Advanced Materials Interfaces最新文献

The contamination of soil and water by heavy metals poses a significant environmental and public health concern worldwide. To address this issue, a novel graphene quantum dot (GQD)-based surface plasmon resonance (SPR) sensor is developed for the detection of mercury ions (Hg²⁺), a notorious heavy metal pollutant. The thiol and amine-functionalized GQDs (S,N-GQDs), synthesized via pyrolysis of citric acid and L-cysteine, are directly immobilized onto the SPR chip surface without prior pretreatment, demonstrating their potential as efficient sensing materials. The SPR sensor exhibits high sensitivity and selectivity toward Hg²⁺ ions, as confirmed by kinetic binding analysis and isotherm modeling. The Langmuir isotherm model, which accurately describes the interactions between Hg²⁺ and S,N-GQDs, provides insights into the sensor's mechanism of action. Furthermore, the sensor demonstrates robustness and reusability, with recoveries ranging from 98% to 104% over multiple cycles of analysis. Given the presence of contaminants in tap water, the developed sensor system holds significant importance for environmental monitoring and public health protection, offering a rapid, accurate, and cost-effective solution for detecting Hg²⁺ ions in such samples. Overall, this study represents a significant advancement in the field of heavy metal detection, with potential implications for addressing environmental pollution and ensuring water quality.

All-solid-state polymer dielectrics benefit from a superior voltage window and conveniently circumvent fire hazards associated with liquid electrolytes. Nevertheless, their future competitiveness with alternative energy storage technologies requires a significant enhancement in their energy density. The addition of conductive 2D MXene particles is a promising strategy for creating percolation-based nanodielectrics with improved dielectric response. However, a full understanding of the nanodielectric production – microstructure – dielectric performance correlations is crucial. Therefore, this research considered Ti₃AlC₂ MAX phase and Ti₃C₂T_z MXene as electrically conductive ceramic fillers in polyvinylidene fluoride (PVDF). Microstructural characterization of both nanodielectrics demonstrated excellent filler dispersion. Additionally, the exfoliation of Ti₃AlC₂ brought forth extensive alignment and interface accessibility, synergistically activating a pronounced interfacial polarization and nanocapacitor mechanism that enhanced the energy density of PVDF by a factor 100 to 3.1 Wh kg⁻¹@0.1 Hz at 22.9 vol% MXene filler. The stellar increase in the PVDF energy density occurred for a broad MXene filler loading range owing to the unique 2D morphology of MXenes, whereas the addition of Ti₃AlC₂ fillers only caused a detrimental reduction. Hence, this study buttressed the importance to exfoliate the parental MAX phase into multi-layered MXene as a decisive strategy for boosting nanodielectric performance.

Infection-induced bone defects present significant challenges in clinical bone regeneration, frequently leading to poor bone induction, recurring infections, and complications such as pain and chronic inflammation. This study introduces a novel Ti/Lignin-Ag@PLL composite coating with a “sandwich” structure, designed to integrate pro-adhesion, photothermal-photodynamic antibacterial, and osteogenic properties. The Ti/Lignin-Ag@PLL composite coating is fabricated using self-assembly technology, in which Ag⁺ is reduced to silver nanoparticles (Ag-NPs) by lignin, followed by Polylysine (PLL) grafting. Photothermal conversion efficiency is evaluated under near-infrared (NIR) laser irradiation, while antibacterial activity is tested against E. coli and S. aureus. Biocompatibility is also assessed using vascular endothelial cells (VECs) and osteoblasts (OBs). The results indicate that the Ti/Lignin-Ag@PLL coating demonstrates a 31% photothermal conversion efficiency and nearly 100% antibacterial efficacy against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under NIR irradiation for 10 min. Without irradiation, the antibacterial rates are 85% and 94%, respectively, after 24 h. Additionally, the coating significantly promotes cell adhesion, proliferation, and osteogenesis, as evidenced by the upregulation of Runx2 and Collagen I. This study uniquely contributes to the development of a multifunctional composite coating that effectively combines robust antibacterial properties with enhanced osteogenic potential, offering a promising solution for bone tissue repair and infection prevention.

Thermal atomic layer deposition (ALD) of cerium oxide using commercial Ce(thd)₄ precursor and O₃ on SiO₂ substrates is studied employing in-situ X-ray photoelectron spectroscopy (XPS). The system presents a complex growth behavior determined by the change in the reaction mechanism when the precursor interacts with the substrate or the cerium oxide surface. During the first growth stage, non-ALD side reactions promoted by the substrate affect the growth per cycle, the amount of carbon residue on the surface, and the oxidation degree of cerium oxide. On the contrary, the second growth stage is characterized by a constant growth per cycle in good agreement with the literature, low carbon residues, and almost fully oxidized cerium oxide films. This distinction between two growth regimes is not unique to the CeO_x/SiO₂ system but can be generalized to other metal oxide substrates. Furthermore, the film growth deviates from the ideal layer-by-layer mode, forming micrometric inhomogeneous and defective flakes that eventually coalesce for deposit thicknesses above 10 nm. The ALD-cerium oxide films present less order and a higher density of defects than films grown by physical vapor deposition techniques, likely affecting their reactivity in oxidizing and reducing conditions.

Enhancing the performance of thermoelectric materials remains critical for practical applications. Increasing the power factor and reducing the thermal conductivity are key strategies for improving the thermoelectric performance. Doping, incorporating secondary phases, and generating dislocations can be used to introduce defects and grain boundaries to improve the thermoelectric performance. The application of an ultrathin film as a coating on thermoelectric materials via atomic layer deposition (ALD) has recently attracted attention as a novel approach to enhance the performance. The excellent conformality of ALD enables the conformal deposition of ultrathin films on powder to enable the interfacial properties to be meticulously controlled even after sintering. Using ALD to deposit an ultrathin layer on the thermoelectric powder matrix induces various defects through the interactions of the coating material with the thermoelectric matrix, which provide exquisite control over the material properties. This review discusses the phenomena induced by applying ultrathin coatings to thermoelectric materials through ALD, elucidates the underlying mechanisms, and examines the effects on the thermoelectric performance. Based on these insights, innovative pathways for applying ALD to thermoelectric materials are proposed, and robust strategies for enhancing these properties through the precise modulation of diverse defects and interfaces are discussed.

The explosion of artificial intelligence, the possible end of Moore's law, dawn of quantum computing, and the continued exponential growth of data communications traffic have brought new urgency to the need for laser integration on the diversified Si platform. While diode lasers on group III-V platforms have long-powered internet data communications and other optoelectronic technologies, direct integration with Si remains problematic. A paradigm-shifting solution requires exploring new and unconventional materials and integration approaches. In this work, it is shown that a sub-10-nm ultra-thin Si_1−xGe_x buffer layer fabricated by an oxidative solid-phase epitaxy process can facilitate extraordinarily efficient strain relaxation. The Si_1−xGe_x layer is formed by ion implanting Ge into Si(111) and selectively oxidizing Si atoms in the resulting ion-damaged layer, precipitating a fully strain-relaxed Ge-rich layer between the Si substrate and surface oxide. The efficient strain relaxation results from the high oxidation temperature, producing a periodic network of dislocations at the substrate interface, coinciding with modulations of the Ge content in the Si_1−xGe_x layer and indicating the presence of defect-mediated diffusion of Si through the layer. The epitaxial growth of high-quality GaAs is demonstrated on this ultra-thin Si_1−xGe_x layer, demonstrating a promising new pathway for integrating III-V lasers directly on the Si platform.

Optically addressable light valves (OALVs) are specialized optical components utilized for spatial beam shaping in various laser-based applications, including optics damage mitigation, and enhanced functionality in diode-based additive manufacturing requiring high intensities. Current state-of-the-art OALVs employ photoconductors such as Bismuth Silicon Oxide (BSO) or Bismuth Germanium Oxide (BGO), which suffer from limited laser-induced damage thresholds (LiDT) and inadequate thermal conductivities, thus restricting their use in high peak and average power applications. Aluminum nitride (AlN), an emerging ultra-wide band gap (UWBG) III–V semiconductor, offers promising optoelectronic properties and superior thermal conductivity (>300 Wm⁻¹K⁻¹ at 298° K, compared to BSO's 3.29 Wm⁻¹K⁻¹). In this study, the first AlN-based OALVs are designed, fabricated, and experimentally demonstrated using commercially available single-crystal AlN substrates. These AlN-based OALVs have shown clear superiority over BSO and BGO-based devices. Design considerations for OALVs incorporating UWBG photoconductors are discussed, and the photoresponsivity from defect-mediated sub-bandgap absorption in AlN crystals is verified as sufficient for OALVs operating under high light fluences. The optimum driving voltage for the AlN-based OALV is determined to be ≈ 45 V_pp at 100 Hz, achieving a transmittance of 91.3%, an extinction ratio (ER) of more than 100, and a 51:1 image contrast.

One of the key parameters of an artificial biosensor is a high signal-to-noise ratio. This is achieved by limiting non-specific interactions while simultaneously maximizing the targeted specific interaction. Here, it is combined non-fouling characteristics of poly(2-methyl-2-oxazoline) (PMOXA) coatings with an abundance of azide groups to create a multi-azide containing poly(2-methyl-2-oxazoline-co-2-(3-azidopropyl)-2-oxazoline) (PMCA) that can participate in bioorthogonal strain-promoted azide-alkyne cycloaddition (SPAAC) for functionalization. This functional polymer is made surface-active using the PAcrAm™ technology to obtain well-defined spontaneously adsorbed monolayers on gold surfaces. The resistance to non-specific interactions is tested against full human serum (HS), analyzed via variable angle spectroscopic ellipsometry (VASE), and compared to equivalent coatings based on PMOXA and azido-poly(ethylene glycol) (PEG-N₃). The specific interactions are investigated via VASE and quartz crystal microbalance with dissipation (QCM-D) by immobilization of dibenzocyclooctyne-PEG4-biotin conjugate (DBCO-biotin) and streptavidin. The new PMCA-based coating shows superior resistance to non-specific protein adhesion than equivalent coatings based on commercially available PEG-N₃ and significantly increases capacity for SPAAC. A proof of principle assay (biotin-streptavidin/biotin-BSA/anti-BSA) shows improved binding for the new PMCA polymer compared with single azide PEG.

Atomic Layer Processing (ALP) techniques have transformed materials engineering by enabling atomic/molecular-level control over composition, fidelity in structure replication, and properties. Tracing its origins to pioneering molecular layering and atomic layer deposition work in the mid-20th century, this multifaceted field has remarkably diversified to include molecular layer deposition (MLD), atomic layer etching (ALE), area-selective deposition (ASD), and vapor-phase infiltration (VPI) processes. ALP is making great impacts across diverse disciplines – facilitating semiconductor miniaturization through ultrathin dielectric films, improving battery materials and engineering catalysts for energy applications, creating bioactive surfaces for advanced biomaterials, and promoting sustainable membranes for environmental remediation. As ALP techniques continue evolving through integration with additive manufacturing, machine learning, and in situ diagnostics, new frontiers in materials design are emerging, driven by the growing focus on environmental considerations like renewable precursors, energy-efficient processes, and waste minimization. This perspective article examines ALP's historical development, highlights current state-of-the-art applications across selected fields, and provides insights into the anticipated future trajectory, emerging application domains, and the pivotal role of academic-industry-research laboratory collaborations in catalyzing ALP innovations and facilitating its widespread adoption as a transformative manufacturing platform.