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991.
Eun-Sil Park Dae-Hwan Jang Young-In Lee Chan Woo Jung Dong woo Lim Bum Sung Kim Young-keun Jeong Nosang V. Myung Yong-Ho Choa 《Research on Chemical Intermediates》2014,40(7):2565-2570
Conducting polymers are excellent sensing materials in the design of bioanalytical sensors because of their electronic conductivity, low energy optical transitions, biocompatibility, and room temperature operation. Among them, Polypyrrole (Ppy) is one of the most extensively used conducting polymers because of a number of properties such as redox activity, rapid electron transfer, and ability to link a variety of biomolecules to pyrrole groups by chemical treatment. In this study, Ppy nanowires were synthesized by an electrospinning method. The nanowires were prepared from a solution mixture of Ppy and poly(ethylene oxide). The method of detection in such a device is based on the selective binding of antigen onto an antibody that is covalently attached to the nanowires. Thus, anti-IgG was immobilized on Ppy nanowires using an EDC {[N-(3-dimethyl aminopropyl)-N2-ethylcarbodiimide hydrochloride]}-NHS(N-hydrosuccinimide) modified technique. Fluorescence images of BSA–FITC (fluorescein isothiocyanate labeling of bovine serum albumin) conjugation demonstrated that antibody was functionalized on the Ppy nanowires without non-specific binding and facilitated selective detection of antigen. Current–voltage (I–V) characterization was used to monitor the change in the conductivity of nanowires while the specific binding interaction occurred. These results of electrical properties enable Ppy nanowire-based biosensors to detect biomolecules in real-time. 相似文献
992.
Wentao Yi Chunyan Yan Peng Yan Faqiang Li 《Journal of Sol-Gel Science and Technology》2014,69(2):386-396
Sulfur and copper codoped TiO2 nanoparticles were prepared by sol-hydrothermal process. And the samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectra analysis, scanning electron microscopy, Brunauer Emmett Teller analysis, UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectra and X-ray fluorescence analysis. It was found that the S, Cu-codoped TiO2 became amorphous with the increase of Cu content, and copper on the surface of TiO2 existed in the oxidation state of Cu(II) while S in the form of S6+ species. And the codoped particles had higher surface area, smaller particle size, stronger spectral response in visible region compared with pure TiO2. The effects of doping amount in a wide range, catalyst dosage, and recycle on the photocatalytic activity of the codoped catalysts were investigated with Acid Orange 7 as the model compound under visible light illumination (λ > 447 nm). The results showed that S (2.0 %), Cu (5.0 %) codoped TiO2 had the highest visible light photocatalytic activity and good reusability performance. The kinetic study showed that this photocatalytic process coincided with the Langmuir–Hinshelwood pseudo first order reaction model. 相似文献
993.
994.
Dr. Guangwu Li Prof. Taisuke Matsuno Yi Han Dr. Hoa Phan Shaofei Wu Dr. Qing Jiang Ya Zou Prof. Hiroyuki Isobe Prof. Jishan Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(24):9814-9822
Synthesis of fully conjugated cyclophanes containing large-size polycyclic aromatics is challenging. Now, three benzidine-linked, hexa-peri-hexabenzocoronene (superbenzene)-based ortho-, para-, and meta-cyclophanes are synthesized through intermolecular Yamamoto coupling reaction of structurally pre-organized precursors. Subsequent oxidative dehydrogenation gave the corresponding quinoidal benzidine-linked cyclophanes. Their geometries were confirmed by X-ray crystallographic analysis and their electronic properties were investigated by electronic absorption, cyclic voltammetry, and DFT calculations. The quinoidal benzidine-linked cyclophanes show thermally populated paramagnetic activity with a relatively large singlet-triplet energy gap. Two enantiomers for the ortho-cyclophanes ( 1-NH and 1-N ) were isolated and their chiral figure-of-eight macrocyclic structures were identified. The cage-like cyclophanes 2-NH and 3-NH with concave surface can selectively encapsulate fullerene C70. 相似文献
995.
Dr. Ding Yi Fei Lu Fengchu Zhang Dr. Shoujie Liu Dr. Bo Zhou Denglei Gao Prof. Xi Wang Prof. Jiannian Yao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):15989-15993
Single-atom catalysts have attracted much attention. Reported herein is that regulating charge transfer of lattice oxygen atoms in serial single-atom-doped titania enables tunable hydrogen evolution reaction (HER) activity. First-principles calculations disclose that the activity of lattice oxygen for the HER can be regularly promoted by substituting its nearest metal atom, and doping-induced charge transfer plays an essential role. Besides, the realm of the charge transfer of the active site can be enlarged to the second nearest atom by creating oxygen vacancies, resulting in further optimization for the HER. Various single-atom-doped titania nanosheets were fabricated to validate the proposed model. Taking advantage of the localized charge transfer to the lattice atom is demonstrated to be feasible for realizing precise regulation of the electronic structures and thus catalytic activity of the nanosheets. 相似文献
996.
Dr. Linzhou Zhuang Dr. Yi Jia Hongli Liu Zhiheng Li Dr. Mengran Li Dr. Longzhou Zhang Dr. Xin Wang Prof. Dongjiang Yang Prof. Zhonghua Zhu Prof. Xiangdong Yao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14772-14778
The oxygen vacancies of defective iron–cobalt oxide (FeCoOx-Vo) nanosheets are modified by the homogeneously distributed sulfur (S) atoms. S atoms can not only effectively stabilize oxygen vacancies (Vo), but also form the Co−S coordination with Co active site in the Vo, which can modulate the electronic structure of the active site, enabling FeCoOx-Vo-S to exhibit much superior OER activity. FeCoOx-Vo-S exhibits a mass activity of 2440.0 A g−1 at 1.5 V vs. RHE in 1.0 m KOH, 25.4 times higher than that of RuO2. The Tafel slope is as low as 21.0 mV dec−1, indicative of its excellent charge transfer rate. When FeCoOx-Vo-S (anode catalyst) is paired with the defective CoP3/Ni2P (cathode catalyst) for overall water splitting, current densities of as high as 249.0 mA cm−2 and 406.0 mA cm−2 at a cell voltage of 2.0 V and 2.3 V, respectively, can be achieved. 相似文献
997.
Dr. Wei Bai Jingyu Gao Dr. Kun Li Gongrui Wang Dr. Tengfei Zhou Pengju Li Prof. Shengyong Qin Prof. Genqiang Zhang Prof. Zaiping Guo Prof. Chong Xiao Prof. Yi Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17647-17651
Volume expansion and poor conductivity are two major obstacles that hinder the pursuit of the lithium-ion batteries with long cycling life and high power density. Herein, we highlight a misfit compound PbNbS3 with a soft/rigid superlattice structure, confirmed by scanning tunneling microscopy and electrochemical characterization, as a promising anode material for high performance lithium-ion batteries with optimized capacity, stability, and conductivity. The soft PbS sublayers primarily react with lithium, endowing capacity and preventing decomposition of the superlattice structure, while the rigid NbS2 sublayers support the skeleton and enhance the migration of electrons and lithium ions, as a result leading to a specific capacity of 710 mAh g−1 at 100 mA g−1, which is 1.6 times of NbS2 and 3.9 times of PbS. Our finding reveals the competitive strategy of soft/rigid structure in lithium-ion batteries and broadens the horizons of single-phase anode material design. 相似文献
998.
Luocai Yi Dr. Junxiang Chen Ping Shao Dr. Junheng Huang Xinxin Peng Junwei Li Dr. Genxiang Wang Chi Zhang Prof. Zhenhai Wen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(45):20287-20294
Two-dimensional (2D) monometallic pnictogens (antimony or Sb, and bismuth or Bi) nanosheets demonstrate potential in a variety of fields, including quantum devices, catalysis, biomedicine and energy, because of their unique physical, chemical, electronic and optical properties. However, the development of general and high-efficiency preparative routes toward high-quality pnictogen nanosheets is challenging. A general method involving a molten-salt-assisted aluminothermic reduction process is reported for the synthesis of Sb and Bi nanosheets in high yields (>90 %). Electrocatalytic CO2 reduction was investigated on the Bi nanosheets, and high catalytic selectively to formate was demonstrated with a considerable current density at a low overpotential and an impressive stability. Bi nanosheets continuously convert CO2 into formate in a flow cell operating for one month, with a yield rate of 787.5 mmol cm−2 h−1. Theoretical results suggest that the edge sites of Bi are far more active than the terrace sites. 相似文献
999.
Xuan Wei Diao Zheng Ming Zhao Dr. Hongzhong Chen Xun Fan Bin Gao Dr. Long Gu Dr. Yi Guo Dr. Jianbin Qin Prof. Jing Wei Prof. Yanli Zhao Prof. Guangcheng Zhang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(34):14747-14754
Heteroatom-doped polymers or carbon nanospheres have attracted broad research interest. However, rational synthesis of these nanospheres with controllable properties is still a great challenge. Herein, we develop a template-free approach to construct cross-linked polyphosphazene nanospheres with tunable hollow structures. As comonomers, hexachlorocyclotriphosphazene provides N and P atoms, tannic acid can coordinate with metal ions, and the replaceable third comonomer can endow the materials with various properties. After carbonization, N/P-doped mesoporous carbon nanospheres were obtained with small particle size (≈50 nm) and high surface area (411.60 m2 g−1). Structural characterization confirmed uniform dispersion of the single atom transition metal sites (i.e., Co-N2P2) with N and P dual coordination. Electrochemical measurements and theoretical simulations revealed the oxygen reduction reaction performance. This work provides a solution for fabricating diverse heteroatom-containing polymer nanospheres and their derived single metal atom doped carbon catalysts. 相似文献
1000.
Howard Yi Fan Sim Jaslyn Ru Ting Chen Charlynn Sher Lin Koh Dr. Hiang Kwee Lee Dr. Xuemei Han Gia Chuong Phan-Quang Jing Yi Pang Dr. Chee Leng Lay Dr. Srikanth Pedireddy Dr. In Yee Phang Prof. Edwin Kok Lee Yeow Prof. Xing Yi Ling 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(39):17145-17151
The electrochemical nitrogen reduction reaction (NRR) offers a sustainable solution towards ammonia production but suffers poor reaction performance owing to preferential catalyst–H formation and the consequential hydrogen evolution reaction (HER). Now, the Pt/Au electrocatalyst d-band structure is electronically modified using zeolitic imidazole framework (ZIF) to achieve a Faradaic efficiency (FE) of >44 % with high ammonia yield rate of >161 μg mgcat−1 h−1 under ambient conditions. The strategy lowers electrocatalyst d-band position to weaken H adsorption and concurrently creates electron-deficient sites to kinetically drive NRR by promoting catalyst–N2 interaction. The ZIF coating on the electrocatalyst doubles as a hydrophobic layer to suppress HER, further improving FE by >44-fold compared to without ZIF (ca. 1 %). The Pt/Au-NZIF interaction is key to enable strong N2 adsorption over H atom. 相似文献