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Laser Induced Periodic Surface Structure Enhances Neuroelectrode Charge Transfer Capabilities and Modulates Astrocyte Function
摘要： The brain machine interface (BMI) describes a group of technologies capable of communicating with excitable nervous tissue within the central nervous system (CNS). BMI’s have seen major advances in recent years but these advances have been impeded due to a temporal deterioration in the signal to noise ratio of recording electrodes following insertion into the CNS. This deterioration has been attributed to an intrinsic host tissue response, namely reactive gliosis which involves a complex series of immune mediators resulting in implant encapsulation via the synthesis of pro-inflammatory signaling molecules and the recruitment of glial cells. There is a clinical need to reduce tissue encapsulation in situ and improve long-term neuroelectrode functionality. Physical modification of the electrode surface at the nanoscale could satisfy these requirements by integrating electrochemical and topographical signals to modulate neural cell behavior. In this study, commercially available platinum iridium (Pt/Ir) microelectrode probes were nanotopographically (NT) functionalized using femto/picosecond laser processing to generate laser induced periodic surface structures (LIPSS). Three different topographies and their physical properties were assessed by scanning electron microscopy and atomic force microscopy. The electrochemical properties of these interfaces were investigated using electrochemical impedance spectroscopy and cyclic voltammetry. The in vitro response of mixed cortical cultures (embryonic rat E14/E17), was subsequently assessed by confocal microscopy, ELISA and multiplex protein array analysis. Overall LIPSS features improved the electrochemical properties of the electrodes, promoted cell alignment and modulated the expression of multiple ion channels involved in key neuronal functions.
关键词： astrogliosis,electrochemical impedance,platinum/iridium,neuroelectrode,cell alignment,LIPSS
更新于2025-09-16 10:30:52
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Cation-controlled luminescence behavior of anionic cyclometalated platinum(II) complexes
摘要： The characteristic luminescence properties of anionic cyclometalated Pt(II) complexes are discussed from the viewpoint of the counter cations. To date, various cyclometalated Pt(II) complexes have been developed as promising luminescent materials because cyclometalating ligands provide stable and strong ligand fields. In addition to the molecular design of cyclometalated Pt(II) complexes, control of the intermolecular interactions is particularly important for Pt(II) complexes with square-planar geometry. In this context, we focus on the effects of counter cations on anionic cyclometalated Pt(II) complexes by classifying such complexes into three categories, i.e., (i) systems with bulky organic cations, which enable the formation of isolated Pt(II) complexes, (ii) systems with non-innocent cations, which interact with anionic Pt(II) complexes through dative bonds or charge transfer, and (iii) systems including adaptable cations, which support the assembly of the Pt(II) complexes by cancelling out the electrostatic repulsion between Pt(II) complex anions that form stacking structures with Pt···Pt interactions. For this category, the formation and properties of ionic liquids using asymmetric cations is discussed.
关键词： Luminescence,Chromic behavior,Cation-controlled anionic complex,Intermolecular interaction,Cyclometalated platinum(II) complex
更新于2025-09-16 10:30:52
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Ultrafast Elemental Mapping of Platinum Group Elements and Mineral Identification in Platinum-Palladium Ore Using Laser Induced Breakdown Spectroscopy
摘要： This paper demonstrates the capability of performing an ultrafast chemical mapping of drill cores collected from a platinum/palladium mine using laser‐induced breakdown spectroscopy (LIBS). A scan of 40 mm × 30 mm was performed, using a commercial LIBS analyzer, onto the flat surface of a drill core with a scanning speed of 1000 Hz, and a spatial resolution of 50 μm, in about 8 min. Maps of the scanned areas for seven chemical elements (platinum, palladium, nickel, copper, iron, silicon, and magnesium), as well as a single map including the seven elements altogether, were then generated using the proprietary software integrated into the LIBS analyzer. Based on the latter image, seven minerals were identified using the principal component analysis (PCA) and correlations with the elemental maps.
关键词： laser induced breakdown spectroscopy (LIBS),mineral identification,platinum‐group elements (PGE),principal component analysis (PCA),scanning speed at 1000 Hz
更新于2025-09-16 10:30:52
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Platinum leaf counter electrodes for dye-sensitized solar cells
摘要： In this study, a platinum (Pt) leaf was introduced as a counter electrode (CE) with thickness of 100 nm in dye-sensitized solar cells (DSCs). Fundamental characteristics were investigated and compared with Pt leaf, Pt plate, and sputtered-Pt as the CEs. The power conversion efficiencies of DSCs with a Pt leaf as the CEs were as high as 4.78%, which is higher to those of DSCs with Pt plate and sputtered-Pt as the CEs (4.11% and 4.40%, respectively). In contrast to other CEs, Pt leaf features a large surface area. This implies that Pt leaf serves as an active CE and can be a good candidate for DSCs.
关键词： dye-sensitized solar cells,platinum leaf,power conversion efficiency,counter electrode
更新于2025-09-16 10:30:52
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Rational Design of Axially Chiral Platinabinaphthalenes with Aggregation-Induced Emission for Red Circularly Polarized Phosphorescent Organic Light-Emitting Diodes
摘要： Circly polarized luminescent (CPL) materials have received great interest due to their potential applications in next-generation displays. However, the development of easily accessible red circularly polarized phosphorescent emitters for practical organic light-emitting diodes fabrication remains a grand challenge. In this paper, we report a new family of CPL-active platinum complexes based on the binaphthalene chiral platform. These axially chiral platinabinaphthalenes were facile synthesized by directly incorporating platinum(II) into the π-conjugated backbone of commercially available enantiopure binaphthalene derivate. These complexes exhibit aggregation-induced circularly polarized phosphorescence enhancement with high quantum yields up to 66% and luminescence dissymmetry factors around 2.6×10?3. Moreover, solution-processable circularly polarized organic light-emitting diodes (CPOLEDs) using these complexes as emitters show good performance with the maximum luminance up to 3500 cd m2 and dissymmetry factor values around 1.0×10?3. These findings by rational design of axially chiral platinabinaphthalenes are important for the development of high-performance CPL complexes for CPOLEDs.
关键词： circularly polarized luminescence,binaphthalene,organic light-emitting diode,platinum complex,aggregation-induced emission
更新于2025-09-16 10:30:52
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Enhanced Visible Light Photodegradation of Microplastic Fragments with Plasmonic Platinum/Zinc Oxide Nanorod Photocatalysts
摘要： Microplastics are persistent anthropogenic pollutants which have become a global concern owing to their widespread existence and unfamiliar threats to the environment and living organisms. This study demonstrates the degradation of fragmented microplastics particularly low-density polyethylene (LDPE) film in water, through visible light-induced plasmonic photocatalysts comprising of platinum nanoparticles deposited on zinc oxide (ZnO) nanorods (ZnO-Pt). The ZnO-Pt nanocomposite photocatalysts were observed to have better degradation kinetics for a model organic dye (methylene blue) compared to bare ZnO nanorods, attributed to the plasmonic effects leading to better interfacial exciton separation and improved hydroxyl radical activity along with a 78% increase in visible light absorption. These demonstrations of the plasmonically enhanced photocatalyst enabled it to effectively degrade microplastic fragments as confirmed following the changes in carbonyl and vinyl indices in infrared absorption. In addition, visual proof of physical surface damage of the LDPE film establishes the efficacy of using plasmonically enhanced nanocomposite photocatalytic materials to tackle the microplastic menace using just sunlight for a clean and green approach towards mitigation of microplastics in the ecosystem.
关键词： microplastics,platinum nanoparticle,ZnO nanorod,LDPE film,visible light photodegradation,nanocomposite
更新于2025-09-16 10:30:52
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Pt Nanoclusters Sandwiched between Hexagonal Boron Nitride and Nanographene as van der Waals Heterostructures for Optoelectronics
摘要： We report on the formation of nanoscopic heterostructures composed of the semimetal graphene, the metal platinum, and the insulator hexagonal boron nitride (h-BN). Both graphene and h-BN are chemically inert 2D materials with similar geometric but different electronic properties. Between these materials, a Pt nanoparticle array was encapsulated. Thereby, the h-BN/Rh(111) nanomesh served as a template for a well-ordered array of Pt nanoclusters, which were overgrown with graphene, forming single nano-heterostructures. We investigated this process in situ by high-resolution, synchrotron radiation-based XPS, and NEXFAS. The nanographene layers proofed tight against CO under the tested conditions. These nano-heterostructures could find a possible application in optoelectronics or as data storage material. At the same time, our approach represents a new route for the synthesis of nanographene.
关键词： nanoclusters,optoelectronics,hexagonal boron nitride,nanographene,data storage,graphene,platinum
更新于2025-09-12 10:27:22
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Size-Controlled Synthesis of Pt Particles on TiO2 Surface: Physicochemical Characteristic and Photocatalytic Activity
摘要： Different TiO2 photocatalysts, i.e., commercial samples (ST‐01 and P25 with minority of rutile phase), nanotubes, well‐crystallized faceted particles of decahedral shape and mesoporous spheres, were used as supports for deposition of Pt nanoparticles (NPs). Size‐controlled Pt NPs embedded in TiO2 were successfully prepared by microemulsion and wet‐impregnation methods. Obtained photocatalysts were characterized using XRD, TEM, X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) specific surface area, DR/UV‐vis and action spectrum analysis. The effect of deposition method, amount of Pt precursor and TiO2 properties on size, distribution, and chemical states of deposited Pt NPs were investigated. Finally, the correlations between the physicochemical properties and photocatalytic activities in oxidation and reduction reactions under UV and Vis light of different Pt‐TiO2 photocatalysts were discussed. It was found that, regardless of preparation method, the photoactivity mainly depended on platinum and TiO2 morphology. In view of this, we claim that the tight control of NPs’ morphology allows us to design highly active materials with enhanced photocatalytic performance. Action spectrum analysis for the most active Pt‐modified TiO2 sample showed that visible light‐induced phenol oxidation is initiated by excitation of platinum surface plasmon, and photocatalytic activity analysis revealed that photoactivity depended strongly on morphology of the obtained Pt‐modified TiO2 photocatalysts.
关键词： titania morphology,microemulsion,platinum size,Pt‐TiO2,TiO2 particle size,heterogeneous photocatalysis
更新于2025-09-12 10:27:22
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Influence of Semiconductor Morphology on Photocatalytic Activity of Plasmonic Photocatalysts: Titanate Nanowires and Octahedral Anatase Nanoparticles
摘要： Octahedral anatase particles (OAP) with eight exposed and thermodynamically most stable (101) facets were prepared by an ultrasonication-hydrothermal (US-HT) reaction from potassium titanate nanowires (TNW). The precursor (TNW) and the product (OAP) of US-HT reaction were modi?ed with nanoparticles of noble metals (Au, Ag or Pt) by photodeposition. Samples were characterized by X-ray di?raction (XRD), X-ray photoelectron spectroscopy (XPS), di?use re?ectance spectroscopy (DRS), scanning transmission electron microscopy (STEM) and time-resolved microwave conductivity (TRMC). The photocatalytic activity was investigated in three reaction systems, i.e., anaerobic dehydrogenation of methanol and oxidative decomposition of acetic acid under UV/vis irradiation, and oxidation of 2-propanol under vis irradiation. It was found that hydrogen liberation correlated with work function of metals, and thus the most active were platinum-modi?ed samples. Photocatalytic activities of bare and modi?ed OAP samples were much higher than those of TNW samples, probably due to anatase presence, higher crystallinity and electron mobility in faceted NPs. Interestingly, noble metals showed di?erent in?uence on the activity depending on the semiconductor support, i.e., gold-modi?ed TNW and platinum-modi?ed OAP exhibited the highest activity for acetic acid decomposition, whereas silver- and gold-modi?ed samples were the most active under vis irradiation, respectively. It is proposed that the form of noble metal (metallic vs. oxidized) as well as the morphology (well-organized vs. uncontrolled) have a critical e?ect on the overall photocatalytic performance. TRMC analysis con?rmed that fast electron transfer to noble metal is a key factor for UV activity. It is proposed that the e?ciency of plasmonic photocatalysis (under vis irradiation) depends on the oxidation form of metal (zero-valent preferable), photoabsorption properties (broad localized surface plasmon resonance (LSPR)), kind of metal (silver) and counteraction of “hot” electrons back transfer to noble metal NPs (by controlled morphology and high crystallinity).
关键词： silver,platinum,gold,photocatalyst morphology,faceted titania,morphology-governed activity,plasmonic photocatalysis,octahedral particle,titanate nanowire,noble metal
更新于2025-09-11 14:15:04
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Challenges arising from the use of TiO2/rGO/Pt photocatalysts to produce hydrogen from crude glycerol compared to synthetic glycerol
摘要： Photoreforming has emerged as a novel technology expected to obtain chemical energy through solar energy transformation. In this way, sustainable valorization of glycerol, a biodiesel by-product, to clean fuels is a promising alternative to help meet the world's growing energy demand. In this work, TiO2/rGO(x)/Pt(y) photocatalysts have been developed for hydrogen production from synthetic and crude glycerol solutions. The effect of several key operating parameters (including vol% of glycerol, pH, catalyst loading, wt% of GO, wt% of Pt, temperature, and light source) on hydrogen production rate has been studied. The results indicated different optimal operating parameters depending on glycerol origin, achieving up to 70.8 and 12.7 mmol h?1 g?1 of hydrogen using synthetic glycerol and crude glycerol, respectively. Additionally, GO nanosheets and Pt nanoparticles strongly influenced the hydrogen production rate but not the overall reaction mechanism. Impurities contented in crude glycerol are key factors in developing realistic hydrogen production processes.
关键词： Platinum,Graphene,Hydrogen production,Photoreforming,TiO2,Crude glycerol
更新于2025-09-11 14:15:04