The new instrument for near-ambient-pressure X-ray photoelectron spectroscopy which has been installed at the MAX II ring of the Swedish synchrotron radiation facility MAX IV Laboratory in Lund is presented. The new instrument, which is based on a SPECS PHOIBOS 150 NAP analyser, is the first to feature the use of retractable and exchangeable high-pressure cells. This implies that clean vacuum conditions are retained in the instrument's analysis chamber and that it is possible to swiftly change between near-ambient and ultrahigh-vacuum conditions. In this way the instrument implements a direct link between ultrahigh-vacuum and in situ studies, and the entire pressure range from ultrahigh-vacuum to near-ambient conditions is available to the user. Measurements at pressures up to 10(-5) mbar are carried out in the ultrahigh-vacuum analysis chamber, while measurements at higher pressures are performed in the high-pressure cell. The installation of a mass spectrometer on the exhaust line of the reaction cell offers the users the additional dimension of simultaneous reaction data monitoring. Moreover, the chosen design approach allows the use of dedicated cells for different sample environments, rendering the Swedish ambient-pressure X-ray photoelectron spectroscopy instrument a highly versatile and flexible tool.
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http://dx.doi.org/10.1107/S0909049512032700 | DOI Listing |
J Am Chem Soc
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Hydrogen spillover is an important process in catalytic hydrogenation reactions, facilitating H activation and modulating surface chemistry of reducible oxide catalysts. This study focuses on the unveiling of platinum-induced hydrogen spillover on monoclinic tungsten trioxide (γ-WO), employing ambient pressure X-ray photoelectron spectroscopy, density functional theory calculations and microkinetic modeling to investigate the dynamic evolution of surface states at varied temperatures. At room temperature, hydrogen spillover results in the formation of W and hydrogen intermediates (hydroxyl species and adsorbed water), facilitated by Pt metal clusters.
View Article and Find Full Text PDFChemSusChem
January 2025
Swinburne University of Technology - Hawthorn Campus: Swinburne University of Technology, Chemistry and Biotechnology, AUSTRALIA.
The removal of heavy metal ions, such as lead (Pb2+), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb2+ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe2O3) phase.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
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Department of Robotics and Mechatronics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Republic of Korea. Electronic address:
In recent years, the design of various ultrasound responsive echogenic nanomaterials offers many advantages such as deep tissue penetration, high signal intensity, colloidal stability, biocompatibility and less expensive for ultrasound-based cancer cell imaging while providing the option to monitor the progress of tumor volume during the treatment. Further, the ability of nanomaterials to combine photo-thermal therapy (PTT) and chemotherapy has opened a new avenue in the development of cancer theranostics for synergistic cancer therapy. Herein, we report MoS nanoflowers (NFs) surface decorated with CuS nanorods (NRs) and folic acid-derived carbon dots (FACDs) using cystine-polyethyleneimine (PEI) linker for PTT-chemotherapy.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Università di Milano-Bicocca, Dipartimento di Scienza dei Materiali, via Cozzi 55, 20125, Milano, ITALY.
Confined single metal atoms in graphene-based materials have proven to be excellent catalysts for several reactions and promising gas sensing systems. However, whether the chemical activity arises from the specific type of metal atom or is a direct consequence of the confinement itself remains unclear. In this work, through a combined density functional theory and experimental surface science study, we address this question by investigating Co and Ni single atoms embedded in graphene (Gr) on a Ni(111) support.
View Article and Find Full Text PDFChemSusChem
January 2025
Brandenburgische Technische Universitat Cottbus-Senftenberg, Angewandte Physik und Halbleiterspektroskopie, Konrad-Zuse-Str. 1, 03046, Cottbus, GERMANY.
Ultrathin atomic layer deposited ceria films (< 20 nm) are capable of H2 heterolytic activation at room temperature, undergoing a significant reduction regardless of the absolute pressure, as measured under in-situ conditions by near ambient pressure X-ray photoelectron spectroscopy. ALD-ceria can gradually reduce as a function of H2 concentration under H2/O2 environments, especially for diluted mixtures below 10%. At room temperature, this reduction is limited to the surface region, where the hydroxylation of the ceria surface induces a charge transfer towards the ceria matrix, reducing Ce4+ cations to Ce3+.
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