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171.
Pang HL Zhang XH Zhong XX Liu B Wei XG Kuang YF Chen JH 《Journal of colloid and interface science》2008,319(1):193-198
Ru-doped SnO2 nanoparticles were prepared by chemical precipitation and calcinations at 823 K. Due to high stability in diluted acidic solution, Ru-doped SnO2 nanoparticles were selected as the catalyst support and second catalyst for methanol electrooxidation. The micrograph, elemental composition, and structure of the Ru-doped SnO2 nanoparticles were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction, respectively. The electrocatalytic properties of the Ru-doped SnO2-supported Pt catalyst (Pt/Ru-doped SnO2) for methanol oxidation have been investigated by cyclic voltammetry. Under the same loading mass of Pt, the Pt/Ru-doped SnO2 catalyst shows better electrocatalytic performance than the Pt/SnO2 catalyst and the best atomic ratio of Ru to Sn in Ru-doped SnO2 is 1/75. Additionally, the Pt/Ru-doped SnO2 catalyst possesses good long-term cycle stability. 相似文献
172.
Dr. Hui Zhang Chuqi Wang Hongxia Luo Junliang Chen Prof. Min Kuang Prof. Jianping Yang 《Angewandte Chemie (International ed. in English)》2023,62(5):e202217071
The electrochemical nitrate reduction reaction (NO3RR) is an appealing technology for regulating the nitrogen cycle. Metallic iron is one of the well-known electrocatalysts for NO3RR, but it suffers from poor durability due to leaching and oxidation of iron during the electrocatalytic process. In this work, a graphene-nanochainmail-protected iron nanoparticle (Fe@Gnc) electrocatalyst is reported. It displays superior nitrate removal efficiency and high nitrogen selectivity. Notably, the catalyst delivers exceptional stability and durability, with the nitrate removal rate and nitrogen selectivity remained ≈96 % of that of the first time after up to 40 cycles (24 h for one cycle). As expected, the conductive graphene nanochainmail provides robust protection for the internal iron active sites, allowing Fe@Gnc to maintain its long-lasting electrochemical nitrate catalytic activity. This research proposes a workable solution for the scientific challenge of poor lasting ability of iron-based electrocatalysts in large-scale industrialization. 相似文献
173.
Tuoya Naren Gui-Chao Kuang Ruheng Jiang Piao Qing Hao Yang Jialin Lin Yuejiao Chen Weifeng Wei Xiaobo Ji Libao Chen 《Angewandte Chemie (International ed. in English)》2023,62(26):e202305287
Lithium (Li) metal anodes have the highest theoretical capacity and lowest electrochemical potential making them ideal for Li metal batteries (LMBs). However, Li dendrite formation on the anode impedes the proper discharge capacity and practical cycle life of LMBs, particularly in carbonate electrolytes. Herein, we developed a reactive alternative polymer named P(St-MaI) containing carboxylic acid and cyclic ether moieties which would in situ form artificial polymeric solid electrolyte interface (SEI) with Li. This SEI can accommodate volume changes and maintain good interfacial contact. The presence of carboxylic acid and cyclic ether pendant groups greatly contribute to the induction of uniform Li ion deposition. In addition, the presence of benzyl rings makes the polymer have a certain mechanical strength and plays a key role in inhibiting the growth of Li dendrites. As a result, the symmetric Li||Li cell with P(St-MaI)@Li layer can stably cycle for over 900 h under 1 mA cm−2 without polarization voltage increasing, while their Li||LiFePO4 full batteries maintain high capacity retention of 96 % after 930 cycles at 1C in carbonate electrolytes. The innovative strategy of artificial SEI is broadly applicable in designing new materials to inhibit Li dendrite growth on Li metal anodes. 相似文献
174.
175.
A six‐step asymmetric total synthesis of (20S)‐camptothecin ( 1 ) has been accomplished in 25% overall yield starting from the known pyridone 3 . The key steps in this synthesis are the chemoselective Ni‐catalyzed hydrogenation of 3‐cyanopyridone 6 to 3‐formylpyridone 7 in AcOH/pyridine/H2O and the Davis asymmetric hydroxylation of tricyclic lactone 4 utilizing a chiral N‐sulfonyloxaziridine into (4′S)‐tricyclic hydroxylactone 2 . 相似文献
176.
177.
Xinghao Lin Youzhong Dong Quan Kuang Danlin Yan Xudong Liu Wei Han Yanming Zhao 《Journal of Solid State Electrochemistry》2016,20(5):1241-1250
A new Co-base sodium metaphosphate compound, NaCo(PO3)3, has been synthesized here by solid-state method. The crystal structure is refined by the Rietveld method, and the results reveal that NaCo(PO3)3 has an orthorhombic structure with the space group of P2 1 2 1 2 1 and lattice parameters of a = 14.2453(2) Å, b = 14.2306(1) Å, and c = 14.2603(2) Å. Its typical morphology and chemical composition are confirmed by scanning electron microscopy (SEM) and energy-dispersive spectrometry (EDS). The valence states of all elements and the internal/external vibrational modes of NaCoP3O9 compound are measured by X-ray photoelectron and vibrational spectrum, where a typical feature of the (PO3)? polyanion group is observed. Meanwhile, the electrochemical properties of NaCo(PO3)3 cathode for sodium-ion batteries are also elevated and an initial discharge capacity of 33.8 mAh/g can be obtained at 0.05 C within 1.5–4.2 V. After 20 cycles, a discharge capacity of 26.7 mAh/g can be obtained and a well-kept oxidation–reduction plateau is still observed for NaCo(PO3)3 cathode, indicating the good reversibility of this metaphosphate electrode. 相似文献
178.
Chemical composition and biological activities of essential oil from Filifolium sibiricum (L.) Kitam
Shanshan Liang Qing Wei Juan Xue Yichun Sun Zhili Chen Haixue Kuang 《Natural product research》2016,30(24):2861-2863
The essential oil from Filifolium sibiricum (L.) Kitam were extracted using hydrodistillation and GC-MS was used to analyse the essential oil. The main components were espatulenol (8.55%), geranyl acetate (8.03%), caryophyllene oxide (5.47%), calamenene (4.79%), geraniol (4.28%), calamenene (4.53%), geraniol (4.06%), cedrene epoxide (3.23%), myrtenol (3.18%), transgeranylgeranio (3.13%), etc. The essential oil showed intensive inhibitory effects against MCF-7 with IC50 level of 0.78 mg/mL, HepG-2 with IC50 level of 0.44 mg/mL, SKOV-3 with IC50 level of 0.27 mg/mL, BGC-823 with IC50 level of 0.34 mg/mL. In the antibacterial test, the essential oil showed the significant antibacterial activities. The MIC and MBC values were 5.20 and 5.20 mg/mL against Staphylococcus aureus. 相似文献
179.
180.
A simple theoretical method is shown to yield a detailed explanation of numerous EPR parameters for a d4 configuration ion in tetragonal ligand field. Using the unified ligand-field-coupling (ULFC) scheme, the formulas relating the microscopic spin Hamiltonian parameters with the crystal structure parameters are derived. On the basis of the theoretical formulas, the 210 x 210 complete energy matrices including all the spin states are constructed within a strong field representation. By diagonalizing the complete energy matrices, the local lattice structure and Jahn-Teller energy of Cr(2+) ions in ZnS:Cr(2+) system have been investigated. It is found that the theoretical results are in good agreement with the experimental values. Moreover, the contributions of the spin singlets to the zero-field splitting (ZFS) parameters of Cr(2+) ions in ZnS crystals are investigated for the first time. The results indicate that the spin singlets contributions to ZFS parameter b(0)(4) is negligible, but the contributions to ZFS parameters b(0)(4) and b(4)(4) cannot be neglected. 相似文献