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Dive into the research topics where Gao Hong-Jun is active.

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Featured researches published by Gao Hong-Jun.


Chinese Physics | 2007

Formation of graphene on Ru(0001) surface

Pan Yi; Shi Dongxia; Gao Hong-Jun

The samples are characterized by scanning tunnelling microscopy (STM) and Auger electron spectroscopy (AES). STM images show that the Moire pattern is caused by the graphene layer mismatched with the underlying Ru(0001) surface and has an N × N superlattice. It is further found that the graphene monolayer on a Ru(0001) surface is very stable at high temperatures. Our results provide a simple and convenient method to produce a graphene monolayer on the Ru(0001) surface, which is used as a template for fabricating functional nanostructures needed in future nano devices and catalysis.


Chinese Physics B | 2010

Synthesis of monodisperse palladium nanocubes and their catalytic activity for methanol electrooxidation

Ding Hao; Shi Xue-Zhao; Shen Cheng-Min; Hui Chao; Xu Zhi-Chuan; Li Chen; Tian Yuan; Wang Deng-Ke; Gao Hong-Jun

The single crystalline palladium nanocubes with an average size of 7 nm were prepared in the presence of poly (vinyl pyrrolidone) (PVP) and KBr using the polyol method. The as-prepared Pd nanocubes were highly uniform in both size and shape. The ordered packing structures including monolayer and multilayer can be fabricated via the rate-controlled evaporation of solution solvent. The electrochemical catalytic activity of these Pd nanocubes towards methanol oxidation was found to be higher than that of spherical Pd nanoparticles of similar size.


Chinese Physics | 2005

Four-probe scanning tunnelling microscope with atomic resolution for electrical and electro-optical property measurements of nanosystems

Lin Xiao; He Xiaobo; Lu Jun-Ling; Gao Li; Huan Qing; Shi Dongxia; Gao Hong-Jun

We demonstrate a special four-probe scanning tunnelling microscope (STM) system in ultrahigh vacuum (UHV), which can provide coarse positioning for every probe independently with the help of scanning electron microscope (SEM) and fine positioning down to nanometre using the STM technology. The system allows conductivity measurement by means of a four-point probe method, which can draw out more accurate electron transport characteristics in nanostructures and provides easy manipulation of low dimension materials. All measurements can be performed in variable temperature (from 30K to 500K), magnetic field (from 0 to 0.1T) and different gas environments. Simultaneously, the cathodoluminescence (CL) spectrum can be achieved through an optical subsystem. Test measurements using some nanowire samples show that this system is a powerful tool in exploring electron transport characteristics and spectra in nanoscale physics.


Chinese Physics Letters | 2008

Monodispersive CoPt Nanoparticles Synthesized Using Chemical Reduction Method

Shen Cheng-Min; Hui Chao; Yang Tian-Zhong; Xiao Cong-Wen; En Shu-Tang; Ding Hao; Gao Hong-Jun

Monodispersive CoPt nanoparticles in sizes of about 2.2 nm are synthesized by superhydride reduction of CoCl2 and PtCl2 in diphenyl ether. The as-prepared nanoparticles show a chemically disordered A1 structure and are superparamagnetic. Thermal annealing transforms the A1 structure into chemically ordered L10 structure and the particles are ferromagnetic at room temperature.


Chinese Physics B | 2008

Synthesis and photoluminescence property of boron carbide nanowires

Bao Li-Hong; Li Chen; Tian Yuan; Tian Ji-Fa; Hui Chao; Wang Xing-Jun; Shen Cheng-Min; Gao Hong-Jun

Large scale, high density boron carbide nanowires have been synthesized by using an improved carbothermal reduction method with B/B2O3/C powder precursors under an argon flow at 1100°C. The boron carbide nanowires are 5–10 μm in length and 80–100 nm in diameter. Transmission electron microscopy (TEM) and selected area electron diffraction (SAED) characterizations show that the boron carbide nanowire has a B4C rhombohedral structure with good crystallization. The Raman spectrum of the as-grown boron carbide nanowires is consistent with that of a B4C structure consisting of B11C icosahedra and C-B-C chains. The room temperature photoluminescence spectrum of the boron carbide nanowires exhibits a visible range of emission centred at 638 nm.


Chinese Physics B | 2009

Transport properties of boron nanotubes investigated by ab initio calculation

Guo Wei; Hu Yi-Bin; Zhang Yuyang; Du Shi-Xuan; Gao Hong-Jun

We investigate atomic and electronic structures of boron nanotubes (BNTs) by using the density functional theory (DFT). The transport properties of BNTs with different diameters and chiralities are studied by the Keldysh nonequilibrium Green function (NEGF) method. It is found that the cohesive energies and conductances of BNTs decrease as their diameters decrease. It is more difficult to form (N, 0) tubes than (M, M) tubes when the diameters of the two kinds of tubes are comparable. However, the (N, 0) tubes have a higher conductance than the (M, M) tubes. When the BNTs are connected to gold electrodes, the coupling between the BNTs and the electrodes will affect the transport properties of tubes significantly.


Chinese Physics | 2005

Controlled growth of large'scale silver nanowires

Xiao Cong-Wen; Yang Hai-Tao; Shen Cheng-Min; Li Zi-An; Zhang Huai-Ruo; Liu Fei; Yang Tian-Zhong; Chen Shu-Tang; Gao Hong-Jun

Large-scale silver nanowires with controlled aspect ratio were synthesized via reducing silver nitrate with 1, 2-propanediol in the presence of poly (vinyl pyrrolidone) (PVP). Scanning electron microscopy, transmission electron microscopy and x-ray powder diffraction were employed to characterize these silver nanowires. The diameter of the silver nanowires can be readily controlled in the range of 100 to 400 nm by varying the experimental conditions. X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results show that there exists no chemical bond between the silver and the nitrogen atoms. The interaction between PVP and silver nanowires is mainly through the oxygen atom in the carbonyl group.


Chinese Physics Letters | 2008

Probing Field Emission from Boron Carbide Nanowires

Tian Ji-Fa; Bao Li-Hong; Wang Xing-Jun; Hui Chao; Liu Fei; Li Chen; Shen Cheng-Min; Wang Zong-Li; Gu Changzhi; Gao Hong-Jun

High density boron carbide nanowires are grown by an improved carbon thermal reduction technique. Transmission electron microscopy and electron energy lose spectroscopy of the sample show that the synthesized nanowires are B4 C with good crystallization. The field emission measurement for an individual boron nanowire is performed by using a Pt tip installed in the focused ion beam system. A field emission current with enhancement factor of 106 is observed and the evolution process during emission is also carefully studied. Furthermore, a two-step field emission with stable emission current density is found from the high-density nanowire film. Our results together suggest that boron carbide nanowires are promising candidates for electron emission nanodevices.


Chinese Physics B | 2008

Single crystalline boron carbide nanobelts: synthesis and characterization

Bao Li-Hong; Li Chen; Tian Yuan; Tian Ji-Fa; Hui Chao; Wang Xing-Jun; Shen Cheng-Min; Gao Hong-Jun

This paper reports that the large-scale single crystalline boron carbide nanobelts have been fabricated through a simple carbothermal reduction method with B/B2O3/C/Fe powder as precursors at 1100°C. Transmission electron microscopy and selected area electron diffraction characterizations show that the boron carbide nanobelt has a B4C rhomb-centred hexagonal structure with good crystallization. Electron energy loss spectroscopy analysis indicates that the nanobelt contains only B and C, and the atomic ratio of B to C is close to 4:1. High resolution transmission electron microscopy results show that the preferential growth direction of the nanobelt is [101]. A possible growth mechanism is also discussed.


Chinese Physics B | 2008

Anomalous aggregation growth of palladium nanosphere with SPR band in visible range

Xiao Cong-Wen; Shen Cheng-Min; Xu Zhi-Chuan; Yang Tian-Zhong; Gao Hong-Jun

The morphology and properties of nanostructures are significantly influenced by the chemical coordination during their growth procedure. Using small molecule N-vinyl pyrolidone as stabilizer, this paper introduces a new strategy for synthesis of palladium nanospheres, which has a novel surface plasmon resonance band in the visible range. An aggregation growth mode was observed in the growth process. More specifically, the growth rate increases with increasing concentration of stabilizer. The absorption in visible region suggests new optical applications for these Pd nanospheres, such as photocatalysis, photothermal heating and surface enhanced Raman scattering.

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Shen Cheng-Min

Chinese Academy of Sciences

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Du Shi-Xuan

Beijing Normal University

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Wang Yeliang

Chinese Academy of Sciences

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Shi Dongxia

Chinese Academy of Sciences

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Bao Li-Hong

Chinese Academy of Sciences

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Guo Hai-Ming

Chinese Academy of Sciences

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Hui Chao

Chinese Academy of Sciences

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Pang Shi-Jin

Chinese Academy of Sciences

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Yang Tian-Zhong

Chinese Academy of Sciences

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Li Chen

Chinese Academy of Sciences

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