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991.
Integration of Multiple Plasmonic and Co‐Catalyst Nanostructures on TiO2 Nanosheets for Visible‐Near‐Infrared Photocatalytic Hydrogen Evolution 下载免费PDF全文
Wenya Jiang Song Bai Limin Wang Xijun Wang Li Yang Yanrui Li Dong Liu Xiaonong Wang Zhengquan Li Jun Jiang Yujie Xiong 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(12):1640-1648
Utilization of visible and near‐infrared light has always been the pursuit of photocatalysis research. In this article, an approach is developed to integrate dual plasmonic nanostructures with TiO2 semiconductor nanosheets for photocatalytic hydrogen production in visible and near‐infrared spectral regions. Specifically, the Au nanocubes and nanocages used in this work can harvest visible and near‐infrared light, respectively, and generate and inject hot electrons into TiO2. Meanwhile, Pd nanocubes that can trap the energetic electrons from TiO2 and efficiently participate in the hydrogen evolution reaction are employed as co‐catalysts for improved catalytic activity. Enabled by this unique integration design, the hydrogen production rate achieved is dramatically higher than those of its counterpart structures. This work represents a step toward the rational design of semiconductor–metal hybrid structures for broad‐spectrum photocatalysis. 相似文献
992.
Atomically Precise Prediction of 2D Self‐Assembly of Weakly Bonded Nanostructures: STM Insight into Concentration‐Dependent Architectures 下载免费PDF全文
Mohamed El Garah Arezoo Dianat Andrea Cadeddu Rafael Gutierrez Marco Cecchini Artur Ciesielski Peter J. Stang Gianaurelio Cuniberti Paolo Samorì 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(3):343-350
A joint experimental and computational study is reported on the concentration‐dependant self‐assembly of a flat C3‐symmetric molecule on a graphite surface. As a model system a tripodal molecule, 1,3,5‐tris(pyridin‐3‐ylethynyl)benzene, has been chosen, which can adopt either C3h or Cs symmetry when planar, as a result of pyridyl rotation along the alkynyl spacers. Density functional theory (DFT) simulations of 2D nanopatterns with different surface coverage reveal that the molecule can generate different types of self‐assembled motifs. The stability of fourteen 2D patterns and the influence of concentration are analyzed. It is found that ordered, densely packed monolayers and 2D porous networks are obtained at high and low concentrations, respectively. A concentration‐dependent scanning tunneling microscopy (STM) investigation of this molecular self‐assembly system at a solution/graphite interface reveals four supramolecular motifs, which are in perfect agreement with those predicted by simulations. Therefore, this DFT method represents a key step forward toward the atomically precise prediction of molecular self‐assembly on surfaces and at interfaces. 相似文献
993.
Self‐Sensitized Carbon Nitride Microspheres for Long‐Lasting Visible‐Light‐Driven Hydrogen Generation 下载免费PDF全文
A new type of metal‐free photocatalyst is reported having a microsphere core of oxygen‐containing carbon nitride and self‐sensitized surfaces by covalently linked polymeric triazine dyes. These self‐sensitized carbon nitride microspheres exhibit high visible‐light activities in photocatalytic H2 generation with excellent stability for more than 100 h reaction. Comparing to the traditional g‐C3N4 with activities terminated at 450 nm, the polymeric triazine dyes on the carbon nitride microsphere surface allow for effective wide‐range visible‐light harvesting and extend the H2 generation activities up to 600 nm. It is believed that this new type of highly stable self‐sensitized metal‐free structure opens a new direction of future development of low‐cost photocatalysts for efficient and long‐term solar fuels production. 相似文献
994.
Au NPs@MoS2 Sub‐Micrometer Sphere‐ZnO Nanorod Hybrid Structures for Efficient Photocatalytic Hydrogen Evolution with Excellent Stability 下载免费PDF全文
Shaohui Guo Xuanhua Li Jinmeng Zhu Tengteng Tong Bingqing Wei 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(41):5692-5701
MoS2 shows promising applications in photocatalytic water splitting, owing to its uniquely optical and electric properties. However, the insufficient light absorption and lack of performance stability are two crucial issues for efficient application of MoS2 nanomaterials. Here, Au nanoparticles (NPs)@MoS2 sub‐micrometer sphere‐ZnO nanorod (Au NPs@MoS2‐ZnO) hybrid photocatalysts have been successfully synthesized by a facile process combining the hydrothermal method and seed‐growth method. Such photocatalysts exhibit high efficiency and excellent stability for hydrogen production via multiple optical‐electrical effects. The introduction of Au NPs to MoS2 sub‐micrometer spheres forming a core–shell structure demonstrates strong plasmonic absorption enhancement and facilitates exciton separation. The incorporation of ZnO nanorods to the Au NPs@MoS2 hybrids further extends the light absorption to a broader wavelength region and enhances the exciton dissociation. In addition, mutual contacts between Au NPs (or ZnO nanorods) and the MoS2 spheres effectively protect the MoS2 nanosheets from peeling off from the spheres. More importantly, efficiently multiple exciton separations help to restrain the MoS2 nanomaterials from photocorrosion. As a result, the Au@MoS2‐ZnO hybrid structures exhibit an excellent hydrogen gas evolution (3737.4 μmol g?1) with improved stability (91.9% of activity remaining) after a long‐time test (32 h), which is one of the highest photocatalytic activities to date among the MoS2 based photocatalysts. 相似文献
995.
996.
997.
Mikhail B. Novikov Tatiana A. Borodulina Sergey V. Kotomin Valery G. Kulichikhin 《The Journal of Adhesion》2013,89(1):77-107
Relaxation properties of pressure-sensitive adhesives (PSA) have been studied with the squeeze-recoil tester used in the regime of parallel-plate dilatometer under conditions imitating the removal of compressive force in the course of adhesive bond formation. The relaxation properties of PSAs are compared with their adhesive behavior measured using the 180-Deg Peel Test. Two classes of PSAs are considered: 1) conventional rubbery adhesives based on the mixtures of styrene-isoprene-styrene (SIS) block copolymer with a tackifier resin and a plasticizer, and butyl rubber plasticized with low-molecular-weight polyisobutylene, and 2) hydrophilic PSAs composed of the blends of high-molecular-weight poly(N-vinyl pyrrolidone) (PVP) with oligomeric polyethylene glycol (PEG). By comparing the adhesive and relaxation behaviors of different PSAs, the relaxation criteria for pressure-sensitive adhesion have been stated. Relaxation behavior of the examined PSAs demonstrates two values of retardation time: the shorter retardation time of 10–70?sec and the longer time of 300–660?sec. These times can be associated, respectively, with small- and large-scale mechanisms of strain recovery. By comparing the relaxation and adhesive properties of PVP-PEG blend (which involves the formation of a hydrogen-bonded network through both terminal hydroxyl groups in PEG short chains) with the properties of covalently crosslinked copolymers of vinyl pyrrolidone (VP) with PEG-diacrylate and comb-like VP copolymers with PEG-monomethacrylate, the contributions of covalent crosslinking and H-bonding network have been characterized. 相似文献
998.
We present the results of the experimental investigation of hydrogen storage in glass capillary arrays. It is demonstrated that quartz–epoxy capillary arrays can have extremely high gravimetric and volumetric capacity, exceeding US DOE 2010 target values. The new method of pressurized hydrogen loading and releasing is developed based on plugging up the capillaries with stoppers in high-pressure environment. 相似文献
999.
M. BayatM.R. Rahimpour 《International Journal of Hydrogen Energy》2011,36(12):7310-7325
The potential of simultaneous hydrogen production and in situ water removal in a thermally coupled multitubular two-membrane reactor (TCTMR) were studied numerically. Methanol synthesis is carried out in exothermic side with H-SOD membrane and supplies the necessary heat for the endothermic side. Dehydrogenation of cyclohexane is carried out in endothermic side with hydrogen-permselective Pd/Ag membrane wall. Therefore, the proposed reactor consists of two membranes, one for separation of pure hydrogen from endothermic side and another one for separation of water from exothermic side. The motivation for in situ H2O removal during methanol synthesis by using H-SOD membranes is to displace the water-gas shift equilibrium to enhance conversion of CO2 to improve methanol productivity. A steady-state heterogeneous model is developed to analyze the operation of the coupled methanol synthesis. The proposed model has been used to compare the performance of a TCTMR with conventional reactor (CR) and thermally coupled membrane reactor (TCMR) at identical process conditions. This comparison shows that TCTMR in addition to possessing advantages of a TCMR has a more favorable profile of temperature and increased productivity compared with other reactors. Furthermore, lower water production rate in TCTMR reduces catalyst re-crystallization. 相似文献
1000.
Highly dispersed,high performance Pt and PtRu catalysts,supported on multiwalled carbon nanotubes(CNTs),were prepared by a high pressure organic colloid method.The particle sizes of the active components were as small as 1.2 nm for Pt and 1.1 nm for PtRu,and the active Pt surface areas were 295 and 395 m2/g,respectively.The catalysts showed very high activities toward the anodic oxidation of methanol,evaluated by cyclic voltammetry,being up to 4 times higher than that of commercial Johnson Matthey Hispec 20... 相似文献