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Grapefruit peel carbon (GPC) is prepared from waste grapefruit peel and further used as substrate for in situ construction of MoS2 arrays, forming MoS2/GPC heterostructured materials. Based on the effect of the mass ratio between MoS2 and GPC on the morphology and structure, it can be found that the mass ratio not only has an important impact on the morphology and structure of MoS2, but also further affects the energy storage performance when used as the anode in lithium-ion batteries. Under the optimal mass ratio of 3:1, flower-like MoS2 is uniformly dotted on the GPC surface, presenting a special heterostructure, which has been successfully synthesized via the hydrothermal method. The electrochemical study shows that the MoS2/GPC composite obtained exhibits satisfying charge–discharge stability and rate capability thanks to the short diffusion channel for lithium ions and very low charge transfer resistance. Electrochemical impedance spectroscopy at different states of charge reveals that the passivation layer formed in the initial stage plays an important role in maintaining the stability of the electrode.

Z-scheme heterostructure photocatalysts for the transfer and separation efficiency of carriers are increasingly popular. CdS nanoparticle decorated three-dimensional (3D) flower-like Zn3(PO4)2 nanostructures were prepared through a simple hydrothermal route and precipitation methods. The CdS/Zn3(PO4)2 heteronanostructures were characterized through X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), UV-visible light spectroscopy (UV-vis), photoluminescence (PL) spectroscopy and photoelectrochemical measurements. The results showed that the three-dimensional flower-like structure of Zn3(PO4)2 composed of two-dimensional nanoplates and CdS/Zn3(PO4)2 heteronanostructures was obtained. The results of the Mott–Schottky measurements and the active species trapping experiments suggested that a Z-scheme system between the CdS nanoparticles and Zn3(PO4)2 nanoplates was formed. Meanwhile, the CdS/Zn3(PO4)2 heteronanostructures exhibited much higher photocatalytic activity for the degradation of MB under visible light, and that of the CdS/Zn3(PO4)2-13 heteronanostructure with excellent photocatalytic stability is nearly 3.04 times higher than that of pure Zn3(PO4)2 nanostructures.

The green treatment of dye wastewater has always been a research hotspot in the environmental field. The photocatalytic technology is considered to be a simple and effective strategy to remove dyes in wastewater. A new type of NiWO4/WO3 Z-scheme heterojunction microspheres were synthesized by a simple hydrothermal method and impregnation-calcination process. The crystal structure, microscopic morphology, optical and electrochemical properties of the samples were systematically characterized. The photocatalytic activity of methylene blue (MB) was studied by visible light irradiation. The results show that the direct Z-scheme heterojunction formed by NiWO4/WO3 effectively reduces the transfer resistance of photogenerated carriers and improves the separation efficiency of photogenerated carriers. The degradation rates of NiWO4/WO3-4 Z-scheme heterojunction microspheres to MB dye are 1.8 and 3.2 times higher than that of pure WO3·2H2O and WO3 microspheres, respectively. Combined with the Mott-Schottky curve and the active species capture experiments, a possible Z-scheme photogenerated carrier transfer mechanism is proposed. This study provides a method for the development and design of Z-scheme heterojunction photocatalysts in the field of wastewater purification.

Understanding the structural reconstruction of metal nanoparticles (NPs) under working conditions is of particular importance to catalytic processes. Here, using Wulff construction combined with de...

Co-doped Bi2MoO6 photocatalyst has been synthesized by a simple and facile solvothermal method. It exhibits the flower-like microspheres composed of orthorhombic Bi2MoO6 nanoplates with the increase of the Co doping amount from 0 to 0.4%. Among these Co-doped samples, 0.1% Co–Bi2MoO6 sample shows the degradation efficiency of 99.7% for Rhodamine B under visible-light-irradiation within 120 min, which is higher than pure Bi2MoO6 and other Co-doping Bi2MoO6 flower-like microspheres. The calculated apparent reaction rate constant for the 0.1% Co–Bi2MoO6 of 0.0298 ± 0.0028 min–1 is 4.18 times of pure Bi2MoO6 photocatalyst (0.0071 ± 0.0010 min–1). The flower-like microspheres of 0.1% Co–Bi2MoO6 with high efficient photocatalytic performance is a promising photocatalytic material.

In this paper, the cellulose/polyacrylonitrile(PAN) composite nanofibers were prepared via electrospinning technique firstly. Then, cellulose/PAN/Cu nanofibers were fabricated with antibacterial function by loading Cu(II) ions. The morphology, mechanical properties and hydrophilicity of nanofibers was characterized. Antibacterial performance of cellulose/PAN/Cu nanofiber with against Staphylococcus aureus and Escherichia coli were evaluated. The results showed that the cellulose/PAN/Cu nanofiber demonstrated excellent mechanical property and antibacterial activity when the concentration of Cu(II) ions is set to be 0.01 mol/L.

A novel CC@MoS2-Ag3PO4 heterostructure, composed of Ag3PO4 nanoparticles decorated MoS2 nanosheets on carbon fiber cloth (CC), is fabricated by a simple hydrothermal method and a successive ionic layer absorption reaction. The CC@MoS2-Ag3PO4 heterostructure displays an excellent photocatalytic activity of ∼96% degradation rate for RhB solution under simulated daylight, which is more than 10 times as much as that of pure Ag3PO4 or MoS2. The CC@MoS2-Ag3PO4 heterostructure with optimized photoactivity is investigated by optical and electrochemical measurements. The CC@MoS2-Ag3PO4 heterostructure can not only broaden the photoresponse range of MoS2, but also alleviate the photodegradation of Ag3PO4, and the easily separated CC provides a proper conductive substrate and rapid charge transfer channels. The probable photocatalytic mechanism of CC@MoS2-Ag3PO4 heterostructure is discussed in detail. Therefore, the CC@MoS2-Ag3PO4 heterostructure with high efficient photocatalytic performance and easy separation is a promising photocatalytic material.

s A facile solution deposition method using the etched Cu2O truncated octahedrons as the substrates has been successfully demonstrated for tailoring Ag/Cu2O heterostructures with excellent reproducibility, and Ag nanoparticles have been deposited on the surface of different Cu2O particles including freshly prepared Cu2O truncated octahedrons, the etched Cu2O truncated octahedrons, Cu2O cube assemblies and Cu2O octahedron assemblies. The obtained tailoring Ag/Cu2O heterostructures prepared by the etched Cu2O truncated octahedrons exhibits enhanced photocatalytic activity for the degradation of MB solution under visible-light irradiation, and the photocatalytic activity of tailoring Ag/Cu2O heterostructures was 3.1 and 5.7 times higher than those of the etched Cu2O truncated octahedrons and bare Cu2O truncated octahedrons. The enhanced photocatalytic activity of tailoring Ag/Cu2O heterostructures can be attributed to tailoring surface of Cu2O truncated octahedrons, the enhancement of UV–vis absorbance spectra and electron sink effect due to Ag nanoparticle deposition. The facilely prepared tailoring Ag/Cu2O heterostructure products are promising materials in fields such as photocatalytic and optoelectronic applications.

Cobalt and zinc bi-metal organic frameworks (CoZn-MOF) derived from double metal hydroxides (CoZn-DMH) is synthesized on the surface of rice husk carbon via hydrothermal method. The obtained CoZn-MOF/RHC is then used as electrochemical sensor for dopamine detection. SEM and TEM characterization displays that the morphology of CoZn-MOF/RHC is different from CoZn-DMH, as well as the electrochemical performance. Further investigation reveals that the kinetic process of the redox reaction of dopamine on CoZn-MOF/RHC electrode is controlled by diffusion process. Under the optimum conditions, the redox peak current linearly relates with the concentration of dopamine in the range of 2 μM~0.8 mM, with the low detection limit of 0.67 μM. During the anti-interference experiment, CoZn-MOF/RHC exhibits good selectivity toward dopamine detection but inappreciable response for interferent.

Organic pollutants coming from various industry processes are harmful to the environment, and semiconductor heterostructure is a promising candidate catalyst for poisonous wastewater treatment in the future. In this study, CuOx/MnO2 heterostructures were successfully constructed, using a facile and effective hydrothermal method and chemical both/calcination route, which exhibited higher photocatalytic activity towards the photodegradation of organic contaminants under visible-light driven irradiation. The resulting CuOx/MnO2 heterostructures were systematically characterized using various microscopic and spectroscopic techniques. Morphological characterizations show that the CuOx nanoparticles are well anchored on the surface of the MnO2 nanowires (NMs). The photocatalytic activity enhancement of the CuOx/MnO2 heterostructures (M-4) could be ascribed to the introduction of CuOx on the surface of MnO2 NWs and the efficient separation of the electron-hole pairs compared to other CuOx/MnO2 heterostructures and pure MnO2 NMs. These results show that CuOx/MnO2 heterostructures can be a suitable candidate for efficient visible light photocatalysts.

Limited by the relatively low adsorption capacity of inorganic nanomaterials for antibiotics , ultralong hydrogen titanate nanobelts (UHTNs) with a hollow structure and high surface area (442.21 m2 g−1) were synthesized to evaluate the feasibility as a potential adsorbent material for antibiotic removal. A batch of adsorption experiments were conducted by using norfloxacin (NFO), tetracycline (TC) and ofloxacin (OFO) as the model antibiotic molecules. The results indicate that the adsorption of antibiotics on UHTNs is better fitted to the pseudo-second-order kinetic model, and the UHTNs' maximum adsorption capacities calculated from the Langmuir isotherm model were 151.51 mg g−1 for TC, 111.73 mg g−1 for NFO, and 148.14 mg g−1 for OFO at pH = 7, which are far better than those of most reported inorganic adsorbent materials. In the adsorption process of tetracycline, the surface complexation between the adsorbent and TC contributed most to the adsorption; this has been elucidated by Fourier Transform Infrared (FT-IR) spectroscopy and X-ray photoelectron spectroscopy (XPS). In addition, because the UHTNs are up to tens of micrometers in length, they can be easily aggregated to form a network. Therefore, a novel paper-like, free-standing UHTN membrane was fabricated via a simple vacuum filtration method, which also exhibits good adsorption capacity.

Herein, a simple and an environmentally friendly approach is developed to fabricate the novel MnO@C hierarchical structure, derived from Mn-based metal organic frameworks, which is explored as an anode material for lithium ion batteries. Remarkably, the MnO@C microsphere electrode delivers an outstanding, long cycling capacity of 596.3 mA h g−1 at 5C (1C = 765 mA g−1) after 1000 cycles, and an excellent rate performance of 380.1 mA h g−1 at 10C. The overall outstanding properties of the hierarchical MnO@C composite can be attributed to the success of a new strategy for dual structure design, which provides two pathways for effectively alleviating volume changes and enhancing conductivity based on in situ TEM electrochemical experiments and electrochemical impedance spectra. Both the poor conductivity and great volume changes of the MnO electrode material can be effectively improved in two ways: the porous carbon matrix confining the MnO nanoparticles, and the hierarchical nanorod-assembled architecture. The structures herein suggest new design concepts for metal oxide nanoarchitectures for high performance electrode materials in lithium ion batteries.

Nickel-based metal organic framework (Ni-MOF) and carbon nanotubes composite (Ni-MOF/CNTs) is constructed via in situ self-assembly of Ni-MOF in the presence of CNTs solution. The obtained electrode (Ni-MOF/CNTs) exhibits sensitive response toward the detection of taxifolin by significantly enhancing the redox peak currents and decreasing the peak-to-peak separation. Under the selected conditions, the peak current linearly relates with taxifolin concentration in the range of 4.0 × 10−8 ~ 1.0 × 10−5 mol L−1 with the detection limit of 1.33 × 10−8 mol L−1 (S/N = 3). Otherwise, the lithium storage results reveal that Ni-MOF/CNTs with enhanced conductivity exhibits benign cycling stability and rate capability, with coulomb efficiency around 100%. This Ni-MOF/CNTs electrode may lay the foundation for the Ni-MOF based materials in electrochemical application.

A multicolor photodetector based on the heterojunction of n-Si(111)/TiO2 nanorod arrays responding to both ultraviolet (UV) and visible light is developed by utilizing interface engineering. The photodetector is fabricated via a consecutive process including chemical etching, magnetron sputtering, hydrothermal growth, and assembling. Under a small reverse bias (from 0 to approximate to-2 V), only the photogenerated electrons in TiO2 are possible to tunnel through the low barrier of Delta E-C, and the device only responses to UV light; as the reverse bias increases, the photogenerated holes in Si also begin to tunnel through the high barrier of. E V. As a result, the device is demonstrated to have the capacity to detect both UV and visible lights, which is useful in the fields of rapid detection and multicolor imaging. It has been also observed that the crystal orientation of Si affects the characteristics of bias-controlled spectral response of the n-Si/TiO2 heterojunctions. Refereed/Peer-reviewed

Bi2MoO6 with a tunable morphology was synthesized by a facile hydrothermal route using different surfactants, including nanosheet-assembled microspheres, smooth microspheres, nanoparticle aggregates and nanoparticles. The morphology, crystal structure and photocatalytic activity of as-obtained Bi2MoO6 were characterized by scanning electron microscopes (SEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), Brunauer&ndash, Emmett&ndash, Teller (BET) and UV&ndash, Vis spectrophotometer. Bi2MoO6 flower-like microspheres using cetyl-trimethyl-ammonium bromide (BET) as the surfactant exhibited much better photocatalytic activity than Bi2MoO6 with the other morphologies, with a degradation efficiency of 98.4%. It can be summarized that the photocatalytic activity of Bi2MoO6 samples depends on their morphology and composition.

CuS/CuO nanowire heterostructures grown on copper mesh (CuS/CuO/Cu) have been successfully synthesized by a liquid–solid reaction at room temperature followed by annealing. The proposed structure has been verified by X-ray diffraction analysis. Scanning electron microscopy images have indicated that the density and diameter of CuS nanoparticles on CuO nanowires can be tuned by controlling the duration of sulfonation with Na2S. Photocatalytic studies have revealed that CuS/CuO/Cu heterostructures offer improved photocatalytic activity in the degradation of Methylene Blue (MB) in the presence of H2O2. A sample designated as CuS/CuO/Cu-10, where “10” denotes sulfonation with Na2S for 10 min, showed the best photocatalytic properties, with MB degradation efficiencies under visible light irradiation of 87.4% after 20 min and 98.6% after 40 min. The enhanced photocatalytic activity can be attributed to effective electron–hole separation and improved visible light utilization due to the cooperative effect of the CuS/CuO heterostructures and conductive copper mesh.

3D flower-like porous NiO architectures were synthesized via a facile and green method. When applied as an electrode material for supercapacitors, the as-prepared 3D flower-like porous NiO exhibited an outstanding electrochemical performance, such as a high specific capacitance (1609 F g−1 at 2 A g−1), and a long-term cycling stability (4.3% loss after 3000 cycles). The excellent electrochemical performance is mainly attributed to the morphology of the porous ultrathin nanosheets self-assembling into flower-like architectures, which facilitate fast and efficient diffusion of the electrolyte ions. Thus, it is expected that the 3D flower-like porous NiO can be a perspective electrode material for electrochemical energy storage applications.

CuS nanoparticle/ZnO nanorod heterostructure arrays grown on carbon fibers (CuS/ZnO/CFs) were prepared successfully by a simple combination of a hydrothermal (HT) process and successive ionic layer adsorption and reaction (SILAR). The heterostructures of CuS/ZnO/CFs showed improved photocatalytic activity in the degradation of methylene blue (MB). Under visible light irradiation, the CuS/ZnO/CF heterostructures exhibited remarkable visible light photocatalytic activity, which was 7.1 and 8.0 times higher than those of ZnO/CFs and ZnO, respectively. Under simulated solar light irradiation, the photocatalytic activity of the CuS/ZnO/CF heterostructures was 1.4 and 2.2 times higher than those of ZnO/CFs and ZnO, respectively. The enhanced photocatalytic activity could be ascribed to the effective electron–hole separation and improved visible light utilization from the cooperative effect of the type II CuS/ZnO heterostructures and conductive CFs, as well as the efficient light harvesting and high surface area of the heterostructure arrays. Moreover, the CuS/ZnO/CF heterostructures can be easily separated and recycled with little loss in the photocatalytic activity due to their unique structural features.

In this report, a simple Kirkendall-based process using freshly prepared Cu2O microcubes as sacrificial templates has been successfully demonstrated for the fabrication of CuS hierarchical and hollow micro/nanocubes (HHCs). Individual CuS HHCs were assembled with plenty of nanosheet-like building units. CuS HHCs showed improved photocatalytic activity in the degradation of methylene blue (MB) in the presence of H2O2. Under visible light irradiation, the photocatalytic activity of CuS HHCs was 3.7 and 5.8 times higher than those of Cu2O/CuS and Cu2O, respectively. Furthermore, they also showed good recyclability in the visible region. It appears that the enhanced photocatalytic performance of the hierarchical and hollow micro/nanostructures can be ascribed to the synergetic effect of the efficient light harvesting and high surface area of the CuS HHCs. The facilely prepared CuS HHC products are promising materials in the fields of photocatalytic and optoelectronic applications.

A simple one-pot hydrothermal route has been demonstrated for the fabrication of 3D ZnO@hemimorphite zinc silicate (ZSO) core–shell nano-heterostructures on the Si substrate. Individual 3D ZnO@ZSO core–shell nano-heterostructures were assembled with many bundle-like branches, and each bundle-like branch was composed of the ZnO rod as the core and ZSO nanowires as the shell. The structure and composition of the 3D ZnO@ZSO nano-heterostructures could be varied with different reaction conditions and exhibit excellent reproducibility as well. In addition, a possible mechanism for the fabrication of 3D ZnO@ZSO nanohybrids was proposed, suggesting that heterogeneous nucleation played important roles in the formation of 3D nanostructures. The resultant 3D ZnO@ZSO nano-heterostructure films exhibited hydrophobic adhesive characteristic with a water contact angle of 142.1° and a high contact angle hysteresis, which held a great potential in surface wettability and other opto-electronic applications.

Nanosheet-assembled ZnO flower-like ensembles, urchin-like ZnO nanorod assemblies and ZnO nanorods, were synthesised by a facile solution-based route. The Zn2+:OH− molar ratio was adjusted to obtain ZnO with different morphologies. Scanning electron microscopy, X-ray diffraction and an ultraviolet spectrophotometer were used to observe the morphology, crystal structure and photocatalytic activity of obtained ZnO in detail. The flower-like ZnO ensembles composed of ultra-thin nanosheets exhibited a much better photocatalytic activity than ZnO in the other morphologies, and the decomposition efficiency was 90.26%. It can be concluded that the presence of the photocatalytic activity depends on the morphology of the ZnO samples.

A novel and facile synthetic route has been developed to fabricate porous SiO2-coated ultrasmall Se particles (Se@SiO2 nanospheres) as a drug delivery nanoplatform which combines Se quantum dots and doxorubicin (DOX) for efficient synergistic treatment of cancer cells.

A graphene-based device requires the graphene to have an ideal shape, structure, and orientation, and be large enough, to allow them to be formed into a new device. Here the joining of individual single-layer and multi-layer graphene is performed in a transmission electron microscope-scanning tunneling microscope (TEM–STM) holder inside a 200 kV field emission TEM. Attempts have been made to join individual graphene sheets (GSs) with the so-called “top-to-top” and “layer-to-layer” geometries by applying a voltage. In the two geometries, the “top-to-top” form has resulted in a seamless joining for both single-layer and multi-layer GSs. The as-joined GSs show the same excellent electrical and mechanical properties as those of the original GSs. Large Joule heating originating from the field emission current will cause atom diffusion and self-assembly and then rearrangement of carbon networks at the GS edge front. In this way individual GSs could be extended and mended with the so-called “top-to-top” geometries by applying a constant voltage, to meet the required and desired shape, size, configuration, and functions for a variety of the special micro/nano scaled devices.

Nanosheet-assembled ZnO flake-like ensembles were fabricated by a facile solution-based route. The morphology, size and micro/nanostructure of the ZnO flake-like ensembles were investigated in detail. X-ray diffraction and scanning electron microscopy indicated that all the ZnO flake-like ensembles with the porous features were composed of many nanosheets with a hexagonal wurtzite structure. After visible-light irradiation for 3 h, the as-obtained ZnO flake-like ensembles exhibited significantly high photocatalytic activity for decomposing malachite green, and the decomposition efficiency was 76.8 . All of which indicates that the ZnO flake-like ensembles could serve as a good candidate for the degradation of organic pollutants.

A simple hydrothermal method has been developed for fabricating hemimorphite zinc silicate, Zn 4 Si 2 O 7 (OH) 2 ·H 2 O (ZSO). Three-dimensional ZSO hierarchal superstructures are deposited on the Si substrate. The product is characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscope. The characterization results of the sample show individual ZSO hierarchical architectures are assembled by many well-aligned and highly ordered rod bundles. The morphologies of the rod bundles within the ZSO hierarchal superstructures can be conveniently controlled, by selecting the different reactant concentrations, with excellent reproducibility. The luminescence spectra showed that the ZSO hierarchical superstructure had a stronger emission peak at 436 nm and a weaker emission peak at 418 nm.

Photothermal ablation (PTA) therapy has attracted much interest in recent years as a minimally invasive alternative to conventional approaches, such as surgery and chemotherapy, for therapeutic intervention of specifi c biological targets. [ 1 , 2 ] In particular, near-infrared (NIR, λ = 700–1100 nm) laser-induced PTA, which converts NIR optical energy into thermal energy, has attracted increasing attention, because the NIR laser is absorbed less by biological tissues and the typical penetration depth of the NIR (such as 980 nm) light can be several centimeters in biological tissues. [ 3 , 4 ] A prerequisite for the development of the NIR laser-induced PTA is to gain access to biocompatible and effi cient photothermal coupling agents. As the well-known NIR photothermal conversion agents, gold (Au) nanostructures, including supramolecularly assembled nanoparticles, [ 5–8 ]

Large-scale and uniform ZnSe solid and hollow microspheres have been prepared via controllable self-assembly of ZnSe faceted nanocrystals under hydrothermal conditions. During the process, using the surfactant or not plays a key role in the ZnSe faceted nanocrystals' self-assembly into the ZnSe microspheres. Using PVP as the surfactant, the ZnSe monodisperse faceted shaped (including cubes, hexagons, and pentagons) nanocrystals with a diameter of ∼50 nm have been obtained; without using PVP surfactant, the ZnSe solid microspheres with a diameter of ∼3 μm have been achieved by the self-assembly of ZnSe faceted shaped nanocrystals; while using oleyl amine as the surfactant, which combines with N2 bubbles from the decomposition of N2H4·H2O, forming a new “soft-template”, the ZnSe hollow microspheres have been synthesized through as-called “soft-template” process. Meanwhile, hydrothermal temperature, time, and reducing agent have significant effects on the surface morphology of the ZnSe microspheres, i.e., a suitable temperature (e.g., 180 °C), longer reaction time, and using a small quantity of N2H4·H2O could be beneficial to the growth of the well-defined ZnSe faceted nanocrystals and their self-assembly into microspheres. A possible mechanism for the formation of ZnSe nanocrystals and their self-assembly into ZnSe microspheres has been proposed.

Large-scale synthesis of highly graphitic carbon nanotubes (with a diameter of ∼5−8 nm) from a thermal reaction of activated carbon and Bi2O3 powders, which was grown via a carbon-thermal reduction and Bi catalyzed vapor−liquid−solid process has been obtained. Individual carbon nanotubes were terminated with an onion-shaped carbon tip, which has never been observed in growth of a carbon nanotube. Field emitters made from the present carbon nanotubes exhibit excellent emission properties: they can be operated at a very large current density of ∼145 mA/cm2 at a low voltage of 5.5 V/μm, and possess a long period (>32 h) of high emission stability at a high emission current density of ∼9 mA/cm2 and under a constant applied voltage. These properties are equally important for high image quality in field emission display fabrication. Hence, as-fabricated CNTs could act as excellent electron emitters and have great potential application in field emission panel displays.

The synthesis of the (rocksalt phase) single-crystal square-like cross-sectional MgS nanotubes via a thermal reaction process was reported for the first time in the family of II–VI sulfide semiconductors, which enriches the wide spectrum of diverse inorganic nanotubular structures. As-grown MgS nanotubes are structurally uniform single-crystals; an individual faceted tube is enclosed by four {020} crystal planes and grows along the [001] orientation. The MgS nanotubes exhibited efficient hydrogen-storage capacity of ∼ 2.2 wt% at room temperature under hydrogen pressure of 33.6 atm and one intensive cathodoluminescence emission band centered at ∼ 688 nm. The new concept established here will be very helpful in developing other types of Mg-based material nanotubes with high a hydrogen-storage capacity. Moreover, the MgS nanotubes' cavity could be filled with different semiconducting materials with various band gaps to give interesting electrical and optical nanodevices.

A prerequisite for designing and constructing wireless biological nanorobots is to obtain an electrical source that is continuously available in the operational biological environment. Herein the first preparation of 980-nm laser-driven photovoltaic cells (980LD-PVCs) by introducing of a film of rare-earth up-converting nanophosphors in conventional dye-sensitized solar cells is reported. Under the irradiation of a 980-nm laser with a power of 1 W, the visible up-converting luminescence of rare-earth nanophosphors can be efficiently absorbed by the dyes in 980LD-PVCs so that they exhibit a maximal output power of 0.47 mW. In particular, after being covered with 1 to 6 layers of pig intestines (thickness: ca. 1 mm per layer) as a model of biological tissues, 980LD-PVCs still possess a maximal output power of between 0.28 and 0.02 mW, which is efficient enough to drive many kinds of biodevices. This research opens up the possibility of preparing and/or developing novel electrical sources for wireless biological nanorobots and many other biodevices.

In situ electron-beam irradiation was performed in a transmission electron microscope to fabricate nanocrystals of IV−VI semiconducting lead chalcogenides PbE (E = S, Se, and Te) and low-melting-point metals (Zn, Ga, Sn, and Cd). The source powders consisting particles of 300−1000 nm in diameter were supported on a thin carbon (C) film. A convergent electron beam was focused on an individual particle, which caused partial melting and evaporation of the particle and subsequent nucleation and growth of new nanoparticles on the C film. These nanocrystals are structurally uniform and free of any linear and planar defect and do not have any other impurity contamination. The method is easy to set up and is low in cost and is very fast (several seconds to several minutes) in process. It is believed that this new method can also be employed to synthesize many other material nanocrystals and one-dimensional nanostructures, beyond semiconductors and (low melting point) metals, such as oxides and even sulfides and n...

Nd-doped TiO2 mesoporous microspheres with possessing regular micro/nanostructure were synthesized by a simple and facile method. The structure and optical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption–desorption isotherms and UV-Visible absorbance spectroscopy. It was revealed that Nd-doped TiO2 mesoporous microspheres are composed of primary nanoparticles with a particle size of [Formula: see text]25[Formula: see text]nm. The photocatalytic activities of all the samples were evaluated by degradation methyl orange (MO) in aqueous solution as a model reaction under xenon lamp light irradiation. The results showed that the doped samples demonstrated a higher photocatalytic activity than TiO2 mesoporous microspheres, and the MO of 10[Formula: see text]mg/mL almost could be completely degraded by the Nd-doped TiO2 mesoporous sample (the dosage of Nd salt to TiO2 is 6%) under xenon lamp light irradiation within 1[Formula: see text]h.

A cooperative thermal decomposition route to large-scaled star-shaped α-MnS nanocrystals, which show novel magnetic properties, i.e., a high blocking temperature (275 K) and a large coercive field (1573 Oe), is reported.

Carbon nanotubes (CNTs) have recently emerged as a promising material of electron field emitters. They exhibit extraordinary field emission properties because of their high electrical conductivity, high aspect ratio "needle like" shape for optimum geometrical field enhancement, and remarkable thermal stability. In this Review, we emphasize the estimation and influencing factors of CNTs' emission properties, and discuss in detail the emission properties of macroscopic CNT cathodes, especially fabricated by transplant methods, and describe recent progress on understanding of CNT field emitters and analyze issues related to applications of CNT based cold cathodes in field emission display (FED). We foresee that CNT-FED will take an important place in display technologies in the near future.

Large scaled hexagonal prismatic sub-micro sized Mg crystals were grown by a vapor-liquid-solid process, and found to be sensitive to electron beam irradiation in transmission electron microscope imaging, making hollow prismatic MgO boxes.

The rational design and fabrication of more multi-component (material-combination) 3D hierarchical heterostructures for high-performance pseudocapacitor applications still remains a challenge. Herein, we have designed and synthesized a 3D hierarchical heterostructure of MnO2 nanosheets or nanorods grown on an Au-coated Co3O4 porous nanowall array, resembling a sandwich configuration of Co3O4@Au@MnO2, by a facial and controllable electrochemical deposition process. Due to their unique self-assembling architecture and characteristics including porous Co3O4 nanowalls, ultrathin MnO2 nanosheets, and a high conductivity Au layer sandwiched between them, each component provides a much-needed critical function for the efficient use of metal oxides for energy storage. The synthesized 3D hierarchical heterostructures exhibited favorable electrochemical performances, such as a high specific capacitances of 851.4 F g−1 at 10 mV s−1 and 1532.4 F g−1 at 1 A g−1, good rate performance and an excellent long-term cycling stability (almost no degradation after 5000 cycles), which are better than those of the reported Co3O4 or MnO2 based electrode materials, and thus could be considered as perspective materials for high-performance electrochemical capacitors.

Single-crystal α-MnO2 ultralong nanowires (∼40 μm in length, ∼15 nm in diameter), which were synthesized by a simple polyvinylpyrrolidone (PVP) assisted hydrothermal route, exhibited a better electrical conductivity, a highest specific capacitance of 345 F g−1 at a current density of 1 A g−1 with high rate capability (54.7% at 10 A g−1) and good cycling stability.

A one-step route to the synthesis of Ge nanocrystals on a large-scale from GeO2 powders in aqueous solution at 60 °C under an ambient atmosphere is reported, which avoids toxic precursors and by-products, high temperature, and inert atmospheres.

ZnO films composed of uniform three-dimensional (3D) hierarchical microstructures on the conductive glass were synthesized by a one-step polyethylene glycol-assisted hydrothermal route with excellent reproducibility. The morphology of the ZnO hierarchical structured films was controlled by adjusting hydrothermal reaction conditions, i.e., time, temperature, reactant concentration, Zn source and surfactant. A specific growth mechanism for the ZnO hierarchical microstructured films is proposed, and the hydrothermal time is found to be a crucial role in the formation of the hierarchical structures either from the initial nucleation and growth of the primary rods or secondary/tertiary nucleation and growth on the the column facets of the primary rods. As-fabricated ZnO films show a strong photoluminescence emission peak at 435 nm, and a superhydrophobic adhesive surface with a water contact angle of 154.1° and a high contact angle hysteresis.

The morphology-selective synthesis of well-aligned Cu2-xSe nanostructures including nanosheets, nanoribbons, and heterostructures on copper substrate has been achieved by a simple hydrothermal route; the micropatterned assembly of Cu2-xSe nanostructures has been realized using a copper grid to direct the growth on prescribed arbitrary patterns with unprecedented control and selectivity. The control experimental conditions, such as hydrothermal temperature and time, and concentration of NaOH have been found to be important parameters for the growth process of the Cu2-xSe nanostructures. So-called “coordination assembly” has shown to be dominant in the formation of the Cu2-xSe nanostructures, consisting of an initial nucleation and subsequent vertical growth on the copper substrate. The wettability properties of the Cu2-xSe nanostructures have been investigated, and the water contact angle from these nanostructured materials has been measured to be up to 160°, showing a superhydrophobicity. These results might provide a facile route for the preparation of novel micropatterned and high assemblies of nanostructures on other metal substrates (e.g.Al, Zn, Mg, etc.), for which a number of promising applications in microelectronic fields can be envisioned.

Using as-obtained ZnS–Si biaxial nanowires as templates, which were prepared via a thermal evaporation of a mixed powder of SiO and ZnS under controlled temperature, ZnO–Si biaxial nanowire heterostructures were achieved by a simple post-oxidation process. Each ZnO–Si composite nanowire has a uniform diameter along its whole length; the typical diameter of the nanowires ranges from 100 to 500 nm, and the diameters of Si- and ZnO-side sub-nanowires within a nanowire heterostructure are ∼50–250 nm. Significant enhancement of green luminescence compared to the ZnO nanowires has been observed from these ZnO–Si biaxial nanowire heterostructures, which may find the applications in short wavelength photoelectric devices, fluorescence labels, and biological detectors. The present template-assisted method demonstrated here could be a general approach of fabricating nanowire heterostructures made of Si-based materials.

Semiconducting nanotubes with well-controlled dimensions, compositions and crystal structures represent a new class of intriguing systems for detailed studies of structure–property relationships at the nanoscale and prospective functional applications. This article features recent research progress in the design of different synthetic routes towards important semiconducting nanotubes made of groupIV: silicon; groupIII–V: GaN, GaP, AlN, InN and InP, and groupII–VI: ZnO, ZnS, ZnSe, CdS and CdSe. The fabricated nanotubes possess desirable atomic structures, surfaces, morphologies and properties to meet the growing demands and specific requirements of new technologies.

A simple hydrothermal route has been developed for the fabricating ZnO hierarchical micro/nanostructure with excellent reproducibility. SEM and TEM analysis show that the hierarchical rod is a single-crystal, suggesting that many single-crystal micro/nanorods are assembled into ZnO hierarchical micro/nanostructures. The morphologies of the hierarchical rods can be conveniently tailored by changing the reaction parameters. And we also found citric acid plays a crucial role in the formation process of ZnO micro/nanostructures. Room-temperature photoluminescence spectra reveals that the ZnO hierarchical micro/nanostructures have a strong emission peak at 440 nm and several weak emission peaks at 420, 471 and 541 nm, respectively.