排序方式: 共有83条查询结果,搜索用时 15 毫秒
1.
Ziwei Xu Hongwei Dong Dr. Wanmiao Gu Dr. Zhen He Fengming Jin Dr. Chengming Wang Dr. Qing You Prof. Dr. Jin Li Prof. Dr. Haiteng Deng Dr. Lingwen Liao Dr. Dong Chen Prof. Dr. Jun Yang Prof. Dr. Zhikun Wu 《Angewandte Chemie (International ed. in English)》2023,62(39):e202308441
Lattice tuning at the ≈1 nm scale is fascinating and challenging; for instance, lattice compression at such a minuscule scale has not been observed. The lattice compression might also bring about some unusual properties, which waits to be verified. Through ligand induction, we herein achieve the lattice compression in a ≈1 nm gold nanocluster for the first time, as detected by the single-crystal X-ray crystallography. In a freshly synthesized Au52(CHT)28 (CHT=S-c−C6H11) nanocluster, the lattice distance of the (110) facet is found to be compressed from 4.51 to 3.58 Å at the near end. However, the lattice distances of the (111) and (100) facets show no change in different positions. The lattice-compressed nanocluster exhibits superior electrocatalytic activity for the CO2 reduction reaction (CO2RR) compared to that exhibited by the same-sized Au52(TBBT)32 (TBBT=4-tert-butyl-benzenethiolate) nanocluster and larger Au nanocrystals without lattice variation, indicating that lattice tuning is an efficient method for tailoring the properties of metal nanoclusters. Further theoretical calculations explain the high CO2RR performance of the lattice-compressed Au52(CHT)28 and provide a correlation between its structure and catalytic activity. 相似文献
2.
Hui Xu Dr. Shengbo Zhang Xinyuan Zhang Min Xu Dr. Miaomiao Han Prof. Li Rong Zheng Prof. Yunxia Zhang Prof. Guozhong Wang Prof. Haimin Zhang Prof. Huijun Zhao 《Angewandte Chemie (International ed. in English)》2023,62(52):e202314414
The integration of highly active single atoms (SAs) and atom clusters (ACs) into an electrocatalyst is critically important for high-efficiency two-electron oxygen reduction reaction (2e− ORR) to hydrogen peroxide (H2O2). Here we report a tandem impregnation-pyrolysis-etching strategy to fabricate the oxygen-coordinated Fe SAs and ACs anchored on bacterial cellulose-derived carbon (BCC) (FeSAs/ACs-BCC). As the electrocatalyst, FeSAs/ACs-BCC exhibits superior electrocatalytic activity and selectivity toward 2e− ORR, affording an onset potential of 0.78 V (vs. RHE) and a high H2O2 selectivity of 96.5 % in 0.1 M KOH. In a flow cell reactor, the FeSAs/ACs-BCC also achieves high-efficiency H2O2 production with a yield rate of 12.51±0.18 mol gcat−1 h−1 and a faradaic efficiency of 89.4 %±1.3 % at 150 mA cm−2. Additionally, the feasibility of coupling the produced H2O2 and electro-Fenton process for the valorization of ethylene glycol was explored in detail. The theoretical calculations uncover that the oxygen-coordinated Fe SAs effectively regulate the electronic structure of Fe ACs which are the 2e− ORR active sites, resulting in the optimal binding strength of *OOH intermediate for high-efficiency H2O2 production. 相似文献
3.
The cleaning of water contaminated with organic dyes is a crucial problem nowadays. The search for good catalysts is intense, and bismuth tungstates have attracted a lot of attention because of their catalytic properties which are related to their crystal structure and morphology. In this study, we show that Bi2WO6 (BWO) crystals synthesized by the surfactant-assisted hydrothermal method create a different morphology than non-assisted crystals. With the assistance of the PVP surfactant, even the BWO crystalline structure could change, crystallizing into a high-symmetry metastable phase. These changes in morphology imply a decrease in BWO catalytic activity, which shows that insightful control of BWO synthesis is necessary to improve the BWO properties. 相似文献
4.
Yang Lv Dr. Miaomiao Han Dr. Wanbing Gong Dongdong Wang Dr. Chun Chen Prof. Guozhong Wang Prof. Haimin Zhang Prof. Huijun Zhao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23727-23732
Selective hydrogenation of C=O against the conjugated C=C in cinnamaldehyde (CAL) is indispensable to produce cinnamyl alcohol (COL). Nonetheless, it is challenged by the low selectivity and the need to use organic solvents. Herein, for the first time, we report the use of Fe-Co alloy nanoparticles (NPs) on N-doped carbon support as a selective hydrogenation catalyst to efficiently convert CAL to COL. The resultant catalyst with the optimized Fe/Co ratio of 0.5 can achieve an exceptional COL selectivity of 91.7 % at a CAL conversion of 95.1 % in pure water medium under mild reaction conditions, ranking it the best performed catalyst reported to date. The experimental results confirm that the COL selectivity and CAL conversion efficiency are, respectively promoted by the presence of Fe and Co, while the synergism of the alloyed Fe-Co is the key to concurrently achieve high COL selectivity and CAL conversion efficiency. 相似文献
5.
A new polymorph of Bi2(SO4)3 was prepared by reaction of LiBiO2 with H2SO4 and its crystal structure was solved from X-ray powder diffraction. This new polymorph crystallizes in C2/c space group with lattice parameters a = 17.3383(3) Å, b = 6.77803(12) Å, c = 8.30978(13) Å, β = 101.4300(12)°. Bi2(SO4)3 presents a layered structure made of SO4 sulfate groups and signs of stereochemically active Bi3+ lone pairs. The new Bi2(SO4)3 absorbs water to form Bi2(H2O)2(SO4)2(OH)2 through an intermediate Bi2O(OH)2SO4 phase, and the transition is reversible when heated under vacuum. 相似文献
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Tantalum(Ta) oxide films with tunable structural color were fabricated easily using anodic oxidation.The structure,components,and surface valence states of the oxide films were investigated by using gazing incidence X-ray diffractometry,X-ray photoelectron microscopy,and surface analytical techniques.Their thickness and optical properties were studied by using spectroscopic ellipsometry and total reflectance spectrum.Color was accurately defined using L*a*b* scale.The thickness of compact Ta2O5 films was linearly dependent on anodizing voltage.The film color was tunable by adjusting the anodic voltage.The difference in color appearance resulted from the interference behavior between the interfaces of air-oxide and oxide-metal. 相似文献
8.
《Solid State Communications》2002,121(9-10):493-496
The CuGaS2 crystallites with different morphologies were prepared at 160 °C through hydrothermal process by using CuCl, GaCl3 solution, and thiourea as source materials. The samples were characterized by means of X-ray powder diffraction, element analysis, transmission electron microscopy, and photoluminescence (PL). In present route, as-prepared CuGaS2 crystallites displayed spherical and whisker-like nanoparticles and snowflake-like micrometer particles. Room temperature PL spectrum of the snowflake-like crystallites exhibits a weak emission band at 540 nm and a broad strong emission band at 735 nm. The role that the reaction media played in the morphologies of the CuGaS2 crystallites was investigated, and a possible reaction mechanism was proposed. 相似文献
9.
《Solid State Sciences》2001,3(3):267-274
High and low temperature forms of In16Sn4S32 differ in color (black and orange-red, respectively) and lithium insertion properties. We have studied both forms by X-ray and neutron diffraction techniques and 119Sn Mössbauer spectroscopy. While diffraction techniques show no structural difference, Mössbauer spectra allow to differentiate both phases, as a consequence of the presence of SnII in the high-temperature form. We show from tight-binding calculations that both the differences in color and the tin oxidation states are related to the existence of sulfur vacancies in the local environment of the tin atoms. 相似文献
10.
A facile and high-throughput strategy is presented to fabricate three-dimensional (3D) hierarchically porous Ag films, with clean surfaces, via plasma etching Ag-coated electrospun nanofiber template. The films are built of Ag porous nanotubes and are homogeneous in macro-size but rough and porous in nanoscale. Each nanotube-block is micro/nanostructured with evenly distributed nanopores on the tube walls. The film architecture (or the shape, arrangement, and distribution density of porous nanotubes; the number and size of nanopores) can be easily controlled by the nanofiber-template configuration, Ag coating, and plasma etching conditions. Such hierarchically porous films could be very useful, such as in catalysis, sensors, and nanodevices. They have exhibited significantly structurally enhanced surface-enhanced Raman scattering performance with good stability and reproduction, and shown the possibility of molecule-level detection. Also, the strategy is universal for fabricating other hierarchically structured 3D metal porous films, such as porous Ag hollow sphere arrays. 相似文献