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The BOLS-NEP theory reconciling the attributes of undercoordinated adatoms,defects,surfaces and nanostructures

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Nano Materials Science 2020年第4期2卷 333-345页

作者： Changqing Sun NOVITAS School of EEENanyang Technological UniversitySingapore639798Singapore EBEAM School of MaterialsYangtze Normal UniversityChongqing408100China

This article describes a theory unifying the unusual performance of the undercoordinated adatoms,point defects,terrace edges,surfaces,and nanostructures of various shapes.The ideas of bond order-length-strength correlation and the associated nonbonding electron polarization(BOLS-NEP)feature that bonds between undercoordinated atoms contract spontaneously.Bond contraction raises the local density of charge and energy.Bond strength gain deepens the interatomic potential well to trap the core and bonding electrons deeply.In turn,the locally and densely entrapped electrons polarize those partially occupying the valence band and above pertaining to the lower-coordinated atoms.The BOLS-NEP theory reconciles the unusual behaviors of undercoordinated systems and the size dependency of nanostructures in their lattice oscillating dynamics,mechanical strength,thermal stability,photon emissivity,chemical reactivity,dielectric permeability,associated with generation of polarized Dirac fermions,serving as carriers for extraordinary catalysis,hydrophobicity,fluidity,lubricity,as well as monolayer high-TC superconductivity and topological insulator conductivity.

关键词： nanostructures Surface Defect Bond relaxation Entrapment Polarization Single-atom catalysis Superconductivity IHPR

Kinetic study of methane hydrate formation in the presence of carbon nanostructures

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Petroleum Science 2019年第3期16卷 657-668页

作者： Saeid Abedi-Farizhendi Mina Iranshahi Abolfazl Mohammadi Mehrdad Manteghian Amir H. Mohammadi Faculty of Chemical Engineering Tarbiat Modares University Tehran Iran Department of Petroleum Engineering South Tehran Branch Islamic Azad University Tehran Iran Department of Chemical Engineering University of Bojnord Bojnord Iran Institut de Recherche en Genie Chimique et Petrolier (IRGCP) Paris Cedex France Discipline of Chemical Engineering School of Engineering University of KwaZulu-Natal Howard College Campus King George V Avenue Durban 4041 South Africa

The effect of synthesized nanostructures,including graphene oxide,chemically reduced graphene oxide with sodium dodecyl sulfate(SDS),chemically reduced graphene oxide with polyvinylpyrrolidone,and multi-walled carbon nanotubes,on the kinetics of methane hydrate formation was investigated in this work.The experiments were carried out at a pressure of 4.5 MPa and a temperature of 0 ℃ in a batch reactor.By adding nanostructures,the induction time decreases,and the shortest induction time appeares at certain concentrations of reduced graphene oxide with SDS and graphene oxide,that is,at a concentration of 360 ppm for reduced graphene oxide with SDS and 180 ppm for graphene oxide,with a 98% decrease in induction time compared to that in pure water.Moreover,utilization of carbon nanostructures increases the amount and the rate of methane consumed during the hydrate formation process.Utilization of multi-walled carbon nanotubes with a concentration of 90 ppm showes the highest amount of methane consumption.The amount of methane consumption increases by 173% in comparison with that in pure water.The addition of carbon nanostructures does not change the storage capacity of methane hydrate in the hydrate formation process,while the percentage of water conversion to hydrate in the presence of carbon nanotubes increases considerably,the greatest value of which occurres at a 90 ppm concentration of carbon nanotubes,that is,a 253% increase in the presence of carbon nanotubes compared to that of pure water.

关键词： Clathrate hydrate Kinetics Carbon nanostructures Graphene oxide SDS PVP

Bi_(2)S_(3) nanostructures: A New Photocatalyst

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Nano Research 2010年第5期3卷 379-386页

作者： Tong Wu Xinggui Zhou Hua Zhang Xinhua Zhong State Key Laboratory of Chemical Engineering Department of ChemistryEast China University of Science and TechnologyShanghai 200237China

Uniform colloidal Bi_(2)S_(3) nanodots and nanorods with different sizes have been prepared in a controllable manner via a hot injection method. X-ray diffraction (XRD) results show that the resulting nanocrystals have an orthorhombic structure. Both the diameter and length of the nanorods increase with increasing concentration of the precursors. All of the prepared Bi_(2)S_(3) nanostructures show high efficiency in the photodegradation of rhodamine B, especially in the case of small sized nanodots-which is possibly due to their high surface area. The dynamics of the photocatalysis is also discussed.

关键词： Bi_(2)S_(3) nanostructures hot injection photocatalyst

Plasmon-enhanced solar water splitting with metal oxide nanostructures： A brief overview of recent trends

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Frontiers of Materials Science 2018年第3期12卷 207-213页

作者： Timur Sh. ATABAEV Department of Chemistry School of Science and Technology Nazarbayev University Astana 010000 Kazakhstan

In the last decade, the surface plasmon resonance-enhanced solar water splitting （SWS） has been actively investigated for improved hydrogen production. In this mini-review, we briefly introduce the mechanisms for plasmon-enhanced SWS and then review some representative studies related to these mechanisms. In addition, we also briefly discuss how metal oxide geometry affects the SWS activity in combined metalsemiconductor nanostructures. Finally, we summarize the recent discoveries and proposed a future vision for plasmon-enhanced SWS with metal oxide nanostructures.

关键词： surface plasmon resonance solar water splitting nanostructures noble metals metal oxides

Master equation approach to transient quantum transport in nanostructures

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Frontiers of physics 2017年第4期12卷 43-78页

作者： Pei-Yun Yang Wei-Min Zhang Department of Physics and Centre for Quantum Information Science Cheng Kung University Tainan 70101

In this review article, we present a non-equilibrium quantum transport theory for transient electron dynamics in nanodevices based on exact Master equation derived with the path integral method in the fermion coherent-state representation. Applying the exact Master equation to nanodevices, we also establish the connection of the reduced density matrix and the transient quantum transport current with the Keldysh nonequilibrium Green functions. The theory enables us to study transient quantum transport in nanostructures with back-reaction effects from the contacts, with non-Markovian dissipa- tion and decoherence being fully taken into account. In applications, we utilize the theory to specific quantum transport systems, a variety of quantum decoherence and quantum transport phenomena involving the non-Markovian memory effect are investigated in both transient and stationary scenarios at arbitrary initial temperatures of the contacts.

关键词： quantum transport Master equation open systems nanostructures

Ag_(2)Se Complex nanostructures with Photocatalytic Activity and Superhydrophobicity

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Nano Research 2010年第12期3卷 863-873页

作者： Huaqiang Cao Yujiang Xiao Yuexiang Lu Jiefu Yin Baojun Li Shuisheng Wu Xiaoming Wu Department of Chemistry Tsinghua UniversityBeijing 100084China School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083China College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China

Single-crystalline Ag_(2)Se complex nanostructures have been synthesized via a solvothermal route in which selenophene(C4H4Se)as a selenylation source reacts with AgNO3 at a temperature of 240°C.An orthorhombic phaseβ-Ag_(2)Se nanostructure was identified by X-ray diffraction(XRD),Raman spectroscopy,field emission scanning electron microscopy(FE-SEM),high resolution transmission electron microscopy(HRTEM),and photoluminescence(PL)spectroscopy.The wettability of the as-synthesizedβ-Ag_(2)Se nanostructure was studied by measurement of the water contact angle(CA).Static water CA values of over 150°were obtained,which can be attributed to theβ-Ag_(2)Se complex nanostructure having a combination of micro-and nanostructures.The superhydrophobic Ag_(2)Se nanostructure may find applications in self-cleaning.Additionally,the photocatalytic activity of the as-synthesizedβ-Ag_(2)Se nanostructure was evaluated by photodegradation of rhodamine B(RhB)dye under ultraviolet(UV)light irradiation.

关键词： nanostructures photocatalytic photoluminescence superhydrophobicity silver selenide

Syntheses of CuO nanostructures in ionic liquids

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Science China Chemistry 2007年第1期50卷 63-69页

作者： WANG Li ZHAO Bin YUAN ZhongYong ZHANG XueJun Wu QingDuan CHANG LiXian ZHENG WenJun College of Chemistry Nankai UniversityTianjin 300071China

A simple and efficient approach is developed to fabricate single-crystalline CuO nanostructures through an ionic liquid assisted one-step low-temperature solid-state route.Both nanoparticles(5 nm in size)and nanorods(5-10 nm in diameter and 50-100 nm in length)of monoclinic CuO were obtained. These synthesized CuO nanostructures were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),X-ray photoelectron spectros- copy(XPS),energy dispersive spectroscopy(EDS)and nitrogen adsorption analysis.The morpholo- gies of the nanostructures can be controlled by tuning the amount of NaOH and ionic liquids.The growth mechanism of CuO nanostructures is investigated.

关键词： CuO nanostructures ionic liquids low-temperature solid-state route

Solution-phase synthesis of inorganic nanostructures by chemical transformation from reactive templates

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Science China Chemistry 2010年第2期53卷 365-371页

作者： HUANG Teng QI LiMin Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesCollege of ChemistryPeking UniversityBeijing 100871China

The solution-phase synthesis by chemical transformation from reactive templates has proved to be very effective in morphology-controlled synthesis of inorganic nanostructures. This review paper summarizes the recent progress in solution-phase synthesis of one-dimensional and hollow inorganic nanostructures via reactive templates, focusing on the approaches developed in our lab. The formation mechanisms based on reactive templates are discussed in depth to show the general concepts for the preparation processes. An outlook on the future development in this area is also presented.

关键词： reactive template morphology-controlled synthesis nanostructures one-dimensional structures hollow structures

Zinc Stannate nanostructures for Energy Conversion

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Chinese Journal of Chemistry 2021年第2期39卷 367-380页

作者： Jie Dou Qi Chen Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications Experimental Center of Advanced MaterialsSchool of Materials Science&EngineeringBeijing Institute of TechnologyBeijing100081 China Beijing Institute of Technology Chongqing Innovation Center Chongqing 4004100Beijing100081 China

To date,ternary metal oxide semiconductor materials have attracted extensive attention worldwide due to their unique optoelectronic properties.As a classical ternary oxide,Zn2SnO4 is featured with the high electron mobility,wide band gap,negligible visible light absorption and tailorable electronic band structures.Thus,it is an ideal material for practical use in solar cells,lithium batteries,sensors,and photo-catalysts.In this review,we summarize the recent research progress of this material with the focus on the synthesis methods,nanostructures,and the resulting effects on the crystal structure,optical properties,and photoelectrochemical properties.Moreover,their potential applications in different devices are highlighted and carefully discussed.

关键词： Zinc stannate Synthesis design nanostructures Applications Energy conversion