ACS Applied Materials & Interfaces最新文献

Lithium-oxygen (Li-O₂) batteries have high theoretical energy density, but the discharge product Li₂O₂ of Li-O₂ batteries is difficult to decompose, resulting in the undesirably high charging potential. The use of soluble redox mediators (RMs) can usually reduce the high charging potential of Li-O₂ batteries, but the RM on the cathode side can diffuse to the Li metal anode and react with it, leading to continuous loss of the RM and causing damage to the fragile Li anode interface. So, it is necessary to develop a bifunctional redox mediator (BRM) that can simultaneously reduce the charging potential and protect the Li anode. Herein, we introduced 4-bromomethyl-phenylboronic acid (BPLA) as a BRM. The Br^- ions can be dissociated from BPLA during cycling and serve as an effective component of RM, thereby significantly facilitating the reduction of charging potential of Li-O₂ batteries. Meanwhile, the boronic acid groups in BPLA have the capability to engage in cross-linking reactions on the Li-metal surface, forming a flexible and continuous solid-electrolyte interphase (SEI) layer. More importantly, the SEI layer contains the reversible dynamic B-O covalent bond, which possesses a characteristic of continuous dissociation and rearrangement. Thereby the SEI layer possesses the shape adaptability, inhibits the growth of Li dendrites, and suppresses the reaction between RM and Li. Consequently, our BPLA, serving as the BRM, can enable Li-O₂ batteries to achieve a stable cycle life of 180 cycles under the low charge potential up to 4.0 V.

Aliovalent substitution is a ubiquitous strategy to increase ionic conductivity in solid-state electrolytes, often by many orders of magnitude. However, the structural and compositional changes that occur upon aliovalent substitution are highly interrelated, and a deep understanding of how substitutions simultaneously impact ion transport and the chemical evolution of interfaces during electrochemical cycling remain as prevailing challenges. Here, we interrogate aliovalent pnictogen substitution of Li₄GeS₄ in the series Li_3.7Ge_0.7Pn_0.3S₄ (Pn = P, As, Sb) and unravel the impact on ion transport processes and degradation during electrochemical cycling. High-resolution powder X-ray diffraction and pair distribution function analysis reveal that all substituted compounds exhibit an anisometric distortion of the Li₄GeS₄ structure. Temperature-dependent potentiostatic electrochemical impedance spectroscopy reveals that aliovalent substitution increases the room-temperature lithium ionic conductivity by 2 orders of magnitude. Curiously, aliovalent substitution results in a simultaneous increase in the Arrhenius prefactor and decrease in the activation barrier, which contribute to the significant increase in lithium-ion conductivity. We attribute this apparent violation of the "Meyer-Neldel" entropy-enthalpy compensation to the introduction of Li⁺ vacancies that elicit a redistribution of the lithium substructure. Electrochemical stability and cycling performance were interrogated by critical current density tests on symmetric cells with Li electrodes coupled with virtual electrode X-ray photoelectron spectroscopy measurements. In all substituted compounds, we observe the growth of electronically conductive phases that result in continual growth of the solid electrolyte interphase and increase in interfacial impedance during electrochemical cycling. We find that electrochemical instability against Li⁰ is predominantly driven by reduced Ge species. Taken together, our study presents holistic insights into the structural and compositional factors that drive ionic conductivity and electrochemical degradation in lithium metal sulfide solid-state electrolytes.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a widely used hole transport material in inverted tin-based perovskite solar cells (Sn-PSCs). However, the efficiency and stability of these Sn-PSCs that utilize PEDOT:PSS are unsatisfactory, partly due to concerns about their mismatched work functions, hydrophobicity, and chemical interactions. Here, we introduce a self-assembled monolayer (SAM), (2-(7H-dibenzo[c,g]carbazol-7-yl)ethyl) phosphonic acid (2PADCB) as a multifunctional buffer molecule at the buried PEDOT:PSS/Sn perovskite interface. The phosphate group in the 2PADCB molecule reacts with the sulfur atom on the thiophene ring in PEDOT:PSS. This reaction process effectively anchors the SAM molecule firmly to the surface of PEDOT:PSS. Additionally, it reduces the binding sites between PEDOT and PSS, alleviating the acidification of the PEDOT:PSS surface and the poor conductivity caused by excessive PSS. Furthermore, the presence of two additional benzene rings in the 2PADCB molecule terminal group increases the electron density around Sn²⁺, thereby inhibiting its oxidation. Additionally, the hydrophobic characteristics of the 2PADCB molecule mitigate moisture infiltration from PEDOT:PSS, thereby protecting the degradation of Sn perovskite. Consequently, the Sn-PSCs based on the PEDOT:PSS/2PADCB film achieve a champion efficiency of 14.7%, higher than that of their pristine counterpart (12.5%). Moreover, the 2PADCB molecule improves the stability of the device by maintaining 90% of its initial efficiency after 160 h under 1 Sun illumination. Such enhancement in efficiency and stability is mainly attributed to the improved interface quality with the 2PADCB molecule, leading to better carrier transport and suppressed charge recombination at the buried PEDOT:PSS/Sn perovskite interface. Our work suggests that introducing the 2PADCB molecule at the PEDOT:PSS/perovskite interface is a promising method for efficient and stable Sn-PSCs.

Despite the recent rapid advancements in room-temperature self-healing waterborne polyurethanes, imparting fast self-healing ability while concurrently maintaining robust mechanical performance of waterborne polyurethanes remains a formidable challenge. Herein, we propose a molecular structure design strategy for developing visible light-responsive, room-temperature self-healing, and antibacterial waterborne polyurethane (DMZWPU) containing triple dynamic bonds of diselenide bonds, multiple hydrogen bonds, and Zn(II)-carboxylate coordination bonds. This innovative approach effectively balances the tensile stress, fracture toughness, and self-healing ability of the material. Thanks to the synergy of the three dynamic bonds, the resulting DMZWPU film demonstrates a tensile stress of 40.32 MPa and a fracture toughness of 119.29 MJ/m³, respectively. Furthermore, based on the dynamic characteristics of three dynamic bonds and the dual induction of trace ethanol and visible light, the damaged DMZWPU film can recover more than 85% of the tensile stress at room temperature within 2 h. These performances outperform those of most of the currently reported room-temperature self-healable polymers (healing efficiency >80%). Due to the combined action of selenium and zinc ions, the DWZWPU film exhibits excellent antibacterial properties (sterilization rate of 100% in 24 h). Finally, the DMZWPU emulsion is effectively applied for leather finishing processes, and the results show that the DMZWPU coating exhibits excellent folding resistance, wear resistance, and room-temperature self-healing function, as well as enhanced water resistance and dry friction resistance. In summary, this study provides a novel perspective for the development of waterborne polyurethane with high mechanical performances and rapid self-healable ability at room temperature.

The integration of metal halide perovskite quantum dots (PQDs) into sensing technologies has been hindered by challenges in balancing environmental stability and sensing sensitivity. In this work, mesoporous silica nanoparticles (MSNs) with tunable pore sizes were employed as nanoconfinement reactors to synthesize size-controlled CsPbBr₃ PQDs (3.0-12.0 nm). The nanoconfined environment facilitated the selective growth of pure CsPbBr₃ phases, avoiding unwanted Cs₄PbBr₆ formation. The resulting nanoconfined PQDs, CsPbBr₃@MSN, exhibited tunable emission from blue to green (470 to 515 nm), a high quantum yield (36.8%), and enhanced stability. Moreover, the PQD composites demonstrated exceptional performance in detecting the pesticide dicloran, achieving a detection limit of 0.16 μM, far below China's national standard requirement (34.0 μM). The detection mechanism involved competitive adsorption and phase transitions from the cubic CsPbBr₃ phase to the quasi-2D CsPb₂Br₅ phase. The porous MSN structure maintained efficient mass and energy transfer, ensuring both stability and sensitivity. Beyond sensing, these nanocomposites show potential for applications in anticounterfeiting and fingerprint recognition. This study highlights nanoconfinement as a powerful strategy for developing robust, high-performance PQD-based fluorescent sensors.

The growing need for fast and reliable energy delivery in various applications ranging from electric vehicles and portable electronics to grid-scale storage demands high-performance energy storage systems capable of operating at high charge/discharge rates (C-rates). Aqueous zinc-ion batteries (AZIBs) offer a promising alternative to conventional lithium-ion batteries primarily due to their inherent safety, environmental friendliness, low cost, and high theoretical capacity. Quinone-based cathodes, with their fast redox kinetics and high theoretical capacities, are particularly suitable for high-rate applications. However, their practical application in AZIBs is limited by their high solubility in aqueous electrolytes, leading to significant capacity fading and poor long-term cycling stability, especially at elevated C-rates. To address these challenges, this study investigates the use of Nafion membranes as ion-selective barriers to stabilize quinone cathodes and prevent the dissolution of active materials. The study evaluates four quinone-based cathodes─2,3,5,6-tetrachloro-1,4-benzoquinone (TCBQ), 1,4-naphthoquinone (NQ), anthraquinone (AQ), and poly(2-chloro-3,5,6-trisulfide-1,4-benzoquinone) (PCTBQ)─in AZIBs, focusing on the effect of Nafion membrane conditioning in 1 M ZnSO₄ electrolyte. The results demonstrate that optimized Nafion conditioning significantly enhances the stability and performance of quinone cathodes, reducing dissolution, improving cyclability, and maintaining stable capacity retention under high-rate conditions, i.e., 35C. These findings emphasize the importance of membrane conditioning and demonstrate its potential to advance the development of durable, high-rate AZIBs for rapid energy storage applications.

Suspended nanoscale one-dimensional (1D) arrays have attracted substantial interest due to their promising applications in nanodevice fabrication. In this study, we propose a novel strategy for fabricating precisely positioned, long-range ordered nanowire arrays by controlling the directional liquid transport of conical fiber arrays (CFAs) on asymmetrically modified silicon templates patterned with periodic spindle-shaped micropillars. The intrinsic properties of CFAs and the tailored wettability of silicon templates play critical roles in nanowire fabrication. CFAs generates quasi-unidirectional surface tension (F_γ), facilitating precise control over the retraction of liquid films and ensuring strict nanowire alignment in the dewetting direction. Meanwhile, high-adhesion hydrophobic surfaces effectively enhance the pinning behavior of the three-phase contact line during the retraction process, thereby improving the liquid bridge stability. It is noteworthy that the method developed for preparing high-yield arrays of ultralong nanowires exhibits remarkable universality. This approach can be widely applied to the synthesis of suspended nanowires using diverse polymers such as polystyrene sulfonic acid, poly(vinyl alcohol), polyvinylpyrrolidone, polyethylene glycol, and sodium alginate as solutes, achieving a robust formation rate exceeding 80% for nanowires that surpass 16 μm in length. These findings contribute valuable knowledge for the scalable production of suspended 1D nanostructures, furthering advancements in nanoscale device development.

MXenes have gained significant attention as multifunctional fillers in MXene-polymer nanocomposites. However, their inherently hydrophilic surfaces pose challenges in compatibility with hydrophobic polymers such as epoxy, potentially limiting composite performance. In this study, high-crystalline Ti₃C₂T_x MXenes were functionalized with alkylated 3,4-dihydroxy-l-phenylalanine ligands, transforming the hydrophilic MXene flakes into a more hydrophobic form, thus significantly enhancing compatibility with the epoxy matrix. This surface functionalization enabled uniform dispersion and supported the formation of a percolation network within the epoxy matrix at a low filler loading of just 0.12 vol %. Consequently, the functionalized MXene-epoxy nanocomposites exhibited remarkable performance, including an electrical conductivity of 8200 S m^-1, outstanding electromagnetic interference (EMI) shielding effectiveness (SE) of 100 dB at 110 GHz (61 dB at 8.2 GHz), improved thermal conductivity of 1.37 W m^-1 K^-1, and a 300% increase in tensile toughness (271 KJ m^-3). These properties substantially outperformed those of their nonfunctionalized counterparts and surpassed previously reported MXene-polymer nanocomposites. This study underscores the critical role of surface functionalization in unlocking the full potential of two-dimensional (2D) MXenes in polymer composites, providing a pathway to advanced multifunctional nanocomposite materials.

Atomic layer deposition (ALD) is notable for highly controlled syntheses of ultrathin materials through self-limiting reactions. However, ALD materials have strong bonding interactions with substrates, which have generally made substrate removal for the preparation of freestanding large-area 2D films challenging. Here, we report a strategy for the fabrication of freestanding, amorphous ultrathin films by growing on single-crystal NaCl. NaCl surfaces, typically poor substrates, are improved by inserting hydroxyl groups across the surface. This heterogeneous surface forms bonding and nonbonding interactions with ALD materials, allowing us to grow amorphous ultrathin alumina and titania on the surface and remove the films with minimal damage. We show that this tailored substrate can be removed under mild conditions and that the ultrathin material can be transferred to an arbitrary substrate with assistance from a poly(methyl methacrylate) scaffold. This simple process results in materials that span 1 cm² and have few cracks and pinholes. This strategy provides easy access to an expansive class of freestanding 2D glasses that have previously been challenging targets of fabrication at this scale.

Nitric oxide (NO)-based gas therapy has attracted increasing attention as a promising approach for tumor treatment, but elevated levels of glutathione (GSH) in the tumor microenvironment significantly limit their therapeutic effectiveness. In this study, a type of engineered photoactivatable nanomicelles Ce6/NI@PEP@HA (CNPH) were developed for combinational photodynamic and NO gas therapy. CNPH was capable of targeted accumulation to tumors, where it depleted GSH and released NO to effectively produce reactive oxygen species (ROS) with oxidative damage under laser irradiation at 660 nm. The GSH consumption induced the deactivation of glutathione peroxidase activity, leading to enhanced accumulation of toxic lipid peroxide and enabled a ferroptosis-like therapeutic outcome. Additionally, the effective production of NO and ROS resulted in mitochondrial dysfunction, characterized by the disruption of mitochondrial membrane potential and decreased adenosine triphosphate concentration. The in vivo animal experiments indicated that the combinational photodynamic and NO gas therapy achieved a tumor inhibition of 89.1%, and it has proven to be a more effective tumor therapy strategy in contrast to any single modality. In consequence, ferroptosis-like combinational tumor therapy has opened up a new horizon to a cutting-edge and noninvasive paradigm for advanced tumor treatments.