RESUMO
Selective conversion of carbon dioxide (CO2) to multi-carbon products (CO2-to-C2+) at high current densities is in essential demand for the practical application of the resultant valuable products, yet it remains challenging to conduct due to the lack of efficient electrocatalysts. Herein, three-dimensional ordered porous cuprous oxide cuboctahedra (3DOP Cu2O-CO) were designed and synthesized by a molecular fence-assisted hard templating approach. Capitalizing on the merits of interconnected and uniformly distributed pore channels, 3DOP Cu2O-CO exhibited outstanding electrochemical CO2-to-C2+ conversion, achieving faradaic efficiency and partial current density for C2+ products of up to 81.7% and -0.89 A cm-2, respectively, with an optimal formation rate of 2.92 mmol h-1 cm-2 under an applied current density of -1.2 A cm-2. In situ spectroscopy and simulation results demonstrated that the ordered pores of 3DOP Cu2O-CO can effectively confine and accumulate sufficient *CO adsorption during electrochemical CO2 reduction, which facilitates efficient dimerization for the formation of C2+ products. Furthermore, the 3DOP structure induces a higher local pH value, which not only enhances the C-C coupling reaction, but also suppresses competing H2 evolution.
RESUMO
An effective yet simple approach was developed to synthesize mesoporous PdBi nanocages for electrochemical applications. This technique relies on the subtle utilization of the hydrolysis of a metal salt to generate precipitate cores in situ as templates for navigating the growth of mesoporous shells with the assistance of polymeric micelles. The mesoporous PdBi nanocages are then obtained by excavating vulnerable cores and regulating the crystals of mesoporous metallic skeletons. The resultant mesoporous PdBi nanocages exhibited excellent electrocatalytic performance toward the ethanol oxidation reaction with a mass activity of 3.56 A mg-1_Pd, specific activity of 17.82 mA cm-2 and faradaic efficiency of up to 55.69% for C1 products.
RESUMO
Submicron structures of NiII/CoII-based coordination polymers (CPs) [Ni(L1)(mip)·H2O]n (1) and {[Co(L2)(mip)]·0·.5H2O}n(2) (L1=1,6-bis(5,6-dimethylbenzimidazole)hexane, L2=1,6-bis(benzimidazole)hexane, H2mip=5-methylisophthalic acid) were obtained by ultrasonic irradiation and structurally characterized by elemental analysis, powder X-ray diffraction and scanning electron microscopy. Structural analysis show that two CPs feature uninodal 3-connected 2D hcb layer, whilst CP 2 is further extended into a 3D complicated supramolecular network by C14-H14â¯O2 hydrogen bonds. Ultrasonic time and power influencing morphology of sub-micron sized CPs, were also discussed. Besides that, thermal stability, luminescence, electrochemical properties and photocatalytic activity of sub-micron sized 1 and 2 were presented in detail. Moreover, sub-micron sized 1 manifests the higher photocatalytic activity than sub-micron sized 2 for decomposition of methylene blue (MB) under UV irradiation.
RESUMO
Two new Ag(I) coordination polymers (CPs), namely, Ag(L)(Htp) (1) and [Ag(L)]·(Htp)·2H2O (2) were synthesized from the long flexible ligand of 1,6-bis(2-methylbenzimidazolyl)hexane (L), terephthalic acid (H2tp) and different silver(I) salts using hydrothermal and sonochemical methods, These CPs were characterized by elemental analysis, IR spectra, scanning electron microscopy, single-crystal and powder X-ray diffraction analysis. 1 features a uninodal 3-connected 2D hcb layered structure, while 2 exhibits an infinite 1D linear chain and ultimately extended into 3D supramolecular framework via O-Hâ¯O and Agâ¯O interactions. In addition, the effect of various sonication concentrations of the initial reagents, ultrasonic time and power of ultrasound irradiation on the size and morphology of nanostructured 1 and 2 were evaluated. Nano-sized 1 and 2 exhibit relatively high performance as UV light driven photocatalysts for the degradation of methylene blue.
RESUMO
BACKGROUND: Increased oxidative stress, inflammation, and malnutrition are important risk factors for cardiovascular disease in hemodialysis patients. High dietary intake in soluble fiber can decrease the elevated level of serum c-reactive protein in patients with chronic kidney disease. The aim of this study was to evaluate the effect of supplementation of dietary water-soluble fiber on oxidative and inflammatory status in hemodialysis patients. METHODS: In a randomized placebo-controlled trial, we examined the effects of supplementation of dietary fiber on oxidative and inflammatory status in hemodialysis patients. 124 hemodialysis patients were randomly selected and given either 10 g/d, 20 g/d of fiber or placebo for 6 weeks. Anthropometric indices and 24 h diet recall intake was assessed. The CRP, albumin, triglyceride, total cholesterol, LDL, HDL were measured before and after of the intervention. The malondialdehyde (MDA), total antioxidant capacity (T-AOC), Cu-Zn superoxidase dismutase (SOD), glutathione peroxidase (GSH-Px) high-sensitivity C-Reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-8 (IL-8) were measured. RESULTS: After 6 weeks of intervention, in 10 g and 20 g/d of fiber supplement groups, TC and LDL level and TC:LDL ratio were significantly decreased, T-AOC was significantly increased, MDA level was significantly deceased, TNF-α, IL-6, IL-8 and CRP level were significantly deceased. TG, HDL, SOD and GSH-Px had no change before and after the intervention. CONCLUSIONS: Dietary fermentable fiber supplementation improved lipid profile and oxidative status, decreased systemic inflammatory state of hemodialysis patients. Thus, it may decrease the risk of cardiovascular events in these patients.