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Figure 7 in the original version of this article was unfortunately wrong on page 23

This paper reports a high-performance transparent electromagnetic shielding material based on an ultrathin and large-area metallic nanomesh, which was fabricated by a facile and rational process utilizing ultraviolet lithography and the ion beam etching technique. Measurements reveal that a single-layer metallic nanomesh can harvest excellent shielding effectiveness exceeding 40 dB in the wide frequency range from 500 MHz to 40 GHz. Besides, efficient light transmittance (85% at 550 nm) is achieved in both visible and near-infrared regions. Furthermore, the proposed structure remains excellent performance at wide incident angles even up to 50°. Hence, it is believed that this metallic nanomesh with easy fabrication can be a potential alternative in the transparent electromagnetic shielding domain.

In the study, the yttrium (Y)-doped vanadium oxide (VOx:Y) films used as the sensitive layers of microbolometers were deposited using a radio frequency magnetron co-sputtering system. The temperature coefficient of resistance (TCR) of the VOx:Y films was enhanced from −1.88%/°C to −2.85%/°C in comparison with that of the VOx films. To further improve the performance of microbolometers, the nanomesh antireflection layer was placed on the top surface of the microbolometers to reduce the infrared reflection. The responsivity, thermal time constant, thermal conductivity, absorptance, and detectivity of the VOx:Y microbolometers with nanomesh antireflection layer were 931.89 ± 48 kV/W, 4.48 ms, 6.19×10−8 W/K, 74.41% and 2.20×108 cmHz0.5W−1, respectively.

In this study, we apply the economically feasible liquid ALD process to deposit a 2 nm amorphous MnO2 thin-film on our high surface-area 3D Ni nanomesh substrate, which shows a high surface to footprint area ratio (30 cm2:1 cm2 for 1 μm thick Ni nanomesh), and demonstrate its preliminary electrochemical activity as a cathode under N2 and O2. The excellent footprint charge density and faradaic efficiency can be attributed to the catalytic oxygen reduction reaction, followed by Li-intercalation thus forming a hybrid combination of Li-ion and Li-O2 activity, alleviating the detrimental deactivation process of pristine MnO2.

Due to their high intrinsic conductivity and narrow band gap, nanostructured metal sulfides have attracted considerable attention as promising gas sensing materials. Here, we report the WS2 nanosheets with edge size only about 10 nm synthesized by sulfurization of the WO3 nanomesh. The WS2 nanosheets exhibit p-type sensing characteristics and excellent selectivity to NO2 at a low temperature of 160 °C, which can be attributed to the strong physical affinity of the WS2 nanosheets to the NO2 gas molecules. Importantly, by designing sensing experiments under different background gases, we found that WS2 nanosheets do not require oxygen for NO2 sensing, while oxygen is required for H2S sensing. Therefore, based on the adsorption and desorption and charge transfer between WS2 nanosheets and adsorbed gas molecules, we propose different sensing mechanisms of WS2 nanosheets for NO2 and H2S sensing.

Micro-nanostructures were successfully synthesized on a Ti6Al4V alloy and then coated with a monolayer of hydrophobic groups to obtain the superhydrophobic surfaces. The effect of secondary nanostructures (nanotube, nanowire and nanomesh) on superhydrophobic performance was investigated by the characterization of contact process of a falling water droplet onto the superhydrophobic surface via a high-speed camera. Meanwhile, the apparent contact angle and sliding angle of the water droplet were measured by a contact angle analyzer. The results indicated that the superhydrophobic surface with micro-nanostructures (microscale pits and nanowire) exhibited robust superhydrophobic properties (apparent contact angle 161° and sliding angle approximately 3°) due to the large amount of flowing air being trapped underneath the droplet. Moreover, it was observed that once the impacting droplet contacted with the superhydrophobic surface, it spread uniformly before retracting and finally lifted off the surface within 13 ms.

We report on excellent hydrogen sensing properties of a Pt/TiO 2 system based on mesoporous titania grown by plasma electrolytic oxidation of a Ti metal substrate. The Pt phase is deposited onto the titania surface as an electrically continuous Pt nanomesh layer with an e-beam process. Resistive sensor response between the Pt and Ti terminals of the resultant structure is studied at room temperature for different partial pressures of H 2 gas (0.003–3 Torr) and different source voltages (0.5–2.0 V). A maximum resistance effect, reaching four orders of the magnitude for 3 Torr H 2 in 160 Torr O 2 is obtained at the bias voltage 1.4 V, and a strong effect is detected for only 0.003 Torr, or 20 ppm H 2 concentration. For voltages in the range 1.0–1.4 V, electrical conductance of the sample is about a linear function of the H 2 partial pressure in the gas phase. Influence of the background atmosphere (O 2 , N 2 and vacuum) and the effect of bias reversal were investigated also, leading to a conclusion that the sensing mechanism can be related to ionic transport in the TiO 2 layer.

Graphene nanomesh was prepared via one-step hydrothermal process in a teflon-lined autoclave. The graphite flakes were used as the raw materials and no templates were adopted during the preparation. Experiment results showed that as the hydrothermal temperature increased, there was an obvious transition in the structure and morphology of the final products. When the temperature was set at 95 °C, the graphite was oxidized to graphite oxide. The structural transition of the sample could be observed at 115 °C, part of the sample was reduced during the hydrothermal treatment. When the temperature reached to 135 or 155 °C, there appeared signals related to graphene; no obvious information about graphene oxide could be detected. Some holes were discovered in the samples. These structural changes were confirmed by X-ray diffraction, thermo-gravimetric analysis, and Fourier transform infrared spectroscopy and laser Raman spectroscopy. Moreover, atomic force microscope and transmission electron microscope revealed the as-prepared graphene was monolayer or few-layer nanomesh.

Based on detailed first-principles investigations of the hexagonal antidot patterned graphene nanomeshes, we have studied the mechanisms of the conducting property modification of graphene. The band-folding analysis shows that the (3n,3m) (n and m are integers) superlattice would have fourfold degeneracy at Г point. An effective method by removing this fourfold degeneracy, such as regularly arranging antidots to make the (3n,3m) nanomesh, is proposed to open a sizable bandgap no matter whether the sublattice equivalence keeps or not. In the nanomeshes patterned with the magnetic antidots, the antiferromagnetic coupling adds a quantum parameter to break the sublattice equivalence, resulting in the bandgap opening at the twofold degenerate K (K′) point. Our studies also show that the gap width could be tuned by controlling the antidot density. These results could facilitate the fascinating applications of graphene in the next-generation nanoelectronics.

Graphene has been widely used in composite materials, electronic devices, energy-storage systems, adsorption separation and other fields because of its unique structure and outstanding properties. Graphene nanomesh, which is obtained by integrating nanopores into the interlayer of graphene, exhibits not only the intrinsic properties of graphene, but also controllable design of porous structure, making it attractive for functional applications. In this review, several general routes to synthesize graphene nanomesh are summarized and possible trends for the future design of graphene nanomesh are also discussed.

Atomic or molecular preferential adsorption on a surface template provides a facile and feasible means of fabricating ordered low-dimensional nanostructures with tailored functionality for novel applications. In this study, we demonstrate that functionality of C-doped BN nanomesh can be tailored by an external electric field which modifies the strength of the adsorbate binding to the nanomesh. Specifically, selective binding of H, O, H2, and O2 at various sites of the C-doped nanomesh—within the pore, on the wire, and at an intermediate site—is investigated with density functional theory. The calculated results find that atomic species are bound, but the molecular species are not bound to the nanomesh. We have shown that it is possible to modify the adsorbate binding energy with the application of an external field, such that the molecular H2 can be bound at the pore region of the nanomesh. Interestingly, the work function of the nanomesh has a close correlation with the adsorbate binding energy with the ...

We fabricated ultra-high aspect ratio silicon nanomaterials, including a silicon nanomesh and silicon nanowire array, on a wafer scale for efficient photoelectrochemical hydrogen production. These silicon nanomaterials (feature size≈20 nm) possess a high aspect ratio to increase the optical absorptivity of the cells to approximately 95 % over a broad range of wavelengths. The silicon nanomesh and Si nanowire cells achieved high photocurrent values of 13 and 28 mA cm−2, respectively, which are increased by 200 % and 570 % in comparison to their bulk counterparts. In addition, these scalable Si nanomaterials remained stable for up to 100 min of hydrogen evolution. Detailed studies on the doping and geometrical structures of the resulting hydrogen evolution cells suggest that both the n+ pp+ doping and thickness of nanostructures are keys to the enhancement of the hydrogen evolution efficiency. The results obtained in this work show that these silicon nanomaterials can be used for high-performance water-splitting system applications.

Graphene, an atomic-scale honeycomb crystal lattice, is increasingly becoming popular because of its excellent mechanical, electrical, chemical, and physical properties. However, its zero bandgap places restrictions on its applications in field-effect transistors (FETs). Graphene nanomesh (GNM), a new graphene nanostructure with a tunable bandgap, shows more excellent performance. It can be widely applied in electronic or photonic devices such as highly sensitive biosensors, new generation of spintronics and energy materials. These illustrate significant opportunities for the industrial use of GNM, and hence they push nanoscience and nanotechnology one step toward practical applications. This review briefly describes the current status of the design, synthesis, and potential applications of GNM. Finally, the perspectives and challenges of GNM development are presented and some suggestions are made for its further development and exploration.

Flexible transparent electrodes (FTEs) are key elements in flexible photoelectronics. The durability of FTEs is determined by two effects caused by deformations: the damage effect, and the recovery effect. The damage effect, that under how much strain and how many cycles an FTE can be destroyed, has been investigated in a few existing works. However, people did not perform any systematic studies on the recovery effect of FTEs and has not yet realized its importance. Herein, we demonstrate that metallic nanowires may recover with strain cycling. Pre-damaged Au nanomesh FTEs can recover under cyclic strains due to the spontaneous cold-welding of fractured nanowires by natural relaxing, or cyclic compressing, or cyclic stretching (with a strain up to 70%), or random deformations within modest strain ranges. Under small tensile strains (

We present a Monte Carlo study of heat transport in Si nanomeshes. Phonons are treated semiclassically as particles of specific energy and velocity that undergo phonon–phonon scattering and boundary scattering on the surfaces of the nanomesh pores. We investigate the influence of: (1) geometric parameters such as the pore arrangement/randomness and porosity, and (2) the roughness amplitude of the pore surfaces on the thermal conductivity of the nanomeshes. We show that the nanomesh porosity has a strong detrimental influence on the thermal conductivity. Boundary roughness still degrades the thermal conductivity, but its influence is smaller.

A 2H-MoS2 (H=hexagonal) ultrathin nanomesh with high defect generation and large porosity is demonstrated to improving electrochemical performance, including in lithium-ion batteries (LIBs) and the hydrogen evolution reaction (HER), with the aid of a 3D reduced graphene oxide (RGO) scaffold as fast electron and ion channels. The 3D defect-rich MoS2 nanomesh/RGO foam (Dr-MoS2 Nm/RGO) can be easily obtained through a one-pot cobalt acetate/graphene oxide (GO) co-assisted hydrothermal reaction, in which GO, cobalt and acetate ions are co-morphology-controlling agents and defect inducers. As an anode material for LIBs, Dr-MoS2 Nm/RGO has only a 9% capacity decay at a 10 C discharge rate versus 0.2 C with stable cyclability at the optimized composition (5 wt% RGO to MoS2 and 2 mol% Co to Mo), and significantly achieves 810 mA h g(-1) at a high current density of 9.46 A g(-1) over at least 150 cycles. Moreover, Dr-MoS2 Nm/RGO exhibits superior activity for the HER with an overpotential as low as 80 mV and a Tafel slope of about 36 mV per decade. In contrast to the MoS2 nanosheet/RGO (MoS2 Ns/RGO), which is synthesized in the absence of cobalt ions, Dr-MoS2 Nm/RGO provides high interconnectivity for efficient lithium-ion transport, and rich defects as electrochemically active sites. DFT is used to prove the existence of rich defects due to anion replacement to become a Co-Mo-S atomic structure, releasing inert basal planes to active sites.

Methods of fabrication of nanomesh aluminum films for LC alignment and their structure are described. A dependence of the pores' diameter vs. their fabrication conditions is found. A dependence of the alumina nanomesh on the pores' performances is simulated too. A theory of LC alignment in such system is proposed that allows prediction of the alignment type and explanation of experimental data. The LC orientation type is determined by the free anchoring energy and the micropore diameter. The difference of both planar and homeotropic anchoring energy is lower than the interaction energy by two orders of magnitude.

Uniform metal nanomesh structures are promising candidates that may replace of indium-tin oxide (ITO) in transparent conducting electrodes (TCEs). However, the durability of the uniform metal mesh has not yet been studied. For this reason, a comparative analysis of the durability of TCEs based on pure Ag and AgNi nanomesh, which are fabricated by using simple transfer printing, is performed. The AgNi nanomesh shows high long-term stability to oxidation, heat, and chemicals compared with that of pure Ag nanomesh. This is because of nickel in the AgNi nanomesh. Furthermore, the AgNi nanomesh shows strong adhesion to a transparent substrate and good stability after repeated bending.

O rdered metal nanopatterns are crucial requirements for electronics, magnetics, catalysts, photonics, and so on. Despite considerable progress in the synthetic route to metal nanostructures, highly ordered metal nanopatterning over a large-area is still challenging. Nanodomain swelling block copolymer lithography is presented as a general route to the systematic morphology tuning of metal nanopatterns from amphiphilic diblock copolymer self-assembly. Selective swelling of hydrophilic nanocylinder domains in amphiphilic block copolymer fi lms during metal precursor loading and subsequent oxygen based etching generates diverse shapes of metal nanopatterns, including hexagonal nanoring array and hexagonal nanomesh and double line array in addition to common nanodot and nanowire arrays. Solvent annealing condition of block copolymer templates, selective swelling of hydrophilic cylinder nanodomains, block copolymer template thickness, and oxygen based etching methods are the decisive parameters for systematic morphology evolution. The plasmonic properties of ordered Au nanopatterns are characterized and analyzed with fi nite differential time domain calculation. This approach offers unprecedented opportunity for diverse metal nanopatterns from commonly used diblock copolymer self-assembly.

Nanostructured Fe2O3-nanomesh graphene (NMG) composites containing ∼3 nm Fe2O3 nanoparticles (NPs) uniformly distributed in the nanopores of NMG are synthesized by an adsorption-precipitation process. As anodes for Li ion batteries (LIBs), the 10%Fe2O3-NMG composite exhibits an upward trend in the capacity and delivers a reversible specific capacity of 1567 mA h g(-1) after 50 cycles at 150 mA g(-1), and 883 mA h g(-1) after 100 cycles at 1000 mA g(-1), much higher than the corresponding values for the NMG electrode. The significant capacity enhancement of the 10%Fe-NMG composite is attributed to the positive synergistic effect between NMG and Fe2O3 NPs due to the catalytic activity of Fe2O3 NPs for decomposition of the solid electrolyte interface film. Our results indicate that decoration of ultrasmall Fe2O3 NPs can significantly change the surface condition of graphene. This synthesis strategy is simple, effective, and broadly applicable for constructing other electrode materials for LIBs.

Chemical vapor deposited graphene is nanopatterned by a spherical block-copolymer etch mask. The use of spherical rather than cylindrical block copolymers allows homogeneous patterning of cm-scale areas without any substrate surface treatment. Raman spectroscopy was used to study the controlled generation of point defects in the graphene lattice with increasing etching time, confirming that alongside the nanomesh patterning, the nanopatterned CVD graphene presents a high defect density between the mesh holes. The nanopatterned samples showed sensitivities for NO2 of more than one order of magnitude higher than for non-patterned graphene. NO2 concentrations as low as 300 ppt were detected with an ultimate detection limit of tens of ppt. This is so far the smallest value reported for not UV illuminated graphene chemiresistive NO2 gas sensors. The drastic improvement in the gas sensitivity is believed to be due to the high adsorption site density, thanks to the combination of edge sites and point defect sites. This work opens the possibility of large area fabrication of nanopatterned graphene with extreme density of adsorption sites for sensing applications., Comment: The final publication will be aviable http://www.springer.com/materials/nanotechnology/journal/12274

Layered bismuth sulfide (Bi2S3) has emerged as an important type of Li-storage material due to its high theoretical capacity and intriguing reaction mechanism. The engineering and fabrication of Bi2S3 materials with large capacity and stable cyclability via a facile approach is essential, but still remains a great challenge. Herein, we employ a one-pot hydrothermal route to fabricate carbon-coated Bi2S3 nanomeshes (Bi2S3/C) as an efficient Li-storage material. The nanomeshes serve as a highly conducting and porous scaffold facilitating electron and ion transport, while the carbon coating layer provides flexible space for efficient reduction of mechanical strain upon electrochemical cycling. Consequently, the fabricated Bi2S3/C exhibits a high and stable capacity delivery in the 0.01–2.5 V region, notably outperforming previously reported Bi2S3 materials. It is able to discharge 472 mA·h·g−1 at 120 mA·g−1 over 50 full cycles, and to retain 301 mA·h·g−1 in the 40th cycle at 600 mA·g−1, demonstrating the potential of Bi2S3 as electrode materials for rechargeable batteries.

We study the graphene band-gap engineering by introducing different defects, namely the defects breaking the inversion symmetry and the ones periodically patterning graphene into superlattice such as the regularly arranged antidots, etc. Comparing to the primitive unit cell of graphene, the pseudo-graphene superlattice, referred to the pristine graphene supercell, modulates the boundary condition accordingly. According to the energy band-folding picture, these superlattices can be categorized into two groups on the basis of the Dirac cone position. In some cases, the Dirac points K and K′ in primitive cell are folded to the Γ point of pseudo-superlattices. The coincidence of Dirac points with Γ point results in the fourfold degeneracy. In these systems, a band gap at Γ point can be opened by introducing periodically arranged defects such as the antidots, which could be easily utilized in experiment, for example, by making the graphene nanomesh through lithography technique. In the other cases, the twofold...

Flexible photodetector shows great potential applications in intelligent wearable devices, health monitoring, and biological sensing. In this work, single crystal β-tellurium nanowires were grown on flexible muscovite by molecular beam epitaxy, constructing high-density ordered nanomesh structure. The prepared photodetectors based on tellurium nanomesh exhibit excellent mechanical flexibility, fast response in a broad range from ultraviolet to near-infrared, and good photosensitivity. We found that the flexible photodetectors with Shottky contact drastically suppressed dark current, while the response speed was lowered in comparison to the devices with ohmic contact, as holes would take a long time to tunnel through the Shottky barrier between metal and p-type Te. Moreover, the photoresponse of flexible Shottky photodetectors can be modulated by piezoelectricity of tellurium, and pronounced photocurrent increase after bending many times. Under external stress, polarization charges could tune Shottky barrier height of the metal/tellurium, resulting in variation of photocurrent. This research not only explores the broadband photoresponse and piezoelectric effect of tellurium nanomesh, but also promotes the integration and development of broadband flexible optoelectronic devices.

We introduce a hybrid visible photocatalyst using an organic and inorganic p-n junction, which is formed by a self-assembled poly (3-hexylthiophene) (P3HT) nanomesh (NM) as a p-type semiconductor and a zinc oxide (ZnO) nanorod (NR) as an n-type semiconductor for indoor air purification. The self-grown P3HT nanofibrils form the hybrid NM p-n junction on the surface of the ZnO NR, which absorbs visible light, separates photo-generated electron-hole pairs, and forms numerous redox sites. Based on these three functions, the hybrid catalyst can effectively decompose pollutants under visible light illumination. Here, 80% of Rhodamine 6G was decomposed using the hybrid visible catalyst within 30 min, which is 33% higher than that of a catalyst without the NM structure. Moreover, the P3HT NM of the hybrid catalyst showed excellent chemical stability for washing with various organic solvents and durability during 20 photocatalytic cycles. Finally, we successfully created an artificial flower with the hybrid catalyst as an air purifier to eliminate acetyl acetate, which is a representative volatile organic compound responsible for the sick building syndrome, under illumination from a 30 W fluorescent lamp.

The present work reports an organic molecule electrode (OME) based on the graphene and graphene nanomesh (GNM) hydrogel non-covalently functionalized by caffeic acid (CFA) molecules (denoted as G&GMH-CFA). In such electrode system, the three-dimensional conductive network has a cross-linking channel constructed by means of the in-plane pores on the graphene nanomesh, which is benefit for exposing more active sites accessible to electrolyte and accordingly enhancing supercapacitive behaviors of the OME. The G&GMH-CFA delivers a specific capacitance of 482.6 F g−1 at current density of 1 A g−1. And it is noted that the Faraday current response peaks are located in the positive potential range of 0.6 V, which is superior to the organic molecules electrode reported in the correlative works. In addition, the density functional theory (DFT) calculations are used to illuminate the core issue of charge storage mechanism and binding interactions between CFA and graphene. To match with the resultant positive electrode, AQ functionalize graphene-like nanoflower (CNF-AQ) was prepared as counterpart (negative) electrode. The assembled asymmetric supercapacitors (ASC) CNF-AQ//G&GMH-CFA2 could exhaustively release the supercapacitive performance due to match and self-coordination based on the reasonable matching of two electrodes in structure, charge quantity and kinetics during the electrochemical energy storage process. The CNF-AQ//G&GMH-CFA2 delivered energy density of 26.4 Wh kg−1 at the power density of 0.7 kW kg−1. Two tandem CNF-AQ//G&GMH-CFA2 devices could easily light 88 LEDs.

We report results of a systematic computational study on the mechanical response of graphene nanomeshes (GNMs) to uniaxial tensile straining based on molecular-dynamics simulations of dynamic deformation tests according to a reliable bond-order interatomic potential. We examine the effects on the GNM mechanical behavior under straining along different directions of the nanomesh pore morphology and pore edge passivation by testing GNMs with elliptical pores of various aspect ratios and different extents of edge passivation through termination with H atoms of under-coordinated edge C atoms. We establish the dependences of the ultimate tensile strength, fracture strain, and toughness of the GNMs on the nanomesh porosity, derive scaling laws for GNM strength-density relations, and find the GNMs' mechanical response to uniaxial straining to be anisotropic for pore morphologies deviating from circular pores. We also find that the GNM tensile strength decays exponentially with increasing GNM porosity and that pore edge termination with H atoms causes a reduction in the GNMs' elastic stiffening, strength, deformability, and toughness; this hydrogen embrittlement effect is more pronounced at a high level of pore edge passivation that renders the edge C atoms sp3-hybridized. The underlying mechanisms of crack initiation and propagation and nanomesh failure for the various types of GNMs examined also are characterized in atomistic detail. Overall, even highly porous GNMs remain particularly strong and deformable and, therefore, constitute very promising 2D mechanical metamaterials.We report results of a systematic computational study on the mechanical response of graphene nanomeshes (GNMs) to uniaxial tensile straining based on molecular-dynamics simulations of dynamic deformation tests according to a reliable bond-order interatomic potential. We examine the effects on the GNM mechanical behavior under straining along different directions of the nanomesh pore morphology and pore edge passivation by testing GNMs with elliptical pores of various aspect ratios and different extents of edge passivation through termination with H atoms of under-coordinated edge C atoms. We establish the dependences of the ultimate tensile strength, fracture strain, and toughness of the GNMs on the nanomesh porosity, derive scaling laws for GNM strength-density relations, and find the GNMs' mechanical response to uniaxial straining to be anisotropic for pore morphologies deviating from circular pores. We also find that the GNM tensile strength decays exponentially with increasing GNM porosity and that po...

Pristine topological insulators (TIs) with no carrier doping principally suffer from a lack of magnetic ordering. We create a nanomesh structure, a honeycomblike array of hexagonal nanopores with extremely high density, on a nondoped two-dimensional (2D) thin TI (Bi2Te3). We observe antiferromagnetism (AFM) in completely hydrogen-terminated nanomeshes, while it is eliminated by ferromagnetism (FM) in completely O-terminated nanomeshes. Interplay between the AFM and FM is observed in partially O-terminated nanomeshes. As a possible origin for the observed magnetisms, Kramers doublets, which may exist around nanopore edges, for AFM and those eliminated by FM spin alignment due to O-Te coupling along pore edges are discussed based on the structure and annealing dependence of the magnetisms. The nondoped 2D nanomesh formed on a TI will lead to new avenues of research on topological magnetisms and spintronics.

The development of non-noble metal hydrogen evolution catalysts that can replace Pt is crucial for efficient hydrogen production. Herein, we develop a type of well-dispersed Ni2P on N-doped nanomesh carbon (NC) electrocatalyst by a facile pyrolysis method, which shows excellent hydrogen evolution reaction (HER) catalytic performance. It is rather remarkable that the overpotential of Ni2P/NC prepared under optimal proportion is 108 mV at 10 mA&middot, cm&minus, 2 current density in 1 M KOH solution with the tafel slope of 67.3 mV&middot, dec&minus, 1, the catalytic activity has no significant attenuation after 1000 cycles of cyclic voltammetry (CV)method. The hydrogen evolution performance of the electrocatalytic is better than most similar catalysts in alkaline media. The unique mesh structure of the carbon component in the catalyst facilitates the exposure of the active site and reduces the impedance, which improves the efficiency of electron transport as well as ensuring the stability of the hydrogen evolution reaction. In addition, we prove that nitrogen doping and pore structure are also important factors affecting catalytic activity by control experiments. Our results show that N-doped nanomesh carbon, as an efficient support, combined with Ni2P nanoparticles is of great significance for the development of efficient hydrogen evolution electrodes.

We used in situ scanning tunneling microscopy to investigate the formation of two-dimensional supramolecules by means of reversible azomethine condensation reactions between aqueous 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) and terephthaldicarboxaldehyde (TPA) or benzaldehyde (BA) at the solid/liquid interface of an iodine-modified Au(1 1 1) surface. A nanomesh and a close-packed array were formed by the reaction of TAPP with the dicarboxaldehyde. Formation of these structures was driven by Schiff base (azomethine) bonding and simultaneous self-assembly controlled by adsorption and condensation equilibria. Surface cross coupling between TAPP and the monocarboxaldehyde (BA) formed highly ordered adlayers consisting solely of TAPP symmetrically disubstituted with two BA molecules attached at diagonally opposite corners. The position selectivity was achieved through simultaneous coupling reaction equilibria and the thermodynamic self-assembly.

Here, we report a facile method to fabricate a graphene nanomesh (GNM) by using a platinum (Pt) metal nano-network as a pattern mask. A hexagonally ordered Pt nano-network (i.e. nanomesh) with high-density arrays of periodic nano-holes was synthesized using an anodized alumina template, which served perfectly as a pattern mask for generating GNMs with tunable pore neck widths. Altering the neck width of the pores allows the modulation of the electrical conductivity of the GNMs. Resultant GNMs were further characterized using Raman spectroscopy and their electrical properties as conducting channels in field-effect transistors (FETs) were evaluated as a function of neck width. This synthetic route for producing GNMs provides a low-cost and simple way to fabricate GNMs for use in future fundamental studies related to graphene.

A photoactivated ZnO nanomesh with precisely controlled dimensions and geometries is fabricated by using nanosphere lithography process. The nanomesh structures effectively increase the surface-to-volume ratio to improve the sensing response under the same testing gas. And the periodical nanostructures also increase the effective light path and lead to more efficient light activation for gas sensing. With the increase of the photoinduced oxygen ions by UV illumination, a distinguished sensing response is observed at room temperature. In the optimized case, the sensing response (△R/R0) of the ZnO nanomesh at the butanol concentration of 500 ppm is 97.5%, which is 4.54 times higher than the unpatterned one.

Experiment and computer simulations were conducted in order to study the adsorption of the phthalocyanine molecules H2Pc and CuPc on the h-BN/Rh(111) nanomesh. We combine STM investigations with the exploration of the potential energy surface as resulting from density functional theory calculations. Both approaches indicate a pronounced adsorption selectivity in the so called pore regions of the h-BN nanomesh, whereas the adsorption energy landscape in the pore turns out to be very shallow. This is seen by the inability to image the molecule stably at 77 K by scanning tunneling microscopy. Understanding the nature of the binding by rationalizing the site-selectivity and the mobility of the molecules is quite a challenge for both experiment and theory. In particular, we observe that the choice of the functional in the DFT description is crucial to be able to discriminate among adsorption sites that are very close in energy and to resolve low energy barriers. Our study reveals how the shape of the corrugated h-BN layer is the dominant factor that determines the subtle features of the potential energy surface for the adsorption of phthalocyanine.

The exposure of hexagonal boron nitride single layers to low energy ions leads to the formation of vacancy defects that are mobile at elevated temperatures. For the case of h-BN on rhodium, a superhoneycomb surface with 3 nm lattice constant (nanomesh), a concerted self-assembly of these defects is observed, where the "can-opener" effect leads to the cut-out of 2 nm "lids" and stable voids in the h-BN layer. These clean-cut voids repel each other, which enables the formation of arrays with a nearest neighbor distance down to about 8 nm. The density of voids depends on the Ar ion dose, and can reach 10(12) cm(-2). If the structures are annealed above 1000 K, the voids disappear and pristine h-BN nanomesh with larger holes is recovered. The results are obtained by scanning tunneling microscopy and density functional theory calculations.

In order to make full utilization of the high intrinsic surface area of graphene, recently, porous graphene materials including graphene nanomesh, crumpled graphene and graphene foam, have attracted tremendous attention and research interest, owing to their exceptional porous structure (high surface area, and high pore volume) in combination with the inherent properties of graphene, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Interestingly, porous graphene materials and their derivatives have been explored in a wide range of applications in the fields of electronic and photonic devices, energy storage, gas separation/storage, oil absorption and sensors. This article reviews recent progress in the synthesis, characterization, properties, and applications of porous graphene materials. We aim to highlight the importance of designing different porous structures of graphene to meet future challenges, and the trend on future design of porous graphene materials is analyzed.

The bandgap engineering of graphene is a challenging task for its potential application. Forming unique structures such as nanoribbons or nanomeshes is an effective way to open up a bandgap in graphene. In this work, a graphene nanomesh (GNM) was prepared through UV-mediated oxidation of a graphene oxide (GO) film at atmosphere. Atomic force microscopy (AFM) was used to track the evolution of the surface morphology of GO during the irradiation. It was observed that a nanoporous network structure was progressively produced in the basal plane, which can be attributed to the fact that highly reactive oxygen species preferentially attack sp3 carbon-rich regions of the GO. In particular, the as-prepared GNM shows interesting semiconducting characteristics and photoluminescence (PL) phenomenon, which make it become a promising candidate for the use of electronics, optoelectronics, and biomedical engineering. Finally, the field-effect transistors (FETs) were fabricated using the as-prepared GNM as the active cha...

Spintronics, which manipulate spins but not electron charge, are highly valued as energy and thermal dissipationless systems. A variety of materials are challenging the realization of spintronic devices. Among those, graphene, a carbon mono-atomic layer, is very promising for efficient spin manipulation and the creation of a full spectrum of beyond-CMOS spin-based nano-devices. In the present article, the recent advancements in graphene spintronics are reviewed, introducing the observation of spin coherence and the spin Hall effect. Some research has reported the strong spin coherence of graphene. Avoiding undesirable influences from the substrate are crucial. Magnetism and spintronics arising from graphene edges are reviewed based on my previous results. In spite of carbon-based material with only sp2 bonds, the zigzag-type atomic structure of graphene edges theoretically produces spontaneous spin polarization of electrons due to mutual Coulomb interaction of extremely high electron density of states (edge states) localizing at the flat energy band. We fabricate honeycomb-like arrays of low-defect hexagonal nanopores (graphene nanomeshes; GNMs) on graphenes, which produce a large amount of zigzag pore edges, by using a nonlithographic method (nanoporous alumina templates) and critical temperature annealing under high vacuum and hydrogen atmosphere. We observe large-magnitude ferromagnetism, which arises from polarized spins localizing at the hydrogen-terminated zigzag-nanopore edges of the GNMs, even at room temperature. Moreover, spin pumping effects are found for magnetic fields applied in parallel with the few-layer GNM planes. Strong spin coherence and spontaneously polarized edge spins of graphene can be expected to lead to novel spintronics with invisible, flexible, and ultra-light (wearable) features.

The Cu nanomesh was obtained by a combination of nanosphere lithography (NSL) and high power pulsed magnetron sputtering (HiPPMS). A deposition mask was formed on TiO2 substrates by the self-assembly of polystyrene latex spheres with a diameter of 1 μm, then Cu nanomesh structure was produced on the substrate using sputtering. The structures were investigated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results show the increase of temperature of the polystyrene mask caused by the thermal radiation from the target and the bombardment of sputtering particles would affect the quality of the final nanopattern. The tests of photocatalytic degradation, platelet adhesion and human umbilical artery smooth muscle cells (HUASMCs) culture show Cu deposition could promote the photocatalytic efficiency of TiO2, affect platelet adhesion and inhibit smooth muscle cell adhesion and proliferation. It is highlighted that these findings may serve as a guide for the research of multifunctional surface structure.

Two-dimensional ordered arrays of honeycomb morphology of platinum are fabricated by using anodized aluminum oxide template and metal sputtering methods. The resulting metal films are highly conductible (71 Ω/sq), stretchable (16.8%), and transparent (75.2% at 550 nm). The presented synthetic strategy is scalable to large area without noticeable defects by incorporating the deposition of a thin layer of silver. In addition, both the pore size and wall thickness of platinum nanomesh films are straightforwardly controlled with sputtering time. As a proof of concept, the metal nanomesh films using AAO template suggest a new concept of synthesizing transparent and stretchable metal electrodes for future electronic devices.

Nanomesh graphene (NMG) obtained by template chemical vapor deposition was used to synthesize the binder-free graphene monoliths by simple tablet pressing. The stacking manner of the NMG sheets was crucial to the cohesion interaction between the graphene sheets, only the NMG materials with a loosely stacking manner could be pressed into binder-free monoliths. At the tableting pressure of 2–8 MPa, both the bulk densities and the specific surface areas of the monoliths keep nearly constant as the tableting pressure increases, indicating that the NMG monoliths have obvious elasticity and a porous structure due to the large corrugations and the mesh structures of the graphene sheets. As a result, an extraordinary methane storage capacity of 236 (v/v) at 9 MPa was obtained in the graphene monolith prepared by tableting at 4 MPa.

The self-organized formation of tin (Sn) and lead (Pb) atoms in a well ordered (4 × 4) vanadium oxide nanomesh on Pd(111) has been investigated using scanning tunneling microscopy (STM) and ab initio calculations based on density functional theory (DFT). At a very low Sn coverage, most of the Sn atoms filled the vanadium oxide nanohole and a few of them were adsorbed on top of the vanadium oxide nanomesh. On the contrary, all of Pb atoms were located in the vanadium oxide nanohole. The ab initio DFT total-energy calculations indicated that the Sn and Pb atoms preferred to adsorb in the nanohole rather than on the nanomesh. The simulated STM images for the Sn and Pb atoms exhibited a local protrusion, while the experimental STM images showed a large, uniform protrusion. The adsorbed Sn and Pb atoms might be mobile in the nanohole at room temperature, possibly as a result of interaction with the STM tip.

Molecular doping and detection are at the forefront of graphene research, a topic of great interest in physical and materials science. Molecules adsorb strongly on graphene, leading to a change in electrical conductivity at room temperature. However, a common impediment for practical applications reported by all studies to date is the excessively slow rate of desorption of important reactive gases such as ammonia and nitrogen dioxide. Annealing at high temperatures, or exposure to strong ultraviolet light under vacuum, is employed to facilitate desorption of these gases. In this article, the molecules adsorbed on graphene nanoflakes and on chemically derived graphene-nanomesh flakes are displaced rapidly at room temperature in air by the use of gaseous polar molecules such as water and ethanol. The mechanism for desorption is proposed to arise from the electrostatic forces exerted by the polar molecules, which decouples the overlap between substrate defect states, molecule states, and graphene states near the Fermi level. Using chemiresistors prepared from water-based dispersions of single-layer graphene on mesoporous alumina membranes, the study further shows that the edges of the graphene flakes (showing p-type responses to NO2 and NH3) and the edges of graphene nanomesh structures (showing n-type responses to NO2 and NH3) have enhanced sensitivity. The measured responses towards gases are comparable to or better than those which have been obtained using devices that are more sophisticated. The higher sensitivity and rapid regeneration of the sensor at room temperature provides a clear advancement towards practical molecule detection using graphene-based materials. Molecules bind strongly to graphene and graphene nanomesh edges. Annealing at high temperature or exposure to strong UV light is required for desorption. Alternatively, polar molecules can mediate rapid and complete desorption at room temperature. Electrostatic forces of polar molecules alter the overlap of graphene bands with substrate defect bands and molecule bands near Fermi level and cause desorption. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Reduced graphene oxide nanomesh (rGONM), as one of the recent structures of graphene with a surprisingly strong near-infrared (NIR) absorption, is used for achieving ultraefficient photothermal therapy. First, by using TiO2 nanoparticles, graphene oxide nanoplatelets (GONPs) are transformed into GONMs through photocatalytic degradation. Then rGONMs functionalized by polyethylene glycol (PEG), arginine-glycine-aspartic acid (RGD)-based peptide, and cyanine 7 (Cy7) are utilized for in vivo tumor targeting and fluorescence imaging of human glioblastoma U87MG tumors having αν β3 integrin receptors, in mouse models. The rGONM-PEG suspension (1 μg mL(-1) ) exhibits about 4.2- and 22.4-fold higher NIR absorption at 808 nm than rGONP-PEG and graphene oxide (GO) with lateral dimensions of ≈60 nm and ≈2 μm. In vivo fluorescence imaging demonstrates high selective tumor uptake of rGONM-PEG-Cy7-RGD in mice bearing U87MG cells. The excellent NIR absorbance and tumor targeting of rGONM-PEG-Cy7-RGD results in an ultraefficient photothermal therapy (100% tumor elimination 48 h after intravenous injection of an ultralow concentration (10 μg mL(-1) ) of rGONM-PEG-Cy7-RGD followed by irradiation with an ultralow laser power (0.1 W cm(-2) ) for 7 min), whereas the corresponding rGO- and rGONP-based composites do not present remarkable treatments under the same conditions. All the mice treated by rGONM-PEG-Cy7-RGD survived over 100 days, whereas the mice treated by other usual rGO-based composites were dead before 38 days. The results introduce rGONM as one of the most promising nanomaterials in developing highly desired ultraefficient photothermal therapy.

With the recent emergence of flexible and wearable optoelectronic devices, the achievement of sufficient bendability and stretchability of transparent and conducting electrodes (TCEs) has become an important requirement. Although metal-mesh-based structures have been investigated for TCEs because of their excellent performances, the fabrication of mesh or grid structures with a submicron line width is still complex due to the requirements of laborious lithography and pattern transfer steps. Here, we introduce an extremely facile fabrication technique for metal patterns embedded in a flexible substrate based on submicron replication and an area-selective delamination (ASD) pattern. The high-yield, area-specific lift-off process is based on the principle of solvent-assisted delamination of deposited metal thin films and a mechanical triggering effect by soft wiping or ultrasonication. Our fabrication process is very simple, convenient, and cost-effective in that it does not require any lithography/etching steps or sophisticated facilities. Moreover, their outstanding optical and electrical properties (e.g., sheet resistances of 0.43 Ω sq