Ultraviolet Photoelectron Spectroscopy Research Articles

Na0.6Co3O4- La/Pr co-Doped Ceria as Semiconductor-Ionic Heterostructure Material for Fuel Cell Application

Functional Sodium-doped cobalt oxide (Na0.6Co3O4, NCO) was incorporated to regulate and improve the electrochemical performance of La/Pr co-doped ceria (LCP) electrolytic materials with good operative stability, forming an p-n heterostructure electrolyte (LCP-NCO) for low-temperature solid oxide fuel cell (LTSOFC) application. LCP-NCO is a new potential semiconductor-ionic material, achieving a maximum power density of 1075 mW cm−2 along with a high open-circuit voltage of 1.061 V at 520 °C. Scanning electron microscopy combined with transmission electron microscopy unveiled the crystallographic microstructure of heterostructure interface between LCP and NCO. Raman spectra and Fourier transform infrared spectroscopy spectra were analyzed to distinguish the functional groups and the vibrational properties. Ultraviolet–visible absorption and ultraviolet photoelectron spectroscopy have determined the accurate band edge positions of LCP and NCO and p-n heterojunction nature. Built-in electric field in semiconductor heterostructure and more oxygen vacancies created through the variation of Co3+/Co2+ ratio in LCP-NCO during the fuel cell test, contributed to the enhanced ionic transport. Characteristic of competent conductivity of 0.26–0.42 S cm−1 at 400 °C–520 °C, and the improved cell duration, revealed that the LCP-NCO as a hybrid oxygen ion and protonic conductor would be a potential electrolyte for LTSOFC.

High‐Performance of Self‐Powered UV–Visible CdS (PVP)/PbI2 Heterojunction Photodetector

Herein, the Polyvinyl pyrrolidone (PVP)‐assisted CdS/PbI2 heterojunction UV–visible photodetector is constructed by the sol–gel spin coating method. The X‐ray diffraction, scanning electron microscopy, and energy dispersive spectrometer demonstrate the synthesis and successful complexation of PVP, CdS, and PbI2. The UV–visible absorption spectroscopy and UV photoelectron spectroscopy measurements of CdS and PbI2 are carried out to prove that the CdS and PbI2 form a type II heterojunction. Compared with pure CdS film photodetector, the CdS (PVP)/PbI2 heterojunction photodetector has self‐powered characteristics, and exhibits excellent photoconductivity in the UV–visible with higher switching ratios, detection rates, and faster response times of 1.1 × 105, 9.77 × 1011 Jones, and 20 ms, respectively, which has great potential in the field of UV–visible self‐powered photodetector.

Moderately Reconstructed Ternary Metal Nitride Nanoparticles for Highly Efficient and Robust Freshwater and Seawater Oxidation under Industrial Current Density

Transition metal nitrides (TMNs) electrocatalysts experience rapid performance degradation during oxygen evolution reaction (OER) due to severe and irreversible electrochemical reconstruction, impeding their practical application in electrochemical water splitting. To address this issue, ternary metal (Ni, Fe, Cr) nitride nanoparticles on spongy nitrogen‐doped disordered carbon skeleton electrocatalyst (NFCN/C) is synthesized using a novel one‐pot pyrolysis of eutectic mixture method. The ionomer‐free NFCN/C electrode, which undergoes moderate electrochemical reconstruction, demonstrates high OER performance in both alkaline freshwater and seawater solutions, achieving a current density of 250 mA cm−2 with low overpotentials of 349 and 364 mV, respectively. The NFCN/C anode with Pt/C cathode delivers 10 mA cm−2 at a low cell voltage of 1.49 V and exhibits long‐term durability of 450 h at 500 mA cm−2. In situ Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS), along with pre‐ and post‐characterizations, elucidate that both high electrocatalytic activity and robustness of NFCN/C for OER stem from the proposed intrinsic strategy integrating physical and electronic structures. This work paves the way for designing highly efficient and robust TMNs electrocatalysts with moderate electrochemical reconstruction for industrial freshwater and seawater electrolysis.

Fabrication of soy protein nanoparticles based on metal-phenolic networks for stabilization of nano-emulsions delivery system

The use of soy protein isolate (SPI) nanoparticles as a stabilizer in nano-emulsion systems has garnered significant interest. While metal-phenolic networks (MPNs) have been explored for their multifunctional surface modification capabilities, their integration with food protein-based delivery systems remains less explored. In this study, we attempt to develop a novel strategy to encapsulate cinnamaldehyde using MPNs (EGCG-Fe3+) with self-assembling soy protein nanoparticles (SE-Fe NPs) as a stabilizer for nano-emulsions. UV, Raman, and X-ray photoelectron spectroscopy analyses demonstrated that SE-Fe NPs were generated through metal-phenolic coordination and covalent interactions. SE-Fe NPs had a narrower particle size distribution and enhanced radical scavenging (up to 3.35-fold), as well as thermal stability. Furthermore, the smaller droplet size, higher modulus, higher cinnamaldehyde encapsulation efficiency (from 63.5% to 84.2%), and improved bio-accessibility of SE-Fe NPs stabilized nano-emulsions delivery system demonstrated in this study shows promising future applications in the food industry.

Enhanced visible light photocatalytic degradation of dyes by the oxygen-rich vacancy-assisted S-scheme heterojunction Al2O3/BiOBr: Catalytic mechanism and performance evaluation

A heterojunction Al2O3/BiOBr composite photocatalyst, characterized by an S-scheme structure and enriched with oxygen vacancies, was synthesized through a solvothermal reaction coupled with an in situ growth approach. Oxygen vacancies on the catalyst surface, enhanced by the robust coupling between Al2O3 and BiOBr, were corroborated by X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). Techniques such as UV–vis diffuse reflectance spectroscopy (DRS), UV photoelectron spectroscopy (UPS), Mott–Schottky characterization, and experimental radical trapping experiments collectively validated the pathways for migrating photogenerated carriers. The interplay between the surface oxygen vacancies and the S-scheme Al2O3/BiOBr heterojunction, which possesses potent redox capabilities, significantly improved the photocatalytic degradation. This enhancement was particularly evident in the outstanding visible photocatalytic degradation performance against rhodamine B (RhB), methyl orange (MO), and basic fuchsin (BF). The synthesized composite photocatalysts demonstrated 92% retention of degradation efficiency after five recycling cycles, indicating their considerable stability.

Utilizing Constant Energy Difference between sp-Peak and C 1s Core Level in Photoelectron Spectra for Unambiguous Identification and Quantification of Diamond Phase in Nanodiamonds.

The modification of nanodiamond (ND) surfaces has significant applications in sensing devices, drug delivery, bioimaging, and tissue engineering. Precise control of the diamond phase composition and bond configurations during ND processing and surface finalization is crucial. In this study, we conducted a comparative analysis of the graphitization process in various types of hydrogenated NDs, considering differences in ND size and quality. We prepared three types of hydrogenated NDs: high-pressure high-temperature NDs (HPHT ND-H; 0-30 nm), conventional detonation nanodiamonds (DND-H; ~5 nm), and size- and nitrogen-reduced hydrogenated nanodiamonds (snr-DND-H; 2-3 nm). The samples underwent annealing in an ultra-high vacuum and sputtering by Ar cluster ion beam (ArCIB). Samples were investigated by in situ X-ray photoelectron spectroscopy (XPS), in situ ultraviolet photoelectron spectroscopy (UPS), and Raman spectroscopy (RS). Our investigation revealed that the graphitization temperature of NDs ranges from 600 °C to 700 °C and depends on the size and crystallinity of the NDs. Smaller DND particles with a high density of defects exhibit a lower graphitization temperature. We revealed a constant energy difference of 271.3 eV between the sp-peak in the valence band spectra (at around 13.7 eV) and the sp3 component in the C 1s core level spectra (at 285.0 eV). The identification of this energy difference helps in calibrating charge shifts and serves the unambiguous identification of the sp3 bond contribution in the C 1s spectra obtained from ND samples. Results were validated through reference measurements on hydrogenated single crystal C(111)-H and highly-ordered pyrolytic graphite (HOPG).

Bismuth-Based Perovskite Derivates with Thermal Voltage Exceeding 40 mV/K.

Heat is an inexhaustible source of energy, and it can be exploited by thermoelectronics to produce electrical power or electrical responses. The search for a low-cost thermoelectric material that could achieve high efficiencies and can also be straightforwardly scalable has turned significant attention to the halide perovskite family. Here, we report the thermal voltage response of bismuth-based perovskite derivates and suggest a path to increase the electrical conductivity by applying chalcogenide doping. The films were produced by drop-casting or spin coating, and sulfur was introduced in the precursor solution using bismuth triethylxanthate. The physical-chemical analysis confirms the substitution. The sulfur introduction caused resistivity reduction by 2 orders of magnitude, and the thermal voltage exceeded 40 mV K-1 near 300 K in doped and undoped bismuth-based perovskite derivates. X-ray diffraction, Raman spectroscopy, and grazing-incidence wide-angle X-ray scattering were employed to confirm the structure. X-ray photoelectron spectroscopy, elemental analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were employed to study the composition and morphology of the produced thin films. UV-visible absorbance, photoluminescence, inverse photoemission, and ultraviolet photoelectron spectroscopies have been used to investigate the energy band gap.

High–Quality and Stable Quasi‐2D Perovskite Film Prepared by Introducing Alkali Metal Ion Additive

AbstractDue to the excellent stability, researchers have shown great interest in quasi two–dimensional (2D) perovskite in recent years. However, the poor film quality and low photoelectric conversion efficiency (PCE) of 2D perovskite solar cells are still a major issue that restricts them from catching up with three–dimensional (3D) perovskite. Herein, we introduce sodium iodide as an additive to improve the surface coverage of 2D perovskite ((BA)2(MA)3Pb4I13) films and reduce the number of grain boundaries. Steady–state photoluminescence (PL) and ultraviolet photoelectron spectroscopy (UPS) indicate that non–radiative defects are suppressed and the band alignment is regulated. After modified by NaI, the film surface coverage enhances and the number of holes decreases. As a result, the PCE of device with NaI increases from 13.63 % to 16.40 % at optimal concentration, and the hysteresis effect is also suppressed. Besides, the humidity and thermal stability of perovskite are enhanced. The device with NaI modification can keep 80 % of initial efficiency, compared to 30 % for reference device after stored 30 days under ambient air condition. This work provides a simple method to improve the quality of quasi 2D perovskite films.

The space-charge region at CsPbBr3 NC⊆Pb-MOF p-n junction by self-sacrificing MOFs to selective detect NH3·H2O or Fe3+

The rational design of p-n heterojunction is highly desirable to optimize electron distribution and photocarriers’ transfer pathway at space-charge region, which would influence the fluorescence detection. Herein, the inorganic perovskite CsPbBr3 nanocrystals (CPB NCs) have been encapsulated into Pb-centered MOFs via simple wet-chemical self-sacrifice to construct a “turn-off” sensor for the sensitive detection of NH3·H2O or Fe3+ in aqueous solution. The Mott-Schottky plots (M-S), ultraviolet photoelectron spectroscopy (UPS) and density functional theory (DFT) calculation have proved the formation of p-n junction between the derived CsPbBr3 and parent Pb-MOF. The CPB⊆Pb-MOF heterojunction has provided a strong platform to maintain high fluorescence performance and stability in aqueous solution as sensor. It is found that the static quenching process has affected the detection of Fe3+. More importantly, the occurrence of dynamic quenching with electron transfer is also verified by fluorescence lifetime, in-situ X-ray photoelectron spectroscopy (XPS) analysis. The phase transfer has taken major reason when being introduced by NH3·H2O. Fortunately, the 0.4CPB⊆Pb-MOF has exhibited best analytical performance for NH3·H2O or Fe3+. What’s more, it has been manufactured for the visual detection for NH3·H2O or Fe3+ in the real environmental water samples. Thereby, this perovskite based water detection system would broaden the application in point-to-point precise diagnostics.

ZnxFe3-xO4–ZnO heterojunction interfaced with poly(L-DOPA) electron transfer mediator layer for enhanced visible light photocatalytic activity

Z-scheme heterojunctions comprising ZnxFe3-xO4@poly(L-DOPA)@ZnO (ZF@PD@ZnO) were synthesized using solvothermal and precipitation techniques. The study aimed to investigate the impact of the poly(L-DOPA) electron transfer mediator on the photocatalytic performance of ZnxFe3-xO4@ZnO (ZF@ZnO) nanocomposites under visible light irradiation. X-ray diffraction (XRD) and HRTEM analysis confirmed the formation of heterostructures, identifying the crystalline phases of both ZnO and zinc ferrite. BFTEM images revealed a polyhedral shape for all samples, with a tendency toward mild agglomeration. The partial inversion of the zinc ferrite cubic spinel structure was evidenced by FT-IR, XPS, and VSM analyses. Zinc ferrite was found to be ferromagnetic, with cation distributions between tetrahedral (A) and octahedral (B) positions as [Zn0.62+Fe0.43+]A[Fe0.42+Fe1.63+]BO4. The samples exhibited notable photocatalytic activity against Rhodamine B, serving as a model contaminant. Furthermore, the stability and reusability of the samples were examined. Additionally, the study elucidated the photocatalytic mechanism produced by the ternary Z-scheme ZF@PD@ZnO, involving spin-polarized charge carriers. Energy band alignment was evaluated by combining ultraviolet photoelectron spectroscopy (UPS) with UV-Vis spectroscopy. The interplay between band alignment and reactive oxygen species (ROS) generation was discussed in correlation with EPR results. Enhanced ROS generation under visible light illumination, observed in the ZF@PD@ZnO nanocomposite, is mainly due to the addition of the conductive poly(L-DOPA) layer, acting as an electron transfer mediator in the Z-scheme heterojunction, ensuring enhanced charge separation.

Etching and Compositional Ratio Effect on the Surface Properties of Bismuth Telluride Thin Films

Bismuth telluride has garnered considerable attention owing to its versatile properties applicable in thermoelectric and antibacterial domains, as well as its intriguing topological insulating properties. In this work, our group fabricated bismuth telluride thin films with various ratios using radio frequency magnetron sputtering. The surface properties of these thin films were thoroughly analyzed by employing a diverse array of analytical techniques, including X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), four-point probe and contact angle (CA) measurements. Specifically, our XPS findings indicated that Bi is more susceptible to oxidation than Te following Ar+-ion etching. Pure Te thin films exhibited the highest Rq value of 31.2 nm based on AFM and SEM results due to their larger grain sizes. The XRD patterns revealed a peak at 27.75° for thin films with 20% Te, attributed to its rhombohedral structure. Moreover, thin films with 30% Te yielded the highest weighted average work function with a value of 4.95 eV after etching. Additionally, pristine Bi and Te thin films demonstrated the most robust hydrophobic properties compared to intermediate-composition thin films, as determined by CA measurements.

Electronic structure of superconducting VN(111) films

Vanadium nitride (VN) is a transition-metal nitride with remarkable properties that have prompted extensive experimental and theoretical investigations in recent years. However, there is a current paucity of experimental research investigating the temperature-dependent electronic structure of single-crystalline VN. In this study, high-quality VN(111) films were successfully synthesized on α\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\alpha$$\\end{document}-Al2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_2$$\\end{document}O3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$_3$$\\end{document}(0001) substrates using magnetron sputtering. The crystal and electronic structures of the VN films were characterized by a combination of high-resolution X-ray diffraction, low-energy electron diffraction, resonant soft X-ray absorption spectroscopy, and ultraviolet photoelectron spectroscopy. The electrical transport measurements indicate that the superconducting critical temperature of the VN films is around 8.1 K. Intriguingly, the temperature-dependent photoelectron spectroscopy measurements demonstrate a weak temperature dependence in the electronic structure of the VN films, which is significant for understanding the ground state of VN compounds.

Observations on Valence‐Band Electronic Structure and Surface States of Bulk Insulators Based on Fast Stabilization Process of Sample Charging in UPS

AbstractThe valence‐band electronic structure is one of the most basic properties of materials and ultraviolet photoelectron spectroscopy (UPS) is the most commonly used technique for its measurement. To obtain credible UPS spectra on insulator surfaces, eliminating the charging effects at the surfaces is essential but is very difficult. Here, a reliable measurement for the valence‐band structure of bulk insulators is shown. It has been observed that, during UPS measurements without any charge compensation, the charging on irradiated insulator surfaces reaches its steady state very quickly and the fluctuation of the charging‐induced surface potential is very small. Therefore, the whole UPS spectrum undergoes just a parallel shift and can be calibrated by comparison with the corresponding X‐ray photoelectron spectroscopy (XPS) spectrum even though XPS often has a poorer resolution than UPS. From the calibrated valence‐band spectra, it is found that noticeable electronic energy levels (i.e., the “surface states”) exist in the bandgap, and based on the density of states (DOS) calculations, the surface states are attributed to the truncation of the bulk periodic structure at the surfaces. This work is anticipated to provide a way to obtain the valence band structure and the surface states of bulk insulators which play crucial roles in many physical processes.

On the combination of ultraviolet photoelectron spectroscopy with optical absorption studies to investigate Cu2O||TiO2 direct Z-scheme junctions with different Cu2O loading

Among the electronic properties, the positions of the electronic band edges and the work function are essential parameters for determining the potential of a photocatalyst and its ability to function in a solar conversion system. A novel type of photocatalysts, called direct Z-schemes, possesses many advantages over conventional heterojunctions, which all benefit the catalytic performance under solar light. As oxidation and reduction reactions are greatly affected by the electrical characteristics of the material, ultraviolet photoelectron spectroscopy (UPS) is a powerful tool to determine and quantify important electronic parameters of previously fabricated TiO2‖Cu2O junctions. TiO2 nanotubes modified with Cu2O nanoparticles exhibit a reduction in the value of the work function (WF = 3.67 ± 0.01 eV) and ionization potential (IP = 6.01 ± 0.04 eV) with respect to the TiO2 substrate (WF = 4.29 ± 0.02 eV and IP = 7.65 ± 0.05 eV). By varying the electrodeposition time, an optimized amount of deposited Cu2O nanoparticles was proven to reduce the WF and IP to facilitate the excitation of electrons, which could be correlated to the improved absorbance in the visible wavelength range. This work proposes a valuable methodology for band diagram tracing from UPS spectra and provides new insights in the relationship between synthesis, electronic properties and visible light absorption of titania based Z-schemes for photocatalytic applications with a combination of surface sensitive techniques and optical absorption studies.

Electronic energy structure of the (100) In4Se3 surfaces at different preparation and treatment in ultraviolet photoelectron spectroscopy study

The (100) surface of In4Se3 layered crystal was obtained in situ, ions sputtered and exposed to UHV for hours. The UPS spectra for these surfaces, atomically clean, and after the mentioned treatments, were recorded and analyzed to obtain electronic spectra of In4Se3 (100) surface. The first-principles calculations were performed by DFT-GGA method, and for the In4Se3 underestimated (0.21 eV) band gap was attained. The calculated total density of states of In4Se3 in general coincides with a UPS spectrum for an atomically clean cleaved surface. Thus the study of the band structure of (100) In4Se3 cleavage surfaces after the ion sputtering or exposure to UHV for more than several hours is uninformative, and such effects on the sample should be avoided.

Impact of photoinduced phase segregation in mixed-halide perovskite absorbers on their material and device stability

Mixed-halide perovskites enable bandgap engineering for tandem solar cell and light-emitting diode applications. However, photoinduced halide phase segregation introduces a compositional instability, that is, formation of I-rich and Br-rich phases, which compromises photovoltaic efficiency and stability. While optical and structural studies of the photoinduced phase segregation in mixed-halide perovskites have been reported, its impact on the material stability is missing. Here, a detailed compositional analysis of mixed-halide perovskite films using x-ray and ultraviolet photoelectron spectroscopy (UPS) was carried out to determine how their stability in various environments depends on the halide ratio. A series of perovskite thin films were fabricated with the composition CH3NH3Pb(IxBr1−x)3, where x = 0.00, 0.25, 0.50, 0.75, and 1.00, and analyzed under different conditions, such as exposure to light in ambient and in nitrogen atmosphere, as well as storage in the dark. From the spectroscopy results, complemented with structural and optical properties, it was found that the deletion of halide ions from the surface is facilitated in mixed-halide perovskites in comparison with pure halide perovskites. A higher stability was found for the mixed-halide perovskite containing less than 25% Br, and it decreases with increasing Br content. This study also established the effect of the Br/I ratio on the energy landscape of the materials. The UPS spectra reveal that photoinduced degradation results in a mismatch of the energy levels at the perovskite/transport layer interface, which may limit the collection of charge carriers. These findings correlate well with the photovoltaic device stability under similar degradation conditions.

Band alignment of γ-phase CuI/high-k Al2O3 heterointerface by X-ray photoelectron spectroscopy

Copper Iodide (CuI) has attracted considerable attention as a p-channel building block for advanced optoelectronic applications. Here, we determine the energy band alignment at the γ-phase CuI/high-k Al2O3 heterointerface by high-resolution X-ray photoelectron spectroscopy. The optical characteristics of the γ-phase CuI are studied by UV–Vis spectrophotometry and Raman spectroscopy, and the surface topography is evaluated by atomic force microscopic and scanning electron microscopic analysis. The energy band alignments with the valence band offset (VBO) and the conduction band offset (CBO) at the γ-phase CuI/high-k Al2O3 heterojunction are experimentally determined, which are also confirmed by using Anderson's rule measured by ultraviolet photoelectron spectroscopy. The interfacial charge transport dynamics across the heterointerface are systematically investigated, revealing a type I band alignment at the γ-phase CuI/high-k Al2O3 heterojunction with the higher VBO of 2.93 ± 0.05 eV than the CBO of 0.65 eV ± 0.05 eV with band bending effect. Thus, this work can provide valuable information on the determination of the energy band alignment at the metal halide/high-k Al2O3 heterointerface for designing high performance optoelectronic applications.

Enhancement of the Visible Light Photodetection of Inorganic Photodiodes via Additional Quantum Dots Layers.

Visible light photodetectors are extensively researched with transparent metal oxide holes/electron layers for various applications. Among the metal oxide transporting layers, nickel oxide (NiO) and zinc oxide (ZnO) are commonly adopted due to their wide band gap and high transparency. The objective of this study was to improve the visible light detection of NiO/ZnO photodiodes by introducing an additional quantum dot (QD) layer between the NiO and ZnO layers. Utilizing the unique property of QDs, we could select different sizes of QDs and responsive light wavelength ranges. The resulting red QDs utilized device that could detect light starting at 635 nm to UV (Ultra-violet) light wavelength and exhibited a photoresponsivity and external quantum efficiency (EQE) of 14.99 mA/W and 2.92% under 635 nm wavelength light illumination, respectively. Additionally, the green QDs, which utilized a device that could detect light starting at 520 nm, demonstrated photoresponsivity values of 8.34 mA/W and an EQE of 1.99% under 520 nm wavelength light illumination, respectively. In addition, we used X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) to investigate the origin of the photocurrents and the enhancement of the device's performance. This study suggests that incorporating QDs with metal oxide semiconductors is an effective approach for detecting visible light wavelengths in transparent optoelectronic devices.

Spatiotemporal Synergism in Osteomyelitis Treatment with Photoactivated Core-Shell Zinc Oxide/Silver Sulfide Heterogeneous Nanoparticles.

Osteomyelitis is primarily caused by bacterial infections, and treatment requires precise sequential therapy, including antibacterial therapy in the early stages and bone defect reconstruction in later stages. We aimed to synthesize core-shell-structured zinc oxide/silver sulfide heterogeneous nanoparticles (ZnO/Ag2S NPs) using wet chemical methods. Using density functional theory and ultraviolet photoelectron spectroscopy, we showed that the optimized band structure endowed ZnO/Ag2S NPs with photodynamic properties under near-infrared (NIR) irradiation. Moreover, ZnO/Ag2S NPs exhibited a distinguished and stable photothermal performance within the same wavelength range. With single-wavelength irradiation, ZnO/Ag2S NPs achieved a bifunctional antibacterial effect during the acute stage of osteomyelitis. Antibacterial action was confirmed through colony-forming unit (CFU) counting assays, scanning electronic microscopy (SEM) observations, live-dead staining, growth curves, and quantitative real-time polymerase chain reaction (qPCR) assays. The Ag2S coating on the NPs realized the sustained release of zinc ions, thereby controlling the zinc ion concentration. Alkaline phosphatase (ALP) staining, alizarin red S (ARS) staining, and qPCR assays confirmed that the ZnO/Ag2S NPs exhibited good osteogenic effects in vitro. These effects were verified in an in vivo mouse femur model during chronic stages using micro-computed tomography (micro-CT) and histological analysis. This study provides a novel biocompatible core-shell nanomaterial for the two-phase treatment of osteomyelitis, contributing to versatile nanotherapies for infections and inflammation.

Signatures of Conical Intersections in Extreme Ultraviolet Photoelectron Spectra of Furan Measured with 15 fs Time Resolution.

Ultrafast internal conversion of furan upon deep UV excitation at 200 nm is studied by using extreme ultraviolet time-resolved photoelectron spectroscopy with a time resolution of 15 fs. Ballistic nuclear wavepacket motion from the 1B2(ππ*) state to the ground state is fully observed using 21.7 eV probe pulses. Through the performance of a comparison with the results of electronic structure calculations at the MS(3)-CASPT2(10,10)/cc-pVTZ level of theory, the photoelectron signals from the conical intersection regions are identified.