The development of future mobility (e.g. electric vehicles) requires supercapacitors with high voltage and high energy density. Conventional active carbon-based supercapacitors have almost reached their limit of energy density which is still far below the desired performance. Advanced materials, particularly metal hydroxides/oxides with tailored structure are promising supercapacitor electrodes to push the limit of energy density. To date, research has largely focused on evaluation of these materials in aqueous electrolyte, while this may enable high specific capacitance, it results in low working voltage window and poor cycle stability. Herein, we report the development of Ni2Mn-layered double oxides (Ni2Mn-LDOs) as mixed metal oxide-based supercapacitor electrodes for use in an organic electrolyte. Ni2Mn-LDO obtained by calcination of [Ni0.66Mn0.33(OH)2](CO3)0.175·nH2O at 400 °C produced the best performing Ni2Mn-LDOs with high working voltage of 2.5 V and a specific capacitance of 44 F g-1 (at 1 A g-1). We believe the performance of the Ni2Mn-LDOs is related to its unique porous structure, high surface area and the homogeneous mixed metal oxide network. Ni2Mn-LDO outperforms both the single metal oxides (NiO, MnO2) and the equivalent physical mixture of the two oxides. We propose this performance boost arises from synergy between NiO and MnO x due to a more effective homogeneous network of NiO/MnO x domains in the Ni2Mn-LDO. This work clearly shows the advantage of an LDO over the single component metal oxides as well as the physical mixture of mixed metal oxides and highlights the possibilities of development of further mixed metal oxides-based supercapacitors in organic electrolyte using LDH precursors.

引入图像、属性、实体描述文本等来自外部的信息有助于丰富知识表示模型中的实体向量表示.但是,外部信息并不总是有效而且目前的引入方法往往效率较低.针对以上问题,本文提出了一种结合实体邻居信息的知识表示模型,该模型把从知识图谱内部获取的实体邻居作为引入的信息,然后利用自动关键词抽取技术从实体邻居中选取出部分关键的邻居,最后使用本文提出的短接联合表示方法高效地将选出的邻居结合到知识表示模型中.实验结果表明,该模型在知识图谱的链接预测任务上优于目前的最优方法.

Efficient photocatalysis is important for sustainable energy. Recently, an unconventional photocatalyst based on intrinsic plasmon, called intrinsic plasmonic photocatalyst (IPP), seems promising for higher efficiency in hydrogen evolution. This catalyst seems to benefit from the advantages of visible light absorption, plasmon-assisted hot carrier generation, and good catalytic stability over conventional semiconductor photocatalysts. In this work, we report the relative hydrogen evolution efficiency under visible light irradiation of a family of IPP based on alkaline earth niobates (MNbO3, where M = Ca, Sr, or Ba), with efficiency of CaNbO3 > SrNbO3 > BaNbO3. The contributions of electron phonon coupling time constant and solar energy absorption to the hydrogen evolution efficiency are identified as key based on our comprehensive study and characterization of carrier density (10(22) cm(-3)), plasmon absorption, carrier dynamics, and surface area. This study demonstrates a generic approach to create a family of IPPs and further validates the role of solar energy absorption by intrinsic plasmon resonance in the enhancement of photocatalytic efficiency.

Photocatalytic reduction of CO2 to useful fuel has been identified as a promising strategy to address the energy and environmental issues. Development of well-defined photocatalysts toward CO2 reduction has attracted increasing interest to gain insight into the reactive mechanism. Herein, by post-synthetic ligand exchange, a bifunctional Re-based metal–organic framework (MOF) was successfully prepared. It not only serves as a photosensitizer but also acts as a catalyst for photochemical reduction of CO2. Furthermore, it is found that a Re-based MOF containing 30% Re-based ligands displays improved activity compared to MOF with 100% Re-based ligands. This work provides clues to the design and synthesis of bifunctional MOFs toward photocatalytic CO2 reduction. A bifunctional UiO-67-Re was developed as a photocatalyst for CO2 reduction by post-synthetic ligand exchange strategy. Its synthesis and photocatalytic performance were investigated.

Silicon is of interest owing to its high theoretical capacity (4200 mAh/g). However, its enormous volume expansion of silicon during cycling is one of the main reasons for the rapid capacity fading and pulverisation of the anode commonly observed. Here, freestanding multi-wall carbon nanotube (MWCNT)/silicon anodes were prepared using so-called MWCNT buckypapers (BPs) as current collectors instead of the traditional metallic foils. To prepare the anodes, silicon was deposited on these MWCNT BPs to form silicon nanoparticles (SiNPs) and subsequent annealing resulted in the formation of a connecting SiC interface preventing the SiNPs from detaching. An amorphous carbon coating was applied in order to enhance electrical conductivity and overall integrity of these hierarchical anode materials. The morphology and chemical composition of the Si-BP anodes were characterised by means of SEM, TEM, EDX, STEM, XRD, RAMAN, etc. Cycling tests of these binder and additive-free anodes revealed an areal capacity of 0.55 mAh/cm2 after 300 cycles with 99.7% of Columbic efficiency and showed that the presence of the SiC interface and a-C coating played a crucial role in improving their rate capability and stability.

Vertically-aligned SiC nanowires with tunable length and diameter were produced in gram scale which showed efficient photocatalytic activity towards dye degradation under visible light.

Photocatalytic water splitting and carbon dioxide reduction provide us clean and sustainable energy resources. The carbon dioxide reduction is also the redemption of the greenhouse effect. MoS3/TiO2 photocatalysts based on TiO2 nanoplates have been synthesized via a hydrothermal acidification route for water and carbon dioxide reduction reactions. This facile approach generates well dispersed MoS3 with low crystallinity on the surface of TiO2 nanoplates. The as-synthesized MoS3/TiO2 photocatalyst showed considerable activity for both water reduction and carbon dioxide reduction. The thermal treatment effects of TiO2, the loading percentage of MoS3 and the crystalline phase of TiO2 have been investigated towards the photocatalytic performance. TiO2 nanoplate synthesized through hydrothermal reaction with the presence of HF acid is an ideal semiconductor material for the loading of MoS3 for photocatalytic water and carbon dioxide reduction simultaneously in EDTA sacrificial solution.

Polymeric g-C3N4 is a promising candidate for solar hydrogen production. However, its hydrogen production rate is low when used alone due to fast recombination of photogenerated electron-hole pairs. In this paper, we report much improved hydrogen production by coupling g-C3N4 with two-phase anatase/brookite TiO2 nanoparticles to form multiple heterojunctions. Results have shown that under visible light illumination, photogenerated electrons transfer from g-C3N4 to TiO. In addition, systematic comparison was carried out among different type of heterojunctions, viz., g-C3N4 coupled with a single phase of TiO2 (anatase or brookite), dual-phase TiO2 (anatase/brookite or anatase/rutile), or a three-phase TiO2 (anatase/brookite/rutile) mixture. g-C3N4 with two-phase anatase/brookite TiO2 produces the largest amount of hydrogen under visible light illumination. The comparison reveals two important factors behind photo catalytic hydrogen generation: effective charge transfer and the conduction band potential position. The band edge positions of all the constituent phases of the heterojunction have to be more cathodic than the hydrogen reduction potential in order to realize the full benefit of effective charge separation. (C) 2016 Elsevier Inc. All rights reserved.

Rod-like molybdenum carbide (Mo2C) microcrystals were obtained from the pyrolysis of Mo-containing organic-inorganic hybrid composite. We investigated the photocatalytic H-2 evolution activity of Mo2C by constructing a Mo2C-dye sensitizer photocatalyst system. A high quantum efficiency of 29.7% was obtained at 480 nm. Moreover, Mo2C catalyst can be easily recycled by simple filtration. (C) 2016 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.

Photocatalytic water splitting and carbon dioxide reduction provide us clean and sustainable energy resources. The carbon dioxide reduction is also the redemption of the greenhouse effect. MoS 3 /TiO 2 photocatalysts based on TiO 2 nanoplates have been synthesized via a hydrothermal acidification route for water and carbon dioxide reduction reactions. This facile approach generates well dispersed Mo S3 with low crystallinity on the surface of TiO 2 nanoplates. The as-synthesized MoS 3 /TiO 2 photocatalyst showed considerable activity for both water reduction and carbon dioxide reduction. The thermal treatment effects of TiO 2 , the loading percentage of MoS 3 and the crystalline phase of TiO 2 have been investigated towards the photocatalytic performance. TiO 2 nanoplate synthesized through hydrothermal reaction with the presence of HF acid is an ideal semiconductor material for the loading of MoS 3 for photocatalytic water and carbon dioxide reduction simultaneously in EDTA sacrificial solution.

A noble-metal-free CdS/WC/TiO2 photocatalyst with water-soluble CdS quantum dots (<5 nm) and anatase–rutile composite TiO2 is highly efficient for H2 evolution from visible-light-driven photocatalytic water reduction.

Carbon foams were produced from a macroporous poly(divinylbenzene) (poly(DVB) precursor, synthesized by polymerizing the continuous but minority phase of water-in-oil high internal phase emulsions (HIPEs) stabilized by molecular and/or particulate emulsifiers. Both permeable and non-permeable hierarchically porous carbon foams, or 'carboHIPEs', were prepared by carbonization of the resulting macroporous polymers at 800 degrees C. The carbon yields were as high as 26 wt.% of the original polymer. CarboHIPEs retain the pore structure of the macroporous polymer precursor, but with surface areas of up to 505 m(2)/g and excellent electrical conductivities of 81 S/m. Contrary to some previous reports, the method does not require further modification, such as sulfonation or additional crosslinking of the polyHIPE prior to carbonization, due to the inherently crosslinked structure of poly(DVB). The use of a pourable, aqueous emulsion-template enables simple moulding, minimises waste and avoids the strong acid treatments used to remove many conventional solid-templates. The retention of the macroporous structure is coupled with the introduction of micropores during carbonization, producing hierarchically porous carboHIPEs, suitable for a wide range of applications as sorbents and electrodes. (C) 2016 Published by Elsevier Ltd.

Carbon nitride nanosheet/metal–ogranic framework nanocomposites with heterojunction were synthesised via an in-situ method, leading to better electron–hole transfer and more efficient photocatalytic activities.

Glycerol derived from biomass is increasingly attractive as a renewable feedstock for production of bulk and specialty chemicals. In this work, we have developed an efficient Pt9Sn1/C nanocatalyst for oxidation of glycerol to glyceric acid, with its activity the highest among various PtM/C (M = Mn, Fe, Co, Ni, Cu, Zn, Au) bimetallic nanocatalysts. Under the optimized conditions, 91% of glycerol can be oxidized within 8 h at 60 degrees C, with 50% yield of glyceric acid. Without incorporation of Sn, a lower glycerol conversion of around 69% was obtained over the monometallic 2.0%Pt/C-R catalyst under the same reaction conditions. Furthermore, the calculated turn over frequency (TOF) based on surface Pt atoms is 938 h(-1) for 2.0%Pt9Sn1/C-R nanocatalyst, which is three times as high as that of 2.0%Pt/C-R catalyst (281 h(-1)). The enhancement of activity by modifying Pt nanoparticles with Sn is attributed to activation of oxygen molecules and/or deprotonation of hydroxyl group by surface stannous oxide (SnO) species. In addition, the Pt9Sn1/C-R catalyst has been shown to be robust and stable without substantial loss of activity after being recycled for four times. (C) 2015 Elsevier B.V. All rights reserved.

Water oxidation reactions driven by visible light play an important role in solar fuel production. Recently, catalysts based on earth abundant elements, such as cobalt oxides, have been studied extensively. Out of many factors, the catalyst particle size certainly affects the photocatalytic activity. To reduce the catalyst particle size below 5 nm without encountering agglomeration, a practical approach is to adopt a proper substrate to immobilize the catalyst nanoparticles. Herein, we utilized MIL-101, a highly porous and robust metal-organic framework (MOF), to immobilize cobalt oxide nanoparticles by a simple and facile method involving double solvent impregnation followed by a mild heat treatment. With cobalt loading in the range of 1.4-4.9 wt%, ultra small cobalt oxide nanoparticles (2-3 nm) have been successfully immobilized in the cages of MIL-101 with a good dispersion and narrow size distribution. Photocatalytic and electrochemical studies have indicated that the resultant cobalt oxide nanoparticles embedded in the MOF are highly efficient and stable water oxidation catalysts. A high turnover frequency (TOF) of 0.012 s(-1) per cobalt atom and oxygen yield of 88% were obtained under the optimized conditions in the [Ru(bpy)(3)](2+)-Na2S2O8 system. The MIL-101 support plays the roles of confining the size of catalyst nanoparticles and promoting charge transfer, leading to an enhanced photocatalytic performance.

Polyvinylpyrrolidone (PVP)-modified MoS3 nanoparticles with unusual water solubility up to 1.0mgmL(-1) were synthesized through a facile hydrothermal method in the presence of thioacetic acid. The amorphous nanoparticles wrapped by PVP have sizes of around 2.5nm, which represent the smallest MoS3 clusters reported. The photocatalytic performance of the MoS3 nanoparticles was evaluated under visible light for H-2 evolution using xanthene dyes as photosensitizers. The quantum efficiency of the optimized system for H-2 evolution under green light irradiation (520nm) is up to 36.2%, which is comparable with those of other excellent photocatalytic systems involving earth-abundant catalysts. The excellent photocatalytic activity can be attributed to its good dispersion in water, amorphous nature and limited layers with abundant surface active sites, and possibly higher conduction band potential for proton reduction and larger indirect band gap for a longer lifetime of the excited electrons.

A new layered metal–organic phosphonate crystal with both mono- and di-μ-oxo bridged octahedral cobalt was synthesized and acts as an efficient and stable heterogeneous catalyst for water oxidation.

Metallic Ag nanoparticles deposited on BiVO4promote the separation of photo-induced electron/hole pairs for the generation of reactive oxygen species, leading to excellent photocatalytic disinfection activity under both visible light and natural sunlight.

In this work, CdS quantum dots (QDs) supported on Ga2O3 and In2O3 are applied for visible-light-driven H2 evolution from aqueous solutions that contain lactic acid. With Pt as the cocatalyst, the H2 evolution rates on CdS/Pt/Ga2O3 and CdS/Pt/In2O3 are as high as 995.8 and 1032.2 μmol h(-1), respectively, under visible light (λ>420 nm) with apparent quantum efficiencies of 43.6 and 45.3% obtained at 460 nm, respectively. These are much higher than those on Pt/CdS (108.09 μmol h(-1)), Pt/Ga2O3 (0.12 μmol h(-1)), and Pt/In2O3 (0.05 μmol h(-1)). The photocatalysts have been characterized thoroughly and their band structures and photocurrent responses have been measured. The band alignment between the CdS QDs and In2O3 can lead to interfacial charge separation, which cannot occur between the CdS QDs and Ga2O3. Among the various possible factors that contribute to the high H2 evolution rates on CdS/Pt/oxide, the surface properties of the metal oxides play important roles, which include (i) the anchoring of CdS QDs and Pt nanoparticles for favorable interactions and (ii) the efficient trapping of photogenerated electrons from the CdS QDs because of surface defects (such as oxygen defects) based on photoluminescence and photocurrent studies.