Modern optoelectronics needs development of new materials characterized not only by high optical transparency and electrical conductivity, but also by mechanical strength, and flexibility. Recent ...advances employ grids of metallic micro- and nanowires, but the overall performance of the resulting material composites remains unsatisfactory. In this work, we propose a new strategy: application of natural scaffoldings perfected by evolution. In this context, we study two bio-inspired networks for two specific optoelectronic applications. The first network, intended for solar cells, light sources and similar devices, has a quasi-fractal structure and is derived directly from a chemically extracted leaf venation system. The second network is intended for touch screens and flexible displays, and is obtained by metalizing a spider's silk web. We demonstrate that each of these networks attain an exceptional optoelectonic and mechanical performance for its intended purpose, providing a promising direction in the development of more efficient optoelectronic devices.
Highlights
A promising solar-powered environmentally friendly process for the synthesis and application of catalysts for hydrogen evolution reaction has been proposed.
A delicate NiCo(OH)
x
-Co
y
W ...catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by electrochemical etching process.
The excellent catalytic effect of NiCo(OH)
x
-Co
y
W for the hydrogen evolution reaction was systematically investigated through various physical and electrochemical analyses.
To achieve high efficiency of water electrolysis to produce hydrogen (H
2
), developing non-noble metal-based catalysts with considerable performance have been considered as a crucial strategy, which is correlated with both the interphase properties and multi-metal synergistic effects. Herein, as a proof of concept, a delicate NiCo(OH)
x
-Co
y
W catalyst with a bush-like heterostructure was realized via gas-template-assisted electrodeposition, followed by an electrochemical etching-growth process, which ensured a high active area and fast gas release kinetics for a superior hydrogen evolution reaction, with an overpotential of 21 and 139 mV at 10 and 500 mA cm
−2
, respectively. Physical and electrochemical analyses demonstrated that the synergistic effect of the NiCo(OH)
x
/Co
y
W heterogeneous interface resulted in favorable electron redistribution and faster electron transfer efficiency. The amorphous NiCo(OH)
x
strengthened the water dissociation step, and metal phase of CoW provided sufficient sites for moderate H immediate adsorption/H
2
desorption. In addition, NiCo(OH)
x
-Co
y
W exhibited desirable urea oxidation reaction activity for matching H
2
generation with a low voltage of 1.51 V at 50 mA cm
−2
. More importantly, the synthesis and testing of the NiCo(OH)
x
-Co
y
W catalyst in this study were all solar-powered, suggesting a promising environmentally friendly process for practical applications.
Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global pandemic. The interplay between innate and adaptive immune responses ...plays a crucial role in managing COVID-19. Cell therapy has recently emerged as a promising strategy to modulate the immune system, offering immense potential for the treatment of COVID-19 due to its customizability and regenerative capabilities. This review provides an overview of the various subsets of immune cell subsets implicated in the pathogenesis of COVID-19 and a comprehensive summary of the current status of immune cell therapy in COVID-19 treatment.
An ideal network window electrode for photovoltaic applications should provide an optimal surface coverage, a uniform current density into and/or from a substrate, and a minimum of the overall ...resistance for a given shading ratio. Here we show that metallic networks with quasi-fractal structure provides a near-perfect practical realization of such an ideal electrode. We find that a leaf venation network, which possesses key characteristics of the optimal structure, indeed outperforms other networks. We further show that elements of hierarchal topology, rather than details of the branching geometry, are of primary importance in optimizing the networks, and demonstrate this experimentally on five model artificial hierarchical networks of varied levels of complexity. In addition to these structural effects, networks containing nanowires are shown to acquire transparency exceeding the geometric constraint due to the plasmonic refraction.
Zinc–air batteries are regarded as ideal candidates for next-generation energy conversion and storage devices, but their conversion efficiency is mainly limited by the sluggish kinetics of the oxygen ...evolution reaction (OER). Therefore, development of highly active and durable non-noble-metal OER catalysts is of great significance to promote their industrialization process. Herein, we electrodeposit amorphous CoSe2 ultrathin nanosheet arrays which exhibit a low overpotential of ∼0.287 V at 10 mA/cm2 and a Tafel slope of ∼62 mV/dec toward the OER in 1 M KOH. This catalytic activity is superior to their crystalline counterpart, commercial RuO2, and most of the reported Co-based catalysts. It can be mainly attributed to the lowered adsorption free energy of OER intermediates and improved charge transfer ability with a phase transformation from the crystalline state to the amorphous state, besides the intrinsic catalytic activity of CoSe2. When serving as an air cathode in a zinc–air battery, the amorphous CoSe2 also realizes a larger power density and a better long-term cyclability compared with those of crystalline CoSe2 and Pt/C–RuO2 electrodes. This work offers a new underpotential deposition strategy to fabricate high-activity amorphous catalysts and demonstrates its great potential for practical applications.
Display omitted
•An amorphous CoSe2 ultrathin nanosheet array is potentiostatically deposited.•Its formation mechanism may be due to the underpotential deposition induced by Se.•Its catalytic activity is superior to RuO2 and most of the reported Co-based catalysts.•DFT proves that the amorphization accelerates OER kinetics of crystalline CoSe2.
In most coastal oceans, the impacts of global warming on season duration and timing of seasonal transitions remain unknown. To mirror the reality of the ongoing climate change, the summer and winter ...seasons are redefined using the local water temperature thresholds in the Bohai Sea. Then the phase variations of these seasons are quantified using the duration and transition timing indices, including the duration (DUR), onset (ONS), and withdrawal (WIT) indices derived from the OSTIA SST dataset at a very high resolution (0.05°). During the last four decades (1982–2019), secular trends of summer indices extracted by the ensemble empirical mode decomposition (EEMD) method reveal that the summer DUR has an accumulated increase of about 17 days (4.5 days decade
-1
), which is primarily induced by the phase advance of the summer ONS by about 16 days (4.2 days decade
-1
). Spatial features of the duration and timing indices demonstrate that the lengthening of summer DUR and the phase advance of summer ONS have significantly enhanced in the shallow regions, due to the limited thermal inertia and the shorter period of the ocean’s memory. In contrast, the secular trend of winter DUR exhibits an accumulated shortening of about 18 days (4.8 days decade
-1
), which is induced by a moderately delayed winter ONS of 6 days (1.6 days decade
-1
) and a significantly advanced winter WIT of 12 days (3.2 days decade
-1
). The potential linkage between the phase variations in the oceanic seasonal cycle and those of the atmospheric forcing was investigated by analyzing both the interannual variability and the secular trend. Over the analysis period, the secular trend of an earlier summer ONS is related to a total reduction of cloud cover by 30% of its climatological mean and an increase of incoming solar radiation of 10 W m
-2
month
-1
in the late spring. Thus, our results highlight the influence of cloud cover in addition to wind speed on the temporal variations of season transition timing.
LiAlCl
4
·3SO
2
is a promising electrolyte used for Li metal batteries. At room and low temperature, a stable solid electrolyte interface film can be formed in LiAlCl
4
·3SO
2
to achieve favorable ...protection for Li metal anodes. Here, Li|Cu cells with SO
2
-based inorganic electrolyte (LiAlCl
4
·3SO
2
) display higher average coulombic efficiency and more excellent cycling stability compared with a conventional organic electrolyte. Moreover, at 0.5 mA cm
−2
, the coulombic efficiency of Li|Cu cells with LiAlCl
4
·3SO
2
electrolyte can reach 95% at − 20 °C, while the coulombic efficiency of the conventional organic electrolyte at − 20 °C is only about 79%. Furthermore, LiAlCl
4
·3SO
2
electrolyte is non-combustible. Based on all the experimental results, LiAlCl
4
·3SO
2
is a promising electrolyte candidate for safe Li metal batteries.
Graphic abstract
Lithium metal anode, protected by the stable and dense SEI films formed in non-flammable and inorganic non-aqueous liquid electrolyte-LiAlCl
4
·3SO
2
(IE), exhibits small and stable over-potential during Li stripping/plating compared with conventional organic electrolyte (OE) even at − 20 °C.
Soil salinization is one of the most important abiotic stresses which can seriously affect the growth and development of rice, leading to the decrease in or even loss of a rice harvest. Increasing ...the rice yield of saline soil is a key issue for agricultural production. The utilization of heterosis could significantly increase crop biomass and yield, which might be an effective way to meet the demand for rice cultivation in saline soil. In this study, to elucidate the regulatory mechanisms of rice hybrids and their parents that respond to salt stress, we investigated the phenotypic characteristics, physiological and biochemical indexes, and expression level of salt-related genes at the seedling stage. In this study, two sets of materials, encapsulating the most significant differences between the rice hybrids and their parents, were screened using the salt damage index and a hybrid superiority analysis. Compared with their parents, the rice hybrids Guang-Ba-You-Hua-Zhan (BB1) and Y-Liang-You-900 (GD1) exhibited much better salt tolerance, including an increased fresh weight and higher survival rate, a better scavenging ability towards reactive oxygen species (ROS), better ionic homeostasis with lower content of Na
in their Na
/K
ratio, and a higher expression of salt-stress-responsive genes. These results indicated that rice hybrids developed complex regulatory mechanisms involving multiple pathways and genes to adapt to salt stress and provided a physiological basis for the utilization of heterosis for improving the yield of rice under salt stress.
With the scarcity of fuel energy, non-noble metal compounds assisted water of electrolysis is becoming a potential candidate for cost-effective and high-quality hydrogen production. To date, ...transition metal phosphide (TMP) has been considered as one of the most promising catalysts for water splitting because of its multitudinous but controlled constituent elements and stoichiometric ratios. In this review, the electronic structure analysis of TMP dialectically reveals the active derivation for catalyzing hydrogen evolution (HER) and oxygen evolution reaction (OER). And then the strategies of rationally designing the structure and composition of electrocatalyst to improve its intrinsic activity are discussed, especially interface engineering. Besides, this review also focuses on the negligible stability issue during the water splitting process. In the end, some key challenges and research orientations of TMPs are pointed out, which is instructive for developing high-efficient and stable electrocatalysts for water splitting.
•The activity derivation of transition metal phosphide (TMP) for water splitting.•Optimization strategies for TMPs to modulate their electron structure.•Strategies to improve conductivity and durability for the first time.•Prospects for the development of the design and synthesis of TMP in water splitting.
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