ACS Publications最新文献

The advancement of water electrolysis highlights the growing importance of electrolyzers capable of operating at high current densities, where mass transfer dynamics plays a crucial role. In the electrode reactions, the interfacial water is a key factor in regulating these dynamics. However, the potential of utilizing interfacial-free water (IFW) to modulate electrode behavior remains underexplored. Herein, we investigate the effect of interfacial water structure on hydrogen evolution reaction (HER) performance across different current density ranges, using designed platinum-coated nickel hydroxide on nickel foam (Pt@Ni(OH)₂-NF) electrodes. We reveal that with increasing current density, changes in interfacial water structure alter the rate-determining step of the HER. Pt@Ni(OH)₂-NF exhibited excellent performance in alkaline electrolytes, achieving 1000 mA cm^–2 at 114 mV overpotential. This study provides a novel approach to optimizing alkaline water electrolysis dynamics by enhancing mass transfer, further paving the way for more efficient and energy-saving hydrogen production.

Phase engineering offers a novel approach to modulate the properties of materials for versatile applications. Two-dimensional (2D) GaTe, an emerging III–VI semiconductor, can exist in hexagonal (h) or monoclinic (m) phases with fascinating phase-dependent properties (e.g., isotropic or anisotropic electrical transport). However, the key factors governing GaTe phases remain obscure. Herein, we achieve phase modulation of GaTe by tuning two previously overlooked factors: layer thickness and strain. The precise layer-controlled synthesis of GaTe from a monolayer (1L) to >10L is achieved via molecular beam epitaxy. A layer-dependent phase transition from h-GaTe (1–5L) to m-GaTe (>10L) is unambiguously unveiled by scanning tunneling microscopy/spectroscopy, driven by system energy minimization according to density functional theory calculations. Local phase transitions from ultrathin h-GaTe to m-GaTe are also obtained via introduced tensile strain. This work clarifies the factors influencing GaTe phases, providing valuable guidance for the phase engineering of other 2D materials toward the desired properties and applications.

The increasing demands for all-carbon-based flexible sensors in engineering have intensified research efforts toward multifunctional integration that responds to diverse stimuli. In this study, a three-dimensional (3D) reduced graphene oxide thermoelectric aerogel (rGOTEA) was created by a chemical agent-assisted bottom-up assembly with nanometer-thick rGO sheets as basic building units. Through bidirectional freeze-squeezing and reconstructing treatments, the hyperbolically patterned 3D rGOTEA exhibited lightweight density (≤5.4 mg cm^–3), superelastic deformation capability (recoverable strain ≥ 90%) and remarkable fatigue resistance. By quantitative regulation of oxygen-containing groups’ distribution and interfacial bonding conditions, the carrier transport and phonon scattering over the multilayered rGO sheets were decoupled to optimize rather than that of 3D graphene monoliths with intact crystal structures. Attributed to numerous graphitized domains and in-plane defects (e.g., dangling bonds and holes), the 3D rGOTEA exhibited high electrical conductivity (95.834 S m^–1) yet low thermal conductivity (0.028 W m^–1 K^–1). 3D rGOTEA demonstrated a programmable thermoelectric performance with a tunable Seebeck coefficient ranging from 6.9 to 19.5 μV/K. This tunability endowed the material with a heightened sensitivity for detecting fluctuations in external physical signals. As a result, the flexible rGOTEA device displayed multifunctional sensing responses to changes in thermal insulation, electrical conductivity, and mechanical deformation. Moreover, an rGOTEA-based thermal energy converter was assembled to deliver a maximum output of 600 μV under a temperature gradient of 2.4 K/mm. The versatility of the 3D rGOTEA suggested its promising applications as multifunctional sensors, thermal insulator, and energy harvestor.

Bromine and hydrogen play unusual roles as mobile atom and dissociation dynamics moderator, respectively, during roaming in the 3-bromo-4H-1,2,4-triazole anion. The present study of the reactivity of 3-bromo-1H-1,2,4-triazole and 3-bromo-4H-1,2,4-triazole with low-energy electrons reveals the effect of the hydrogen position on the reaction dynamics. We report energy-dependent ion yields for both molecules showing significant differences. Quantum chemical calculations reveal that heavy Br atom migration is energetically more favored than H atom migration in the case of the H atom adjacent to Br. This is enabled by the energetically favorable formation of a noncovalent complex of Br^– around the triazole ring. Recently, such complexes have been reported for several other biologically relevant molecules. In the present work, we demonstrate that the position of hydrogen on the ring influences the character of the lowest resonant state and, consequently, the Br^– roaming and dissociation dynamics, particularly the neutral release of hydrogen bromide.

Targeted delivery of therapeutic agents to malignant tissues is crucial for enhancing clinical outcomes and reducing side effects. Magnetic nanorobots (MNRs) present a promising strategy for controlled delivery, leveraging external magnetic fields to achieve precise in vivo targeting. This work develops elongated MNRs comprising linearly arranged magnetic nanoparticles linked by metal-polyphenol complexes (MPCs) for magnetic-field-directed active tumor targeting and synergistic tumor therapy. The MNRs are created by assembling 30 nm Fe₃O₄ nanoparticles, tannic acid, and ferrous ions (Fe²⁺) under a uniform magnetic field, resulting in elongated chain-like structures fixed by MPCs, which also promotes peroxidase-like activity. These structures show a greater magnetic response than individual nanoparticles, offering flexibility in magnetic manipulation. The MPCs coating allows tailored surface modifications with glucose oxidase, copper ions (Cu²⁺), and human serum albumin (HSA), producing colloidally stable MNRs with a built-in multienzymatic cascade (MNRs@GOx/Cu/HSA) that consumes glucose, generates ^•OH, and depletes the antioxidant glutathione (GSH). Collectively, surface-engineered multifunctional MNRs demonstrate improved in vivo tumor targeting driven by external magnetic fields, leading to efficient localized chemodynamic therapy. The tailored structural and functional properties of the developed MNRs render them suitable for targeted cargo delivery, minimally invasive surgery, and localized treatments in disease sites.

Different extraction methods of separating lignin from biomass have resulted in considerable differences in the structure, purity, and properties of the material, which may affect its utilization and valorization. Differences in the lignin molecular structure also affect morphology, including size and structural rearrangement. Furthermore, knowledge of lignin morphology can help us understand its interfacial interactions with other materials. This study investigates the molecular structure, physicochemical characteristics, and morphological features of lignin samples obtained using various extraction processes, including milled wood lignin (MWL), organosolv lignin (OSL), softwood kraft lignin (SKL), and hardwood kraft lignin (HKL). The results indicate notable variations in structural units, total hydroxyl groups, and physicochemical properties among the various lignin samples. In particular, the larger amounts of oxygenated aliphatic linkages and aliphatic OH groups of MWL, along with its lower numbers of C–H aromatic bonds and higher molecular weight (M_w) relative to the other types of lignin, result in a higher glass transition temperature (T_g), a smaller radius of gyration (R_g), and a higher fraction of T-shaped π–π stacking. Conversely, the fewer oxygenated aliphatic linkages, larger amounts of phenolic OH groups, and lower M_w of OSL result in a relatively lower T_g, higher R_g, and greater fraction of sandwich-like π–π stacking. These properties of OSL, along with its good purity, make it more accessible than the other lignins for interactions or reactions with other materials.

Due to the promising energy density (2800 Wh kg^–1) and high theoretical specific capacity (1675 mAh g^–1), there has been significant research interest in lithium–sulfur batteries (LSBs) recently. However, the shuttle effect and sluggish redox kinetics impede the commercial application of LSBs. In this work, a MoS₂@C interlayer-modified commercial polypropylene (PP) (MoS₂@C-PP) separator is designed to improve the electrochemical performance of LSBs. The active sites provided by MoS₂ are conducive to enhancing the absorption of polysulfide lithium and improving the electrochemical performance. The N-doped carbon not only facilitates electrolyte penetration but also enhances ion transfer to promote reaction kinetics. Additionally, the formation of C–S bonds significantly reduces the shuttle effect. These factors largely accelerate the redox kinetics and decrease the shuttle effect, thereby improving the electrochemical performance of LSBs. As a consequence, the LSB with the MoS₂@C-PP separator achieves a high discharge capacity of 860.5 mAh g^–1 at 0.5 C after 200 cycles and a superior rate performance of 711.5 mAh g^–1 at 2 C. This work offers a promising direction for enhancing the electrochemical performance of LSBs through separator modification .

This study probes the effectiveness of using a Ag/CeO₂–Al₂O₃ mixed metal oxide support compared to Ag-modified single supports (Ag/CeO₂ and Ag/Al₂O₃) on acetone removal under VUV irradiation at room temperature. It is shown that under VUV light, the type of support can affect acetone oxidation at the microscopic and macroscopic levels. At the microscopic level, the findings from X-ray photoemission spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) analyses showed that the nature of the support can influence the oxidation state of silver. At the macroscopic level, it was demonstrated that the support can control the dominance of the oxidation mechanism. While Ag/Al₂O₃, compared to Ag/CeO₂, can boost acetone and ozone conversion, the selectivity of Ag/Al₂O₃ (88%) was lower than that of Ag/CeO₂ (96%). However, not only can Ag/CeO₂–Al₂O₃ with an optimized 1:1 ratio of CeO₂/Al₂O₃ oxidize 96 and 98% of the inlet acetone and ozone, respectively, but also the reaction selectivity was above 97%. Moreover, the influence of relative humidity (RH) on Ag/CeO₂–Al₂O₃ activity under VUV light was investigated, and it proved the dual character of RH. Although RH improved the VUV photolysis performance in the gaseous state, it poisoned the gas–catalyst interface, leading to an inhibition role in the catalytic reactions. The high and sustainable performance of the Ag/CeO₂–Al₂O₃ catalyst at room temperature, achieved through engineering of the mixed metal oxide support and maintained even under humid conditions, offers a promising solution for indoor air quality control in diverse settings. These include residential, commercial, and industrial spaces and potential applications in reducing volatile organic compounds (VOCs) from automotive emissions.

Amine oxidases have strong capabilities for the degradation of biogenic amines (BAs) in fermented foods. However, their application is limited by substrate specificity, and high concentrations of ethanol and salt can hinder their effectiveness. This study presents a novel approach utilizing comparative genomics, protein clustering analysis, and full homology modeling to identify three amine oxidases: KCYOBN from the salt-resistant Bacillus subtilis, and LYYOBN1 and LYYOBN2 from the ethanol-resistant Bacillus cereus. These enzymes are highly similar in structure and exhibit broad substrate specificities. KCYOBN maintains over 84% relative activity at 20% (w/v) NaCl, while LYYOBN1 and LYYOBN2 retain over 32 and 21% relative activity at 25% vol ethanol. Variations in key residues are one of the reasons for the differences in tolerance. In fermented foods, KCYOBN degraded 45.97% of the total BAs in cooking wine and 38.33% in fish sauce. LYYOBN1 achieved the highest degradation rate of 32.93% in huangjiu. LYYOBN2 exhibited degradation rates of 30.00% in soy sauce and 35.14% in wine with no significant impact on flavor compounds. The significance of this work lies in the identification of the novel salt-resistant KCYOBN and ethanol-resistant LYYOBN1 and LYYOBN2 through this new method, which can simultaneously degrade multiple BAs and have a broad application potential.

Capacitors, renowned for their high power and energy density attributed to their rapid discharge capabilities, hold significant promise as energy storage devices. While capacitors with various junctions have been the subject of extensive research, there remains a significant knowledge gap concerning the fundamental photoelectron dynamics within metal–semiconductor (MS) junction capacitance, which is crucial for the development of photodevices. Here, we demonstrate the effects of localized surface plasmon resonance (LSPR) on the capacitance behavior of Au/TiO₂ Schottky diodes, one of the MS junction diode systems. We have confirmed that the plasmonic Au/TiO₂ shows substantial photoresponsiveness, with an increase in net total capacitance under stronger plasmonic effects, as confirmed by wavelength- and power-dependent studies. To enhance our understanding of the electron transfer process occurring at the MS junction, we expand our investigation of capacitance within a catalytic reaction environment, specifically focusing on Pt/TiO₂ Schottky diodes. We show the catalytic environment changes capacitance values of the Pt/TiO₂, and more active catalytic reactions decrease net total capacitance due to catalytic electrons interfering with diffusion electrons. The LSPR effect and catalytic reaction significantly impact the net total capacitance with a predominant contribution associated with hot electrons, catalytic electrons, and diffusion effects. These findings provide valuable insights for designing and optimizing efficient optical and catalytic devices across diverse applications.