Highly efficient and bendable organic solar cells (OSCs) are fabricated using solution‐processed silver nanowire (Ag NW) electrodes. The Ag NW films were highly transparent (diffusive transmittance ≈ 95% at a wavelength of 550 nm), highly conductive (sheet resistance ≈ 10 Ω sq−1), and highly flexible (change in resistance ≈ 1.1 ± 1% at a bending radius of ≈200 μm). Power conversion efficiencies of ≈5.80 and 5.02% were obtained for devices fabricated on Ag NWs/glass and Ag NWs/poly(ethylene terephthalate) (PET), respectively. Moreover, the bendable devices fabricated using the Ag NWs/PET films decrease slightly in their efficiency (to ≈96% of the initial value) even after the devices had been bent 1000 times with a radius of ≈1.5 mm.

their strong potential as replacements for ITO these materials suffer from the classic trade-off between optical transmittance and electrical conductivity. Thicker layers afford higher conductivity, but this increase comes at the expense of optical transmittance and vice versa. In addition, large-area organic devices built using fl exible transparent conducting electrodes based on these materials exhibit low efficiency, owing to the low conductivity of TCEs, in the absence of additional metal grids. [17][18][19][20][21][22] It is possible to improve the conductivity of TCEs by incorporating metal grids in the organic devices. These metal grids are either deposited by thermal evaporation using a shadow mask, [ 17,18 ] patterned by lithographic methods, [ 19,20 ] or printed. [ 21,22 ] In organic devices, however, there is a limit to how thick the metal grids deposited beneath the organic layer can be. Because the organic layer is extremely thin (typically a few hundred nanometers in thickness), there is the possibility of there being electrical short-circuiting between the metal grids and the top electrode. To prevent this, researchers have tried inserting an insulating layer between the metal grids and the organic layers. [ 19 ] However, this process increases the manufacturing cost. Electrical short circuiting due to the use of printed metal grids can be prevented by embedding the grids in a polymer substrate. [ 24,25 ] Recently, a damascene process was used to fabricate a metalembedding fl exible substrate (MEFS). The process involved the fabrication of trench-like structures on fl exible substrates using imprint lithography. Metal was deposited in the trench-like patterns and this was followed by the removal of any superfl uous metal fi lm by chemical-mechanical polishing. [ 23 ] However, this process is expensive.Here we report a universal method to overcome this trade-off by using a combination of metal-embedding architecture into plastic substrate and ultrathin transparent electrodes, leading to highly transparent (optical transmittance ≈93% at a wavelength of 550 nm), highly conducting (sheet resistance ≈13 Ω ٗ −1 ) and extremely fl exible (bending radius ≈200 μ m) electrodes with very smooth surface. These electrodes were used to fabricate fl exible organic devices that exhibited performances similar or superior to that of devices fabricated on glass substrate. In addition, these fabricated fl exible devices did not show degradation in their performance even after being folded with a radius of ≈200 μ m.Extremely fl exible transparent conducting electrodes are developed using a combination of metal-embedding architecture into plastic substrate and ultrathin transparent electrodes, which leads to highly transparent (optical transmittance ≈93% at a wavelength of 550 nm), highly conducting (sheet resistance ≈13 Ω ᮀ −1 ), and extremely fl exible (bending radius ≈ 200 μ m) electrodes. The electrodes are used to fabricate fl exible organic solar cells and organic light-emitting diodes that exhibit performance sim...

Face masks will be used to prevent pandemic recurrence and outbreaks of mutant SARS-CoV-2 strains until mass immunity is confirmed. The polypropylene (PP) filter is a representative disposable mask material that traps virus-containing bioaerosols, preventing secondary transmission. In this study, a copper thin film (20 nm) was deposited via vacuum coating on a spunbond PP filter surrounding a KF94 face mask to provide additional protection and lower the risk of secondary transmission. Film adhesion was improved using oxygen ion beam pretreatment, resulting in cuprous oxide formation on the PP fiber without structural deformation. The copper-coated mask exhibited filtration efficiencies of 95.1 ± 1.32% and 91.6 ± 0.83% for NaCl and paraffin oil particles, respectively. SARS-CoV-2 inactivation was evaluated by transferring virus-containing media onto the copper-coated PP filters and subsequently adding Vero cells. Infection was verified using real-time polymerase chain reaction and immunochemical staining. Vero cells added after contact with the copper-coated mask did not express the RNA-dependent RNA polymerase and envelope genes of SARS-CoV-2. The SARS-CoV-2 nucleocapsid immunofluorescence results indicated a reduction in the amount of virus of more than 75%. Therefore, copper-coated antiviral PP filters could be key materials in personal protective equipment, as well as in air-conditioning systems.

Here, we present a facile and low-cost method to produce hierarchically porous graphene-based carbons from a biomass source. Three-dimensional (3D) graphene-based carbons were produced through continuous sequential steps such as the formation and transformation of glucose-based polymers into 3D foam-like structures and their subsequent carbonization to form the corresponding macroporous carbons with thin graphene-based carbon walls of macropores and intersectional carbon skeletons. Physical and chemical activation was then performed on this carbon to create micro- and meso-pores, thereby producing hierarchically porous biomass-derived graphene-based carbons with a high Brunauer-Emmett-Teller specific surface area of 3,657 m2 g−1. Owing to its exceptionally high surface area, interconnected hierarchical pore networks, and a high degree of graphitization, this carbon exhibited a high specific capacitance of 175 F g−1 in ionic liquid electrolyte. A supercapacitor constructed with this carbon yielded a maximum energy density of 74 Wh kg−1 and a maximum power density of 408 kW kg−1, based on the total mass of electrodes, which is comparable to those of the state-of-the-art graphene-based carbons. This approach holds promise for the low-cost and readily scalable production of high performance electrode materials for supercapacitors.

To resist the energy crisis and increasingly environmental pollution, there is a great demand for the development of sustainable materials for use in high-performance energy storage devices and environmental applications. However, it is a great challenge to realize both ultrahigh power density and high energy density in symmetric supercapacitors (SCs) by using materials synthesized from bioresources. Herein, we report the synthesis of hierarchical and lightweight graphene aerogels (GAs) with interconnected three-dimensional (3D) nanostructures for the fabrication of high performance coin cell-type SCs. GAs synthesized from pear exhibited high surface area (1001 m 2 g −1 ) and pore volume (0.68 cm 3 g −1 ), which tremendously increase its surface area up to 2323 m 2 g −1 and pore volume of 1.15 cm 3 g −1 after chemical activation. SCs based on activated GAs delivered both high energy density of 56.80 Wh kg −1 and high power density of 620.26 kW kg −1 . The capacitance retention was ∼83% after 10 000 successive cycles of charge/discharge, indicating good cyclability. Moreover, GAs showed great potential as excellent adsorbents for the removal of diverse dyes from wastewater. This approach allows us to take the full advantage of raw materials from nature for promising applications in sustainable energy as high-performance SCs and practical environmental remediation.

A graphene aerogel (GA) with a three-dimensional (3D) structure, ultra-lightweight nature, and high hydrophobicity was simply fabricated by the one-step pyrolysis of glucose and ammonium chloride. The as-synthesized GA exhibited a 3D interconnected microporous architecture with a high surface area of ∼2860 m2 g–1 and pore volume of 2.24 cm3 g–1. The hydrophobic GA (10 mg 100 mL–1) demonstrated rapid and excellent adsorption performance for the removal of food toxins such as various biogenic amines (histamine, cadaverine, and spermine) and the hazardous bacterium Staphylococcus aureus (a food contaminant and a cause of poor wound healing) from a liquid matrix with a maximum simultaneous adsorption capacity for multiple biogenic amines of >85.19% (histamine), 74.1% (cadaverine), and 70.11% (spermidine) and a 100% reduction in the viable cell count of S. aureus within 80 min of interaction. The outstanding adsorption capacity can be attributed to a highly interconnected porous network in the 3D architecture and a high surface-to-volume ratio. A case study using soy sauce spiked with multiple biogenic amines showed successful removal of toxins with excellent recyclability without any loss in absorption performance. Biocompatibility of the GA in terms of cell viability was observed even at high concentrations (83.46% and 75.28% at 25 and 50 mg mL–1, respectively). Confirmatory biocompatibility testing was conducted via live/dead cell evaluation, and the morphology of normal lung epithelial cells was examined via scanning electron microscopy showed no cellular shrinkage. Moreover, GA showed excellent removal of live colonies of S. aureus from the food matrix and immunoblotting analysis showed elevated protein expression levels of β-catenin and α-SMA (α-smooth muscle actin). The biocompatible sugar-based GA could simultaneously adsorb multiple biogenic amines and live bacteria and was easy to regenerate via simple separation due to its high floatability, hydrophobicity, surface area, and porosity without any structural and functional loss, making it especially relevant for food safety and biomedical applications.

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