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In this article, a novel SOI MESFET which can be suitable for high power applications is proposed. In order to upgrade its electrical characteristics, a protruded gate and dual wells (PGDW) n-type silicon in the buried oxide are formed. This strategy by using a protruded gate and a right well at the drain side increases the channel thickness causing a rise in the drain current. Besides, a reduction in the electric field maximum value near the drain side leads to improving the maximum power density of the PGDW- structure 143% over a Conventional MESFET. A left well in the proposed structure has been used to absorb the created holes due to the impact ionization mechanism and causes improvement of floating body effect. Also, the PGDW-MESFET demonstrates the improved performance in the RF characteristics, consequently, two parameters h 21, Unilateral power gain boost almost 14%, and 11%, respectively compared to the C-MESFET.

Direct ethanol fuel cells have been widely investigated as nontoxic and low-corrosive energy conversion devices with high energy and power densities. It is still challenging to develop high-activity and durable catalysts for a complete ethanol oxidation reaction on the anode and accelerated oxygen reduction reaction on the cathode. The materials’ physics and chemistry at the catalytic interface play a vital role in determining the overall performance of the catalysts. Herein, we propose a Pd/Co@N-C catalyst that can be used as a model system to study the synergism and engineering at the solid-solid interface. Particularly, the transformation of amorphous carbon to highly graphitic carbon promoted by cobalt nanoparticles helps achieve the spatial confinement effect, which prevents structural degradation of the catalysts. The strong catalyst-support and electronic effects at the interface between palladium and Co@N-C endow the electron-deficient state of palladium, which enhances the electron transfer and improved activity/durability. The Pd/Co@N-C delivers a maximum power density of 438 mW cm −2 in direct ethanol fuel cells and can be operated stably for more than 1000 hours. This work presents a strategy for the ingenious catalyst structural design that will promote the development of fuel cells and other sustainable energy-related technologies. It is challenging to develop high-activity and durable catalysts for both ethanol oxidation reaction on the anode and oxygen reduction reaction on the cathode. Here in this work, authors proposed Pd/Co@N-C catalyst as a model to synergistically maximize the usage of catalyst nanoparticles and active interfaces for direct ethanol fuel cells.

Nanochannel membranes have demonstrated remarkable potential for osmotic energy harvesting; however, their efficiency in practical high-salinity systems is hindered by reduced ion selectivity. Here, we propose a dual-separation transport strategy by constructing a two-dimensional (2D) vermiculite (VMT)-based heterogeneous nanofluidic system via an eco-friendly and scalable method. The cations are initially separated and enriched in micropores of substrates during the transmembrane diffusion, followed by secondary precise sieving in ultra-thin VMT laminates with high ion flux. Resultantly, our nanofluidic system demonstrates efficient osmotic energy harvesting performance, especially in hypersaline environment. Notably, we achieve a maximum power density of 33.76 W m −2 , a 6.2-fold improvement with a ten-fold increase in salinity gradient, surpassing state-of-the-art nanochannel membranes under challenging conditions. Additionally, we confirm practical hypersaline osmotic power generation using various natural salt-lake brines, achieving a power density of 25.9 W m −2 . This work triggers the hopes for practical blue energy conversion using advanced nanoarchitecture. Harvesting osmotic energy in real world high-salinity solutions poses great challenges, authors propose nanofluidic membranes with a dual separation mechanism based on vermiculite nanosheets with an isomorphic substitution structure, showing excellent energy conversion in hypersaline environments.

The flexible thermoelectric technique, which can convert heat from the human body to electricity via the Seebeck effect, is expected to provide a peerless solution for the power supply of wearables. The recent discovery of ductile semiconductors has opened a new avenue for flexible thermoelectric technology, but their power factor and figure-of-merit values are still much lower than those of classic thermoelectric materials. Herein, we demonstrate the presence of morphotropic phase boundary in Ag 2 Se-Ag 2 S pseudobinary compounds. The morphotropic phase boundary can be freely tuned by adjusting the material thermal treatment processes. High-performance ductile thermoelectric materials with excellent power factor (22 μWcm −1  K −2 ) and figure-of-merit (0.61) values are realized near the morphotropic phase boundary at 300 K. These materials perform better than all existing ductile inorganic semiconductors and organic materials. Furthermore, the in-plane flexible thermoelectric device based on these high-performance thermoelectric materials demonstrates a normalized maximum power density reaching 0.26 Wm −1 under a temperature gradient of 20 K, which is at least two orders of magnitude higher than those of flexible organic thermoelectric devices. This work can greatly accelerate the development of flexible thermoelectric technology. Power factor and figure-of-merit values are normally low in flexible thermoelectric materials. Here, the authors fabricate high-performance ductile thermoelectric materials with high power factor and figure-of-merit values near the morphotropic phase boundary in Ag 2 Se-Ag 2 S pseudobinary compound.

Harvesting electricity from ubiquitous water vapor represents a promising route to alleviate the energy crisis. However, existing studies rarely comprehensively consider the impact of natural environmental fluctuations on electrical output. Here, we demonstrate a bilayer polymer enabling self-sustaining and highly efficient moisture-electric generation from the hydrological cycle by establishing a stable internal directed water/ion flow through thermal exchange with the ambient environment. Specifically, the radiative cooling effect of the hydrophobic top layer prevents the excessive daytime evaporation from solar absorption while accelerating nighttime moisture sorption. The introduction of LiCl into the bottom hygroscopic ionic hydrogel enhances moisture sorption capacity and facilitates ion transport, thus ensuring efficient energy conversion. A single device unit (1 cm 2 ) can continuously generate a voltage of ~0.88 V and a current of ~306 μA, delivering a maximum power density of ~51 μW cm −2 at 25 °C and 70% relative humidity (RH). The device has been demonstrated to operate steadily outdoors for continuous 6 days. Harvesting electricity from ubiquitous water vapor represents a promising route to alleviate the energy crisis. Here, authors report a bilayer polymer enabling self-sustaining moisture-electric generation by establishing a stable internal water flow through thermal exchange with the environment.

Load bearing/energy storage integrated devices (LEIDs) allow using structural parts to store energy, and thus become a promising solution to boost the overall energy density of mobile energy storage systems, such as electric cars and drones. Herein, with a new high-strength solid electrolyte, we prepare a practical high-performance load-bearing/energy storage integrated electrochemical capacitors with excellent mechanical strength (flexural modulus: 18.1 GPa, flexural strength: 160.0 MPa) and high energy storage ability (specific capacitance: 32.4 mF cm −2 , energy density: 0.13 Wh m −2 , maximum power density: 1.3 W m −2 ). We design and compare two basic types of multilayered structures for LEID, which significantly enhance the practical bearing ability and working flexibility of the device. Besides, we also demonstrate the excellent processability of the LEID, by forming them into curved shapes, and secondarily machining and assembling them into complex structures without affecting their energy storage ability. High-strength composite materials for electrochemical energy storage is attractive for mobile systems. Here the authors demonstrate high-performance load-bearing integrated electrochemical capacitors, which show high strength, large capacitance, and good machinability.

Owing to their synergistic interactions, dual-atom catalysts (DACs) with well-defined active sites are attracting increasing attention. However, more experimental research and theoretical investigations are needed to further construct explicit dual-atom sites and understand the synergy that facilitates multistep catalytic reactions. Herein, we precisely design a series of asymmetric selenium-based dual-atom catalysts that comprise heteronuclear SeN 2 –MN 2 (M = Fe, Mn, Co, Ni, Cu, Mo, etc.) active sites for the efficient oxygen reduction reaction (ORR). Spectroscopic characterisation and theoretical calculations revealed that heteronuclear selenium atoms can efficiently polarise the charge distribution of other metal atoms through short-range regulation. In addition, compared with the Se or Fe single-atom sites, the SeFe dual-atom sites facilitate a reduction in the conversion energy barrier from *O to *OH via the coadsorption of *O intermediates. Among these designed selenium-based dual-atom catalysts, selenium-iron dual-atom catalysts achieves superior alkaline ORR performance, with a half-wave potential of 0.926 V vs. a reversible hydrogen electrode. In addition, the SeN 2 –FeN 2 -based Zn–air battery has a high specific capacity (764.8 mAh g −1 ) and a maximum power density (287.2 mW cm −2 ). This work may provide a good perspective for designing heteronuclear DACs to improve ORR efficiency. Dual-atom catalysts with precise active sites are gaining attention, but further studies are needed to optimise their construction and understand their catalytic synergy. Here the authors report a series of asymmetric selenium-based dual- atom catalysts that comprise heteronuclear SeN2–MN2 (M = Fe, Mn, Co, Ni, Cu, Mo, etc.) active sites for the efficient oxygen reduction reaction.

Single-walled carbon nanotubes (SWCNTs)-based thermoelectric materials, valued for their flexibility, lightweight, and cost-effectiveness, show promise for wearable thermoelectric devices. However, their thermoelectric performance requires significant enhancement for practical applications. To achieve this goal, in this work, we introduce rational “triple treatments” to improve the overall performance of flexible SWCNT-based films, achieving a high power factor of 20.29 µW cm −1  K −2 at room temperature. Ultrasonic dispersion enhances the conductivity, NaBH 4 treatment reduces defects and enhances the Seebeck coefficient, and cold pressing significantly densifies the SWCNT films while preserving the high Seebeck coefficient. Also, bending tests confirm structural stability and exceptional flexibility, and a six-legged flexible device demonstrates a maximum power density of 2996 μW cm −2 at a 40 K temperature difference, showing great application potential. This advancement positions SWCNT films as promising flexible thermoelectric materials, providing insights into high-performance carbon-based thermoelectrics. Authors introduce triple treatments to advance flexible single-walled carbon nanotube films, achieving a power factor of 20.29 µW cm −1  K −2 . High structural stability and flexibility enable the fabrication of a high-power-density flexible device.

HighlightsA new class of γ-cyclodextrin based metal–organic framework -derived strategy was used to fabricate highly active M–N-C catalysts containing both single-atom sites and nanoparticles.The obtained Co@C-CoNC exhibits remarkable bifunctional oxygen reduction (ORR)/oxygen evolution reactions (OER) performance, which further delivered a high power density and excellent cyclic stability in rechargeable zinc-air batteries.Density functional theory calculation suggests that the mutual self-regulation of d-electron density of both Co NP and Co SAC conjointly reduce the reaction energy barriers and thus boost the ORR/OER kinetics through their fast adsorption/desorption ability of reaction intermediates.Rechargeable zinc-air batteries (ZABs) are a promising energy conversion device, which rely critically on electrocatalysts to accelerate their rate-determining reactions such as oxygen reduction (ORR) and oxygen evolution reactions (OER). Herein, we fabricate a range of bifunctional M–N–C (metal-nitrogen-carbon) catalysts containing M–Nx coordination sites and M/MxC nanoparticles (M = Co, Fe, and Cu) using a new class of γ-cyclodextrin (CD) based metal–organic framework as the precursor. With the two types of active sites interacting with each other in the catalysts, the obtained Fe@C-FeNC and Co@C-CoNC display superior alkaline ORR activity in terms of low half-wave (E1/2) potential (~ 0.917 and 0.906 V, respectively), which are higher than Cu@C-CuNC (~ 0.829 V) and the commercial Pt/C (~ 0.861 V). As a bifunctional electrocatalyst, the Co@C-CoNC exhibits the best performance, showing a bifunctional ORR/OER overpotential (ΔE) of ~ 0.732 V, which is much lower than that of Fe@C-FeNC (~ 0.831 V) and Cu@C-CuNC (~ 1.411 V), as well as most of the robust bifunctional electrocatalysts reported to date. Synchrotron X-ray absorption spectroscopy and density functional theory simulations reveal that the strong electronic correlation between metallic Co nanoparticles and the atomic Co-N4 sites in the Co@C-CoNC catalyst can increase the d-electron density near the Fermi level and thus effectively optimize the adsorption/desorption of intermediates in ORR/OER, resulting in an enhanced bifunctional electrocatalytic performance. The Co@C-CoNC-based rechargeable ZAB exhibited a maximum power density of 162.80 mW cm−2 at 270.30 mA cm−2, higher than the combination of commercial Pt/C + RuO2 (~ 158.90 mW cm−2 at 265.80 mA cm−2) catalysts. During the galvanostatic discharge at 10 mA cm−2, the ZAB delivered an almost stable discharge voltage of 1.2 V for ~ 140 h, signifying the virtue of excellent bifunctional ORR/OER electrocatalytic activity.

Atom trapping of scarce precious metals onto a suitable support at high temperatures has emerged as an effective approach to build thermally stable single-atom catalysts. Here, following a similar mechanism based on atom trapping through support effects, we demonstrate a reverse atom-trapping strategy to controllably extract strontium atoms from a rigid lanthanum strontium cobalt ferrite ((La 0.6 Sr 0.4 ) 0.95 Co 0.2 Fe 0.8 O 3− δ , LSCF) surface with ease. The lattice oxygen redox activity of LSCF is accordingly fine-tuned, leading to enhanced cathode performance in a solid-oxide fuel cell. An over 30−70% increases in maximum power density of the single cells at intermediate temperatures is achieved by LSCF with surface strontium vacancies compared to the pristine surface. In addition, the strontium-deficient surface excludes strontium segregation and formation of electrochemically inert SrO islands, thus improving the longevity of the cathode. This development can be broadly applicable for modifying structurally stable oxide surfaces, and opens more possibilities of scalable single-atom extraction strategies. Atom trapping is a well-established route to prepare single-atom catalysts. Here the authors propose a reverse atom-trapping strategy in which surface strontium atoms of LSCF fuel cell cathodes are extracted by MoO 3 , forming single strontium vacancies on LSCF in a controllable manner and tuning its performance for the oxygen reduction reaction.