Great attentions have been paid to anticorrosion coatings with self-healing performances to enhance its reliability and protection period, but massive challenges still remain for developing a coating with selectively triggered and accurately controllable self-healing behaviors. Herein, by integrating lamellar graphene oxide (GO) into a polycaprolactone (PCL) nanofiber loaded with 8-hydroxyquinoline (8HQ) corrosion inhibitors, a composite coating with precisely controllable self-healing capabilities is developed. The coating defects can be remotely and accurately repaired under near-infrared (NIR) light irradiation within a very short time. Notably, the precisely controllable defect recovery even within a minimal region of similar to 0.03 cm(2) can be achieved, without causing pristine performance recession of irrelevant regions. The embedded GO can work both as efficient photothermal conversion materials, and yield "labyrinth effect" to enhance the passive barrier against corrosive media. Moreover, encapsulated corrosion inhibitors 8HQ can be rapidly released into acid/alkaline microregions in a corrosive-triggered manner, to form self-assembly protective layers and offer instant safeguarding for damaged sites. The integrated precise self-healing system enables extremely high corrosion inhibition efficiency exceeding 98.6 %. This work illustrates a feasible approach for combining remotely precise self-healing and active/passive enhanced passive barrier, presenting perspective potential in practical engineering anticorrosion applications or other controllable micro-reaction function surfaces.

It is well-known that Fe3+ impurities in the electrolyte can significantly promote the oxygen evolution reaction (OER) activity of Co-based and Ni-based electrocatalysts. However, it is not clear if they work for single-metal Fe-based catalysts. Here, we systematically investigate the influence of Fe3+ ions in the electrolyte on the OER activity of core-shell FeOx@C catalytic system. We find that the absorbed Fe3+ can induce the generation of surface oxygen vacancies and regulate the electronic structure of active sites, thus increasing the OER kinetics and decreasing the energy barrier. Combining with in-situ Raman and ex-situ X-ray photoelectron spectroscopy (XPS) analysis, we disclose that Fe4+ species is the active species for the OER and positively correlate the characteristic content of the high-valence Fe species and OER activity.

To realize large-scale hydrogen production by electrolysis of water, it is essential to develop non-precious metal catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Here, we fabricate Sn-, Fe-, and Co-based sulfide/oxyhydroxide heterostructural catalyst on nickel foam (FeSnCo0.2SxOy/NF) by solvothermal method. The FeSnCo0.2SxOy/NF requires low overpotentials of 48 and 186 mV at 10 mA·cm–2, respectively, for HER and OER. When it is assembled into an electrolytic cell as a bifunctional electrocatalyst, it only needs 1.54 V to reach 10 mA·cm–2, far better than IrO2||Pt/C electrolyzer. The formation of sulfide/hydroxide heterostructural interfaces improves the electron transfer and reduces the reaction energy barrier, thus promoting the electrocatalytic processes.

Combining the high abundance of potassium (K) in the Earth's crust and the high theoretical energy density of selenium (Se), a potassium-selenium (K-Se) battery is attractive as an alternative energy storage system. However, some urgent issues still need to be solved to obtain efficient selenium-based cathodes, such as the shuttle effect of high-order selenides in electrolytes and volume expansion during the redox process. Herein, we report Se/heteroatoms (N and O) dual-doped hierarchical porous carbon (Se/HHPC) composite as cathode material for the K-Se battery. The hierarchical porous carbon frameworks not only provide storage and ex-pansion buffer space for Se-based cathode material, but also facilitate the penetration of the electrolyte, which effectively improves the cell's electrical conductivity. In addition, the dual-doped heteroatoms enhance the interaction between potassium selenide and carbon host. When tested for K-ion batteries with carbonate electrolytes, Se/HHPC cathode exhibits a relatively high electrochemical performance (228 mAh g-1, 200 cycles, 0.2 C) under the synergy of space bondage and chemisorption. The electrode could deliver a rate capability of 295 mAh g-1 at 4 C. Furthermore, the hybrid cathode also exhibits excellent properties in ether electrolytes and has a reversible capacity of 236 mA h g-1 at 0.2 C after 300 cycles and a rate capability of 234 mAh g-1 at 4 C.(c) 2022 Elsevier B.V. All rights reserved.

The selective oxidation of alcohols is widely regarded as one of the most important reactions in organic synthesis. Although efficient and environmentally friendly catalysts for alcohol oxidation are highly desirable, their development remains an enormous challenge. Metal-organic framework (MOF)-based catalysts have demonstrated great potential in the catalytic oxidation of alcohols and have remarkably progressed in the past few decades owing to their advantages of large surface area, tunable porous structure, abundant accessible active sites, and ease of reuse and recycling. In this review, recent representative results of the catalytic oxidation of alcohols by MOF-based materials are summarized and classified according to the type of material and reaction, such as pristine MOFs, MOF composites, and MOF derivatives for traditional thermal catalysis, photo-assisted catalysis, and electro-assisted catalysis. Each catalytic system is described in detail from multiple aspects, including the materials synthesis process, catalytic performance, alcohol oxidation mechanisms, and material stability. Thus, the aims of this review are to identify potentially efficient, green, and reusable MOF-based catalytic systems and to provide new insights for the further development of catalytic alcohol oxidation to obtain the target organics.

As a four-electron transfer reaction, oxygen evolution reaction (OER) is limited by large overpotential and slow kinetics. Here, we in-situ synthesized two-dimensional (2D) Ni-Fe metal-organic framework nanosheets on nickel foam (Ni x Fe-TPA/NF, TPA = terephthalic acid) for oxygen evolution in alkaline and alkaline seawater electrolytes. In 1 M KOH, Ni 3 Fe-TPA/NF shows a low overpotential ( η 10 ) of 189 mV at 10 mA·cm −2 and an ultra-low overpotential of only 260 mV at 500 mA·cm −2 . In alkaline seawater, Ni 3 Fe-TPA/NF still provides impressive OER performance, with an η 10 of 265 mV. In-situ Raman characterization results show that the phase transition occurs during the OER, and Ni 3 FeOOH with more oxygen vacancies is in-situ formed, reducing the OER energy barrier. Density functional theory (DFT) reveals that the synergy between Ni and Fe reduces the energy barrier and accelerates the rate-determining step. In addition, the ultra-thin 2D sheet structure and the close combination of Ni 3 FeOOH and highly conductive NF support ensure the high catalytic OER activity. Therefore, the surface reconstruction and structural modification strategy can be used to design and prepare high-performance OER electrocatalysts for energy-related applications.

Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both [Cd(phen)(en)]2[Cd2(phen)2V12O40Ge8(OH)8(H2O)]∙12.5H2O (1) and [Cd(DETA)]2[Cd(DETA)2]0.5[Cd2(phen)2V12O41Ge8(OH)7(0.5H2O)]∙7.5H2O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two [Cd(phen)(en)]2+. Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and [Cd2(DETA)2]4+ transition metal complexes (TMCs). [Cd(en)3]{[Cd(η2-en)2]3[Cd(η2-en)(η2-μ2-en)(η2-en)Cd][Ge6V15O48(H2O)]}∙5.5H2O (3) is a novel 3-D structure which is constructed from [Ge6V15O48(H2O)]12− and four different types of TMCs. We also synthesized [Zn2(enMe)3][Zn(enMe)]2[Zn(enMe)2(H2O)]2[Ge6V15O48(H2O)]∙3H2O (4) and [Cd(en)2]2{H8[Cd(en)]2Ge8V12O48(H2O)}∙6H2O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.

The water oxidation reaction is the pivotal half-reaction for photo-/electro-catalytic water splitting. Fabrication of high-efficiency and robust water oxidation is essential to realize wide-scale artificial photosynthesis. Here, we report an efficient strategy to improve the water oxidation activity of iridium oxide by a nitrogen-coordination method. Due to the coordination effect, the iridium oxide can be well dispersed to generate ultra-small nanoparticles and the intrinsic activity can be improved for the water oxidation reaction. This study suggests that high-performance water oxidation catalysts can be constructed based on a nitrogen-coordination strategy.

The hybrid plasmon composition based on MoS2 has been extensively studied as a higher disposition surface enhanced Raman scattering (SERS) substrate. In this paper, a novel silver nanoparticle based SERS substrate was developed via in situ microwave synthesis approach on a three dimensional (3D) MoS2 nanoflower (MoS2 NF/ Ag NPs). The prepared SERS sensor has strong SERS activity on malachite green (MG), the Raman enhancement factor (EF) is as high as 1.46x10(12). The standard Raman signal peak of MG at 1618 cm(-1) has a good linear relationship at 10(-12) - 10(-2) molL(-1). The limit of detection (LOD) was calculated as approximately 10(-14) molL(-1), which shows the good prospects for MG's microtests. In addition, the SERS sensor still shows good SERS performance stability after 112 days, which improves the shelf life of the SERS sensor and can be effectively applied to fishery water monitoring.

ZnCo2O4@NiMoO4 core-shell nanowires (ZCNM-NW) and nanosheets (ZCNM-NS) on nickel foam (NF) were synthesized by coating NiMoO4 nanosheets on different ZnCo2O4 nanostructures via facile hydrothermal reactions, followed by a calcination process. The synthesized materials were tested as the working electrodes in a three-electrode configuration. By comparing the performances of these electrodes, it was found that both of the ZCNM-NW and ZCNM-NS electrodes exhibited enhanced electrochemical performance and excellent cycling stability, of which the ZCNM-NS delivered an extraordinary specific capacity as high as 1158.0 C g(-1) at a current density of 10 mA cm(-2), and retained 103.4% of the initial specific capacity after 5000 cycles. To further investigate the electrochemical performance of the prepared electrode, a battery-supercapacitor hybrid (BSH) device was assembled with the prepared ZCNM-NS electrode as the positive electrode and activated carbon (AC) as the negative electrode in 2M KOH, which showed a high energy density of 25.3W h kg(-1) at a power density of 787.9W kg(-1) and 18.4W h kg(-1) at a power density of 9467.5W kg(-1). These remarkable electrochemical performances suggest that the as-synthesized ZCNM-NS had a great potential for advanced electrodes of BSH devices.

An efficient and low-cost supported Pt catalyst for hydrogenation of niroarenes was prepared with colloid Pt precursors and α-Fe2O3 as a support. The catalyst with Pt content as low as 0.2 wt% exhibits high activities, chemoselectivities and stability in the hydrogenation of nitrobenzene and a variety of niroarenes. The conversion of nitrobenzene can reach 3170 molconv h−1 molPt−1 under mild conditions (30 °C, 5 bar), which is much higher than that of commercial Pt/C catalyst and many reported catalysts under similar reaction conditions. The spatial separation of the active sites for H2 dissociation and hydrogenation should be responsible for the high chemoselectivity, which decreases the contact possibility between the reducible groups of nitroarenes and Pt nanoparticles. The unique surface properties of α-Fe2O3 play an important role in the reaction process. It provides active sites for hydrogen spillover and reactant adsorption, and ultimately completes the hydrogenation of the nitro group on the catalyst surface.

The design and fabrication of high visible-light activated photoelectrode are essential to precisely detect biomolecule in biological system. Herein, an ultrasensitive photoelectrochemical (PEC) aptasensor for specific recognition of adenosine is established based on carbon dots sensitized-amorphous molybdenum sulfide (a-MoSx/CDs) photoanode and dual amplification strategy. The heterostructured photoanode achieved by sequential electrodeposition reveals significantly boosted photocurrent with good stability and repeatability under visible light illumination, giving the credit to highly activated visible light absorption, uniform coverage and good electric contact to the underlying substrate, as well as the energy-band alignment between the two components. By stepwisely immobilizing complementary DNA probe (NH2-DNA) and adenosine aptamer (Apt), followed by methylene blue (MB) binding with the guanine base on Apt, a dual amplified self-powered PEC aptasensor for adenosine detection is constructed. Based on the co-sensitization effect of CDs and MB, ultrasensitive and high-affinitive determination of adenosine is realized over the concentration range of 0.01 nM-1000 nM at 0 V (vs. SCE), with satisfactory stability and reproducibility. The detection limit is as low as 3.3 pM, demonstrating a performance even surpassing most of the sensors reported so far. The prospective application of the co-sensitized a-MoS photoanode for ultrasensitive aptasensing is highlighted in this work.

Retinal vein occlusion(RVO)is a common retinal vascular disease. Macular edema(ME)secondary to RVO is the main cause of visual impairment in patients. The mechanisms of ME secondary to RVO are intricate and have not yet been fully elucidated. Many cells and cytokines are involved in it, which disrupt the balance between fluid entry and exit in the retina. This review discusses the complex pathogenesis of ME associated with RVO and the mechanisms by which ME affects visual function.

The design and construction of high-performance photoelectrode with efficient visible-light absorption and fast charge transport rate are crucial to developing photoelectrochemical (PEC) sensor. Herein, a well-aligned amorphous MoSx (a-MoSx)@ZnO core-shell nanorod arrays was uniformly grown on indium tin oxide (ITO) via a facile all-electrochemical strategy. Simultaneous boosted PEC performance and stability in the visible region were obtained. Those could be attributed to the collaboration effect of fast electron transfer path within the oriented ZnO nanorod and extended visible-light absorption upon combining a-MoSx, as well as favorable energy-band alignment between the two PEC materials. By employing tobramycin-binding aptamer as recognition element, a self-powered PEC aptasensor for tobramycin was successfully fabricated for the first time. The sensor exhibited a rapid response in a wide linear range of 0.010–50 ng/mL with good stability and reproducibility. The detection limit was as low as 5.7 pg/mL. Ultrasensitive and high-affinitive determination of tobramycin in serum samples was realized at 0 V (vs.SCE) with desired accuracy and satisfactory recovery. This work reveals the promising application of all-electrodeposited a-MoSx@ZnO NR arrays-based photoanode for self-powered PEC bioassay in the tobramycin-related disease diagnosis.

Garnet structure Ga-based oxides are reported here as a new host for inorganic reversible thermochromic materials. Doping of 3d transition metal elements at the Ga site could be an efficient route for controlling the electronic spectrum. Multicolored reversible thermochromic materials have been prepared with Cr3+/Mn3+/Fe3+/Co3+-doped Er3Ga5O12 by a high-temperature solid state reaction method and investigated by X-ray diffraction, Raman spectroscopy, and ultraviolet-visible-near-infrared spectroscopy. The color and CIE-L*ab parameters as a function of temperature were explored from room temperature to 460 degrees C. The color distinction at room temperature was attributed to the unique optical characteristics, and the color for Cr3+- and Mn3+-doped samples arose from Cr3+ d-d transitions at similar to 2.8 and similar to 2.0 eV and the Mn3+ d-d transition at similar to 2.5 eV, respectively. In addition to the d-d transition for Fe3+/Co3+, charge transfer of ligand-metal in the visible region was the primary cause of the color of Fe3+/Co3+-substituted samples. As the temperature increased, a continuous change in color was perceived, and the color recovered when the temperature decreased to room temperature. The thermochromic effect originated from the alteration of the energy required for the d-d transition or charge transfer with temperature, resulting in a characteristic shift and deformation of these absorption bands.

A kind of highly efficient and low cost supported-Pt catalyst for oxidation of toluene is obtained through controlling both the chemical state of Pt active sites and surface properties of supports. The optimized Pt/Al2O3 catalyst with Pt loading as low as 0.1 wt% could completely convert toluene (1000 ppm) to CO2 at about 180 degrees C under a space velocity of 24,000 mL g(-1) h(-1). It also exhibits a high stability and moisture resistance properties under reaction atmosphere. TOF value calculated with the dispersion of Pt can reach 0.0685 s(-1), representing a high utilization efficiency of Pt. A series of characterizations are carried out to investigate the key factors affecting the catalytic performance of Pt/Al2O3, and disclose the concrete role of Pt and Al2O3 in the activation of molecular oxygen and toluene. In situ DRIFTS and EPR results show that Pt is the active center for O-2 activation. Metallic Pt nanoparticles (Pt-0) can activate the molecular O-2 even at room temperature. Al2O3 offers sites for the adsorption of toluene and desorption of CO2 product. The weak and medium strength of acid-base sites favorite the adsorption and desorption process. The oxidation of toluene over Pt/Al2O3 obeys modified L-H mechanism. The synergistic effect of metallic Pt nanoparticles and suitable Al(2)O(3 )support is critical for obtaining highly efficient Pt-based catalysts with low Pt contents for toluene oxidation.

Desulfurization of fuel oil is of great importance for producing clean energy. In this study, we report that tetra-alkyl orthotitanates exhibited efficient catalytic performance in the oxidative desulfurization of dibenzothiophene. The sulfur content in model oil (1000 ppmw) could be reduced to less than 10 ppmw within 10 min at room temperature and ambient pressure. In addition, the formed sulfones can be easily separated from the oil phase without extraction process. This work will provide a basis for the design of novel oxidative desulfurization catalysts with high desulfurization efficiency. (C) 2018 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Nitro- and amino-functionalized UiO-66(Zr) have great potential in some applications.

Oxygen evolution reaction has attracted enormous interest due to sluggish kinetics in water splitting reaction. In recent years, Co and Ni-based materials have been explored as excellent choices in highly efficient and affordable noble metal-free catalysts. Herein, a heterostructure of NiCo alloy and phosphide (NiCo/NiCoP) hybrid is prepared by using hydrothermal and calcination method. This hybrid catalyst manifests outstanding OER electrocatalytic performance, as demonstrated by an ultralow Tafel slope of 55 mV dec(-1), low overpotential of 290 mV at 10 mA cm(-2), and long-term chemical stability. Benefiting from the incorporation of nitrogen atom, surface oxygen vacancies, and synergistic coupling effect between alloy and phosphide, the hybrid catalyst can expose more accessible active sites and facilitate the release of oxygen bubbles. Our findings demonstrated that this bimetallic alloy/phosphide hybrid can serve as an efficient and durable electrocatalyst for the oxygen evolution reaction. (C) 2018 Elsevier Ltd. All rights reserved.

Na2 + 2xFe2-x (SO4)3 (NFS) holds great promise as the cathode material for room-temperature sodium-ion batteries. However, large-scale application of NFS is highly impeded by its low electrical conductivity, which leads to poor cyclability and rate capability. To address these issues, we introduce rice husk-derived carbon with engineered porosity and structure as carrier to load active material NFS. The resultant hybrid material delivers extremely high specific charge capacity of 113.4 mAh g−1 at 0.1 C (1 C = 120 mA g−1), and a large reversible capacity of 81.2 mAh g−1 is retained after 100 cycles with a high retention rate of about 83.9%. The capacity of the composite can reach 60 mAh g−1 even at the current density 5 C. These excellent electrochemical performances are attributed to a favorable combination of the interpenetrating conductive carbon framework and ordered mesoporous structure that maintain well-balanced ionic and electronic conductivities throughout the electrode.