ACS Applied Electronic Materials最新文献

In the 21st century’s wave of technological advancement, sensors, as a key component of the Internet of Things (IoT), have significantly propelled the development of smart cities and intelligent transportation systems. However, the high deployment costs of traditional sensors limit their practicality for large-scale applications and maintenance. To address this issue, this study proposes a low-cost, concealed, durable, and highly scalable multifunctional smart cement sensor based on triboelectric nanogenerators (SC-TENG) for constructing an all-weather intelligent monitoring system. By embedding differently shaped surface insulating electrodes into the cement and applying super-hydrophobic treatment to the cement surface, the SC-TENG can effectively monitor vehicle speed, measure vehicle length, and provide fencing warnings in public places at a low cost. Experimental results indicate that the SC-TENG can operate stably under various environmental conditions, maintaining stable output in ambient temperatures from 0 to 40 °C and relative humidity of 30%–70%, with negligible signal degradation even after approximately 2500 cycles. This research is significantly important for enhancing road safety, improving public security, and reducing energy consumption, providing technical support and solutions for the construction of smart cities.

High-κ gate dielectrics compatible with two-dimensional (2D) materials are crucial for advanced electronics, and Sb₂O₃ (antimony trioxide) shows significant potential. Here, we show that the soft breakdown induces oxygen vacancies and migration of copper into Sb₂O₃. Hard breakdown, driven by joule heating, gives rise to a substantial temperature increase, leading to morphological transformations and oxygen redistribution. In situ transmission electron microscopy (in situ TEM) measurements correlated with device performance show the formation of nanoconducting filaments due to the increased concentration of oxygen vacancies and copper migration in connection with the soft breakdown. The hard breakdown is associated with the formation of antimony-enriched nanocrystals. These findings offer critical insights into the suitability of Sb₂O₃ as a high-κ gate dielectric.

Stretchable thin film heaters (TFHs) are essential for localized thermotherapy, conforming to the skin and joints. However, conventional TFHs made from nonbreathable elastomers often cause discomfort and increase infection risks. We propose a sample TFH design that is both breathable and stretchable. By using nickel (Ni) foam as a sacrificial template, we deposit Ag nanowires (Ag NWs) to form the heating element, which is then encapsulated in polydimethylsiloxane (PDMS). Crucially, the PDMS coats only the inner surfaces of the micropipes, leaving the interstitial spaces unfilled, creating a breathable 3D conductive network. This contrasts with traditional TFHs that are typically nonbreathable and limited in flexibility, often leading to heat accumulation and discomfort. Our TFH maintained consistent performance over 1000 cycles of bending, stretching, and water immersion. Even with up to 25% stretching, resistance changes remained under 13%. Breathability tests revealed a 5:1 ratio in deionized water permeability between an uncovered bottle and one covered with our film with a permeation rate of 7 mg/cm²·h. Also, the TFH effectively reached 67 °C within 1 min under a 3.5 V bias. Unlike existing methods that neglect breathability or require complex fabrication, our strategy offers a simple yet robust solution to the limitations of conventional TFHs, combining both breathability and stretchability.

Bioethanol, as a renewable energy source, is receiving continuous attention for efficient recovery in aqueous solution. In this work, high-permeable ethanol mix matrix membranes (MMMs) were prepared by incorporating covalent organic framework-300 (COF-300) into polydimethylsiloxane (PDMS) by solution blending. The morphology, functional groups, surface roughness, contact angle, and swelling degree of MMMs before and after COF-300 loading were characterized and analyzed. The encouraging finding is that the incorporation of porous COF-300 particles results in a significant enhancement of the hydrophobicity and ethanol affinity, which in turn increases the total flux and separation factor. The pervaporation results showed that the total flux reached 1515.28 g·m^–2·h^–1 and the separation factor reached 8.7 at a 3 wt % COF loading. Compared with pure PDMS, the total flux and separation factor of MMMs increased by 71.4 and 7.8%, respectively. Primarily based on the unique pore structure characteristics of COF-300, it can provide ultrafast channels for ethanol molecules. At the same time, COF-300 itself is a porous hydrophobicity particle with good ethanol affinity, which will promote the diffusion of ethanol molecules, further promote membrane swelling, and thus increase the separation factor and flux. Moreover, the MMMs in this work exhibited satisfactory stability during 6 months of continuous operation. Therefore, COF-300 is expected to be an ideal filler material to improve the separation performance of permeable ethanol membranes.

This study synthesized copolymers using two biomass materials, starch and ι-carrageenan, with poly(acrylic acid) and utilized ethylene glycol as a solvent-based cross-linking agent to produce hydrogels. The hydrogels developed from starch or ι-carrageenan exhibited high extensibility and mechanical strength after absorbing water molecules from the environment and maturing. The Young’s modulus was approximately 0.03 and 0.04 GPa, with elongation exceeding 600%, and the water content remained stable at around 15% over time. Additionally, these hydrogels can be hydrolyzed and recycled to recreate elastomers with similar mechanical properties. By the incorporation of chlorophyll into the hydrogels made from the two biomass hydrogels, they were successfully used as memory layers in phototransistor memory. The hydrogel cross-linking involved the formation of covalent bonds between the hydroxy groups of the biomass materials and carboxylic acid groups of poly(acrylic acid), while the non-cross-linked parts interacted with chlorophyll through hydrogen bonding. The devices perform electrical writing by applying gate bias and optical erasure by exposing them to 455 nm blue light. Notably, the device made from starch-based hydrogel exhibits a high memory window (∼21.8 V) and long-term stability exceeding 10⁴ s. In conclusion, this study successfully derived high-biomass-content hydrogels from biomass materials and applied them to optoelectronic devices, demonstrating the successful application of biomass materials in high-quality optoelectronic devices.

Self-reducing reactive silver inks are promising for printed electronics due to their low processing temperatures, high performance, and prolonged shelf life. Previous research showed that dense, high-quality silver can be printed without needing any postprint sintering steps by preferentially growing silver at the ink–substrate interface while also minimizing silver growth at the ink–vapor interface. This work builds on this concept and highlights importances of suppressing complexing agent evaporation rate to improve ink performance. By suppressing complexing agent evaporation increases silver formation at the ink–substrate interface, electrical conductivity improvement by over 2.5× for some ink formulations. Two independent studies demonstrate the benefits of this approach: one compares inks synthesized with varying vapor pressure complexing agents and the other prints inks in a complexing agent-rich environment to slow evaporation rates. Both approaches consistently yielded denser silver with lower resistances. For instance, using a propylamine complexing agent instead of ammonia at 40 °C resulted in a 96% decrease in resistance. Additionally, the ink printed at 100 °C with propylamine achieved state-of-the-art conductivity equivalent to 80% of bulk silver’s conductivity. The results confirm that slower complexing agent evaporation rates lead to denser silver with significantly lower resistances. This work introduces a unique strategy for enhancing ink performance that differs from conventional methods such as elevated temperatures, ink chemistry alterations, or postprocessing. The significantly improved low-temperature performance may broaden the applications of reactive silver inks and inspire future strategies that leverage suppressed complexing agent evaporation.

Exotic physical phenomena in solids emerge with changes of nonlinear responses (e.g., polarization hysteresis under an electric field) of order parameters to external stimuli. In epitaxial ferroelectric films, polar ordering states of electric dipole moments cooperate with local disorder originating from thickness-dependent mitigation of misfit strain inherently and/or chemical off-stoichiometry extrinsically. The mutual interaction of electric polarization with both intrinsic and extrinsic factors in ferroelectric thin films produces sizable modification of ferroelectric hysteretic characteristics. Herein, we demonstrate defect-induced manipulation of ferroelectric hysteresis in epitaxial Bi_1/2(Na,K)_1/2TiO₃ films. Notably, pinched hysteresis loops and linked double switching current behaviors are observed with the formation of screw dislocations on the surfaces of lead-free ferroelectric films grown at high temperatures. Plausibly, structural transitions of tetragonal phases to rhombohedral-like monoclinic symmetry driven by Na enrichment enable the appearance of ferroelastic domain variants, of which screw dislocations can be created to accommodate local stress at the boundaries. Polarization switching at the dislocation-mediated ferroelastic domain walls has been also limited and thereby, single ferroelectric hysteresis loops evolve to double-like hysteresis loops. Our result of defect-engineered ferroelectric hysteresis is of potential interest for designing advanced electronic devices such as functional energy storage and harvesters with high performance.

This study investigates the effect of combining a free-radical initiator, TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy), and a zeolite catalyst (HY) on the pyrolysis of JP-10 (exotetrahydrodicyclopentadiene) and 3-carene (3,7,7-trimethylbicyclo [4.1.0] hept-3-ene) for their use as endothermic hydrocarbon fuels. Analytical fast pyrolysis experiments were conducted at 445, 590, and 764 °C in a curie point pyrolyzer hyphenated with a gas chromatograph/mass spectrometer. The experiments explored different cracking methods: noncatalytic pyrolysis, free-radical initiator-assisted pyrolysis, zeolite (HY)-assisted pyrolysis, and a combined approach using both HY zeolite and TEMPO, for the pyrolysis of JP-10 and 3-carene. The results demonstrate that the combination of TEMPO and HY enhances the yield of low-molecular-weight (LMW) hydrocarbons compared to thermal cracking or cracking with either initiator or zeolite alone, especially at a low temperature. For JP-10, the TEMPO + HY-assisted cracking at 445 °C resulted in a combined LMW alkane and alkene yield of 19%, which is considerably higher than that achieved with HY-assisted cracking (14%) and TEMPO-assisted cracking (2%). Similarly, the TEMPO + HY-assisted pyrolysis of 3-carene at 445 °C produced ∼17% yield of LMW hydrocarbons, which was higher than the yields achieved using either TEMPO alone (1%) or HY alone (12%). Plausible free-radical reactions were proposed based on the detected products. The findings suggest that TEMPO can be an effective additive for enhancing the yield of LMW hydrocarbons from jet fuels for endothermic fuel applications.

In this study, a MoO₃@TiO₂ composite core–shell material was developed to remove Rhodamine B (RhB) dye through synergistic adsorption and photocatalytic degradation. n–n heterostructures were formed by coupling n-type semiconductors to enhance the efficiency of photocarrier separation and photocatalytic performance. MoO₃, which possesses strong adsorption capacity, was primarily used as a dye adsorbent. Additionally, the formation of an n–n heterojunction with TiO₂ enabled MoO₃ to expand the photocorresponding range of TiO₂, leading to the generation of superoxide (O₂^•) and hydroxyl (^•OH) free radicals for dye degradation. The experimental results demonstrate that the MoO₃@TiO₂ core–shell composite exhibits excellent performance for RhB dye removal, with adsorption and degradation rates reaching 35.7 and 70.3%, respectively, even at low catalyst concentrations. This approach offers new insights into the development of MoO₃ core–shell photocatalysts.