An integrated approach combining scanning tunneling microscopy(STM)and X-ray photoelectron spectroscopy(XPS)is used to investigate the atomic structures and electronic properties of Cr-doped ZnO(1010)*** deposited at ...
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An integrated approach combining scanning tunneling microscopy(STM)and X-ray photoelectron spectroscopy(XPS)is used to investigate the atomic structures and electronic properties of Cr-doped ZnO(1010)*** deposited at 300 K,Cr at low surface coverage(<0.1 ML)appeared either as isolated atoms on the surface terrace of ZnO(1010)or substituting Zn atoms in the ZnO *** structural models could be identified from atomic-resolution STM images and their oxidation states were found as Cr^(3+)based on XPS *** islands nucleated at step edges along the[0001]direction could also be observed during the initial growth of Cr at 300 K and were assigned as Cr *** density of Cr islands as well as their average size increased with the increasing of Cr surface *** treatments at above 600 K could facilitate the decomposition of Cr islands and the re-dispersion of Cr atoms into the ZnO lattice,indicating a strong interaction between Cr and *** adsorption of CO at 78 K showed no preferential adsorption at Cr^(3+)sites embedded in the surface lattice of ***,the re-dispersion of Cr atoms into the ZnO bulk at above 600 K could induce a significant upward band bending,causing a negative shift of core level XPS peaks of Zn 2p and O 1s by~0.5–0.7 *** study has thus constructed a model catalyst for Cr-doped ZnO and provided atomic insight for understanding ZnO-based catalysts.
Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical applicat...
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Fe2O3 has become a promising anode material in lithium-ion batteries (LIBs) in light of its low cost, high theoretical capacity (1007 mA h g^−1) and abundant reserves on the earth. Nevertheless, the practical application of Fe2O3 as the anode material in LIBs is greatly hindered by several severe issues, such as drastic capacity falloff, short cyclic life and huge volume change during the charge/discharge process. To tackle these limitations, carbon-coated Fe2O3 (Fe2O3@MOFC) composites with a hollow sea urchin nanostructure were prepared by an effective and controllable morphology-inherited strategy. Metal-organic framework (MOF)-coated FeOOH (FeOOH@-MIL-100(Fe)) was applied as the precursor and self-sacrificial template. During annealing, the outer MOF layer protected the structure of inner Fe2O3 from collapsing and converted to a carbon coating layer in situ. When applied as anode materials in LIBs, Fe2O3@MOFC composites showed an initial discharge capacity of 1366.9 mA h g^−1 and a capacity preservation of 1551.3 mA h g^−1 after 200 cycles at a current density of 0.1 A g^−1. When increasing the current density to 1 A g^−1, a reversible and high capacity of 1208.6 mA h g^−1 was obtained. The enhanced electrochemical performance was attributed to the MOF-derived carbon coating layers and the unique hollow sea urchin nanostructures. They mitigated the effects of volume expansion, increased the lithium-ion mobility of electrode, and stabilized the as-formed solid electrolyte interphase films.
This study explores the adsorption and reac-tion of methanol on the CeO_(2)(111)and Ni/CeO_(2)(111)surfaces,highlighting the es-sential role of metal-support interaction in methanol decomposition by a synergistic ap-p...
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This study explores the adsorption and reac-tion of methanol on the CeO_(2)(111)and Ni/CeO_(2)(111)surfaces,highlighting the es-sential role of metal-support interaction in methanol decomposition by a synergistic ap-proach encompassing synchrotron radiation photoemission spectroscopy,X-ray photo-electron spectroscopy,infrared reflection and absorption spectroscopy,and temperature-programmed *** findings reveal that Ni deposited on the CeO_(2)(111)surface,followed by annealing to 700 K,leads to the formation of Ce-O-Ni mixed oxide as the dominant *** Ni^(2+)species facilitate the methoxy decomposition into CO and H_(2)within 300-430 K,with a small amount of formalde-hyde also forming at the edge sites of ***,some methoxy adsorbed on the bare CeO_(2)surface migrates to the Ce-O-Ni mixed oxide,where they decompose into CO and H_(2)at 500-600 K,accompanied by a portion of the methoxy interacting with ceria to generate *** exposure to methanol at 500 K,the Ni^(2+)species are reduced to metallic Ni^(0),alongside the formation of coke and Ni_(3)C,ultimately resulting in catalyst ***,reintroducing O_(2)reactivates these sites by oxidizing metallic Ni^(0)and Ni_(3)C *** study highlights the pivotal role of metal-support interaction in promoting oxygen trans-fer from ceria to Ni,thereby enhancing methoxy decomposition and significantly improving the performance of Ni-based catalysts for methanol decomposition into CO and H_(2).
Degradation of polyethylene terephthalate(PET)plastics by the traditional technologies usually requires high energy consumption and encounters poor product ***,we report the photoconversion of PET into carbon dioxide ...
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Degradation of polyethylene terephthalate(PET)plastics by the traditional technologies usually requires high energy consumption and encounters poor product ***,we report the photoconversion of PET into carbon dioxide with 100%selectivity by in-plane heterostructured NiO/Fe_(2)O_(3) nanosheets in pure water under normal temperature and ***-resolution transmission electron microscopy,X-ray absorption near-edge spectroscopy and X-ray photoelectron spectra demonstrate the construction of the Z-scheme heterojunction,which can help to accelerate the separation of electron-hole pairs for enhanced PET conversion *** in-situ characterization techniques and experiments unveil that PET is photodegraded into carbon dioxide by the photogenerated holes,while oxygen is photoreduced into water by the photoexcited *** work will open new avenues toward resolving the white pollution crisis.
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