [Cd(C14H11N4O2S)2(H2O)], has been synthesized hydrothermally and characterized by single-crystal X-ray diffraction, elemental analysis, fluorescence, IR and thermal analysis. Single-crystal X-ray analysis reveals that the complex is a one-dimensional zigzag chain structure, and the Cd(II) cation has a distorted octahedral coordination geometry formed by five N atoms from three different sulfaquinoxaline ligands and one O atom from a water molecule. The fluorescence spectrum reveals that the complex emits strong blue fluorescence and thermal analysis shows that the complex has high thermal stability.

Discovery of all-inorganic lead-free perovskites with high photovoltaic performance via ensemble machine learning.

Growing evidence shows that all-inorganic lead-free perovskites hold promise for solving stability and toxicity problems in perovskite solar cells. However, the power conversion efficiency of all-inorganic perovskites cannot match that of hybrid organic-inorganic perovskites. To face the challenges of efficiency, stability and toxicity simultaneously for application in perovskite solar cells, this study conducts a high-throughput materials search via ensemble machine learning for nearly 12 million all-inorganic perovskites to obtain candidates with non-toxicity and excellent photovoltaic performance. Based on experimental data, models for structure identification and band gap classification are established for , and a physics-inspired multi-component neural network is proposed as part of the exploration of the model's logical structure. It is found that extracting key features for input into the model and treating non-key features as supplements make model learning easier and are more effective in reducing the model parameters. Then, based on established ensemble models as well as the new criteria of ion radius difference and the optimization rules of toxicity and cost, over 80 000 candidates are screened. Among the 34 lead-free identified with suitable band gaps and negative formation energies through first principles calculations, 17 candidates have theoretical power conversion efficiencies over 20%. The Debye temperature of 10 lead-free , basically Bi-based compounds, is greater than 350 K, which is advantageous for suppressing nonradiative recombination and thermally induced degradation.

A new coordination tetra-mer of copper(I) iodide and benzyl-dimethyl-amine: tetra-µ(3)-iodido-tetra-kis[(benzyl-dimethyl-amine-κN)copper(I)].

The title compound, [Cu(4)I(4)(C(9)H(13)N)(4)], has a distorted cubane-like [Cu(4)I(4)] core structure. Each Cu(I) atom is tetra-hedrally coordinated by three I atoms and one N atom of an benzyl-dimethyl-amine ligand. Each I atom acts as a µ(3)-ligand, linking three Cu(I) atoms. The Cu-I bond distances vary between 2.6328 (7) and 2.7121 (6) Å, while the Cu-N bond distances vary between 2.107 (3) and 2.122 (3) Å.

Plasmon enhanced electrocatalytic oxidation of ethanol and organic contaminants on gold/copper iodide composites under visible light irradiation.

In this paper, plasmonic photoelectroncatalyst of gold/copper iodide (Au/CuI) was synthesized and fully characterized. Compared to traditional electrocatalytic procedure under dark condition, the photoelectrocatalytic (PEC) activities of Au/CuI towards ethanol oxidation and organic pollutant degradation were distinctly enhanced under visible light irradiation. The advantages of the PEC process were investigated by photocurrent responses, linear sweep voltammetry, chronoamperometric and chronopotentiometry curves, and electrochemical impedance spectroscopy spectra. Finally, the mechanism of plasmon enhanced PEC performance in ethanol oxidation and organic contaminant degradation under visible light irradiation was proposed. The current studies open a new possibility in the application of ethanol oxidation and organic contaminant degradation by using plasmonic photoelectrocatalysts under visible light irradiation.

Occurrence and distribution of antibiotic resistance genes in the sediments of drinking water sources, urban rivers, and coastal areas in Zhuhai, China.

Antibiotic resistance genes (ARGs) are regarded as emerging contaminants related with human activities. Aquatic environments of an urban city are apt for the persistence and prevalence of ARGs. In this study, we investigated the occurrence and distribution of ARGs and integrase genes in the sediment samples collected from drinking water sources, urban rivers, and coastal areas of Zhuhai, China, in the dry and wet seasons of 2016. The results show that sulfonamide resistance gene of sulII was present at the highest detection frequency (85.71%); and its average concentrations were also the highest in both dry and wet seasons (3.78 × 107 and 9.04 × 107 copies/g sediment, respectively), followed by tetC, tetO, tetA, ermB, dfrA1, and blaPSE-1. Temporally, the concentrations of total ARGs in the wet season were likely higher than those in the dry season; and spatially, the concentrations of total ARGs in the drinking water sources were substantially lower than those in the urban rivers and nearby coastal areas, indicating the different degrees of anthropogenic impact and consequent health risks. Positive correlations were found between intI1 and each quantitative ARG in all wet season samples rather than dry season samples, which suggested higher temperature and more rain in summer might have positive influences on ARG dissemination, especially that mediated by intI1 gene and class I integrons.

Antibiotics in water and sediments of rivers and coastal area of Zhuhai City, Pearl River estuary, south China.

The occurrence, spatiotemporal distribution and ecological risks of 27 antibiotics in water and sediments from rivers and coastal area of Zhuhai, Pearl River estuary, south China were investigated. Higher concentrations of antibiotics were found in river water in dry season than those in wet season (p < 0.01), especially for quinolones (QNs) (6.36-463 ng/L) and aminoglycosides (AGs) (94.9-458 ng/L). In coastal water samples, the concentrations of antibiotics were up to 419 ng/L and 357 ng/L in dry season and wet season, respectively. Higher concentrations of antibiotics in coastal sediment samples were observed in wet season compared with those in dry season (p < 0.01). This may be ascribed to the greater discharge of antibiotics from mariculture and surface sediment flushing in wet season, leading to the accumulation of polluted sediments in the estuary. Redundancy analysis showed that the concentrations of antibiotics in water were correlated with biological/chemical oxygen demand, ammonia nitrogen, and/or total nitrogen (TN). In addition, sediment organic matter (SOC) and TN strongly affected the distribution of antibiotics in sediments. Ecological risk assessment based on risk quotients (RQs) indicated that most antibiotics in water samples posed insignificant risk to fish and green algae, and insignificant to medium risk to daphnid.

[Quantitative analysis of galangin from propolis in different areas by HPLC].

OBJECTIVE: To establish an HPLC method for determination of galangin in propolis. METHODS: HPLC method was established. Diamonsil C18 column was used, CH3OH-4% H3PO4 solution (65:35) as mobile phase, at the flow rate of 1.0 ml/min and the UV detection wavelength at 256 nm. RESULTS: The linear of galangin was 0.00412 - 0.02472 mg/ml (r2 = 0. 9998). The content of galangin was the highest in the propolis from Shandong (11.7 mg/g). The content of galangin was higher in the propolis from Neimeng and Henan, respectively 10. 5 mg/g,10. 3 mg/g, the content of galangin was the lowest in the propolis from Gansu (9.8 mg/g). CONCLUSION: HPLC method is simple and reliable for determination of galangin in propolis.

CuI as Hole-Transport Channel for Enhancing Photoelectrocatalytic Activity by Constructing CuI/BiOI Heterojunction.

In this paper, CuI, as a typical hole-transport channel, was used to construct a high-performance visible-light-driven CuI/BiOI heterostructure for photoelectrocatalytic applications. The heterostructure combines the broad visible absorption of BiOI and high hole mobility of CuI. Compared to pure BiOI, the CuI/BiOI heterostructure exhibited distinctly enhanced photoelectrocatalytic performance for the oxidation of methanol and organic pollutants under visible-light irradiation. The photogenerated electron-hole pairs of the excited BiOI can be separated efficiently through CuI, in which the CuI acts as a superior hole-transport channel to improve photoelectrocatalytic oxidization of methanol and organic pollutants. The outstanding photoelectrocatalytic activity shows that the p-type CuI works as a promising hole-transport channel to improve the photocatalytic performance of traditional semiconductors.

[Supercritical CO2 extraction of fatty oils from bee pollen and its GC-MS analysis].

The extraction of fatty oils from bee pollen with supercritical CO2 was studied. The effects of extraction pressure, extraction temperature and the grinding size of the bee pollen on the yields were discussed. The optimal condition of this method was: extraction pressure 30MPa,extraction temperature 55 degrees C, separator I pressure 14MPa, separator I temperature 45 degrees C, separator II pressure 6MPa, separator II temperature 40 degrees C, extraction period 2 hours. Compared with the traditional solvent extraction, this method had some virtues, such as shortening the extraction period greatly, escaping oxidation of unsaturated fatty acid, and the products from which having better quality. With a GC-MS analysis, the main composition of the fatty oil from the bee pollen was: oleic acid, palmitic acid, linoic acid, pentacosane, octacosane and so on. The contents of alpha-linolenic acid in the fatty oils from separator I and separator II were 42% and 8.8%, which differed greatly. It proved that this method succeeded in extraction, separating and enriching alpha-linolenic acid.

Comparison of LiVPO4F to Li4Ti5O12 as anode materials for lithium-ion batteries.

In this paper, we reported on a comparison of LiVPO4F to Li4Ti5O12 as anode materials for lithium-ion batteries. Combined with powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, galvanostatic discharge/charge tests and in situ X-ray diffraction technologies, we explore and compare the insertion/extraction mechanisms of LiVPO4F based on the V3+/V2+/V+ redox couples and Li4Ti5O12 based on the Ti4+/Ti3+ redox couple cycled in 1.0-3.0 V and 0.0-3.0 V. The electrochemical results indicate that both LiVPO4F and Li4Ti5O12 are solid electrolyte interphase free materials in 1.0-3.0 V. The insertion/extraction mechanisms of LiVPO4F and Li4Ti5O12 are similar with each other in 1.0-3.0 V as proved by in situ X-ray diffraction. It also demonstrates that both samples possess stable structure in 0.0-3.0 V. Additionally, the electrochemical performance tests of LiVPO4F and Li4Ti5O12 indicate that both samples cycled in 0.0-3.0 V exhibit much higher capacities than those cycled in 1.0-3.0 V but display worse cycle performance. The rate performance of Li4Ti5O12 far exceeds that of LiVPO4F in the same electrochemical potential window. In particular, the capacity retention of Li4Ti5O12 cycled in 1.0-3.0 V is as high as 98.2% after 20 cycles. By contrast, Li4Ti5O12 is expected to be a candidate anode material considering its high working potential, structural zero-strain property, and excellent cycle stability and rate performance.