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Upon the osteoporotic condition, sluggish osteogenesis, excessive bone resorption, and chronic inflammation make the osseointegration of bioinert titanium (Ti) implants with surrounding bone tissues difficult, often lead to prosthesis loosening, bone collapse, and implant failure. In this study, we firstly designed clickable mussel-inspired peptides (DOPA-N3) and grafted them onto the surfaces of Ti materials through robust catechol-TiO2 coordinative interactions. Then, two dibenzylcyclooctyne (DBCO)-capped bioactive peptides RGD and BMP-2 bioactive domain (BMP-2) were clicked onto the DOPA-N3-coated Ti material surfaces via bio-orthogonal reaction. We characterized the surface morphology and biocompatibility of the Ti substrates and optimized the osteogenic capacity of Ti surfaces through adjusting the ideal ratios of BMP-2/RGD at 3:1. In vitro, the dual-functionalized Ti substrates exhibited excellent promotion on adhesion and osteogenesis of mesenchymal stem cells (MSCs), and conspicuous immunopolarization-regulation to shift macrophages to alternative (M2) phenotypes and inhibit inflammation, as well as enhancement of osseointegration and mechanical stability in osteoporotic rats. In summary, our biomimetic surface modification strategy by bio-orthogonal reaction provided a convenient and feasible method to resolve the bioinertia and clinical complications of Ti-based implants, which was conducive to the long-term success of Ti implants, especially in the osteoporotic or inflammatory conditions., Graphical abstract Mussel-inspired adhesion and bio-orthogonal reactions are combined for surface modification of Ti-based implants with RGD peptide and BMP-2 peptide. Dual-functionalized Ti-based implants can enhance osteogenesis and osseointegration through promoting BMSCs adhesion and osteodifferentiation, as well as modulate macrophage polarization in the osteoporotic rats.Image 1, Highlight • A clickable mussel-inspired peptide and two DBCO-capped bioactive peptides for facile decoration of Ti prostheses via robust catechol/TiO2 coordinative interactions and click chemical reaction. • Dual functionalized Ti-based surface can improve cell anchoring and osteogenicitity by rationally adjusting the grafting ratio of BMP-2 and RGD peptides. • Dual functionalized Ti-based surface synergistically achieve M2 shifting and efficient inflammation inhibition for osseointegration.

Lithium-sulfur battery cathodes still remain a challenge on capacity decay due to the shuttle effect even though a series of strategies have been tried. Here we report a novel matryoshka-like CuS@void@Co3O4 architecture of double micro-cubes (μ-cubes) that locks sulfur between the CuS core and the Co3O4 shell. Plenty of existing spaces between the μ-cubes suffice a high loading of sulfur and volumetric accommodation. The robust, double closed cubes configuration greatly enhances the confinement of polysulfides. In parallel, the CuS core increases the electronic conductivity and contributes to additional capacity, while the Co3O4 shell ensures a better interface activity. A high Li+ ion diffusion coefficient is obtained during the sulfur and lithium sulfide transformation. The constructed battery displays an initial capacity up to 1480 mAh g−1, and a Coulombic efficiency (CE) exceeding 99%. A capacity retention higher than 500 mAh g−1 with a CE larger than 99.8% after cycling 400 times at 0.2 C are achieved. In addition, under a temperature of −5 °C, a high capacity of 700 mAh g−1 at 0.2 C after 200 cycles is achieved, indicating a good low-temperature tolerance.

To overcome the low mechanical strength and difficult bonding of hydrogels to bones which are the major limitations of hydrogels used in bone-regeneration, a new type of calcium polyphosphate incorporated into bioinspired alginate/polyacrylic acid (CPP/PAA-Alg) hybrid double network (DN) hydrogel with both high strength and enhanced osseointergration was prepared by a two-step polymerization with alginate and polyacrylic acid for bone regeneration. The morphology, mechanical properties, swelling, biocompatibility, osseointegration and osteogenic ability of this CPP/PAA-Alg DN hydrogel were investigated. The results show that CPP/PAA-Alg DN hydrogel with highly porous microstructure possesses high water absorption capacity and highly strength properties which meet the requirements of bone repairing. The results of in vitro studies revealed that the CPP/PAA-Alg DN hydrogels can support the spread of cells and promote the cell proliferation. Animal studies demonstrated that the CPP incorporated would enhance the osseointegration of DN hydrogel with host bone at an early stage after implantation to accelerate the regeneration of bone. This research may provide a new way to develop biocompatible biomaterials with high mechanical strength and good osseointegration to meet the needs of bone regeneration.

The periosteum on the skeletal surface creates a unique micro-environment for cortical bone homeostasis, but how this micro-environment is formed remains a mystery. In our study, we observed the cells in the periosteum presented elongated spindle-like morphology within the aligned collagen fibers, which is in accordance with the differentiated osteoblasts lining on the cortical surface. We planted the bone marrow stromal cells(BMSCs), the regular shaped progenitor cells, on collagen-coated aligned fibers, presenting similar cell morphology as observed in the natural periosteum. The aligned collagen topology induced the elongation of BMSCs, whichfacilitated the osteogenic process. Transcriptome analysis suggested the aligned collagen induced the regular shaped cells to present part of the periosteum derived stromal cells(PDSCs) characteristics by showing close correlation of the two cell populations. In addition, the elevated expression of PDSCs markers in the cells grown on the aligned collagen-coated fibers further indicated the function of periosteal topology in manipulating cells' behavior. Enrichment analysis revealed cell-extracellular matrix interaction was the major pathway initiating this process, which created an osteo-friendly micro-environment as well. At last, we found the aligned topology of collagen induced mechano-growth factor expression as the result of Igf1 alternative splicing, guiding the progenitor cells behavior and osteogenic process in the periosteum. This study uncovers the key role of the aligned topology of collagen in the periosteum and explains the mechanism in creating the periosteal micro-environment, which gives the inspiration for artificial periosteum design.

Hollow nanostructures have received broad attention for lithium-storage owing to their advantages in accommodating volume-change. However, taking the hollow sphere as an example, the void inside consumes a large volume fraction, resulting in a low material loading. Herein, we present a novel hollow nanosheet using Co2SiO4 as demonstrating example. The Co2SiO4 nanosheets-based anode exhibits a high and stable capacity of 1456 mAh g−1 after 200 cycles at 0.2 A g−1, and an excellent rate-performance after three rounds of cycling. In addition, the dynamic lithiation and delithiation of Co2SiO4 are presented using an in situ transmission electron microscopy technology.

High energy density Li-S battery has attracted broad attention; however the capacity retention is still non-ideal. The major challenge is to find a way to effectively prevent the shuttle effect of the lithium polysulfides during charging/discharging. Here, we present a novel wheel-confined composite consisting of MnO2 nano-rod as wedge and SnO2 sphere as the skeleton filled with sulfur, which was synthesized using a facile chemical method. The battery with the S@MnO2@SnO2 composite as cathode exhibits a capacity as high as 1323 mAh g−1 at 0.1 C and a high capacity retention of only 0.03% decay per cycle over 500 cycles, which indicates a greatly reduced shuttle effect in Li-S batteries. The battery also shows good rate-performance and low-temperature properties. In addition, the I-V measurements and the first-principle calculations have demonstrated an enhanced electron transfer through the composite.

The recalcitrant nature of perfluoroalkyl substances (PFASs) urges scientists to discover solutions to permanently remove PFAS contaminations from water with less energy in contrast to incineration. Herein, a duo-functional tri-metallic-oxide (f-TMO) hybrid photocatalyst was developed via a facile process, which displayed both high adsorption capacity and high defluorination rate of a series of PFASs including PFOA, PFOS, PFHpA, PFHxA and PFBA due to the generated holes/electrons (h

Summary: The Li+/Ni2+ mixing in LiNi0.8Mn0.1Co0.1O2 (NMC811) leads to fast battery capacity decay. Here we report a dual-gradient nickel-rich layered cathode material (D-NMC811), using nickel-based metal organic framework of Ni-MOF-74. The formation of a protective layer with rock salt phase due to the reduced nickel oxidation state on the surface of the primary particles resists internal strain and suppresses further phase transition, thus alleviating crack generation. After 300 cycles at ⅓ C, a high half-cell capacity retention of 88.50% with 0.038% decay per cycle is observed. The full-cell battery displays a high capacity retention of >86.7% with a Coulombic efficiency of >99.86% at ⅓ C after 300 cycles. The 300 mAh pouch cell delivers an energy density of 216.4 Wh/kg. After 500 cycles at 1.0 C, it still displays 84.1% capacity retention while the battery with conventional NMC811 only shows a retention of 53.0% after 400 cycles.

In order to determine the pattern and spatial distribution of polycyclic aromatic hydrocarbons (PAHs) in contaminated soil at a site of an organic chemical plant with irregular terrain, we developed a method of soil sampling by subarea that considers topographic features. We divided the site into the west subarea, which had the highest elevation; the southeast subarea (second-highest elevation), and the northeast subarea (lowest elevation). Two- and three-dimensional kriging and principal component analysis (PCA) models were employed to interpret the contamination pattern and spatial distribution of PAH contamination and to calculate the volume of soil contaminated with PAHs. The results show that the total concentrations of 16 priority PAHs in each borehole ranged from 0.7 to 4889.5 mg/kg, with an average of 130 mg/kg. The pollutants mainly accumulated in the first layer of the site (0–1 m). Compared with the pollution levels at other chemical plants reported previously, the soil PAH concentrations measured in this study were higher. PCA results show that the explained variations of the first and second components were 88% and 0.9%, respectively. The samples had good separation characteristics between the different subareas and correlation and pertinence within the same subarea are strong. Volumes of soil contaminated with benzo[a]pyrene calculated using four different interpolation models were 131,019, 135,365, 142,741, 146,783 m3. Three-dimensional kriging that takes into consideration the surface-elevation change showed the lowest root-mean-square error and mean error, as well as higher accuracy compared with the other models. These results are important for defining remediation boundaries and the volume of contaminated soil for sites subjected to risk assessment and remediation.

We developed a tree-ring chronology based on 52 ring-width series from 25 Pinus tabulaeformis trees at Tianlong Mountain (TLM) using the signal - free method. TLM is located in the middle reaches of the Fen River, North China, and is influenced by the East Asian monsoon system. Tree growth was highly correlated (0.789) with the Palmer Drought Severity Index (PDSI) from May to July and indicated a drought-stress growth pattern. Therefore, we developed a robust May-July PDSI reconstruction for 1792–2011 that explained 62.3% of the instrumental variance for 1951–2005. Severe drought years determined by the reconstruction are consistent with conditions reported in historical documents. The TLM PDSI reconstruction was consistent with other tree-ring-based hydroclimate reconstructions in North China; thus, it may accurately represent dry/wet changes that occur over a large area. Cyclical spectral peaks at 2–8 years in the reconstructed PDSI may indicate ENSO activity, as suggested by the positive correlation with the western Pacific sea-surface temperatures (SSTs) and the negative correlation with the eastern Pacific SSTs on the inter-annual scale.

Polycyclic aromatic hydrocarbons (PAHs) from chemical plants can cause serious pollution of surrounding agricultural soils. A comprehensive study of agricultural soils was conducted in the vicinity of a chemical plant in China to characterize the soil PAH concentration, as well as their composition and sources. Human health and a screening-level ecological risk assessment were conducted for PAH contamination in agricultural soils. The results showed that the total concentrations of 16 priority PAHs ranged from 250.49 to 9387.26 ng g(-1), with an average of 2780.42 ng g(-1). High molecular weight PAHs (four to six rings) were the dominant component, accounting for more than 60% of all PAHs. Principal component analysis (PCA) and positive matrix factorization model (PMF) suggested that diesel emissions, coal combustion, coke ovens, and fuel combustion and gasoline emissions were the main sources of PAHs in agricultural soils. The ecological risk assessment results based on the effects range-low (ERL), the effects range-median (ERM), and the ecological screening levels (ESL) indicated that the exposure to ∑PAH16 wasERL,ERM, and ≥ERL andERM at 21.9, 0, and 21.9% of the soil sampling stations, the exposure to ∑PAH16 wasESL at 78.1% of the soil sampling stations, and could induce biological effects in mammals. The Bapeq concentrations posed a potential carcinogenic risk to humans. Further risk management and control of soil PAHs in these agricultural soils is required to ensure the safety of the biocoenosis and human health.

Soil arsenic (As) pollution around large-scale As mine contaminated sites is of great concern, but there have been no detailed reports about them in China. A comprehensive study was conducted to determine the soil pollution characteristics and the multiple potential risks to the environment and the ecosystem of a large-scale arsenic slag contaminated site in southwest China. A total of 2,816 samples from three soil layers were collected and the As concentration was determined. The results showed that the As concentrations in the soil samples were highly variable and ranged from not detectable (N.D.) to 76,400.00 mg/kg, with a mean concentration of 1,205.97 mg/kg. The estimation of the mean value for the potential ecological risk index (Er) was 606, which indicated that there was a potential severe ecological risk, and over 39% of the samples were in the high ecological risk category (Er ≥ 80). The geoaccumulation index (Igeo) results showed that the As levels ranged from uncontaminated (Igeo

High brittleness and lack osteogenesis are two major limitations of calcium phosphate cement (CPC) in application in bone defect reconstruction. Here we prepared a composite calcium phosphate cement by mixing N-acetyl cysteine loaded silk fibroin solution with α-tricalcium phosphate. In vitro cytology experiment revealed that SF-NAC/α-TCP could significantly increase the activity of exocrine ALP and up-regulated expression of bone-related genes. However, NAC up-regulated gene expression could be significantly suppressed by DKK1. We propose that NAC functioning as osteogenic factor by activating the Wnt/β-catenin signaling pathway may be the possible mechanism of up-regulation of osteogenic genes. Bone regeneration in vivo shown in a rat femur defect was enhanced by the addition of NAC in SF/α-TCP. In addition, the combination intensity of cement-bone interface was improved. The combination SF-NAC/α-TCP might be developed into a promising tool for bone tissue repair in the clinic.

Nanodiamond, due to its superior hardness and Young's modulus in combination with its large surface area holds great potential for the mechanical reinforcement of polymer matrices. However, it is still not possible to take full advantage of these properties in polymer matrix composites. The main reasons are poor dispersion, agglomeration and a weak interface between nanodiamond and the polymer. Aminated nanodiamond can be used to form a strong covalent interface with an epoxy polymer. We show how Young's modulus can be further improved if an interference of nanodiamonds amino groups with the epoxy stoichiometry is taken into account. Dispersion of nanodiamond is improved by slightly adjusting the manufacturing process, thus increasing Young's modulus of the composites. Predictions by a micromechanics homogenization method that consider nanodiamond agglomeration and dispersion suggest that Young's modulus can be further increased by slightly improving both parameters. For the first time we show that epoxy can be cured solely by nanodiamonds amino groups without any additions of curing agent, resulting in a composite's Young's modulus measured by nanoindentation of up to ∼18 GPa – a 700% improvement over neat epoxy.

Onion-like carbon (OLC), also known as carbon onions, is an attractive material for electrical energy storage in regards to high rate, high power applications. We report the most up to date, systematic, and extensive study of the electrochemical behavior of carbon onions in aqueous (1 M sulfuric acid, H2SO4) and organic (1 M tetraethylammonium tetrafluoroborate, TEA-BF4, and 1 M tetrabutylammonium tetrafluoroborate, TBA-BF4, in acetonitrile) electrolytes. The physical and electrical properties of OLC are studied as a function of the synthesis temperature and compared with diamond soot, carbon black, and activated carbon. To obtain a molecular scale picture of the processes at the OLC-electrolyte interface, we supplement the experimental work with molecular dynamics (MD) simulations of carbon onions in organic electrolytes. The capacitive performance of OLC exceeds other carbon materials at high charge/discharge rates (up to 50 V s(-1); time constant tau similar to 10 ms). OLC produced from detonation soot has a performance similar to that of OLC from highly purified nanodiamond. While OLC produced at 1500 degrees C has the largest specific surface area, OLC produced at 1800 degrees C has the highest conductivity and shows the best capacitive performance at high rates.

Multifunctional bone scaffold materials have been produced from a biodegradable polymer, poly(L-lactic acid) (PLLA), and 1-10% wt of octadecylamine-functionalized nanodiamond (ND-ODA) via solution casting followed by compression molding. By comparison to pure PLLA, the addition of 10% wt of ND-ODA resulted in a significant improvement of the mechanical properties of the composite matrix, including a 280% increase in the strain at failure and a 310% increase in fracture energy in tensile tests. The biomimetic process of bonelike apatite growth on the ND-ODA/PLLA scaffolds was studied using microscopic and spectroscopic techniques. The enhanced mechanical properties and the increased mineralization capability with higher ND-ODA concentration suggest that these biodegradable composites may potentially be useful for a variety of biomedical applications, including scaffolds for orthopedic regenerative engineering.

The rapid assembly of magnetic carbon nanotubes is mediated through the electrostatic attraction of α-haematite nanoparticles to carboxylic groups decorating their outer surface. The system is then stabilised through covalently bonding a silica coat using a 3-aminopropyltriethoxysilane precursor, which creates a thin barrier protecting the α-haematite particles from aggressive pH solutions. The nanocomposites can be effectively dispersed in aqueous solution and can be attracted to an external magnetic field. The proposed method can be used for synthesis of magnetic CNTs suitable for assembling densely packed magnetic arrays, remotely guided drug delivery and organic chemical wastewater remediation with the added benefit of nanomaterial recovery. Therein, p-nitroaniline was demonstrated to still adsorb to uncoated areas of the silica-sheathed magnetic MWCNT composite.

The dependence on temperature and structure of the electrochemical activity of a catalyst supported on hollow carbon nanocages (HCNCs) with large scales (>5 g h –1 ) by a simple N 2 -bubbling floating method is discussed. The effect of gas flow on an HCNC-supported catalyst was systematically studied in our previous work. Here we specify the electrocatalytic activity of the samples with different temperatures and graphite structures under 900 and 1000 °C by cyclic voltammograms. The peak current density of H 2 -adsorption/desorption is four times higher than that of the commercial Pt/C (Vulcan XC-72). Besides the comparison with commercial carbon, the fuel cell performance was measured. The single fuel cell test for Pt/HCNCs showed a high turn-on voltage of 0.9 V and a relatively high power density of 0.13 W cm –2 under a low temperature of 60 °C and a low gas pressure of 1 atm.

Macroscopic SiC nanowires (SiCNWs) were successfully synthesized at the gram level (2–4 g h−1) by using a simple solid–vapor reaction of silicon powders and carbon oxides, assisted by ZnS. This results in a promising material for a wide range of applications. The obtained products possess a small size of 10–30 nm and a good single-crystal structure. In addition, a specific surface area of 1.6 m2 g−1 was achieved. A high electrochemical activity to H2 adsorption/desorption and methanol oxidation was observed from cyclic voltammograms in H2SO4 and H2SO4/CH3OH solutions after loading with 50 wt.% Pt. Furthermore, a high catalytic performance for oxygen reduction at ∼0.57 V and good chemical stability were displayed. The novel SiCNW-supported catalyst shows potential for fuel cells with long lifetimes.

The electrochemical property of platinum loaded on activated carbon nanotubes (Pt/ACNTs) was investigated by cyclic voltammograms (CVs) recorded in H 2 SO 4 and H 2 SO 4 /CH 3 OH aqueous solutions, respectively. Compared to 0.0046 A/cm 2 of Pt-loaded on pristine carbon nanotubes (Pt/CNTs) with a S BET of 164 m 2 /g and 0.0042 A/cm 2 of conventional carbon black (Pt/C, Vulcan XC-72) with a S BET of ∼250 m 2 /g, a better electrochemical activity (a high current density of 0.0070 A/cm 2 for weak-H 2 adsorption/desorption) of the Pt/ACNTs with high specific surface area ( S BET ) of 830–960 m 2 /g was obtained. Furthermore, the highest current density of 0.079 A/cm 2 at 0.65 V in anodic sweep was observed during the methanol oxidation. On the basis of Pt size, utility ratio, and electro-active specific surface area (EAS), the Pt/ACNTs with a high Pt-loading of 50 wt.% exhibited the best electrochemical activity. The present ACNTs may be an excellent support material for electrochemical catalyst in proton exchange membrane and direct methanol fuel cells.

The growth mechanism of silicon nanowires synthesized with or without a metal catalyst via chemical-vapor-deposition (CVD) is discussed by using a developed vapor–liquid–solid and novel sulfide-assisted growth models, respectively. The metal catalyst plays an important role on the catalytic growth. However, the growth of silicon nanowires with sulfide is chiefly affected by the compound decomposition, gas stream, and temperature difference. Silicon nanowires fabricated with metal can be self-organized while a large scale of samples can be achieved with metal-free catalyst. The growth mechanism comparison between metal- and non-metal assisted methods for synthesizing silicon nanowires will supply a beneficial help in deepening the understanding of crystal procedure and improving the sample quality.

The growth mechanism for synthesizing large scales of one-dimensional silicon nano-structures (silicon nano-wires (SiNWs) or silicon oxide nano-wires (SiO 2 -NWs)) by a simple evaporation of sulfur-contained powders on silicon wafer is discussed. A novel sulfide-assisted mechanism referring to oxygen-assisted mechanism is proposed. Amongst this simple method, sulfide or pure sulfur can both assist the formation of SiNWs. The growth is fast and some SiNWs are easily oxidized to be amorphous structure of SiO 2 -NWs under the low-vacuum system. The simple method suggests a useful route to achieve plenty of one-dimensional silicon nano-structures for further research.

Temperature dependence of the first-order Raman scattering in silicon nanowires was studied using an amended phonon confinement model. The experimental band position and linewidth both showed a better agreement with the calculated data if the temperature effect was considered. Furthermore, a slight improvement in crystal quality was observed.

Quantities of crystalline array-orderly silicon nano-wires (SiNWs) were fabricated using chemical-vapor-deposition (CVD) method at low temperature (550–400 °C). In the experiments, the decreasing temperature process was used. By means of transmission electron spectroscopy, X-ray diffraction and Raman spectroscopy, it was found that the SiNWs were well crystallized. Finally, the growth mechanism of the SiNWs during the decreasing process was discussed.

Crystalline boron oxide nanowires have been synthesized on silicon substrates by chemical vapor deposition (CVD) process without the use of catalysts or templates. It is pointed out that the boron oxide nanowires are cubic and single crystalline, and the diameter of the nanowires is in the range of 20– 80 nm . Some of the nanowires branched, and the diameters of the branches and stems of the branched boron oxide nanowires are in the range of 20–80 and 100– 200 nm , respectively. The crystallinity, morphology, and structure features of the as-prepared boron oxide nanowires were investigated by field emission scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and selected area electron diffraction. Furthermore, Raman spectrum and Fourier transform infrared spectroscopy of the nanowires were also investigated.

Tiny silicon nano-wires (SiNWs) were synthesized on silicon wafers by the chemical vapor deposition (CVD) technique. The morphology and structure of tiny SiNWs were analyzed by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The results indicate that the tiny SiNWs were part-crystalline structure and were about 3 nm in minimal diameter. Based on the line shift of Raman spectra, the structure transform of the tiny SiNWs was discussed. The defect-inducing growth mechanism will probably provide a new method for the minimum of the one-dimensional nano-materials.

Thin silicon nano-wires (SiNWs) with a diameter of ∼10–20 nm were fabricated by a simple thermal evaporation of silicon wafer at 1523 K. The gold produced by an electrochemical method was covered on the wafer surface as catalyst. It was found that the SiNWs are amorphous and its Raman peak shifted down maybe due to the effect of laser heating and quantum confinement. Finally, a temperature gradient growth model is suggested to explain the growth direction of SiNWs.

Silicon nanowires (SiNWs) with a diameter of ∼20 nm were synthesized by the thermal evaporation of sulfur powders on silicon wafers. The source of the SiNWs came from the silicon substrates. It is considered that the generated SiS compound assisted the formation of SiNWs. Finally, the Raman shift of SiNWs was discussed.

Silicon nano-wires (SiNWs) with diameter of ∼30 nm and length of tens of micrometers on silicon wafers were synthesized by a novel thermal evaporation of zinc sulfide. After thermal evaporation at 1080°C for 1 h , crystalline SiNWs were produced. It was found that the tip of SiNWs contained sulfur, while the other places of SiNWs did not. It is considered that the decomposition of SiS resulted in the formation of SiNWs. On the basis of the facts, a sulfide-assisted growth model of SiNWs was suggested.

Tiny SiO2 nano-wires (SiO2-NWs) were synthesized on a p-Si (1 1 1) wafer by the chemical-vapor-deposition method. The minimum diameter of the nano-wires was around 9 nm , and the length was longer than 10 μm . The results of transmission electron microscopy shows that the amorphous nano-wires were composed of Si and O with an approximate atomic ratio of 1:2. Furthermore, the photoluminescence behavior of the SiO2-NWs has been also checked.

Array-ordered single-crystal silicon nanowires were fabricated by the nanochannel-aluminal and CVD method. The average length and diameter of the nanowires is about 10 μm and 60 nm, respectively. A study of the Raman spectrum of the nanowires shows that the Raman shift to low frequency is due to the quantum confinement effect, which is discussed by using the phonon confinement model. Also we determine the peaks of the Raman spectrum to be corresponding to that of crystal silicon (c-Si).

A large-scale crystalline silicon nanowires (SiNWs) with a diameter of ∼30 nm and length of tens of micrometers on Al2O3 templates and silicon wafers were synthesized by the thermal evaporation of silicon monoxide (SiO). The SiNWs were measured by transmission electron microscopy, scanning electron microscopy, X-ray diffraction and Raman spectroscopy, respectively. It was pointed out that the SiNWs possessed the well crystalline structure. Therefore, it is considered that SiO could be used as Si sources to produce larger-scale SiNWs and crystalline SiNWs may grow from amorphous nuclei.

The well aligned boron nanowires (BNWs) with single crystalline structure were successfully prepared by using nanochannel-Al 2 O 3 as a substrate and a chemical vapor deposition process. The diameter and length of BNWs were around of 40 nm and several micrometers, respectively. The formation of single crystal BNWs has been conceptually interpreted.

The crystallization and the disappearance of the defects and impurity stress of silicon nanowires (SiNWs) after annealing at high temperature (900 °C) have been investigated. The chemical-vapor-deposition (CVD) and alumina template technology were used for the synthesis of the SiNWs. Then transmission electron microscopy (TEM), selected-area electron diffraction (SAED) and photoluminescence (PL) spectra were used to study the crystallization procedure and the disappearance of defects of the SiNWs.

Array-orderly single crystal silicon nano-wires (SiNWs) using self-organized nano-holes of anodically oxidized aluminum were fabricated. By field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM), the well-orderly single crystal SiNWs arrays were observed. The interval of the SiNWs is excellent symmetrical and consentaneous. The diameter and the length are around 35 nm and 4 μm, respectively. Furthermore, the energy dispersive X-ray spectroscopy analysis (EDX) indicated that the SiNWs consist of silicon core and silicon oxide sheath mainly. The Raman scattering was also carried out to analyze the structure of the oriented SiNWs. Finally, the growth mechanism of the SiNWs was discussed.

Directional CdS nanowires have been fabricated by using chemical bath deposition (CBD) and porous anodic aluminum oxide (AAO) template. X-ray diffraction and selected area electron diffraction show that the nanowires are hexagonal polycrystalline in nature. Transmission electron microscopy (TEM) reveals that the diameters of nanowires are about 60 nm. Furthermore, the high-resolution TEM illustrates the lattice images of {0 0 2}, {1 0 1} and {1 0 0} planes in the nanowires. The directional growth of nanowires is verified by scanning electron microscopy. It is believed that the ion-by-ion mechanism dictates the CBD of CdS nanowires within the pores of AAO template.

La 1− x Ca x MnO 3 (LCMO) nanowires were prepared using a simple sol–gel process and nano-channel alumina (NCA). X-ray diffraction (XRD) and selected-area electron diffraction (SAED) indicate that the nanowires are of monoclinic perovskite structure. Transmission electron microscopy (TEM) shows that the diameters of nanowires are around 30 nm. Furthermore, high-resolution TEM reveals a clear lattice image of {0 2 1} planes in a LCMO nanowire. It can be expected that the method presented in this Letter is also appropriate for the preparation of nanowires of other mono-component or multi-component oxides.

Infrared (IR) spectra of the silicon nanowires (SiNWs) with oxide layer are analyzed by introducing the disorder-induced mechanical coupling between the optically active oxygen asymmetric stretch (AS) and inactive oxygen asymmetric stretch (I-AS) modes in terms of the transverse-optic (TO) and longitudinal-optic (LO) vibrational modes. The shapes of the IR spectra are similar to that of the reported SiO2, indicating that the SiNWs possess an oxide layer outside. The TO frequencies of coupled AS and I-AS are experimentally observed as peak at approximately 1085 cm− 1 and its shoulder of 1200 cm− 1, respectively. The other TO absorption peaks of ∼ 468 cm− 1, ∼ 480 cm− 1, and ∼ 808 cm− 1 are also observed. Furthermore, the intensity of the AS-mode TO band centered at ∼ 1085 cm− 1 decreases while those of silicon lattice absorption peaks are enhanced with the crystalline quality increased.

Copper sulfide (Cu2S) micro-tubes with the diameter of ∼1–5 μm and the length of tens of μms were successfully synthesized by a simple thermal evaporation of zinc sulfide powders on copper substrates at ∼700 °C for about 1 h. The atom ratio of element Cu and S (2:1at.%) of single micro-tube confirmed that the micro-tube was Cu2S. The samples were indicated to be composed of monoclinic Cu2S and hexagonal β-Cu2S by X-ray diffraction (XRD) data. From the facts of results, a growth mechanism of copper sulfide micro-tubes was discussed briefly.