We have successfully constructed a tetrahedral TiL cage with calixarene-like coordination-active vertices. It further features high solubility and stability in HO and DMF/HO solution, affording an interesting stepwise assembly function with other metal ions. Through trapping of different amounts of Co or Ln ions, the TiL tetrahedra can be organized into various dimensional architectures, including a TiL-Co cage, a TiL-Ln cage, a TiL-Ln chain, and a three-dimensional TiL-Ln framework. An unusual mixed-valence phenomenon was observed in the TiL cage, whose Ti compositions were adequately identified by electron spin resonance and X-ray photoelectron spectroscopy analyses. More remarkably, the calixarene-like oxygen vertices of the TiL cage can also be used for the recognition of C-symmetric dye molecules through N-H···O hydrogen bonding. Accordingly, driven by visible light, selective and efficient homogeneous photodecomposition of acid blue 93 and alkali blue 4B were successfully achieved. Therefore, this work not only represents a milestone in constructing symmetric Ti-based cages with interesting coordination assembly function but also provides a new method for preparing technologically important soluble photoactive cages.

No abstract

Transition-metal oxides are extensively investigated as efficient electrocatalysts for the oxygen evolution reaction (OER). However, large-scale applications remain challenging due to their moderate catalytic activity. Optimized regulation of surface states can lead to improvement of catalytic properties. Here, the design of Mn@Co Mn O nanoparticles with abundant edge sites via a simple seed-mediated growth strategy is described. The unsaturated coordination generated on the edge sites of Co Mn O shells makes a positive contribution to the surface-structure tailoring. Density functional theory calculations indicate that the edge sites with unsaturated coordination exhibit intense affinity for OH in the alkaline electrolyte, which greatly enhances the electrochemical OER performance of the catalysts. The resulting Mn@Co Mn O catalysts yield a current density of 10 mA cm at an overpotential of 246 mV and a relatively low Tafel slope of 46 mV dec . The successful synthesis of these metal oxides nanoparticles with edge sites may pave a new path for rationally fabricating efficient OER catalysts.

The systematic investigation of thermal decomposition of the metal-organic framework Zn 4 O(BDC) 4 (MOF-5) was carried out. It was found that the decomposition of MOF-5, which could take place at 400 °C or above, was due to the breaking of carboxylic bridges between benzene rings and Zn 4 O clusters. The decomposition produced CO 2 , benzene, and amorphous carbon besides crystal ZnO. Furthermore, the ZnO was covered by amorphous carbon, resulting in the C/ZnO nanoparticles of about 10 nm. The removal of ZnO from the C/ZnO nanoparticles could generate mesoporous carbon with a large surface area of 1844 m 2 /g.

In this study, the composite of aluminum metal–organic framework MIL-68(Al) and reduced graphene oxide (MA/RG) was synthesized via a one–step solvothermal method, and their performances for p–nitrophenol (PNP) adsorption from aqueous solution were systematically investigated. The introduction of reduced graphene oxide (RG) into MIL-68(Al) (MA) significantly changes the morphologies of the MA and increases the surface area. The MA/RG-15% prepared at RG-to-MA mass ratio of 15% shows a PNP uptake rate 64% and 123% higher than MIL-68(Al) and reduced graphene oxide (RG), respectively. The hydrogen bond and π – π dispersion were considered to be the major driving force for the spontaneous and endothermic adsorption process for PNP removal. The adsorption kinetics, which was controlled by film–diffusion and intra–particle diffusion, was greatly influenced by solution pH, ionic strength, temperature and initial PNP concentration. The adsorption kinetics and isotherms can be well delineated using pseudo–second–order and Langmuir equations, respectively. The presence of phenol or isomeric nitrophenols in the solution had minimal influence on PNP adsorption by reusable MA/RG composite.

ARTICLEcations. The univalent metal cations showed no effect on the structure of ZIF-8, whereas the bivalent or higher-valent metal cations caused the collapse of the ZIF-8 crystal structure. Therefore, the structural stability of ZIF-8 is considered when it is subjected to the application, in which high-valent metal cations are involved.

Identification of new biomarkers may help in the early diagnosis of inflammatory bowel disease (IBD). In this study, ultrahigh-performance liquid chromatography equipped with quadrupole time-of-flight mass spectrometry (UPLC−QTOF-MS) was used to analyze the untargeted lipidomics and compare plasma lipid profiles between IBD patients and control subjects. The principal component analysis and partial least-squares-discriminant analysis were carried out to distinguish IBD patients from control subjects. Using univariate and multivariate analysis, 55 significantly different metabolites from five lipid classes, fatty acyls (n = 19), glycerophospholipids (n = 5), prenol lipids (n = 10), sphingolipids (n = 2), and sterol lipids (n = 19) were identified. Forty-four of the 55 metabolites were analyzed by receiver operating characteristic (ROC) curve and area under curve (AUC) of >0.80. After validation in an independent cohort, IBD patients were differentiated from the control subjects by significantly altered plasma level of palmitic acid, 7alpha, 25-dihydroxycholesterol, 20-hydroxyeicosatetraenoic (HETE)-d6, (+/−)5,6-epoxyeicosatrienoic acid (EpETrE), docosahexaenoic acid (DHA), 9-heptadecylenic acid, lactucaxanthin, α-carotene, traumatic acid, and neoquassin with both sensitivity and specificity above 80%. Pathway analysis suggested that IBD dysregulation was related to the biosynthesis of primary bile acid, the metabolism of arachidonic acid, the metabolism of sphingolipid, fatty acid elongation, and glycerophospholipid metabolism. Our results suggest that the lipidomic profiling of patients plasma could be a potential method for IBD diagnosis.

A monatomic Pt layer (Pt-skin) on ordered intermetallic PtBi clusters (PtBi@Pt) supported on graphene is fabricated via a single atom self-assembling (SAS) method to form a superior catalyst toward electrochemical ethanol oxidation reaction.