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Heterogeneous catalytic reactions based on single metal–organic framework (MOF) material for the oxidative carboxylation of olefins following a tandem process, which involves the epoxidation of olefins and subsequent epoxide–CO2 cycloaddition, are highly desirable and economical for CO2 chemical fixation. In this work, a new trans-A2B2-type porphyrin ligand, 5,15-di(m-benzoato)-porphyrin (H2DMBP), was successfully synthesized and utilized for constructing a novel, highly porous, and stable Nd-porphyrin MOF, named CSUST-2. (CSUST stands for Changsha University of Science and Technology.) Furthermore, the coordinatively unsaturated Co(II) ions were implanted into the MOF by exploiting the innate non-metallated porphyrin ligands to generate Co(II)@CSUST-2 framework, which was evidenced to act as an efficient recyclable catalyst for oxidative carboxylation of olefins in the presence of tert-butyl hydroperoxide (TBHP) as an oxidant and tetrabutylammonium bromide (n-Bu4NBr) as a co-catalyst under mild conditions (1 atm CO2, 75 °C, and without solvent). more...

Cerium (IV)-based metal-organic frameworks (MOFs) are highly desirable due to their unique potential in fields such as redox catalysis and photocatalysis. However, due to the high reduction potential of Ce(IV) species in solution, it is still a great challenge to synthesize Ce(IV)-MOFs with novel structures, which are extremely dominated by the hexanuclear Ce-O cluster inorganic building units (IBUs). Herein, a Ce-O chain IBU containing Ce(IV)-MOF CSUST-3 (CSUST: Changsha University of Science and Technology) was successfully prepared guided by the kinetic stabilization study of UiO-66(Ce)-NDC (H 2 NDC = 2,6-naphthalenedicarboxylic acid). Furthermore, owing to the superior redox activity, Lewis acidity and semiconductor-like behavior incurred by Ce 4+ , activated CSUST-3 was demonstrated to be an excellent catalyst for CO 2 chemical fixation by virtue of one-pot synthesis of styrene carbonate from styrene and CO 2 under mild conditions (1 atm CO 2 , 80 °C, and solvent-free), as well as to be a remarkable co-catalyst-free photocatalyst for overall water splitting (OWS), which exhibits 59 μmol∙g -1 ∙h -1 of H 2 and 22 μmol∙g -1 ∙h -1 of O 2 under simulated sunlight irradiation (Na 2 S-Na 2 SO 3 as sacrificial agent). more...

Mixed-valence metal-organic frameworks (MOFs) have exhibited unique potential in fields such as catalysis and gas separation. However, it is still an open challenge to prepare mixed-valence MOFs with isolated Ce(IV, III) arrays due to the easy formation of CeIII under the synthetic conditions for MOFs. Meanwhile, the performance of Li-S batteries is greatly limited by the fatal shuttle effect and the slow transmission rate of Li+ caused by the inherent characteristics of sulfur species. Here, we report a mixed-valence cerium MOF, named CSUST-1 (CSUST stands for Changsha University of Science and Technology), with isolated Ce(IV, III) arrays and abundant oxygen vacancies (OVs), synthesized as guided by the facile and elaborate kinetic stability study of UiO-66(Ce), to work as an efficient separator coating for circumventing both issues at the same time. Benefiting from the synergistic function of the Ce(IV, III) arrays (redox couples), the abundant OVs, and the open Ce sites within CSUST-1, the CSUST-1/CNT composite, as a separator coating material in the Li-S battery, can remarkably accelerate the redox kinetics of the polysulfides and the Li+ transportation. Consequently, the Li-S cell with the CSUST-1/CNT-coated separator exhibited a high initial specific capacity of 1468 mA h/g at 0.1 C and maintained long-term stability for a capacity of 538 mA h/g after 1200 cycles at 2 C with a decay rate of only 0.037% per cycle. Even at a high sulfur loading of 8 mg/cm2, the cell with the CSUST/CNT-coated separator still demonstrated excellent performance with an initial areal capacity of 8.7 mA h/cm2 at 0.1 C and retained the areal capacity of 6.1 mA h/cm2 after 60 cycles. more...

Via induction of achiral aromatic solvents, two 3-D monochiral 3d–4f MOFs (1 and 2) from the ligand HIN without any chiral auxiliary are uncommonly constructed. The results show that the homochiral compounds 1 and 2 are enantiopure rather than exhibiting enantiomeric excess. Obviously, this work has brought major synthetic advancement in homochiral framework materials of great significance. more...

This study gives the influence laws of abandoned channel, in-layer interlayer, sand body contact relationship on the development effect of the Alkaline Surfactant Polymer (ASP) flooding based on the data of the industry promotion block ( Pu I32、Pu I33 sedimentation), and give out corresponding adjustment strategy at the same time. The result shows that: The ‘abruptly abandoned’ channels have a bad connection with the main channel and possesses a far lower reservoir producing degree (16.1%) than the ‘gradually-abandoned’ channels (79.9%). The injection wells located upon the channel sand need high concentration inject fluid with lower injection rate to handle the polymer breakthrough; The injection wells located between the channels need lower concentration injection; The injection wells located upon the abandoned channels firstly need high concentration injection to achieve the profile control and then inject low concentration fluid to adjust low permeable sublayer; The production wells located upon abandoned channels need timely fracturing measures. By July 2014, water content of this area is 90.7%, oil recovery improved 18.08% and is expected to reach 22.0%. Similar the success experience we get from this area can guide the study of block geologic factors that affect development result and has important guiding significance to the implementation of pointed development adjustment. more...

3D Ni3S2 /Ni foam electrocatalysts were successfully synthesized through a facile one-step solvothermal method in Methanol, Ethanol and Ethylene glycol solutions, then directly applied as the electrodes for hydrogen evolution reaction and the oxygen evolution reaction. The electrochemical measurements demonstrated the excellent electrochemical activity and stability toward water splitting, Moreover, the electrocatalytic behaviors of the samples were also investigated at various temperatures (0–60 °C), systematically. Remarkably, the electrolyzer based on 3D Ni3S2 /Ni foam electrodes delivered a current density of 20 mA cm−2 at a cell of voltage of 1.89 V and shows excellent long-term stability. The porous three dimensional structure of Ni3S2/NF electrodes, electrical conductivity, and large electrochemical surface area are responsible for the excellent electrocatalytic performances The study presents a feasible and effective strategy to prepare highly efficient electrocatalysts for water splitting. more...

A novel ion-permselective separator comprised the top layer of LiX zeolite membrane and the support layer of commercial Celgard membrane, namely LiX@Celgard, was prepared and employed for the first time in Li–S battery. The LiX zeolite membrane was obtained via the in situ hydrothermal synthesis of NaX zeolite over the X-type zeolite-seeded Celgard membrane and the subsequent Li+ ion-exchange. The characterizations of LiX/Celgard separator by means of XRD, SEM, EDS and XPS showed that a continuous and compact layer of LiX zeolite crystals, with a thickness of ca. 6 μm, has been tightly grafted over the surface of Celgard support. The LiX@Celgard separator was proved to possess an improved electrolyte wettability and high efficiency for inhibiting the penetration of polysulfide (PSs). The electrochemical performance determination indicated that the Li-ion conductivity, diffusion coefficient and transference number were all larger for the battery basing on the LiX/Celgard separator than for that basing on the pristine Celgard separator. The above superior properties of LiX/Celgard separator restrained significantly the shuttle of PSs and improved obviously the efficiency in the utilization of sulfur. At a C-rate of 0.2 C, a specific capacity of ca. 1083 mAh/g, with a capacity retention of 70% after 400 cycles, had been achieved for the Li–S battery employing the LiX/Celgard separator. The strategy adopted in this work can be an enlightenment for the development of ion-selective membranes used in rechargeable battery and other energy storage field. more...

Development of a facile but high-efficient small organic molecule-based photothermal therapy (PTT) in the in vivo transparent window (800–900 nm) has been regarded as a minimally invasive and most promising strategy for potential clinical cancer treatment. Phthalocyanine (Pc) molecules with remarkable photophysical and photochemical properties as well as high extinction coefficients in the near-infrared region are highly desirable for PTT, but as far satisfying single-component Pc-based PTT within the in vivo transparent window (800–900 nm) has very rarely been reported. Herein, inspired by the self-assembly algorithm of natural bacteriochlorophylls c, d, and e, biomimetic self-assembling tetrahexanoyl Pc Bio-ZnPc with outstanding light-harvesting capacity was demonstrated to exhibit excellent PTT efficacy evidenced by both in vitro and in vivo results, within the biological transparent window. more...

Titania/electro-reduced graphene oxide nanohybrids (TiO2/ErGO) were synthesized by the hydrolysis of titanium sulfate in graphene oxide suspension and in situ electrochemical reduction. It provides a facile and efficient method to obtain nanohybrids with TiO2 nanoparticles (TiO2 NPs) uniformly coated by graphene nanoflakes. TiO2/ErGO nanohybrids were characterized by transmission electron microscopy, X-ray diffraction, cyclic voltammogram, and electrochemical impedance spectroscopy in detail. Compared with pure ErGO and TiO2 NPs, TiO2/ErGO nanohybrids greatly enhanced the electrocatalytic activity and voltammetric response of Allura Red. In the concentration range of 0.5&ndash, 5.0 &mu, M, the anodic peak currents of Allura Red were linearly correlated to their concentrations. However, the linear relationship was changed to the semi-logarithmic relationship at a higher concentration region (5.0&ndash, 800 &mu, M). The detection limit (LOD) was 0.05 &mu, M at a signal-to-noise ratio of 3. The superior sensing performances of the proposed sensor can be ascribed to the synergistic effect between TiO2 NPs and ErGO, which provides a favorable microenvironment for the electrochemical oxidation of Allura Red. The proposed TiO2/ErGO/GCE showed good reproducibility and stability both in determination and in storage, and it can accurately detect the concentration of Allura Red in milk drinks, providing an efficient platform for the sensitive determination of Allura Red with high reliability, simplicity, and rapidness. more...

Two low-dimensional oxime-containing Schiff base copper(I/II) complexes with iodine–copper cluster [Cu2I4]2− bridges, namely, {[CuII4I3(pop)4]2(CuI2I4)}·(CH3CN)2·H2O (2) and [CuII4I2(pop)4(CuI2I4)·(CH3CN)]n (3) (Hpop = 2-(hydroxyimino)-N′-[1-(2-yridyl)ethylidene]propanehydrazone), have been synthesized from the reaction of [2 × 2] grid-like compound {[CuIII(pop)]4}2·4H2O (1) with equivalent CuI2I2 (iodine–copper clusters) under solvothermal conditions and characterized by elemental analysis (EA), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and X-ray single-crystal/powder diffraction. The results show that 2 is a 0-D discrete structure from an assembly of one [Cu2I4]2− unit and two [2 × 2] molecular grids (1) via μ3-I atoms coordinating to CuI/CuII atoms. However, compound 3 presents a 1-D wave-like chain, which is constructed by coordination of μ2-I atoms from [CuI2I4]2− units with CuII atoms in [2 × 2] molecular grids (1). Moreover, catalytic experiments demonstrated that compounds 2 and 3 have promising visible-light-driven catalytic activity in degrading various organic dyes. more...

The temperature-driven single-crystal to single-crystal transformation of a new erbium(III) coordination polymer with the ligand benzimidazole-5,6-dicarboxylic acid (H2bidc), {[Er(bidc)(ClO4)((H2O)3]·3H2O}n (1) to [Er(bidc)(ClO4)]n (2), has been reported and the structures of 1 and 2 were determined by X-ray crystallography. The thermal stability of compounds 1 and 2 were studied by thermogravimetric analysis (TGA). Powder X-ray diffraction experiments showed that the phase transitions described for single crystals also occur in the macroscopic powder samples and lead to monophasic products. Interestingly, with the loss of water molecules, the near infrared (NIR) emission of the Er(III) ion in compound 2 can be obviously enhanced compared to that in 1, which provides an effective strategy for enhancing the near infrared luminescence of lanthanide complexes. more...