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The development of high-performance micro-supercapacitors (MSCs) highlights two-dimensional (2D) carbon materials with pseudocapacitive charge storage capacity. However, improving the electrochemical performances of these electrode materials is still challenging. Here, we synthesized 2D borocarbonitride nanomesh (BCNN) by carbonizng gel precursor of milk powder and boron oxide in 700, 800, and 900 °C, respectively, denoted as BCNN700, BCNN800, and BCNN900, as electrode for MSCs. By tailoring defects and atomic contents of BCNN, the areal capacitance increases from 30.5 mF cm−2 for BCNN700-MSCs to 80.1 mF cm−2 for BCNN900-MSCs with a hydrogel electrolyte. Notably, BCNN900-MSCs can provide a high energy density of 67.6 mWh cm−3with an ion-gel electrolyte, efficiently powering a liquid crystal display for 328 s. In addition, a first principles simulation verifies the effects of the dopants and pores on improving the total capacitance of BCNN by enhancing qauntam capacitance. Therefore, BCNN exhibits tremendous potential for applying on future energy storage devices.

In this work, a green Fe-doped TiO2 photocatalyst was successfully synthesized on Ti mesh through the chemical impregnation and anodization method. The influence of sample Fe-content on the photocatalytic performance was investigated in detail. Ordered TiO2 nanomesh was compactly decorated with nanospheres to form a novel photocatalyst Fe-doped TiO2 with anatase phase. Simultaneously, it exhibits higher light absorption intensity compared to the pristine TiO2 within the visible light range, and its absorption peak has a redshift. The VSM results showed that the sample has excellent magnetic properties. It is hard to achieve magnetic agglomeration after magnetic field removal, which benefits the strong recyclability and reusability of Fe-doped TiO2 photocatalyst. Importantly, this higher visible-light photoresponse of TiO2 was clearly obtained after Fe doping. When the Fe-content was 0.6 wt%, the degradation rate of methylene blue reached 87.9% under simulated sunlight irradiation for 2.5 h. The prepared nanocrystalline photocatalyst demonstrated excellent photocatalysis because of its prominent crystal morphology, strengthen light-absorption capacity, and commendable inhibition recombination of photo-induced electron-hole.

Nowadays, the development of promising anodes for Na and K ion batteries (NIB and KIB) has got great attention due to their sustainable and renewable energy applications. Graphite is a good candidate but suffers from low Na (

Ultraviolet absorbing materials have important applications in which graphene is a strong candidate, yet, few efforts are being exerted to improve its absorption in the UV-region. We show that UV absorption in single-layer graphene can be enhanced by manoeuvring its electronic properties through converting it to a nanomembrane-like structure, or nanomesh. Regular and irregular pores were created by Electron Beam Lithography and a lithography-free process respectively. Theoretical calculations, using density functional theory, confirmed the experimental results, and indicated that the absorption peaks are a result of changes in the band structures of the nanomembrane graphene (NMGs) arising from the pore superlattice.

Multilayer graphene nanomeshes (GNMs) are first employed to improve the efficiency and long-term stability of porous-Si (PSi) Schottky-junction solar cells because GNMs exhibit stable p-type characteristics. Photovoltaic parameters of multilayer GNM/PSi solar cells strongly depend on hole size of GNM (S h ) and number of layers ( L n ). Especially, GNMs are advantageous for efficient separation and collection of photo-induced electron-hole pairs due to their low reflectance and high work function. Optimized maximum power conversion efficiency (PCE) is 7.02% at S h = 40 nm and L n = 3, resulting from S h - and L n -dependent trade-off correlation between electrical and optical properties of the GNM/PSi solar cells. The solar cells lose only 1/7% of the initial PCE even under room-temperature atmosphere/continuous light soaking at 60 °C, respectively for 1000 h.

To improve the conversion efficiency of InGaP/InGaAs/Ge triple-junction solar cells, AuGeNi/Au nanomesh electrode structure and TiO2 nanostructured antireflection structure were designed and fabricated. Laser interference photolithography system was used to pattern 330-nm-wide nanomesh electrode structures with various AuGeNi/Au metal line intervals. Oblique evaporation method using electron beam evaporator was used to deposit TiO2 nanorod arrays with various periods. By using the AuGeNi/Au nanomesh electrode structure with metal line interval of 100 μm, the conversion efficiency of the InGaP/InGaAs/Ge triple-junction solar cells was improved to 35.25% compared with 30.84% of that with conventional bus-bar electrode structure. By using the TiO2 nanorod array with a period of 1.00 μm to replace the TiO2/SiO2 antireflection structure, the conversion efficiency was further improved from 35.25% to 37.00%.

Diverse three-dimensional (3D) porous metal electrodes, including meshes, foams and felts, are used in electrochemical flow reactors for a wide range of industrial applications, such as energy storage, electrosynthesis and degradation of pollutants. Recent work centres on the hierarchical decoration and coating of 3D electrodes with catalysts, although the study of their performance in a controlled and reproducible flow and mass transfer environment ought to receive more attention. New advances have considered metal nanofelts and nanomesh porous electrodes with superior electrode surface area. Opportunities are found in additive manufacturing, advanced structural characterisation by, for example, X-ray computed tomography, and in the modelling of hydrodynamic characteristics, current distribution and mass transfer coefficient of these electrode materials.

Nano engineering of semi-metallic graphene can create graphene nanostructures such as nanoribbon and nanomesh for applications in electronic devices. Graphene materials manipulated by delicate patterning technology have exhibited semiconducting behavior, but the complex processes and degradation of the graphene during processing can be a bottleneck for the practical applications. Herein, a direct patterning approach to fabricate mesh-type carbon materials with a nanohole array was developed using phase-separated polyacrylonitrile (PAN)/poly (methyl methacrylate) (PMMA) blends. Carbon nanomeshes (CNMs) with various neck widths less than 100 nm were obtained by controlling the mixing ratio of PAN to PMMA. Gate dependent ambipolar transport behavior was observed even though the CNM exhibits imperfect crystallinity due to the catalyst-free preparation. Based on the systematic investigation of the temperature dependent electrical transport of the CNM-based field effect transistor, it was demonstrated that the charge conduction in CNMs is dominated by variable range hopping between localization states.

CoSe2 has been as one of promising electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) due to its earth-abundant resource, and tunable electronic structure. However, enhancing electrocatalytic activity of CoSe2 to meet the large-scale practical applications is desirable. Herein, we report a facile plasma nitridation strategy to generate N-doped CoSe2 nanomesh arrays on commercial carbon paper (N-CoSe2@CP). The obtained N-CoSe2@CP electrodes combined advantages of abundant electrochemical active sites and beneficial electronic structures, thus exhibiting a low overpotential of 106 mV and 237 mV to drive 10 mA cm−2 towards HER and OER in alkaline medium, respectively. Moreover, it can be employed as bifunctional electrocatalyst for overall water splitting, where a small potential of 1.57 V was required to reach 10 mA cm−2, and long-term stability was also realized. This work develops a promising strategy to explore highly-efficient nanocatalysts towards new energy conversion.

Filtering capacitors with high energy densities are of critical importance in stabilizing the pulse signal of circuits that require the conversion of alternating current to direct current, which is however far from satisfactory at current stage due to lack of a reasonable design. Here, we report an ultrafast aqueous electrochemical capacitor based on highly conductive and continuously cross-linked poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) nanomesh films fabricated using a rational morphology engineering strategy. The interpenetrating polymer network promoted an efficient electron transfer and provided smooth channels for ion transport while exposing a significant number of accessible interfacial area to electrolyte. In addition to the large phase angle of − 84° at 120 Hz, this polymer-based electrochemical capacitor exhibited an extremely high areal specific capacitance of 1087 μF cm−2 and areal specific energy density of 544 μF V2 cm−2, far superior to those of most reported aqueous filtering capacitors. Furthermore, it can efficiently smoothen the ripples generated when arbitrary alternating current waveforms were converted into straight signals over a wide frequency range of 1–10,000 Hz. Moreover, it was conveniently integrated with a rotating disk triboelectric nanogenerator for ripple filtering and pulse energy smoothing. This work brings a view for aqueous filtering capacitors with high performance.

With the aim of improving UV light trapping capability in monolayer graphene, a nanomesh metamaterial absorber is proposed, which exhibits the polarization-insensitive feature due to the geometrical symmetry. Through the functional combination of magnetic resonance and UV mirror, the absorption of unpolarized UV light in monolayer graphene can reach 99.5% under normal incidence. The absorption enhancement is induced by the magnetic resonance mode between the dielectric silica nanomesh and the calcium fluoride base layer. The effects of geometric parameters on the absorption spectra are systematically investigated. The proposed structure shows insensitive to manufacturing deviations, which can maintain at a high UV absorption rate of more than 99% within the nanomesh width ranging from 50 nm to 90 nm. Furthermore, after delicate optimization of the geometric parameters, two sharp resonances with absorbance more than 90% can be excited simultaneously inside the absorber. Our work provides an important theoretical guide for the design of optoelectronic devices based on two-dimensional materials in the UV range.

Improving the energy density of MXene micro-supercapacitors (MSCs) is still a challenge because the MXene nanosheets will easily agglomerate, leading to irreversible reduction of capacity. We present SiC/MXene heterostructure by ionization-bombardment assisted deposition synthesis. Under high voltage, C–C bond and Si-O bond are broken by electron bombardment. After arc sintering, C atom and Si atom form stable Si-C bond with lower bond energy, and then form SiC nanocrystals. Furthermore, SiC nanocrystals were patterned into mesoporous SiC nanonesh to enhance the specific surface area. The surface of SiC framework is full of charge, which makes the MXene nanosheets uniformly deposited and self-assembled to form heterostructure. SiC/MXene heterostructure has low barrier, strong bonding force and fast electron migration rate. SiC nanomesh provide a conductive network, and also serve as a framework to support the MXene film, increasing ion storage space, creating an interconnected path for the conduction of Na ions. The specific capacity of the MXene/SiC MSC is up to 97.8 mF cm−2 at a current density of 1 A cm−2. The fabrication of high-performance nanostructures leads to large-scale production and micro-energy storage devices.

Molybdenum disulfide (MoS2) presents a promising catalyst to replace state-of the-art platinum (Pt) for hydrogen evolution reaction (HER), but it still lacks an effective way due to the catalytically inert basal plane. Herein, we report a rational design of MoS2 nanomesh that possesses evenly distributed holes and defects to make full use of the 2H-MoS2 basal planes by combining ball-milling with ultrasonic methods. The exfoliation of muti-layer MoS2 to fewer layer or enven monolayer is proceed in pure water without using any chemicals or surfactants. The great advantage of the catalyst is the monolayer, holey and defective structure, which maximizing the synergistic activity for both electrocatalytic and photocatalytic HER performances. Impressively, the MoS2 nanomesh renders outstanding electrocatalytic HER activity with an overpotential of 160 mV at a current density of 10 mV cm−2, and a small Tafel slope of 46 mV decade−1. The photocatalytic H2 evolution rate is about 4.84 mmol h−1 when working with Eosin Y as an organic photosensitizer. Additionally, this catalyst shows excellent cycle stability in the electrochemical and photocatalytic reactions. This present work put a new insight into the large-scale production of chemically active 2H MoS2-based catalysts for HER.

The adsorption of molecules on surfaces affects the surface dipole and thus changes in the work function may be expected. The effect in change of work function is particularly strong if charge between substrate and adsorbate is involved. Here we report the deposition of a strong electron acceptor molecule, tetrafluorotetracyanoquinodimethane C$_{12}$F$_4$N$_4$ (F$_{4}$TCNQ) on a monolayer of hexagonal boron nitride nanomesh ($h$-BN on Rh(111)). The work function of the F$_{4}$TCNQ/$h$-BN/Rh system increases upon increasing molecular coverage. The magnitude of the effect indicates electron transfer from the substrate to the F$_{4}$TCNQ molecules. Density functional theory calculations confirm the work function shift and predict doubly charged F$_{4}$TCNQ$^{2-}$ in the nanomesh pores, where the $h$-BN is closest to the Rh substrate, and to have the largest binding energy there. The preferred adsorption in the pores is conjectured from a series of ultraviolet photoelectron spectroscopy data, where the $\sigma$ bands in the pores are first attenuated. Scanning tunneling microscopy measurements indicate that F$_{4}$TCNQ molecules on the nanomesh are mobile at room temperature, as "hopping" between neighboring pores is observed.

Herein, abundant and uniform nanopores with sub-3-nm sizes are introduced to 1.5 nm-thick nickel-iron layered double hydroxide (NiFe LDH) ultrathin nanosheets via an etching-aging process, realizing remarkable enhancement in oxygen evolution reaction (OER) performance. Detailed analyses revealed that the NiFe LDH phase around the nanopores can be preferentially oxidized into electroactive Fe:NiOOH phase. In addition, the buffering space provided by the nanopores can effectively avoid structural deformation during repeated redox cycling, leading to better electrochemical stability, which synergistically make the catalyst a promising candidate for commercial water splitting. This work highlights the positive role of porous structure in accelerating the formation of active phases beyond just increment of surface area, which can provide insight in designing advanced catalysts.

It is well known that introducing periodic holes into graphene can be used to obtain semiconducting graphene nanomeshes (GNM). Using Molecular Dynamics (MD) simulations as well as semi-empirical Extended Huckel (EH) method, the mechanical and electronic properties of GNM heterojunction are studied. In this study the mechanical and electronic properties of graphene nanoribbons with different hole sizes and different hole shapes (circular, square and equilateral triangle) were studied. Midgap states were observed near the Fermi level, which are also affected by the geometries of the holes. Dependence of the properties on the density (ρ) was also investigated for each geometry. It has been found that GNM is significantly brittle compared to pristine graphene nanoribbons. It is observed that the relationship between the hole shape and size and the band gap is different for armchair and zigzag chirality.

Facile yet rational design of efficient electrocatalyst toward triiodide reduction reaction is a persistent challenge for the practical application of dye-sensitized solar cell (DSSC). Here we propose a protocol for fabricating atomic N-coordinated cobalt sites (Co-Nx-C) within nanomesh graphene frameworks (Co-NMG). The as-synthesized Co-NMG combines the features of atomically dispersed active sites and interconnected mesoporous structure with high porosity, which makes these active sites fully exposed and accessible while facilitating the mass transport of reactants. As a result, the Co-NMG electrocatalysts with substantial active sites and desired porous architectures exhibit high electrocatalytic activity and long-term electrochemical stability. Electrochemical measurements and DFT calculations reveal that the catalytic sites toward the reduction of triiodide mainly derive from the abundant topological defects, nitrogen dopants, and especially the atomic Co-Nx-C moieties. Furthermore, with Co-NMG as counter electrodes (CEs), the DSSCs display a power conversion efficiency of 9.06%, which is higher than that of Pt CEs (7.71%). This work not only provides a promising CE material for DSSC to address the issues associated with Pt catalyst, but also opens up new avenues for developing nanocarbon based catalysts with desired features for other energy-related applications.

In this article, 3D pillared carbon nanotube (CNT)-porous graphene (PG) nanomesh architectures are computationally investigated as methane storage nanocontainer. The purpose of this article is to screen the configurations of 3D pillared CNT-PG materials and to select the optimal one for maximizing the methane storage capacity. Molecular mechanics (MM) calculations and MD simulations are executed to depict the structural characteristics and methane adsorption properties. The calculated structural parameters coincide well with the empirical conclusions. The methane adsorption simulations are systematic investigated as a function of geometry variables such as PG interlayer spacing, distance of CNTs, and the number of PG sheets in a wide range of pressure. The average adsorption energy of methane in different configurations is concentrated between 2 and 4 kcal mol−1. The results revealed that the applications of 3D CNT-PG models can significantly enhance methane adsorption performance in comparison to pillared graphene: the maximum amount of adsorbed methane of 3D CNT-PG displays 21.3 mmol/gr (interlayer spacing of 1.2 nm and bilayer PG), which is about 25% higher than that of pillared graphene. Meanwhile, the deformation of (6, 6) carbon nanotubes can significantly improve the methane storage capacity. This provides a viable structure modification method, which is suitable for enhancement of methane storage.

First principles calculation based on density functional theory has been applied to systematically study the electronic structure, especially band gap of recently synthesized periodic porous structure, graphene nanomesh, as well as its analogous system BN nanomesh. These porous structures possess various band gaps due to two parameters: neck length and width. The modulation of these parameters can be achieved through different etching templates in experiments. Two mechanisms, plane and nanoribbon, are proposed to understand the band gap variation with respect to neck length and width, qualitatively. We also examine electronic frontier states around Fermi level. Especially, armchair necked BN nanomesh has separated highest occupied and lowest unoccupied states in real space, which also makes it be reactive at different site. The hydrogen storage potentials based on transition metal atoms such as Sc trapped in anionic decorated pores are also been explored. No clustering problem is found and one Sc can adsorb four H 2 molecules with binding energy per H 2 of 0.13 eV.

Two-dimensional transition-metal dichalcogenides (TMDCs) are very promising for photovoltaic (PV) applications due to their excellent light absorption properties and appropriate bandgap energy, Although multifunctional applications of TMDCs in photovoltaic devices have been achieved, the photovoltaic conversion efficiency under 1 sun is still very low with small active area because of their inexpedient high sheet resistance and limitation of synthesis techniques. In this study, we demonstrate uniform synthesis of 4-in. wafer-scale MoS2 thin films by thermal decomposition of solution precursors. The solar cells are fabricated by transferring n-MoS2 thin films on p-Si substrates to form p-n heterojunctions and then transferring Au nanomeshes prepared in a novel surface treatment as transparent top electrodes onto MoS2. The circular n-MoS2/p-Si heterojunction solar cell exhibited a power conversion efficiency of 5.96% at a diameter of 0.3 in. and proved to be easily scalable to 1-in. diameter with 5.18% efficiency. To the best of our knowledge, the solar cells of this study are the most efficient and the largest in all types of solar cells based on TMDC reported so far. Finally, based on finite difference time-domain simulation, we proposed a strategy for implementing n-MoS2/p-Si heterojunction solar cell with efficiency higher than 15% by introducing optimal doping control of n-MoS2 and efficient anti-reflection layers.

The commercialized aluminum electrolytic capacitors (AECs) currently used for alternating current (AC) line-filtering have low specific capacitances, making them usually the largest components in electronic circuits. Herein, an ultrathin free-standing graphene nanomesh film (GMF) with uniform and dense nanoholes has been successfully fabricated by an in-situ carbothermal reduction strategy on the basis of spontaneously assembled graphene hybrid film. Due to the carbothermal reduction reaction between carbon atoms of graphene and the metal oxide nanoparticles in-situ generated during assembly process, in-plane nanopores are generated within graphene film. The pore size and density of GMF can be conveniently tuned by annealing temperature. With large ion-accessible surface area, efficient ion diffusion and electron transport pathways, the typical GMF-based electrochemical capacitor (EC) exhibits a high volumetric capacitance of up to 7.6 F cm−3 at 120 Hz, unprecedented power density of up to 3000 W cm−3, ultrafast frequency response with a phase angle of −82.3°, and a short resistor-capacitor time constant of 0.32 ms at 120 Hz, as well as long-term cycling stability. The performances of these ECs are superior to those of the state-of-the-art carbon-based ECs for this purpose; thus, it is promising to replace commercialized AECs for AC line-filtering in future electronics.

Although transparent conductive oxides (TCOs) including indium tin oxide (ITO), fluorine tin oxide (FTO) and Aluminum-doped Zinc oxide (AZO) have been commercialized, and they can be found in many consumer electronics, TCOs are mechanically brittle and this issue actually limits them to the application of future flexible solar cell devices. Therefore, one-dimensional (1D) metallic materials such as nanowires (NWs) have widely studied as transparent conductors because they exhibit excellent electrical and optical properties due to the quantum confinement effect that occurs in such structural one-dimensionality. More importantly, they are ductile as compared to traditional TCOs. Since demand for modern electronic devices have been escalating, a great variety of 1D materials such as bimetallic or core–shell metallic NWs, metal–oxide, metal–CNTs/Graphene and metal–polymer composite 1-D nanomaterials have been developing owing to the fact that their electrical, optical, and mechanical performance becomes several order of magnitude higher than the pure metal NWs, especially under extreme mechanical and chemical conditions. Derived from those metal NW researches, advanced two-dimensional (2D) metallic materials such as nanomesh and nanogrid are designed as potential alternative to replace either conventional TCO films or random metal NW-based films due to their ample carriers (electrons) can transport consistently through this solid metallic network and are collected by the contact terminals without significantly compromising the optical transmittance. Moreover, metal nanomesh and nanogrid architectures possesses excellent flexibility, which can withstand even more harsh mechanical conditions. Therefore, they can provide a great potential for the emerging super-flexible and stretchable devices. Despite the aforementioned advantages, scalable fabrication of 1D and 2D nanomaterials is still a challenging research topic, in terms of the yield and quality. To integrate nanoscale building blocks into high-performance devices further requires more sophisticated designs. In this review, we emphasize on the current development of 1D and 2D nanomaterials in the application of transparent conductors in renewable energy devices. Computational simulation methods for property prediction and device design will also be reviewed. Additionally, we also discuss the promising fabrication methods for those nanomaterials that are considered to be scalable, applicable, and budget-wise to this solar industry.

It is of practical and theoretical significance to realize full spectrum-active photocatalytic hydrogen (H2) evolution using a single-component photocatalyst. The bottleneck is the utilization of near infrared (NIR) light with 52% of the energy in solar spectrum due to the mismatch between its low single photon energy and the large bandgaps of many photocatalysts. In fact, except for the intrinsic inter-band transition, charge-transfer transition is another strategy to produce hot electrons as a result of light excitation. Herein, charge-transfer transition is achieved in hydrogen-interstitial CuWO4 nanomesh (H-CuWO4) by introducing low-valence Cu+ and W5+. The resulting polaron absorption produces abundant free electrons upon NIR irradiation. Meanwhile, the intrinsic inter-band transition supplies more electrons upon ultraviolet and visible (UV and Vis) irradiations. The mesh structure induced by the self-assembled orientated attachment facilitates the electron transport in the photocatalytic process. Further, the lattice stress resulting from the H intercalation raises the conduction band (CB) above the H+/H2 potential level. CuWO4, incapable of realizing photocatalytic H2 evolution, is therefore activated to be a single-component full spectrum-active photocatalyst based on the dual-channel mechanism without any assistance of cocatalysts. It exhibits an excellent H2 evolution rate and high stability. This advance may have great potential in the future environmental and energy engineering applications.

The exploration of various porous nanocarbon materials with an extraordinary electrochemical capacitive performance in ionic liquid (IL) electrolytes is urgently needed for development of the next-generation energy storage devices. Significant improvements in energy density have been achieved, however, supercapacitors with IL electrolytes usually suffer from issues related to low power density and large IR drop. Herein, we report an unprecedented carbon nanomesh that is made up of interconnected densely-packed carbon nanocages with ultrathin partially graphitic shells. The large specific surface area and well-developed mesopores combined with its unique structural features, make it a very competitive material for high-performance supercapacitor in IL electrolyte. Notably, this unique nanosheets morphology with lots of in-plane nanopores on their surface can provide fast cross-plane ion diffusion pathways, and meanwhile, the carbon nanocages with partially graphitic shells ensure the rapid electron transfer. The supercapacitor assembled with the optimized sample can deliver a high specific capacitance (up to 194 F/g at 1 A/g), superior rate capability (68% capacitance retention at 70 A/g), low IR drop (0.685 V at 70 A/g). Moreover, benefiting from the wide working voltage and high-rate capability, the energy densities can maintain at 56.1 Wh/kg even at an ultrahigh power density of 61.250 kW/kg. Strikingly, the as-assembled supercapacitor can successfully power a light-emitting diodes (LED, 2.2 V) module with 53 red LED lights demonstrating its great potential for practical applications in energy storage devices.

Herein, we report a facile yet effective fluorescent nanosensor for the direct, selective and sensitive determination of cerebral Cu2+ in the rat brain microdialysate. The fluorescent nanosensor is constructed by utilizing the strong fluorescent graphene quantum dots (GQDs) as the fluorescent signaling output, which were synthesized via chemical oxidation from 3D nanomesh graphene frameworks (NGFs). Initially, the as-prepared GQDs displays a uniform size with lateral size below 5 nm is observed to exhibit photoluminescence properties. The subsequent addition of Cu2+ into the GQDs mixture results in the significant quenching of the fluorescence of GQDs. The quenching degree of Cu2+ towards GQDs is highly sensitive to the concentration of Cu2+ and shows a linear relationship for Cu2+ within the range from 0.1 μM to 1.0 μM with a limit of detection (LOD) of 0.067 μM which substantially enables the GQDs as a nanosensor for Cu2+. Moreover, the as-fabricated nanosenor displays a high specificity for Cu2+ irrespective of the coexistence of other metal ions, amino acids, and biological substance that endogenously existed in the rat brain and has been employed to successfully determination of Cu2+ in rat brain with the basal value of 2.21 ± 0.76 μM (n = 3).

Electromagnetic radiation has become a severe problem due to the widespread utilization of wireless communications and smart electronic devices. Hence, the development of high-performance electromagnetic wave absorbers to overcome the electromagnetic pollution is of utmost significance. Herein, density functional theory (DFT) calculations are adopted to guide the design of high-performance electromagnetic wave absorbers based on layered MoS2. The results indicate that the electronic properties, the dipole moment and the electric polarization of vertically-aligned MoS2 monolayers on N-doped graphene are significantly tuned compared to horizontally-aligned MoS2 monolayers on N-doped graphene and MoS2 nanosheets, favoring the absorption of electromagnetic waves. Based on theoretical predictions, we have combined vertically-aligned MoS2 monolayers and N-doped graphene nanomesh by the spatial confinement effect of the nanomeshs. The experimental results demonstrate that the MoS2 monolayers on N-doped graphene exhibit excellent electromagnetic wave absorption performance with a minimal reflection loss of –72.83 dB and an effective absorption bandwidth of 4.81 GHz even at a matching thickness below 2.0 mm, remarkably outperforming MoS2 nanosheets. The excellent consistency between theoretical and experimental results highlights that the DFT calculations can be employed as a design tool for high-performance electromagnetic wave absorber. Based on the excellent electromagnetic absorption performance of the MoS2 monolayers, a highly sensitive wireless pressure micro-sensor is designed, which has potential apllication in internet of things.

An oxide/metal/oxide multilayer electrode is employed to improve the mechanical flexibility as well as power conversion efficiency of organic photovoltaics. However, its performance needs to be further improved to provide a higher conversion efficiency and better environmental compatibility with curved indoor electronics. In this study, ZnO/Ag/ZnO nanomesh electrodes are incorporated into the inverted non-fullerene organic photovoltaics to enhance the efficiency under indoor and outdoor lighting illumination in a flexible mode. The opto-electrical properties of the perforated ZnO/Ag/ZnO nanomesh electrode with different hole sizes are compared with those of the planar ZnO/Ag/ZnO and indium tin oxide electrodes. The micro-cavity effect and haze effect, which plays a crucial role in determining the performance of the organic photovoltaics, are directly related to the hole diameter. Despite higher transmittance of indium tin oxide, organic photovoltaics using ZnO/Ag/ZnO nanomesh electrodes with a hole diameter of 350 nm exhibits an average conversion efficiency of 15.7% under a 1000 lux light-emitting diode lamp; this efficiency is 45.3% and 27.6% greater than those of organic photovoltaics using indium tin oxide and planar ZnO/Ag/ZnO electrodes, respectively. Furthermore, all ZnO/Ag/ZnO nanomesh-based organic photovoltaics show much higher mechanical flexible properties than those of the planar ZnO/Ag/ZnO-based organic photovoltaics.

Perovskites are highly promising candidates in future energy conversion and storage due to their rich diversities and readily tunable electronic properties. However, the poor morphology controllability and limited surface areas have severely limited their applications. We present a generalizable synthesis strategy to fabricate a library of one-dimensional (1D) inorganic perovskite nanomeshes via pyrolysis of metal salt-polymer fibers. Within the evaluated perovskite nanomeshes, La0.5Ba0.5Co0.8Ni0.2O3 delivers the most remarkable performance for the oxygen evolution reaction (OER). Combined X-ray absorption spectroscopy experiments and density functional theory calculations reveal that introduction of additional metals endows more flexible electronic structures to realize the electron transfer in 1D perovskite nanomeshes. This work demonstrates a scalable and retrosynthetic route to easily synthesize the inorganic perovskite nanomaterials with tunable compositions.

A fundamentally new approach of manipulating thermal properties is utilizing the wave nature of phonons, which can be realized by introducing secondary artificial periodicity in nanostructures. In this paper, we have studied the heat transport in silicene nanomesh (SNM, a silicene sheet with periodically arranged nanopores), using first-principles calculations and molecular dynamics simulations. The results show the thermal conductivity of SNM is obviously lower than that of silicene. Combining with the analysis of wave and particle characteristics of phonons, we reveal the main reasons responsible for the reduction in thermal conductivity of SNM. The coherent Bragg scattering from the secondary artificial periodicity leads to the reduction in phonon group velocities of LA and optical phonons. Different from the graphene nanomesh reported previously, multiple phonon bandgaps in the optical phonon spectrum of SNM are found for the first time. Moreover, it is noticed that, phonons are scattered not only at the hole boundaries, but also at the interface between the surface and interfacial regions in SNMs. In particular, the out-of-plane vibrations are easier to be scattered at the interface than the in-plane vibrations. This study uncovers the coherent and incoherent phonon transport in SNMs, which would deepen our understanding on heat conduction and shed light on the development of Si-based nanoelectronic devices.

Nitrogen-doped graphene aerogel nanomesh (N-GANM) has been hydrothermally prepared from graphene oxide and ammonium hydroxide using iron nitrate as the etching agent. The results showed that N-GANM with an interesting nanomesh structure on the graphene sheets maintained the 3D architecture of graphene aerogel (GA). Furthermore, it exhibited excellent electrochemical capacitive behavior and the specific capacitance value (290.0 F g −1 at 1 A g −1 ) remained approximately 90.3% after 2000 cycles in the three-electrode system. In addition, N-GANM displayed an energy density of 30.9 Wh kg −1 at the power density of 450.3 W kg −1 and excellent cycling stability retention (98%) after 10,000 cycles in the two-electrode symmetric device. The resulting N-GANM was expected to be a much favorable supercapacitor electrode material due to the heteroatom-doping and its unique porous structure.

Sulfur-decorated nanomesh graphene (S@G) has been synthesized by a 155 °C heat treatment of a mixture of nanomesh graphene and S. The as-obtained S@G materials keep a high specific surface area, and exhibit obviously enhanced conductivity and hydrophilicity as compared to the pristine graphene. X-ray photoelectron spectroscopy and thermogravimetric analysis indicate that most S atoms in the S@G samples are stably combined with nanomesh graphene via covalent bonds rather than exist as free elemental S. As an electrode material for aqueous supercapacitors, the S@G with a S content of 5 wt% delivers a specific capacitance up to 257 F/g at the current density of 0.25 A/g, which is 23.6% higher than that of the undoped graphene. Our results provide a simple approach to scalable synthesis of S-doped porous carbon materials, which have potential applications in the high-performance capacitive energy storage devices.

Redirection of energy carrier propagation by geometric confinement is studied through the analysis of in-plane and cross-plane thermal transport within various graphene nanomesh (GNM) configurations using molecular dynamics (MD) simulations. As the transport channel width decreases with an increase in porosity, the effect of redirection increases; thus, the in-plane thermal conductivity of large-porosity GNM is more dependent on hole arrangement. Since higher porosities weaken the GNM structure due to a larger population of broken bonds, carbon atoms within the graphene structures are more easily influenced by interactions with the substrate silicon (Si) block. Subsequently, increase in porosity leads to the decrease of interfacial thermal resistance. At higher porosities, lower interfacial resistance and in-plane thermal conductivity cause diversions (and redirections) in heat flow from the GNM to the underlying Si substrate. Our study suggests that this method of heat flow redirection can be applied as an effective means to control and manage heat transfer within numerous applications; extension to the improved conductivity calculation accuracy can also be achieved through the inclusion of this diversion analysis.

Two-dimensional (2D) porous SiO 2 nanomesh obtained from mixed acid etching of vermiculite (VMT) was successfully used as a catalyst support for CO methanation. Compared with three-dimensional (3D) MCM-41, 2D VMT-SiO 2 provided a superior position for implantation of NiO species. Although NiO/VMT-SiO 2 has a total loading of 10 wt.% NiO as well as the NiO/MCM-41, the NiO particles on VMT-SiO 2 were observed to show a better dispersion as the of 3D MCM-41 channels were easily blocked by large NiO particles. Moreover, on the basis of the H 2 temperature-programming reduction results, NiO particles on VMT-SiO 2 were more easily reduced than those on MCM-41. These characteristics indicated that NiO/VMT-SiO 2 was significantly superior to NiO/MCM-41. The as-obtained NiO/VMT-SiO 2 exhibited a CO conversion of 85.9%, CH 4 selectivity of 78% at 450 °C, 0.1151 s −1 turn over frequency at 320 °C and a gas hourly space velocity of 20745 ml/g/h. All of which were much better than those measured for NiO/MCM-41. We believed that 2D VMT-SiO 2 as a new catalyst support open a prospect application of catalyst.

The 3D N-doped graphene nanomesh foam (3DNGF) has been synthesized as the Lithium-sulfur battery cathode material for the first time. A method of in situ doping nitrogen and meanwhile etching graphene layer is introduced. The BET result shows the 3DNGF has a large specific surface area more than traditional three-dimensional graphene. Transmission electron microscopy (TEM) observation and Raman spectra confirm the nanoholes on the graphene. The 3DNGF/S composite exhibits an initial discharge capacity of 1134 mAh g −1 at 0.2C in the first cycle with the sulfur utilization of 67%. The electrode reserves a specific capacity of 578 mAh g −1 after 500 cycles at 0.5C, with a capacity decay of 0.06% per cycle. Its specific capacity at 2C can still reach to 729 mAh g −1 , indicating the good rate performance.

The hollow activated carbon nanomesh (PCACM) with a hierarchical porous structure is derived from biowaste-poplar catkins by in-situ calcination etching with Ni(NO 3 ) 2 ·6H 2 O and KOH in N 2 flow combined with an acid dissolution technique. This procedure not only inherits the natural tube morphology of poplar catkins, but also generates a fascinating nanomesh structure on the walls. PCACM possesses a large specific surface area (S BET = 1893.0 m 2 g −1 ) and high total pore volume (V p = 1.495 cm 3 g −1 ), and displays an exciting meso-macoporous structure with a concentrated pore size distribution of 4.53 nm. The specific capacitance of PCACM is as high as 314.6 F g −1 at 1.0 A g −1 when used as the electrode materials for supercapacitor. Furthermore, the symmetric supercapacitor of PCACM with 1.0 M Na 2 SO 4 solution as the electrolyte displays a high energy density of 20.86 Wh kg −1 at a power density of 180.13 W kg −1 within a wide voltage rage of 0–1.8 V, which is comparable or even obviously higher than those of other biomass derived carbon reported. It is noteworthy that PCACM also exhibits superior cycling stability and coulombic efficiency. The excellent electrochemical behaviors enable PCACM to be a promising electrode material for supercapacitors.

Phosphorus-doped nanomesh graphene (PG) with huge specific surface area and lamellar hexagonal structure has been synthesized by a thermal annealing method using MgO as a template and triphenylphosphine (TPP) as both phosphorus and carbon source. The synthesized PG with a high phosphorous content of 1.61 at% is found to exhibit efficient metal-free heterogeneous catalytic activity for aerobic oxidative coupling of amines catalysts under mild and neat conditions using molecular oxygen as the oxidant. Moreover, our results indicate that the phosphorus doping is more efficient to promote the catalytic activity than that of nitrogen doping in aerobic oxidative coupling of amines. Based on the results of density function theory (DFT) calculations, it is found that phosphorus incorporated into the graphene matrix exhibit the highest catalytic activity due to its lowest adsorption energy of benzylamine and longest elongation of O O bonds.

Voids in nanostructured silicon (Si) anodes are believed to effectively mitigate the gradual performance degradation during repeated charge/discharge in lithium ion batteries (LIBs). In this work, we first demonstrate an embossing Si nanomesh structure bearing substantial voids in three dimensions for LIB applications. A solid alumina framework and a sacrificial layer of Ag serve as a template for embossing Si nanomesh structures. After complete dissolution of the alumina framework and the Ag layer, an embossing Si nanomesh exhibits highly ordered and high density nanoholes in an interconnected framework. The model Si nanomesh fabricated by our method has holes ∼70 nm in diameter, has ∼96 holes/μm 2 , and is ∼40 nm in thickness. We use this void-rich embossing Si nanomesh as a LIB anode, achieving significant enhancement in battery performance in terms of discharge capacity, cycling stability, and structural maintenance compared to a counterpart Si nanofilm without voids.

Commonly, novel morphology can obviously lead to superior performance. Herein, we have firstly synthesized porous FeSe 2 nanomesh arrays grown on titanium foil, which exhibit remarkable performance during hydrogen evolution reaction (HER). Our sample is fabricated via a general wet-chemical process and then one-step calcination. It is worth noting that the FeSe 2 is tightly stuck on the surface of titanium plate, which could result in enhanced stability in the long-time operation for HER. Moreover, the porous structure could provide large specific surface area and probably more active sites for electrolysis. Based on the above advantages, the as-synthesized material shows a low overpotential of 175 mV at 10 mA cm −2 and excellent stability with 4% increase in overpotential under a constant current density of 10 mA cm −2 for 24 h in 0.5 M H 2 SO 4 solution.

Herein, we introduce a facile two-step means to generate the unique (NiO) 0.25 (MnO) 0.75 nanomesh (NiMnO NM) by employing NiMn 3 O 7 .H 2 O nanosheet as precursor. The characteristics of abundant pores, high specific surface area and decreased ion diffusion distance for meshy NiMnO nanomaterial play a major role in both oxygen evolution reaction (OER) and supercapacitors. For OER, the porous NiMnO NM demonstrates enhanced catalytic properties, such as modest onset overpotential of ∼270 mV as well as Tafel slope of 41 mV dec −1 , large C dl of 22.5 mF cm −2 , attractive durability for at least 3000 cycles and improved stability over 80 h at different temperatures in 0.1 M KOH. Meanwhile, the excellent capacitive properties in supercapacitors, including intriguing specific capacitance of 371 F g −1 at a high current density of 10 A g −1 , admirable rate capability and eminent cycling stability for 5000 cycles at 10 A g −1 , are also displayed by NiMnO NM tested in 0.5 M Na 2 SO 4 . This work gives an example to prepare 2D meshy transition metal composite oxide as highly active electrocatalyst for OER and high-performance electrode material for supercapacitor through a feasible means.

When graphene is shrunk into ~10 nm scale graphene nanoribbons or nanomesh structures, it is expected that not only electrical properties but also thermal conductivity and thermoelectric property are significantly altered due to the quantum confinement effect and extrinsic phonon-edge scattering. Here, we fabricate large-area, sub-10 nm single- and bilayer graphene nanomeshes from block copolymer self-assembly and measure the thermal conductivity, thermoelectric and electrical transport properties to experimentally verify the effect of sub-10 nm quantum confinement, phonon-edge scattering and cross-plane coupling. Among the large variety of the samples, bilayer graphene nanomesh having 8 nm-neck width showed significantly low thermal conductivity down to ~78 W m−1 K−1, which is the lowest thermal conductivity for suspended graphene nanostructures, and a high thermopower value of −520 μV K−1, while it still shows the comparably high carrier mobility. Classical and quantum mechanical calculations successfully supported our nanomesh approach, which can achieve high thermoelectric properties based on the significantly reduced thermal conductivity and higher thermopower due to the confined geometry.

The hexagonal boron nitride ( h -BN) nanomesh is a promising 2D material for driving the self-assembly of metal nanoparticles with potential catalytic applications. Herein the adsorption of Au, Pt, Ag, Pd, Cu, and Ni adatoms on h -BN/Rh(111) is investigated using density functional theory (DFT) calculations to determine the ability of this pore-wire structure to facilitate the formation of size-limited, monodisperse metal nanoparticles. While all six metal atoms exhibit covalent coupling and negative charging following their adsorption in the pore region, only Au and Pt have sufficiently large barriers (>1.2 eV) to prevent pore-to-pore diffusion at room temperature. In contrast, Ag and Cu have pore-to-pore diffusion barriers of only ∼0.5 eV, while Pd and Ni show no special affinity for any specific region of the nanomesh. For verification, we have imaged Au, Pt, and Ag on h -BN/Rh(111) at room temperature and submonolayer depositions using STM. Au and Pt form numerous small nanoparticles confined to the pore regions, whereas Ag only forms a few large particles. The difference is fully consistent with the DFT predictions, indicating that our approach has qualitatively predictive power for nanoparticle nucleation and growth behavior on the h -BN/Rh(111) nanomesh.

s We demonstrate that ultrathin Au nanomesh assisted in transferring pattern of hexagonal packed anodic aluminum oxide (AAO) membrane for formation of Si nanopore arrays. In this technology, the regularity of the AAO mask was inherited by the ultrathin Au nanomesh, which was pressed into the polymethyl methacrylate (PMMA) layer spin-coated on Si substrate. The fixed ultrathin Au nanomesh kept a close contact to the Si substrate through the PMMA layer. The pattern transfer of hexagonal packed AAO membrane to Si substrate was achieved using inductively coupled plasma (ICP) and highly orderly Si nanopore arrays were prepared in this work. Our technology improves the pattern fidelity and reduces defects.

The conversion of excess electrical energy in a power system to hydrogen through the use of water electrolysis is considered an effective alternative to replace fossil fuels. However, the scarcity and high cost of Pt-based materials for the hydrogen evolution reaction (HER) impedes their large-scale application in electric power systems. On the basis of the nanoscale Kirkendall effect, three-dimensional CoMoMg nanomeshes are fabricated by a conventional high-temperature sintering method. The nanomesh CoMoMg alloy mainly consists of intermetallic Co3Mo, which achieves a low overpotential of 36 mV at a current density of 10 mA cm−2 in 1 M KOH. The electrode during a 60,000 s HER process under different current densities, especially 2 A cm−2, displays excellent long-term stability without compromising electrocatalytic activity, which is attributed to the synergistic effect between Co and Mo and three-dimensional nanoporous structure. This work provides a feasible strategy for designing efficient and durable hydrogen evolution electrocatalysts, and effectively solves the problem of expensive Pt-based precious metal catalysts.

The integration of the construction of a novel structure and hetero-element doping in g-C3N4 photocatalyst is highly attractive in achieving high photocatalytic activities. Herein, boron/oxygen-codoped graphitic carbon nitride nanomesh (BO-C3N4 nanomesh) was designed and high throughout prepared via two steps doping & etching strategy. The obtained BO-C3N4 nanomesh exhibited a typical two-dimensional porous nanostructure, giving an enlarged specific surface area up to 160.58 m2 g−1. Moreover, the bandgap was harnessed by the codoping element (Boron and Oxygen) with different electronegativity. The light-harvesting capability and charge separation efficiency enhanced due to the synergistic interaction of nanomesh architecture and co-doping. Consequently, the BO-C3N4 nanomesh shows an outstanding photocatalytic hydrogen production of 9751 μmol h−1g−1 upon visible-light(λ > 420 nm) illumination, nearly 28 times as compared with that of bulk g-C3N4, with 8.1% apparent quantum efficiency at 420 nm and highly stable photocatalytic hydrogen production process over 20 h.

In the present research, ZnO/TiO2 heterojunction nanomeshes (HNMs) were synthesized by anodizing and calcination. The structural study revealed the as-synthesized samples were composed of anatase TiO2, rutile TiO2,and zincblende-structured ZnO. TiO2 segments had a preferred orientation along the [110] direction, whereas ZnO nanoparticles were oriented along the [200] direction. In comparison to pure TiO2 nanomeshes, ZnO/TiO2 HNMs had higher methylene blue (MB) photodegradation capacity. Furthermore, the effects of different parameters, such as calcination temperature, initial pH, and mesh density, on MB photodegradation were investigated. The superior photocatalytic activity was achieved by the sample calcinated at 600°C due to the appearance of zinc-blende ZnO and the mixed crystal phases of anatase and rutile TiO2. A high degradation efficiency was obtained under alkaline conditions. When the mesh density was 200 per inch, the maximum photodegradation efficiency was achieved.

In the past decade, nanoperforated graphene (also known as a graphene nanomesh or holey graphene) has attracted considerable research interest worldwide, predominantly because of its superior properties such as superb electronic properties with a tunable band gap, greatly enhanced mass and charge transport, high specific surface area with abundant useful reaction/adsorption sites and functionalities, and excellent magnetic, photocatalytic, and mechanical properties. Considering the most recent research activities, this comprehensive review first concentrates on the characterization and synthesis particulars of chemistry-based strategies for several state-of-the-art 2D holey nanoarchitectures, including holey graphene, nitrogenated holey carbon networks (C2N), holey graphitic carbon nitride (g-C3N4), and carbon nanomeshes, as well as 2D holey metal oxides, nitrides, sulfides, phosphides, hydroxides, selenides, carbides, carbonates, oxyfluorides, and NASICON-type structures. The pros and cons of each method for designing in-plane nanoperforations are also highlighted. Subsequently, we discuss the electrochemical properties for next-generation batteries including Li–O2, Zn–air, Li–CO2, Li–S, Li–Se, Li–SexSy, and K-ion batteries, while comprehensively evaluating all the parameters that help in improving their performance owing to the existence of the introduced in-plane holes. Finally, we emphasize the substantial limitations and challenges to facilitate further research and development. This comprehensive review might provide a directional, prompt guide for the designation and fabrication of additional innovative holey nanostructures for emerging applications.

Coherent thermal transport has recently become a subject of considerable interest, but whether some intriguing phenomena of phonon coherence (including Brillouin zone folding, phonon localization, and phonon confinement) occur in certain nanostructures remains unclear. We have investigated the thermal transport in graphene nanomesh using molecular dynamics simulations together with first-principles calculations. It is found that the thermal conductivity of nanomesh is significantly reduced compared with graphene, mainly due to the bandgaps, flattened phonon dispersions and reduced phonon group velocities induced by Brillouin zone folding. Meanwhile, the significant decrease in thermal conductivity is induced by phonon localization. Phonon confinement caused by reflecting the optical phonon modes back into the C-H part further leads to the reduction of thermal conductivity. We highlight the coherent mechanism for lowering thermal conductivity, which is useful for manipulating heat conduction for thermoelectrics and thermal insulation applications.

This study reports on the fabrication process of a nanomesh-shaped nickel mold by using phase shift lithography. We also present its application to a transparent electrode film for a touch screen panel. A suitable gap between the checkerboard- shaped patterns on a photomask was chosen to obtain the nickel mold with a mesh-shaped pattern connected to each other. A nanomesh-type trench pattern was transferred from the nickel mold onto a polyethylene terephthalate film through the imprinting lithography process with ultraviolet light. The nanomesh- embedded electrode pattern was fabricated by filling the nanotrench with Ag paste. The light transmittance and sheet and line resistance of the nanomesh-type transparent conducting electrode film were evaluated. The TCE film was then applied to a 7 in. touch sensor module.

Advances in flexible optoelectronic devices have led to increasing need for developing high performance, low cost, and flexible transparent conducting electrodes. Copper-based electrodes have been unattainable due to the relatively thermal instability and poor oxidation resistance. Herein, we present oxidation-resistive CuNi nanomesh electrodes that exhibit a low sheet resistance of ∼7.5 Ω/□ and a high optical transmittance of ∼81% at 550 nm. Further, high long-term stability against the effects of oxidation, heat, and chemicals is exhibited by the CuNi nanomesh, in comparison with the behavior of a pure Cu nanomesh sample.