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Public safety and environmental monitoring are of great significance to maintain human health. Therefore, a simple and effective strategy for preparing the substrate layer of a film-based fluorescent sensor is developed by a nanomesh scaffold technology. The limit of detection of the nanomesh scaffold-modified sensor ranges from 4.8 ppb to 3750 ppm. This can provide an effective method for detecting potential biological warfare agent, 2,6-dicarboxyridine.

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.

Radiative cooling in textiles is one of the important factors enabling cooling of the human body for thermal comfort. In particular, under an intense sunlight environment such as that experienced with outdoor exercise and sports activities, high near-infrared (NIR) reflectance to block sunlight energy influx along with high IR transmittance in textiles for substantial thermal emission from the human body would be highly desirable. This investigation demonstrates that a nanoscale geometric control of textile structure alone, instead of complicated introduction of specialty polymer materials and composites, can enable such desirable NIR and IR optical properties in textiles. A diameter-dependent Mie scattering event in fibers and associated optical and thermal behavior were simulated in relation to a nonwoven, nanomesh textile. As an example, a nanomesh structure made of PVDF (polyvinylidene fluoride) electrospun fibers with ∼600 nm average diameter was examined, which exhibited a significant radiative cooling performance with over 90% solar and NIR reflectance to profoundly block the sunlight energy influx as well as ∼50% IR transmittance for human body radiative heat dissipation. An extraordinary cooling effect, as much as 12 °C, was obtained on a simulated skin compared to the normal textile fabric materials. Such a powerful radiative cooling performance together with IR transmitting capability by the nanomesh textile offers a way to efficiently manage sunlight radiation energy to make persons, devices, and transport vehicles cooler and help to save energy in an outdoor sunlight environment as well as indoor conditions.

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.

16 Pág., Current tissue engineering techniques frequently rely on hydrogels to support cell growth, as these materials strongly mimic the extracellular matrix. However, hydrogels often need ad hoc customization to generate specific tissue constructs. One popular strategy for hydrogel functionalization is to add nanoparticles to them. Here, we present a plant viral nanoparticle the turnip mosaic virus (TuMV), as a promising additive for gelatin methacryloyl (GelMA) hydrogels for the engineering of mammalian tissues. TuMV is a flexuous, elongated, tubular protein nanoparticle (700-750 nm long and 12-15 nm wide) and is incapable of infecting mammalian cells. These flexuous nanoparticles spontaneously form entangled nanomeshes in aqueous environments, and we hypothesized that this nanomesh structure could serve as a nanoscaffold for cells. Human fibroblasts loaded into GelMA-TuMV hydrogels exhibited similar metabolic activity to that of cells loaded in pristine GelMA hydrogels. However, cells cultured in GelMA-TuMV formed clusters and assumed an elongated morphology in contrast to the homogeneous and confluent cultures seen on GelMA surfaces, suggesting that the nanoscaffold material per se did not favor cell adhesion. We also covalently conjugated TuMV particles with epidermal growth factor (EGF) using a straightforward reaction scheme based on a Staudinger reaction. BJ cells cultured on the functionalized scaffolds increased their confluency by approximately 30% compared to growth with unconjugated EGF. We also provide examples of the use of GelMA-TuMV hydrogels in different biofabrication scenarios, include casting, flow-based-manufacture of filaments, and bioprinting. We envision TuMV as a versatile nanobiomaterial that can be useful for tissue engineering., EV-L, AIF-S, MJ-LZ, and JAT-N acknowledge funding from scholarships provided by CONACyT (Consejo Nacional de Ciencia y Tecnología, México). EV-L acknowledges the Nuevo Leon Institute for Innovation and Technology Transference for a PhD student grant (No. 459134, CVU 360539). GT-dS and MMA acknowledge the institutional funding received from Tecnológico de Monterrey (Grant 002EICIS01). MMA, GT-dS, and IG-G acknowledge funding provided by CONACyT (Consejo Nacional de Ciencia y Tecnología, México) through several grants (SNI 26048, SNI 256730, and SNI 313028). FP acknowledge the funding received from RTA 2015-00017 from INIA and EU Arimnet-2 Grant Agreement No. 618127. The CBGP was granted “Severo Ochoa” Distinctions of Excellence by the Spanish Ministry of Science and Innovation (SEV-2016-0672 and CEX 2020-000999-S)

In this work, a facile aqueous synthesis strategy was used (complete in 5 min at room temperature) to produce large-size Pd, PdCu, and PdPtCu nanomeshes without additional organic ligands or solvent and the volume restriction of reaction solution. The obtained metallic nanomeshes possess graphene-like morphology and a large size of dozens of microns. Abundant edges (coordinatively unsaturated sites, steps, and corners), defects (twins), and mesopores are seen in the metallic ultrathin structures. The formation mechanism for porous Pd nanomeshes disclosed that they undergo oriented attachment growth along the ⟨111⟩ direction. Owing to structural and compositional advantages, PdCu porous nanomeshes with certain elemental ratios (e. g., Pd87 Cu13 ) presented enhanced electrocatalytic performance (larger mass activity, better CO tolerance and stability) toward ethanol oxidation.

Benefiting from superior programmability and good biocompatibility, DNA nanomaterials have received considerable attention with promising prospects in biological detection applications. However, their poor stability and operability severely impede further development of the applications of DNA nanomaterials. Here, a thermally stable DNA nanomesh structure is integrated into a microfluidic chip. The specificity of the nucleic acid microfluidic capture device could reach the single-base mismatch level while capturing the ssDNA sample. The microfluidic chip provides a closed environment for the DNA nanomesh, giving the device excellent storage stability. After 6 months of storage at room temperature, the device still has a specific capture function on ssDNA samples with low concentration. The specific nucleic acid microfluidic capture device can be applied to the enrichment of ctDNA in the future and contribute to the early diagnosis of cancer.

Graphene nanomesh material is a new type of two-dimensional porous material at the cutting edge of science and technology. Its planar porous structure is conducive to the longitudinal transmission of electrolyte ions, which shortens the ion transmission path, and effectively avoids the common problems of traditional graphene materials; for instance, electrolyte is not easy to infiltrate and π-π stacking causes low active area, poor longitudinal transmission and long ion transmission path. The graphene nanomesh materials show better performance than traditional graphene-based materials in the field of energy storage and conversion. This paper reviews the recent progress in the design and synthesis of various kinds of graphene nanomesh with customizable structure, high complexity of structure/composition, controllable morphology and enhanced electrochemical properties. The influence of the structural design of graphene nanomesh on the performance of energy storage and conversion is emphatically discussed, which may provide some inspiration for the relevant research in this field.

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 (

Developing highly stable and efficient catalysts toward oxygen reduction reaction is of great importance for the long-term operation in proton exchange membrane fuel cells but still challenging. Herein, we report a facile synthesis of two-dimensional coplanar Pt-carbon nanomeshes (NMs) that are composed of highly distorted Pt networks (neck width of 2.05 ± 0.72 nm) and carbon. X-ray absorption fine structure spectroscopy demonstrated metallic state of Pt in the coplanar Pt/C NMs. Fuel cell tests verified the excellent activity of the coplanar Pt/C NM catalyst with the peak power density of 1.21 W cm -2 and current density of 0.360 A cm -2 at 0.80 V in H 2 /O 2 cell. Moreover, the coplanar Pt/C NM electrocatalysts showed superior stability against aggregation with nanomesh structures preserved intact in a long-term operation over 30,000 cycles for electrode measurement, and the working voltage loss was negligible after 120 h in H 2 /O 2 single cell operation. Density functional theory analysis indicates the increased vacancy formation energy of Pt atoms for coplanar Pt/C NMs, restraining the tendency of Pt dissolution and aggregation.

Conformal integration of an epidermal device with the skin, as well as sweat and air permeability, are crucial to reduce stress on biological tissues. Nanofiber-based porous mesh structures (breathable devices) are commonly utilized to prevent skin problems. Noble metals are normally deposited on nanomesh substrates to form breathable electrodes. However, these are expensive and require high-vacuum processes involving time-consuming multistep procedures. Organic materials are suitable alternatives that can be simply processed in solution. We report a simple, cost-effective, mechanically biocompatible, and breathable organic epidermal electrode for biometric devices. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is sprayed on a nanofiber-mesh structure, treated using only heat and water to enhance its biocompatibility and conductivity, and used as the electrode. The treatment is accomplished using an autoclave, simultaneously reducing the electrical resistance and sterilizing the electrode for practical use. This research can lead to affordable and biocompatible epidermal electrodes with improved suitability for various biomedical applications.

With rapid advances in flexible electronics, transparent conductive electrodes (TCEs) have also been significantly developed as alternatives to the conventional indium tin oxide (ITO)-based material systems that exhibit low mechanical flexibility. Nanomaterial-based alternating materials, such as graphene, nanowire, and nanomesh, exhibit remarkable properties for TCE-based applications, such as high electrical conductivity, high optical transparency, and high mechanical stability. However, these nanomaterial-based systems lack scalability, which is a key requirement for practical applications, and exhibit a size-dependent property variation and inhomogeneous surface uniformity that limit reliable properties over a large area. Here, we exploited a conventional ITO-based material platform; however, we incorporated a transparent molecular adhesive, 4-aminopyridine (4-AP), to improve mechanical flexibility. While the presence of 4-AP barely affected optical transmittance and sheet resistance, it improved interfacial adhesion between the substrate and ITO as well as formed a wavy surface, which could improve the mechanical flexibility. Under various mechanical tests, ITO/4-AP/poly(ethylene terephthalate) (PET) exhibited remarkably improved mechanical flexibility as compared with that of ITO/PET. Furthermore, ITO/4-AP/PET was utilized for a flexible Joule heater application having spatial uniformity of heat generation, voltage-dependent temperature control, and mechanical flexibility under repeated bending tests. This molecular adhesive could overcome the current limitations of material systems for flexible electronics.

Local structure and crystallinity have been confirmed to be critical in the catalytic activity of catalysts, and the formation of amorphous phase can afford significantly enhanced catalytic performance. The controlled distribution of amorphous phase at the nanoscale in materials, however, remains a substantial challenge, which results in the absence of an underlying relationship between the amorphization level and the catalytic activity. In this work, we successfully realize identified amorphization of ultrathin two-dimensional α-Ni(OH)2 nanomeshes through Fe doping, by which the amorphization rates can be controlled over 10–78% in area ratios with the desired amount of Fe doping. The localized amorphization dramatically accelerates the reaction kinetics and thus enhances the overall performance for the oxygen evolution reaction (OER). Specifically, a strong correlation between the OER activity and the amorphization rate is discovered, and α-Ni0.75Fe0.25(OH)2 with the highest amorphization rate of 78% achieves the highest catalytic activity. The enhanced catalytic activity is dominantly attributed to the doping-induced localized amorphization, which provides more accessible active sites and responsible local chemical environments than the fully crystallized structures. The understanding of the amorphization-catalytic activity relationship thus provides new insight into developing highly efficient catalysts.

A hierarchical heterojunction polymer aerogel (HPA) composed of a oxygen- and nitrogen-linked heptazine-based polymer was rationally designed as a donor–acceptor (D–A) light harvester by a facile two-step self-assembly method. The HPA features a three-dimensional (3D) continuous network of 1D holey microfibers assembled from 2D nanomesh. The collaborative engineering of the D–A homojunction and 3D hierarchical open-pore nanoarchitecture in HPA causes a narrowed bandgap, improved hydrophilicity, and dramatically increased charge transfer and separation, and therefore the synthesis of sub-1 nm ultrafine Pt cocatalysts associated with countless bonding sites. It exhibits a high H2 evolution rate of 103.79 μmol h−1 (12 times higher than that of the conventional g-C3N4 powder), and an excellent internal quantum yield of 29.4% at 400 nm, much higher than those of most of the aerogel-based photocatalysts reported.

Global freshwater shortage has become one of the essential issues and many countries are suffering increasing pressure on their environment. Recently, a large-area graphene nanomesh with microsize pores of 0.45–0.55 nm has been found to achieve a nearly 100% desalination efficacy; however, the development of nanoporous structures with excellent cycling, mechanical and electrical properties remains challenging. Based on density-functional theory, a high-performance stable two-dimensional graphene-based material (Kust-I) with a nanometer pore size of 0.45 nm is cleverly constructed with decagonal, hexagonal, and pentagonal carbon rings. First-principles and classical molecular dynamics simulation results indicate that ten-membered and pentagon rings act in parallel in Kust-I to provide sufficient salt-ion selective adsorption sites and the electron concentration and desalination effect of this material is satisfactory. The mechanical and electronic property results further suggest that the periodic pore structure and electron distribution can effectively overcome the stress concentrations, improve the service life, and produce a self-cleaning effect that facilitates recycling. A potentially facile Kust-I synthesis route was proposed. These findings show the material's tremendous potential in addressing the significant challenge of achieving mechanical stability, long service life, ease of recycling, and large-scale application of current two-dimensional carbon materials.

The atomic structure and electronic and optoelectronic properties of nanomesh films made of carbon nanotubes with seamless cross-like X junctions are investigated. It is established that the topology of the arrangement of nonhexagonal elements in the contract region of nanotubes determines the energy stability of the atomic structure. It is revealed that the film pore sizes determine the conductivity type. The film is characterized by metal-type conductivity at the smallest pore sizes; as the gap in the band structure increases with an increase in the pore size, the film becomes semiconducting. Films with a minimal gap size have high photovoltaic characteristics. The photocurrent for the considered film models can reach 2.4 mA cm–2 under atmospheric conditions and 3.25 mA cm–2 outside the atmosphere. The presence of a gap in the band structure makes nanomesh films promising for nanoelectronics and optoelectronics.

The SiCw/SiCf composites composed by SiC whiskers with core–shell structure and SiC fiber with alike-array structure were prepared without growth catalyst, hydrogen silicone oil (H-PSO) as raw material, carbon fiber as the matrix. SiC fibers act as supports for a nanomesh containing interconnected one-dimensional SiC whiskers. The results of studying the absorption properties of the Ku band show that the density of stacking faults decreases and the aspect ratio increases as the heat treatment temperature increases and they jointly affect the dielectric properties of the SiCw/SiCf composites. The minimum reflection loss of the SiCw/SiCf composites obtained at 1400 °C can reach − 29.75 dB when the absorber thickness is 3.0 mm, and the effective bandwidth is 2.25 GHz. The polarization relaxation and interfacial polarization in the unique structure improve the microwave absorption properties and broaden the absorption frequency.

A soft touch Measuring the force it takes for a hand to grasp an object requires sensors to be placed on the fingertips, but these sensors will interfere with or affect how much force ends up being applied. Lee et al. developed a nanomesh sensor built from a series of electrospun materials (see the Perspective by Liu). Using a robotic tester, they show that this device can repeatably detect the pressure involved in gripping an object. They also show that the sensors can be attached to human fingers and that this does not affect the force used to grasp an object. Science , this issue p. 966 ; see also p. 910

A nanomesh organic electrochemical transistor (NMOECT) is proposed. The NMOECT is a porous nanomesh structure, which enables the device to be comfortably laminated on human skin and simultaneously ...

Vanadium (III) oxide nanomaterials have been investigated and considered as potential anode materials for Li-ion batteries (LIBs). Fabrication of two-dimensional (2D) mesoporous nanomeshes from car...

N2 electrolysis has been impeded by efficient catalysts for key reactions: cathodic nitrogen reduction reaction (NRR) and anodic oxygen evolution reaction (OER). A bifunctional nickel, iron-nanomes...

The purpose of this study was to investigate the surface observation of PEO-treated Ti–6Al–4V alloy after 2-step nano-mesh formation was investigated by FE-SEM, EDS, and XRD. Anodic oxidation treatment was performed on the electrolyte containing 0.8 wt.% Na/F and 1M H3PO4 to form a nanotube structure on the Ti–6Al–4V alloy. After removing the nanotube layer, PEO-treatment was performed on the electrolyte containing Mg and Zn ions. After forming the nanotubes, the nanomesh surface was obtained by removing the layer, and the surface roughness increased with cycle number of nanotube formation. Also, as the number of nanotubes increased, the anatase peak increased.

The charge redistribution strategy driven by heteroatom doping or defect engineering has been developed as an efficient method to endow inert carbon with significant oxygen reduction reaction (ORR) activity. The synergetic effect between the two approaches is thus expected to be more effective for manipulating the charge distribution of carbon materials for exceptional ORR performance. Herein we report a novel molecular design strategy to achieve a 2D porous turbostratic carbon nanomesh with abundant N-doped carbon defects (NDC). The molecular level integration of aromatic rings as the carbon source and urea units as the N source and sacrificial template into the novel precursor of polyurea (PU) promises the formation of abundant carbon edge defects and N doping sites. A special active site-a carbon edge defect doped with a graphitic valley N atom-was revealed to be responsible for the exceptional ORR performance of NDC material.

DNA nanostructures are a new type of technology for constructing nanomaterials that has been developed in recent years. By relying on the complementary pairing of DNA molecules to form a double-stranded property, DNA molecules can construct a variety of nanoscale structures of 2D and 3D shapes. However, most of the previously reported DNA nanostructures rely solely on hydrogen bonds to maintain structural stability, resulting in DNA structures that can be maintained only at low temperature and in the presence of Mg2+, which greatly limits the application of DNA nanostructures. This study designed a DNA nanonetwork structure (nanonet) and changed its topological structure to DNA nanomesh by using DNA topoisomerase to make it thermally stable, while escaping the dependence on Mg2+, and the stability of the structure can be maintained in a nonsolution state. Moreover, the nanomesh also has a large amount of ssDNA (about 50%), providing active sites capable of exerting biological functions. Using the above characteristics, we prepared the nanomesh into a device capable of adsorbing specific DNA molecules, and used the device to enrich DNA. We also tried to mount antibodies using DNA probes. Preliminary results show that the DNA nanomesh also has the ability to enrich specific proteins.

Lithium sulfur batteries (Li–S) have been deemed to be the promising energy-storage systems. Nevertheless, the shuttle effect caused by diffusion of polysulfides limit their application. In this work, the different dimensions of g-C3N4 nanomaterials (2D g-C3N4 nanosheets and 3D g-C3N4 nanomesh) were doped in S electrode. Because of the large specific surface area of 3D g-C3N4 nanomesh and strong chemical adsorption of polysulfides can provide better effect for inhibition of shuttling effect and its proper electron passage make electrochemical kinetics of lithium–sulfur battery enhanced. The discharge specific capacity of the 3D g-C3N4 battery is up to 731 mAh/g and longer cycling performance with 540 mAh/g after 180 cycles. This experiment paves the way forward for the application of g-C3N4 on Li–S batteries.

A hybrid graphene-gold nanomesh, realized through Au deposition on a patterned graphene nanomesh with a focused ion beam, is introduced and illustrated for enhanced light absorption in the visible spectrum. Numerical studies reveal that the hybrid nanomesh with dual resonances in the visible spectrum exhibit ~50% light absorption and enhancement factor as high as ~1 × 108. The simulations also show that the enhanced optical absorption is associated with the excitation of surface Plasmons. This is confirmed through the localization of electric fields at the resonant wavelengths. Such a hybrid graphene-gold nanomesh exhibiting enhanced light-matter interactions paves the way toward plasmonics, surface-enhanced Raman scattering applications, etc.

We report the reduction in the wire resistance of gold nanomesh electrodes caused by interconnecting mesh electrodes. The porous-structured electrodes show high resistance because of the high junct...

Leading edge p-i-n type halide perovskite solar cells (PSCs) severely underperform n-i-p PSCs. p-i-n type PSCs that use PEDOT:PSS hole transport layers (HTLs) struggle to generate open-circuit phot...

Three dimensional (3D) graphene-CNT hybrid structures (GCNTs) are promising materials for applications including capacitors and gas storage and separation devices, however until now their thermal conductance mechanism has scarcely been studied. These hybrid nanomaterials are particularly suitable as next-generation thermal interface materials due to the excellent thermal properties of carbon nanotubes and single atomic layer graphene. In this paper, the out-of-plane thermal conductivities of GCNTs, graphene nanomesh (GNM), and graphene sheets are investigated using molecular dynamics (MD) simulations which apply the Green-Kubo method. Distinct from GNMs and graphene sheets, the GCNTs exhibit a relatively high out-of-plane thermal conductivity, stemming from the CNTs' ability to accelerate the energy flow. However, the GCNT out-of-plane thermal conductivity is still far lower than that of pristine graphene due to extreme phonon localizations, which are concentrated on the graphene-CNT junction regions as evidenced by the participation ratio, phonon vibrational density of states, and overlap energy. This study provides microscopic insight into the GCNT heat transfer mechanism and offers design guidelines for application of GCNTs in thermal management devices.

The construction of nanoporous structure combined with the optimization of electronic structure toward electrocatalysts could be a promising and effective approach to boosting their catalytic performance. Herein, we rationally synthesized a novel Ni3+-doped ultrathin NiZn layered double hydroxide nanomesh supported on nickel foam (Ni(II,III)Zn-LDH/NF-nm) by a facile one-step methanol-assisted hydrothermal method. Results show that methanol can not only trigger the generation of ultrathin nanomesh structure, but adjust portion of Ni2+ to Ni3+ and thus to result in the Ni3+-doped NiZn-LDH nanomesh material. The nanoporous feature endows Ni(II,III)Zn-LDH/NF-nm with abundant exposed catalytic active sites and fast mass transfer for alkaline water electrolysis. More importantly, the Ni3+ doping can facilitate the available formation of highly active NiOOH phase on the surface for the oxygen evolution reaction (OER), accompanied by increased oxygen vacancies that can greatly enhance the electronic conductivity, leading to the improved intrinsic activity and the accelerated electrocatalytic OER reaction kinetics. As expected, the as-prepared Ni(II,III)Zn-LDH/NF-nm has relatively low overpotentials of 320 and 370 mV to drive large current densities of 100 and 500 mA cm−2, respectively, and a small Tafel slope of 63.9 mV dec−1, extremely superior to RuO2/NF and NiZn-LDH/NF-ns counterpart. Meanwhile, the electrolyzer assembled for overall water splitting by Ni(II,III)Zn-LDH/NF-nm yields the outstanding catalytic activity and stability. This work highlights a feasible strategy to design and develop high-efficiency water splitting electrocatalysts via engineering on composition and nanostructure.

A novel 2D WSe2 nanomesh material was synthesized with a 3D SBA-15 mesoporous material via a nanocasting strategy. The formation of the 2D sheet-like nanomesh structure of WSe2 inside a 3D confined pore space is mainly attributed to the synergistic effect arising from the crystal self-limitation growth caused by the layered crystal structure of the WSe2 material and to the space-limitation effect coming from the unique pore structure of the SBA-15 template. The 2D WSe2 nanomesh material possesses extremely high exposure of crystal layer edges, making it an excellent photocatalyst. It shows good visible light-driven photocatalytic performance in oxidative coupling of dibenzylamine and 2-amino/hydroxy/mercaptoanilines to prepare a group of heterocyclic compounds, including benzimidazoles, benzoxazoles and benzothiazoles with oxygen as the sole oxidant. A gram-scale experiment was also carried out to exhibit the scope of this method.

In this work, a highly porous ternary NiCoFe oxide nanomesh with two-dimensional morphology and quasi-single-crystalline (QSC) feature was synthesized via a convenient molten-salt protected pyrolysis approach, which achieves remarkable OER performance with a low overpotential, high current density, improved intrinsic activity and superior operational stability.

Abstract The capability to structure two-dimensional materials (2DMs) at the nanoscale with customizable patterns and over large areas is critical for a number of emerging applications, from nanoelectronics to 2D photonic metasurfaces. However, current technologies, such as photo- and electron-beam lithography, often employing masking layers, can significantly contaminate the materials. Large-area chemical vapour deposition-grown graphene is known to have non-ideal properties already due to surface contamination resulting from the transferring process. Additional contamination through the lithographic process might thus reduce the performance of any device based on the structured graphene. Here, we demonstrate a contactless chemical-free approach for simultaneous patterning and cleaning of self-supporting graphene membranes in a single step. Using energetic ions passing through a suspended mask with pre-defined nanopatterns, we deterministically structure graphene with demonstrated feature size of 15 nm, approaching the performance of small-area focused ion beam techniques and extreme ultraviolet lithography. Our approach, however, requires only a broad beam, no nanoscale beam positioning and enables large area patterning of 2DMs. Simultaneously, in regions surrounding the exposed areas, contaminations commonly observed on as-grown graphene targets, are effectively removed. This cleaning mechanism is attributed to coupling of surface diffusion and sputtering effects of adsorbed surface contaminants. For applications using 2DMs, this simultaneous patterning and cleaning mechanism may become essential for preparing the nanostructured materials with improved cleanliness and hence, quality.

A prominent characteristic of two-dimensional higher-order topological insulators (2D-HOTIs) is the topologically protected corner modes associated with gapped edge states. Opening the gap of bulk and edge states is a key to realizing 2D-HOTIs. In this paper, we theoretically propose that 2D-HOTIs can be realized on porous network models. We consider two porous network models, the graphenylenelike and the porous-honeycomb models, which respectively contain 12 and 18 atoms in supercells. These superstructures can open the bulk gap as well as the edge gap and induce HOTIs. Experimentally, graphene nanomesh, other 2D porous materials, and organic molecules naturally host supercells with regular nanoholes, which can be candidates to realizing HOTIs. Our studies reveal that 2D-HOTIs can be realized on some 2D porous network models and provide a promising route to explore HOTI states in real materials.

Self-driven photodetectors are essential for many applications where it is unpractical to provide or replace power sources. Here, we report a new device architecture for self-driven photodetectors with tunable asymmetric Schottky junctions based on a nanomesh electrode. The vertical-channel nanomesh scaffold is composed of a hexagonally ordered nanoelectrode array fabricated via the nanosphere lithography technique. The top and bottom nanoelectrodes are separated by only 30 nm and the areal ratio of the two nanoelectrodes can be fine-tuned, which effectively modifies the geometric asymmetricity of the Schottky junctions in the photodetector devices. The self-driven photodetectors are fabricated by depositing the (FAPbI3)0.97(MAPbBr3)0.03 (MA = methylammonium, FA = formamidinium) perovskite films onto the nanomesh electrodes. Under the self-driven mode, the optimized device demonstrates a high detectivity of 1.05 × 1011 Jones and a large on/off ratio of 2.1 × 103. This nanomesh electrode is very versatile and can be employed to investigate the optoelectronic properties of various semiconducting materials.

Motivated by the successful preparation of two-dimensional transition metal dichalcogenide (2D-TMD) nanomeshes in the last three years, we use density functional theory (DFT) to study the structural stability, mechanical, magnetic, and electronic properties of porous 2H-MoX2 (X = S, Se and Te) without and with pore passivation. We consider structures with multiple, systematically created pores. The molecular dynamics simulations and cohesive energy calculations showed the stability of the 2D-TMD nanomeshes, with larger stability for those with smaller pores. The lattice undergoes some deformations to accommodate the pore energetically, and as the pore size increases Young's modulus decreases. In most cases, the missing metal atoms disrupt the spin states’ even population, resulting in some nanomeshes becoming magnetic. The electronic gaps of the MoX2 nanomesh systems are diminished because of the emergence of pore-edge localized mid-gap metal 4d states in the spin-polarized spectrum, making some systems half-metallic. The oxygen passivation of the pore edges of 2D-TMD nanomeshes restores the even population of spin states, and makes those systems metallic. Our results can be used in different applications such as spintronics, ion chelation, and molecular sensing applications.

Photocatalytic selective oxidation of hydrocarbons to oxygenated chemicals greatly relies on catalytic materials that show high efficiency of photogenerated holes and electrons separation and visib...

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.

We report on the formation of nanoscopic heterostructures composed of the semimetal graphene, the metal platinum, and the insulator hexagonal boron nitride (h-BN). Both graphene and h-BN are chemically inert 2D materials with similar geometric but different electronic properties. Between these materials, a Pt nanoparticle array was encapsulated. Thereby, the h-BN/Rh(111) nanomesh served as a template for a well-ordered array of Pt nanoclusters, which were overgrown with graphene, forming single nano-heterostructures. We investigated this process in situ by high-resolution, synchrotron radiation-based XPS, and NEXFAS. The nanographene layers proofed tight against CO under the tested conditions. These nano-heterostructures could find a possible application in optoelectronics or as data storage material. At the same time, our approach represents a new route for the synthesis of nanographene.

BACKGROUND: The morphology and size of MnO₂ that deposited on a carbon clothelectrode have dramatic effects on the electrochemical properties and cycling life. Currently, MnO₂ and its composite structures with zero‐dimensional (0D) nanospheres, one‐dimension (1D) nanotubes and two‐dimension (2D) nanomesh have been successfully synthesized and employed in MFC. Hence, the development of a three‐dimensional (3D) flexible, cost‐effective and high‐performance anode is of great significance for microbial energy harvesting. RESULT: Herein, we have fabricated 3D cauliflower‐like polypyrrole@manganese dioxide (PPy@MnO₂) composites, which are successfully grown on carbon cloth (CC) anode by electrodeposition to promote the power production and storage in microbial fuel cells (MFCs). Impressively, the as‐prepared PPy@MnO₂ modified CC anode delivers a power density of 2139.7 ± 17.5 mW m⁻² and produces an areal capacitance of 1120 ± 12.8 mF cm⁻², which is 3.58 and 4.84 folds higher than that with bare CC anode, benefiting from the unique cauliflower‐like 3D architecture with increased active centers that host the bacteria for more efficient charge transfer. Electrochemical analyses indicate that the PPy@MnO₂ modified CC electrode has excellent electrochemical activity, capacitive behavior and long‐term cyclabilities with smooth surface morphology and high porosity. CONCLUSION: These findings not only provide a facile electrodeposition strategy for PPy@MnO₂ nanoflowers modified CC anode, but also demonstrates its potential for the production and storage of energy simultaneously in MFC application. © 2019 Society of Chemical Industry

Although graphene nanomesh is an attractive 2D carbon material, general synthetic routes to produce functional graphene nanomesh in large-scale are complex and tedious. Herein, we elaborately design a simple two-step dimensional reduction strategy for exploring nitrogen-doped graphene nanomesh by thermal exfoliation of crystal- and shape-modified metal-organic frameworks (MOFs). MOF nanoleaves with 2D rather than 3D crystal structure are used as the precursor, which are further thermally unraveled into nitrogen-doped graphene nanomesh by using metal chlorides as the exfoliators and etching agent. The nitrogen-doped graphene nanomesh has a unique ultrathin two-dimensional morphology, high porosity, rich and accessible nitrogen-doped active sites, and defective graphene edges, contributing to an unprecedented catalytic activity for the oxygen reduction reaction (ORR) in acid electrolytes. This approach is suitable for scalable production.

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.

Inert single-layer boron nitride (h-BN) grown on a catalytic metal may be functionalized with quaternary ammonium compounds (quats) that are widely used as nonreactive electrolytes. We observe that the quat treatment, which facilitates the electrochemical transfer of two-dimensional materials, involves a decomposition of quat ions and leads to covalently bound quat derivatives on top of the 2D layer. Applying tetraoctylammonium and h-BN on rhodium, the reaction product is top-alkylized h-BN as identified with high-resolution X-ray photoelectron spectroscopy. The alkyl chains are homogeneously distributed across the surface, and the properties thereof are well-tunable by the choice of different quats. The functionalization further weakens the 2D material-substrate interaction and promotes easy transfer. Therefore, the functionalization scheme that is presented enables the design of 2D materials with tailored properties and with the freedom to position and orient them as required. The mechanism of this functionalization route is investigated with density functional theory calculations, and we identify the proximity of the catalytic metal substrate to alter the chemical reactivity of otherwise inert h-BN layers.

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.

Supported graphene-based membranes Porous graphene sheets have excellent filtration capabilities and are able to block most ions, but their fragility limits their scale-up beyond laboratory demonstrations. Yang et al. created a nanoporous graphene membrane reinforced by a network of single-walled carbon nanotubes (SWNTs) to provide mechanical stability (see the Perspective by Mi). The SWNT network also stopped the propagation of cracks in the graphene, effectively localizing the damage to a small area defined by a cell in the carbon nanotube mesh. The membranes showed high water flux rates as well as a high rejection rate for most ions. Science , this issue p. 1057 ; see also p. 1033