177 results on '"Xuefeng Guo"'
Search Results
2. Mild Oxidation of Toluene to Benzaldehyde by Air
- Author
-
Changshun Deng, Kai Wang, Xiaofeng Qian, Jun Yao, Nianhua Xue, Luming Peng, Xuefeng Guo, Yan Zhu, and Weiping Ding
- Subjects
General Chemical Engineering ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2022
- Full Text
- View/download PDF
3. Environment Molecules Boost the Chemoselective Hydrogenation of Nitroarenes on Cobalt Single-Atom Catalysts
- Author
-
Muhong Li, Chunchen Zhang, Yu Tang, Qingliang Chen, Wen Li, Zhen Han, Shanyong Chen, Changchang Lv, Yujie Yan, Yu Zhang, Wenhua Zheng, Peng Wang, Xuefeng Guo, and Weiping Ding
- Subjects
General Chemistry ,Catalysis - Published
- 2022
- Full Text
- View/download PDF
4. Precise edge functionalization and tailoring of graphene via solvent-controlled reactions
- Author
-
Mingyao Li, Shuyao Zhou, Shizhao Ren, Lei Zhang, Bing Yin, Cong Zhao, Zhirong Liu, Chuancheng Jia, and Xuefeng Guo
- Subjects
General Materials Science ,General Chemistry - Published
- 2022
- Full Text
- View/download PDF
5. Real-time monitoring of reaction stereochemistry through single-molecule observations of chirality-induced spin selectivity
- Author
-
Chen Yang, Yanwei Li, Shuyao Zhou, Yilin Guo, Chuancheng Jia, Zhirong Liu, Kendall N. Houk, Yonatan Dubi, and Xuefeng Guo
- Subjects
General Chemical Engineering ,General Chemistry - Published
- 2023
- Full Text
- View/download PDF
6. Dipole-improved gating of azulene-based single-molecule transistors
- Author
-
Huanyan Fu, Cong Zhao, Jie Cheng, Shuyao Zhou, Peizhen Peng, Jie Hao, Zhirong Liu, Xike Gao, Chuancheng Jia, and Xuefeng Guo
- Subjects
Materials Chemistry ,General Chemistry - Abstract
The inherent dipole moment and higher polarizability of azulene lead to ambipolar characteristics and good gate controllability of azulene-based single-molecule transistors.
- Published
- 2022
- Full Text
- View/download PDF
7. Direct mechano-sliding transfer of chemical vapor deposition grown silicon nanowires for nanoscale electronic devices
- Author
-
Dongbao Yin, Jie Li, Jianfei Feng, Wenzhe Liu, Zhiheng Yang, Shiyun Li, Mingliang Li, Lidong Li, and Xuefeng Guo
- Subjects
Materials Chemistry ,General Chemistry - Abstract
A mechano-sliding strategy for controllable assembly of nanowires was demonstrated by directly transferring chemical vapor deposition grown silicon nanowires to obtain nanoscale electronic devices.
- Published
- 2022
- Full Text
- View/download PDF
8. Recent progress in single-molecule transistors: their designs, mechanisms and applications
- Author
-
Xuefeng Guo, Mengmeng Li, Chuancheng Jia, Xin Zhu, Lan Yang, Li Peihui, and Huanyan Fu
- Subjects
Materials science ,Interface (computing) ,Transistor ,General Chemistry ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Engineering physics ,law.invention ,Condensed Matter::Materials Science ,Computer Science::Emerging Technologies ,Coupling (computer programming) ,law ,Thermoelectric effect ,Materials Chemistry ,Kondo effect ,Electronics ,Physics::Chemical Physics ,Electronic circuit ,Block (data storage) - Abstract
A single-molecule field-effect transistor (FET) is the key building block of future electronic circuits. At the same time, a single-molecule FET is also a unique platform for studying physical mechanisms at the single-molecule level. How to construct single-molecule FETs and how to efficiently control the charge transfer characteristics of the devices are two core issues in the development of single-molecule FETs. In this review, we introduce the research progresses of single-molecule FETs with solid or liquid gates. Strategies to design single-molecule FETs are emphasized, including the design of functional molecules, the construction of gate electrodes and the control of molecule-electrode interface coupling. These single-molecule FETs provide a basis for practical applications and the exploration of physical laws. Specifically, the physical mechanisms of single-molecule FETs, especially those related to interfacial coupling, are explained, such as energy level shift, Coulomb blockade effect, Kondo effect and electron-phonon coupling. The applications of single-molecule FETs are summarized, including the regulation of quantum interference, spin, thermoelectric effect and superconductivity. Finally, the current opportunities and challenges in the field of single-molecule FETs are proposed, aiming to promote the future development of single-molecule electronics.
- Published
- 2022
- Full Text
- View/download PDF
9. Single-molecule conductance measurements reveal a new catalytic mechanism of formate dehydrogenase
- Author
-
Shichao Zhong, Zhiheng Yang, and Xuefeng Guo
- Subjects
General Chemistry - Published
- 2023
- Full Text
- View/download PDF
10. Single-exonuclease nanocircuits reveal the RNA degradation dynamics of PNPase and demonstrate potential for RNA sequencing
- Author
-
Zhiheng Yang, Wenzhe Liu, Lihua Zhao, Dongbao Yin, Jianfei Feng, Lidong Li, and Xuefeng Guo
- Subjects
Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
The degradation process of RNA is decisive in guaranteeing high-fidelity translation of genetic information in living organisms. However, visualizing the single-base degradation process in real time and deciphering the degradation mechanism at the single-enzyme level remain formidable challenges. Here, we present a reliable in-situ single-PNPase-molecule dynamic electrical detector based on silicon nanowire field-effect transistors with ultra-high temporal resolution. These devices are capable of realizing real-time and label-free monitoring of RNA analog degradation with single-base resolution, including RNA analog binding, single-nucleotide hydrolysis, and single-base movement. We discover a binding event of the enzyme (near the active site) with the nucleoside, offering a further understanding of the RNA degradation mechanism. Relying on systematic analyses of independent reads, approximately 80% accuracy in RNA nucleoside sequencing is achieved in a single testing process. This proof-of-concept sets up a Complementary Metal Oxide Semiconductor (CMOS)-compatible playground for the development of high-throughput detection technologies toward mechanistic exploration and single-molecule sequencing.
- Published
- 2023
- Full Text
- View/download PDF
11. COx hydrogenation to methanol and other hydrocarbons under mild conditions with Mo3S4@ZSM-5
- Author
-
Gui Liu, Pengfei Liu, Deming Meng, Taotao Zhao, Xiaofeng Qian, Qiang He, Xuefeng Guo, Jizhen Qi, Luming Peng, Nianhua Xue, Yan Zhu, Jingyuan Ma, Qiang Wang, Xi Liu, Liwei Chen, and Weiping Ding
- Subjects
Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
The hydrogenation of CO2 or CO to single organic product has received widespread attentions. Here we show a highly efficient and selective catalyst, Mo3S4@ions-ZSM-5, with molybdenum sulfide clusters ([Mo3S4]n+) confined in zeolitic cages of ZSM-5 molecular sieve for the reactions. Using continuous fixed bed reactor, for CO2 hydrogenation to methanol, the catalyst Mo3S4@NaZSM-5 shows methanol selectivity larger than 98% at 10.2% of carbon dioxide conversion at 180 °C and maintains the catalytic performance without any degeneration during continuous reaction of 1000 h. For CO hydrogenation, the catalyst Mo3S4@HZSM-5 exhibits a selectivity to C2 and C3 hydrocarbons stably larger than 98% in organics at 260 °C. The structure of the catalysts and the mechanism of COx hydrogenation over the catalysts are fully characterized experimentally and theorectically. Based on the results, we envision that the Mo3S4@ions-ZSM-5 catalysts display the importance of active clusters surrounded by permeable materials as mesocatalysts for discovery of new reactions.
- Published
- 2023
- Full Text
- View/download PDF
12. Photoisomerization effects in molecular devices
- Author
-
Chunyan Gao, Xuefeng Guo, Chuangcheng Jia, and Li Cheng
- Subjects
Materials science ,Photoisomerization ,General Chemical Engineering ,Materials Chemistry ,General Chemistry ,Photochemistry ,Biochemistry - Published
- 2021
- Full Text
- View/download PDF
13. Vibration‐Assisted Charge Transport through Positively Charged Dimer Junctions
- Author
-
Xin Zhu, Boyu Wang, Wan Xiong, Shuyao Zhou, Kai Qu, Jing‐Tao Lü, Hongliang Chen, Chuancheng Jia, and Xuefeng Guo
- Subjects
Electron Transport ,General Medicine ,General Chemistry ,Electronics ,Vibration ,Catalysis - Abstract
Intermolecular charge transport plays a vital role in the fields of electronics, as well as biochemical systems. Here, we design supramolecular dimer junctions and investigate the effects of charge state and energy level alignment on charge transport under nanoconfinement. Incoherent tunneling caused by thermally-induced vibrations is enhanced in positively charged systems. The transition between coherent and incoherent tunneling is associated with specific molecular vibration modes. Positively charged systems with smaller torsional barriers and vibrational frequencies result in lower transition temperatures. Multiple thermal effects have a great impact on the conductance in the off-resonant tunneling, while thermally-induced vibron-assisted tunneling contributes more to the transport in the resonant tunneling. These investigations offer a deep mechanism understanding of intermolecular charge transport and facilitate the development of practical functional molecular devices.
- Published
- 2022
- Full Text
- View/download PDF
14. Front Cover
- Author
-
Yancheng Cui, Qinghua Zhong, Dawei Sun, Yan Chen, Zhe Jiang, Xiaodong Yang, Zhanlong Shen, Yunhua Sun, Mujun Yin, Bin Liang, Xin Zhu, Xuefeng Guo, and Yingjiang Ye
- Subjects
General Engineering ,General Physics and Astronomy ,General Materials Science ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Published
- 2022
- Full Text
- View/download PDF
15. Quantum Interference-Controlled Conductance Enhancement in Stacked Graphene-like Dimers
- Author
-
Peihui Li, Songjun Hou, Bader Alharbi, Qingqing Wu, Yijian Chen, Li Zhou, Tengyang Gao, Ruihao Li, Lan Yang, Xinyue Chang, Gang Dong, Xunshan Liu, Silvio Decurtins, Shi-Xia Liu, Wenjing Hong, Colin J. Lambert, Chuancheng Jia, and Xuefeng Guo
- Subjects
Colloid and Surface Chemistry ,Microscopy, Scanning Tunneling ,Polymers ,540 Chemistry ,Electric Conductivity ,570 Life sciences ,biology ,Graphite ,General Chemistry ,Electronics ,Biochemistry ,Electrodes ,000 Computer science, knowledge & systems ,Catalysis - Abstract
Stacking interactions are of significant importance in the fields of chemistry, biology, and material optoelectronics because they determine the efficiency of charge transfer between molecules and their quantum states. Previous studies have proven that when two monomers are π-stacked in series to form a dimer, the electrical conductance of the dimer is significantly lower than that of the monomer. Here, we present a strong opposite case that when two anthanthrene monomers are π-stacked to form a dimer in a scanning tunneling microscopic break junction, the conductance increases by as much as 25 in comparison with a monomer, which originates from a room-temperature quantum interference. Remarkably, both theory and experiment consistently reveal that this effect can be reversed by changing the connectivity of external electrodes to the monomer core. These results demonstrate that synthetic control of connectivity to molecular cores can be combined with stacking interactions between their π systems to modify and optimize charge transfer between molecules, opening up a wide variety of potential applications ranging from organic optoelectronics and photovoltaics to nanoelectronics and single-molecule electronics.
- Published
- 2022
16. Precise electrical gating of the single-molecule Mizoroki-Heck reaction
- Author
-
Lei Zhang, Chen Yang, Chenxi Lu, Xingxing Li, Yilin Guo, Jianning Zhang, Jinglong Lin, Zhizhou Li, Chuancheng Jia, Jinlong Yang, K. N. Houk, Fanyang Mo, and Xuefeng Guo
- Subjects
Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
Precise tuning of chemical reactions with predictable and controllable manners, an ultimate goal chemists desire to achieve, is valuable in the scientific community. This tunability is necessary to understand and regulate chemical transformations at both macroscopic and single-molecule levels to meet demands in potential application scenarios. Herein, we realise accurate tuning of a single-molecule Mizoroki-Heck reaction via applying gate voltages as well as complete deciphering of its detailed intrinsic mechanism by employing an in-situ electrical single-molecule detection, which possesses the capability of single-event tracking. The Mizoroki-Heck reaction can be regulated in different dimensions with a constant catalyst molecule, including the molecular orbital gating of Pd(0) catalyst, the on/off switching of the Mizoroki-Heck reaction, the promotion of its turnover frequency, and the regulation of each elementary reaction within the Mizoroki-Heck catalytic cycle. These results extend the tuning scope of chemical reactions from the macroscopic view to the single-molecule approach, inspiring new insights into designing different strategies or devices to unveil reaction mechanisms and discover novel phenomena.
- Published
- 2022
- Full Text
- View/download PDF
17. Atomically Precise Engineering of Single‐Molecule Stereoelectronic Effect
- Author
-
Na Xin, Jinying Wang, Shizhao Ren, Zhuang Yan, Cheng Shen, Sheng Meng, Linan Meng, Jiyu Xu, Miao Zhang, Xuefeng Guo, and Guangyu Zhang
- Subjects
Materials science ,Bistability ,010405 organic chemistry ,Stereoelectronic effect ,General Chemistry ,Dihedral angle ,010402 general chemistry ,Ring (chemistry) ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,Azobenzene ,chemistry ,Chemical physics ,Terphenyl ,Molecule ,Physics::Chemical Physics ,Isomerization - Abstract
Charge transport in a single-molecule junction is extraordinarily sensitive to both the internal electronic structure of a molecule and its microscopic environment. Two distinct conductance states of a prototype terphenyl molecule are observed, which correspond to the bistability of outer phenyl rings at each end. An azobenzene unit is intentionally introduced through atomically precise side-functionalization at the central ring of the terphenyl, which is reversibly isomerized between trans and cis forms by either electric or optical stimuli. Both experiment and theory demonstrate that the azobenzene side-group delicately modulates charge transport in the backbone via a single-molecule stereoelectronic effect. We reveal that the dihedral angle between the central and outer phenyl ring, as well as the corresponding rotation barrier, is subtly controlled by isomerization, while the behaviors of the phenyl ring away from the azobenzene are hardly affected. This tunability offers a new route to precisely engineer multiconfigurational single-molecule memories, switches, and sensors.
- Published
- 2021
- Full Text
- View/download PDF
18. Origin of the Activity of Co–N–C Catalysts for Chemoselective Hydrogenation of Nitroarenes
- Author
-
Shanyong Chen, Jian Liu, Muhong Li, Chen Qingliang, Xuan Wang, Yan Yong, Qike Jiang, Xuefeng Guo, Changchang Lv, and Weiping Ding
- Subjects
010405 organic chemistry ,Chemistry ,Organic chemistry ,chemistry.chemical_element ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Cobalt ,Nitrogen ,Carbon ,Catalysis ,0104 chemical sciences - Abstract
The production of functionalized anilines by chemoselective hydrogenation of nitroarenes occupies an important position in the chemical industries. Recently, cobalt and nitrogen codoped carbon (Co–...
- Published
- 2021
- Full Text
- View/download PDF
19. Structural Transition Dynamics in Carbon <scp>Electrode‐Based Single‐Molecule</scp> Junctions
- Author
-
Xuefeng Guo, Li Peihui, and Chuancheng Jia
- Subjects
chemistry.chemical_classification ,Chemical physics ,Chemistry ,Dynamics (mechanics) ,Electrode ,Stereoelectronic effect ,Molecular electronics ,Molecule ,Non-covalent interactions ,chemistry.chemical_element ,Structural transition ,General Chemistry ,Carbon - Published
- 2021
- Full Text
- View/download PDF
20. A quasilinear hydrazone-based mononuclear dysprosium compound with C4v symmetry exhibiting field-induced complex magnetic relaxation
- Author
-
Dan Liu, Xiao Sun, Peiqiong Chen, Haiquan Tian, Hou-Ting Liu, Jing Lu, and Xuefeng Guo
- Subjects
chemistry.chemical_classification ,Field (physics) ,Intermolecular force ,Hydrazone ,chemistry.chemical_element ,General Chemistry ,Catalysis ,Ion ,Dipole ,Crystallography ,chemistry ,Magnet ,Materials Chemistry ,Dysprosium ,Spin (physics) - Abstract
This paper reports a quasilinear hydrazone-based mononuclear dysprosium(III) compound, namely, {Dy(Hppyh)2(SCN)3}·2MeOH (I), where Hppyh is pyrazine-2-carboxylic acid pyridin-2-ylmethylene-hydrazide. Compound I behaves as a single-ion magnet (SIM) based on the optimal dc field application of 0.7 kOe, showing a complex magnetic relaxation phenomenon with a tunneling relaxation time of 6.1 ± 0.3 × 10−3 s and an effective spin reversal barrier of 22.6 ± 1.1 K for the low- and high-frequency regions, respectively. More importantly, detailed comparative experimental and theoretical investigations reveal that the complex magnetic relaxation was most likely associated with the single DyIII ion behavior as well as the short-range intermolecular magnetic dipolar interactions.
- Published
- 2021
- Full Text
- View/download PDF
21. Evaluation of histopathological response to neoadjuvant therapy in rectal cancer using slide-free, stain-free multimodal multiphoton microscopy
- Author
-
Yancheng Cui, Qinghua Zhong, Dawei Sun, Yan Chen, Zhe Jiang, Xiaodong Yang, Zhanlong Shen, Yunhua Sun, Mujun Yin, Bin Liang, Xin Zhu, Xuefeng Guo, and Yingjiang Ye
- Subjects
Microscopy ,Treatment Outcome ,Rectal Neoplasms ,General Engineering ,Rectum ,General Physics and Astronomy ,Humans ,General Materials Science ,General Chemistry ,Coloring Agents ,General Biochemistry, Genetics and Molecular Biology ,Neoadjuvant Therapy ,Neoplasm Staging - Abstract
Neoadjuvant therapy has become a standard treatment for patients with locally advanced rectal cancer to achieve better prognostic outcomes. The response to treatment has been shown to correlate closely with the prognosis. However, current evaluation systems only provide coarse assessment on limited information, due to the lack of accurate and reproducible approach for quantitation of different types of responses. In this study, a novel stain-free, slide-free multimodal multiphoton microscopy imaging technique was applied to image rectal cancer tissues after neoadjuvant therapies with high resolution and contrast. Qualitative and quantitative evaluation of tumor, stromal, and inflammatory responses were demonstrated which are consistent with current tumor regression grading system using American Joint Committee on Cancer criteria, showing the great potential of such approach to build a more informative grading system for accurate and standardizable assessment of neoadjuvant therapy in rectal cancer.
- Published
- 2022
22. Unravelling Structural Dynamics within a Photoswitchable Single Peptide: A Step Towards Multimodal Bioinspired Nanodevices
- Author
-
Xinjiani Chen, Yuan Qi Yeoh, Chenguang Zhou, Andrew D. Abell, Jingxian Yu, Xuefeng Guo, John R. Horsley, and Yanbin He
- Subjects
Time Factors ,Molecular Conformation ,Molecular Dynamics Simulation ,Dihedral angle ,010402 general chemistry ,Peptides, Cyclic ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,Molecular dynamics ,Protein structure ,Nanotechnology ,Nanodevice ,Photoswitch ,010405 organic chemistry ,Hydrogen bond ,Conductance ,Stereoisomerism ,General Chemistry ,General Medicine ,Photochemical Processes ,0104 chemical sciences ,Azobenzene ,chemistry ,Chemical physics ,Nanoparticles ,Azo Compounds - Abstract
The majority of the protein structures have been elucidated under equilibrium conditions. The aim herein is to provide a better understanding of the dynamic behavior inherent to proteins by fabricating a label-free nanodevice comprising a single-peptide junction to measure real-time conductance, from which their structural dynamic behavior can be inferred. This device contains an azobenzene photoswitch for interconversion between a well-defined cis, and disordered trans isomer. Real-time conductance measurements revealed three distinct states for each isomer, with molecular dynamics simulations showing each state corresponds to a specific range of hydrogen bond lengths within the cis isomer, and specific dihedral angles in the trans isomer. These insights into the structural dynamic behavior of peptides may rationally extend to proteins. Also demonstrated is the capacity to modulate conductance which advances the design and development of bioinspired electronic nanodevices.
- Published
- 2020
- Full Text
- View/download PDF
23. CO2 Hydrogenation to Ethanol over Cu@Na-Beta
- Author
-
Zhaoxu Chen, Taotao Shi, Weiping Ding, Nianhua Xue, Zhiyang Zhang, Jing Gu, Changju Yang, Luming Peng, Yun Cui, Peng Wang, Yan Zhu, Xuefeng Guo, Ming Lin, Teng Chen, and Liping Ding
- Subjects
Ethanol ,Formic acid ,General Chemical Engineering ,Biochemistry (medical) ,Inorganic chemistry ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Copper ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Yield (chemistry) ,Materials Chemistry ,Environmental Chemistry ,Methanol ,0210 nano-technology ,Zeolite - Abstract
Summary Here, we report a high-performance catalyst Cu@Na-Beta, prepared via a unique method to embed 2∼5 nm Cu nanoparticles in crystalline particles of Na-Beta zeolite, for CO2 hydrogenation to ethanol as the only organic product in a traditional fixed-bed reactor. The ethanol yield in a single pass can reach ∼14% at 300°C, ∼12,000 mL·gcat−1·h−1, and 2.1 MPa, corresponding to a space-time yield of ∼398 mg·gcat−1·h−1. The key step of the reaction is considered as the rapid bonding of CO2∗ with surface methyl species at step sites of Cu nanoparticles to CH3COO∗ that converts to ethanol in following hydrogenation steps. The points of the catalyst seemed to be that the irregular copper nanoparticles stuck in zeolitic frameworks offer high density of step sites and the intimate surrounding of zeolitic frameworks strongly constrain the CO2 reactions at the copper surface and block by-products, such as methanol, formic acid, and acetyl acid.
- Published
- 2020
- Full Text
- View/download PDF
24. Interface Engineering in Organic Field-Effect Transistors: Principles, Applications, and Perspectives
- Author
-
Hongliang Chen, W Zhang, Mingliang Li, Xuefeng Guo, and Gen He
- Subjects
Interface engineering ,010405 organic chemistry ,business.industry ,Chemistry ,media_common.quotation_subject ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Engineering physics ,0104 chemical sciences ,Key (cryptography) ,Microelectronics ,Field-effect transistor ,Prosperity ,business ,media_common - Abstract
Heterogeneous interfaces that are ubiquitous in optoelectronic devices play a key role in the device performance and have led to the prosperity of today's microelectronics. Interface engineering provides an effective and promising approach to enhancing the device performance of organic field-effect transistors (OFETs) and even developing new functions. In fact, researchers from different disciplines have devoted considerable attention to this concept, which has started to evolve from simple improvement of the device performance to sophisticated construction of novel functionalities, indicating great potential for further applications in broad areas ranging from integrated circuits and energy conversion to catalysis and chemical/biological sensors. In this review article, we provide a timely and comprehensive overview of current efficient approaches developed for building various delicate functional interfaces in OFETs, including interfaces within the semiconductor layers, semiconductor/electrode interfaces, semiconductor/dielectric interfaces, and semiconductor/environment interfaces. We also highlight the major contributions and new concepts of integrating molecular functionalities into electrical circuits, which have been neglected in most previous reviews. This review will provide a fundamental understanding of the interplay between the molecular structure, assembly, and emergent functions at the molecular level and consequently offer novel insights into designing a new generation of multifunctional integrated circuits and sensors toward practical applications.
- Published
- 2020
- Full Text
- View/download PDF
25. Morphology‐Reserved Synthesis of Discrete Nanosheets of CuO@SAPO‐34 and Pore Mouth Catalysis for One‐Pot Oxidation of Cyclohexane
- Author
-
Yan Zhu, Minyi She, Xuefeng Guo, Xiangke Guo, Ming Lin, Mengxia Xu, Taotao Shi, Luming Peng, Weiping Ding, and Zhaoxu Chen
- Subjects
Copper oxide ,Adipic acid ,Materials science ,Cyclohexane ,010405 organic chemistry ,General Chemistry ,General Medicine ,010402 general chemistry ,Molecular sieve ,Heterogeneous catalysis ,01 natural sciences ,Catalysis ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Lamellar structure ,Nanosheet - Abstract
Discrete nanosheets of silicon-doped AlPO4 molecular sieves (SAPO-34) with a thickness of ≈7 nm have been prepared through morphology-reserved synthesis with a lamellar aluminum phosphate as precursor. Cages of the nanosheets are in situ incorporated with copper oxide clusters. The CuO@SAPO-34 nanosheets exhibit a large external surface area with a high number of (010) channel pores on the surface. Due to the thin morphology, copper oxide clusters occupy the outmost cages with a probability >50 %. The distinctive configuration facilitates a new concept of pore mouth catalysis, i.e., reactant molecules larger than the pores cannot enter the interior of the molecular sieves but can interact with the CuO clusters at "the mouth" of the pore. In heterogeneous catalysis, CuO@SAPO-34 nanosheets have shown top performance in one-pot oxidation of cyclohexane to adipic acid by O2 , a key compound for the manufacture of nylon-66, which is so far produced using non-green nitric acid oxidation.
- Published
- 2020
- Full Text
- View/download PDF
26. Preparation of highly oriented single crystal arrays of C8-BTBT by epitaxial growth on oriented isotactic polypropylene
- Author
-
Li Shuo, Hongliang Chen, Tingcong Jiang, Xiaoge Wang, Hailing Tu, Zhongjie Ren, Wei Feng, Mingliang Li, Shouke Yan, and Xuefeng Guo
- Subjects
Materials science ,Fabrication ,business.industry ,Annealing (metallurgy) ,Benzothiophene ,General Chemistry ,Epitaxy ,Crystal ,Organic semiconductor ,chemistry.chemical_compound ,chemistry ,Tacticity ,Materials Chemistry ,Optoelectronics ,business ,Single crystal - Abstract
Device fabrication with organic single crystals is an important method for high device performance. High-quality organic semiconductor crystals are usually grown by a lab solution method, by which it is difficult to fabricate crystal arrays on the substrate, let alone achieve industrial production. Therefore, in this work, oriented single crystal arrays have been prepared by epitaxial growth. As an example, 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) was spin-coated on the surface of a highly oriented melt-drawn isotactic polypropylene (iPP) film on 300 nm SiO2 substrates as an auxiliary dielectric layer, and highly oriented arrays of C8-BTBT single crystals are obtained by epitaxial growth in the solvent vapor annealing (SVA) approach. The devices based on the thus prepared C8-BTBT array have a yield of up to 81%, an average mobility of 2.5 cm2 V−1 s−1, a maximum mobility of 9.3 cm2 V−1 s−1 and an on/off ratio of 107. Hence, our method facilitates the large-scale fabrication of highly oriented single crystal arrays with high quality, which will promote further industrial application.
- Published
- 2020
- Full Text
- View/download PDF
27. Dual-gated single-molecule field-effect transistors beyond Moore’s law
- Author
-
Linan Meng, Na Xin, Chen Hu, Hassan Al Sabea, Miao Zhang, Hongyu Jiang, Yiru Ji, Chuancheng Jia, Zhuang Yan, Qinghua Zhang, Lin Gu, Xiaoyan He, Pramila Selvanathan, Lucie Norel, Stéphane Rigaut, Hong Guo, Sheng Meng, Xuefeng Guo, Peking University [Beijing], Chinese Academy of Sciences [Beijing] (CAS), McGill University = Université McGill [Montréal, Canada], Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Nankai University (NKU), We acknowledge primary financial support from the National Key R&D Program of China (2017YFA0204901, 2021YFA1200101, 2016YFA0300902, and 2019YFA0308500), the National Natural Science Foundation of China (22150013, 21727806, 21933001, 51991344, 91850120, and 11934003), the Natural Science Foundation of Beijing (Z181100004418003 and 2222009), 'Strategic Priority Research Program (B)' of Chinese Academy of Sciences (Grant No. XDB330301), the University of Rennes 1, the CNRS and the Agence Nationale de la Recherche (RuOxLux-ANR-12-BS07-0010-01), the Natural Sciences and Engineering Research Council (NSERC) of Canada, and the Fonds de recherche du Quebec-Nature et technologies (FRQNT) of the Province of Quebec (H.G.), Frontiers Science Center for New Organic Matter at Nankai University (63181206) and the Tencent Foundation through the XPLORER PRIZE. The authors also thank the High-Performance Computing Centre of McGill University, CalcuQuebec, and Compute Canada for computation facilities., and ANR-12-BS07-0010,RuOxLux,Modulation redox de la luminescence à l'aide de complexes organométalliques du ruthénium associés à une unité luminescente(2012)
- Subjects
Multidisciplinary ,[CHIM]Chemical Sciences ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
As conventional silicon-based transistors are fast approaching the physical limit, it is essential to seek alternative candidates, which should be compatible with or even replace microelectronics in the future. Here, we report a robust solid-state single-molecule field-effect transistor architecture using graphene source/drain electrodes and a metal back-gate electrode. The transistor is constructed by a single dinuclear ruthenium-diarylethene (Ru-DAE) complex, acting as the conducting channel, connecting covalently with nanogapped graphene electrodes, providing field-effect behaviors with a maximum on/off ratio exceeding three orders of magnitude. Use of ultrathin high-k metal oxides as the dielectric layers is key in successfully achieving such a high performance. Additionally, Ru-DAE preserves its intrinsic photoisomerisation property, which enables a reversible photoswitching function. Both experimental and theoretical results demonstrate these distinct dual-gated behaviors consistently at the single-molecule level, which helps to develop the different technology for creation of practical ultraminiaturised functional electrical circuits beyond Moore’s law.
- Published
- 2022
- Full Text
- View/download PDF
28. Overturned Loading of Inert CeO 2 to Active Co 3 O 4 for Unusually Improved Catalytic Activity in Fenton‐Like Reactions
- Author
-
Chunli Song, Qing Zhan, Fei Liu, Chuan Wang, Hongchao Li, Xuan Wang, Xuefeng Guo, Yingchun Cheng, Wei Sun, Li Wang, Jieshu Qian, and Bingcai Pan
- Subjects
General Medicine ,General Chemistry ,Catalysis - Published
- 2022
- Full Text
- View/download PDF
29. Accurate Single-Molecule Kinetic Isotope Effects
- Author
-
Yilin Guo, Chen Yang, Huiping Li, Lei Zhang, Shuyao Zhou, Xin Zhu, Huanyan Fu, Zhizhou Li, Zhirong Liu, Chuancheng Jia, Zitong Liu, Wenguang Zhu, Fanyang Mo, Deqing Zhang, and Xuefeng Guo
- Subjects
Colloid and Surface Chemistry ,General Chemistry ,Biochemistry ,Catalysis - Abstract
An accurate single-molecule kinetic isotope effect (sm-KIE) was applied to circumvent the inherent limitation of conventional ensemble KIE by using graphene-molecule-graphene single-molecule junctions.
- Published
- 2022
30. Real-time observation of the dynamics of an individual rotaxane molecular shuttle using a single-molecule junction
- Author
-
Sujun Chen, Dingkai Su, Chuancheng Jia, Yanwei Li, Xingxing Li, Xuefeng Guo, David A. Leigh, and Liang Zhang
- Subjects
General Chemical Engineering ,Biochemistry (medical) ,Materials Chemistry ,Environmental Chemistry ,General Chemistry ,Biochemistry - Abstract
Measurements on single molecules can sometimes reveal features that can be difficult to detect using techniques that probe the averaged properties of many molecules. Here, we report on the use of graphene-molecule-graphene single-molecule junctions (GMG-SMJs) to probe the shuttling dynamics of an individual [2]rotaxane molecule. The experiments show variations in the thermodynamic and kinetic shuttling parameters over a temperature range, and in different solvents, allowing the single-molecule data to be quantitatively related to simulation and ensemble experiments. The structural (∼1 nm) and temporal (∼17 μs) resolution of the GMG-SMJ enables direct observation of a previously unidentified weak-binding intermediate, arising from the formation of weak hydrogen bonds between the ring and triazole units. The results illustrate how GMG-SMJ measurements provide new opportunities for elucidating aspects of the structure, dynamics, and operational mechanisms of synthetic molecular machines that may be hidden to techniques that probe averaged behavior of an ensemble.
- Published
- 2022
- Full Text
- View/download PDF
31. Tunable Symmetry-Breaking-Induced Dual Functions in Stable and Photoswitched Single-Molecule Junctions
- Author
-
Hassan Al Sabea, Guojun Ke, Shengxiong Xiao, Na Xin, Mark A. Ratner, Chenguang Zhou, Chen Hu, Pramila Selvanathan, Xiaoyan He, Linan Meng, Xuefeng Guo, Lucie Norel, Chuancheng Jia, Zhirong Liu, Hong Guo, Stéphane Rigaut, Miao Zhang, Yu Li, Yao Gong, College of Chemistry and Molecular Engineering [Beijing], Peking University [Beijing], McGill University = Université McGill [Montréal, Canada], Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Shanghai Normal University (SHNU), Chinese Academy of Sciences [Beijing] (CAS), Nankai University (NKU), Northwestern University [Evanston], Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), RuOxLux-ANR-12-BS07-0010-01, Agence Nationale de la Recherche, 63181206, Nankai University, 2017YFA0204901, Ministry of Science and Technology of the People's Republic of China, Z181100004418003, Natural Science Foundation of Beijing Municipality, Tencent, Centre National de la Recherche Scientifique, Natural Sciences and Engineering Research Council of Canada, 21727806, National Natural Science Foundation of China, Universit?? de Rennes 1, and 18DZ2254200, Shanghai Engineering Research Center of Green Energy Chemical Engineering
- Subjects
Photoswitch ,Chemistry ,Molecular electronics ,Field effect ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Molecular physics ,Catalysis ,0104 chemical sciences ,Colloid and Surface Chemistry ,Rectification ,Electric field ,Molecular symmetry ,[CHIM]Chemical Sciences ,Molecular orbital ,Symmetry breaking ,0210 nano-technology - Abstract
International audience; The aim of molecular electronics is to miniaturize active electronic devices and ultimately construct single-molecule nanocircuits using molecules with diverse structures featuring various functions, which is extremely challenging. Here, we realize a gate-controlled rectifying function (the on/off ratio reaches ∼60) and a high-performance field effect (maximum on/off ratio >100) simultaneously in an initially symmetric single-molecule photoswitch comprising a dinuclear ruthenium-diarylethene (Ru-DAE) complex sandwiched covalently between graphene electrodes. Both experimental and theoretical results consistently demonstrate that the initially degenerated frontier molecular orbitals localized at each Ru fragment in the open-ring Ru-DAE molecule can be tuned separately and shift asymmetrically under gate electric fields. This symmetric orbital shifting (AOS) lifts the degeneracy and breaks the molecular symmetry, which is not only essential to achieve a diode-like behavior with tunable rectification ratio and controlled polarity, but also enhances the field-effect on/off ratio at the rectification direction. In addition, this gate-controlled symmetry-breaking effect can be switched on/off by isomerizing the DAE unit between its open-ring and closed-ring forms with light stimulus. This new scheme offers a general and efficient strategy to build high-performance multifunctional molecular nanocircuits.
- Published
- 2021
- Full Text
- View/download PDF
32. Single-Molecule Nanotechnologies: An Evolution in Biological Dynamics Detection
- Author
-
Xuefeng Guo, Yuan Yao, Lihua Zhao, and Yu Li
- Subjects
Biomaterials ,Physics ,Biochemistry (medical) ,Biomedical Engineering ,Molecule ,Nanotechnology ,General Chemistry ,Label free - Abstract
Single-molecule detection is a rapidly developing area within the analytical chemistry field that requires ultrasensitive technologies to detect a range of molecules. Over the past few decades, various optically-, mechanically-, and electrically-based strategies have been employed for single-molecule detection to uncover information in biological processes. These strategies enable real-time monitoring with single-molecule/single-event sensitivity. In addition, their high temporal resolution enables investigation of the underlying mechanisms of biological functions from static to dynamic, from qualitative to quantitative, and from one to multiple disciplines. In this review, we provide a brief overview of the prominent, real-time single-molecule detection nanotechnologies and their potential applications within the life science fields.
- Published
- 2019
- Full Text
- View/download PDF
33. Effect of Residual Chlorine on the Catalytic Performance of Co3O4 for CO Oxidation
- Author
-
Muhong Li, Shanyong Chen, Jia Guo, Weiping Ding, Yu Zhang, Panpan Hao, Xuefeng Guo, Yida Xu, Feifei Bi, and Kun Xiang
- Subjects
inorganic chemicals ,010405 organic chemistry ,Chemistry ,organic chemicals ,Inorganic chemistry ,Oxide ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Metal ,chemistry.chemical_compound ,Residual chlorine ,visual_art ,polycyclic compounds ,visual_art.visual_art_medium ,heterocyclic compounds - Abstract
An oxide catalyst plays an important role in environmental catalysis. Metal chlorides are widely used as precursors in the preparation of oxide catalysts. However, residual chlorine usually influen...
- Published
- 2019
- Full Text
- View/download PDF
34. Cu3N Nanocubes for Selective Electrochemical Reduction of CO2 to Ethylene
- Author
-
Jie Yin, Zhouyang Yin, Xuefeng Guo, Mengqi Shen, Junrui Li, Dong Su, Zhonglong Zhao, Hu Liu, Gang Lu, Chao Yu, Michelle Muzzio, Na Li, Honghong Lin, and Shouheng Sun
- Subjects
Ethylene ,Materials science ,Ethylene formation ,Mechanical Engineering ,Bioengineering ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Electrochemistry ,Redox ,Reduction (complexity) ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,General Materials Science ,0210 nano-technology - Abstract
Understanding the Cu-catalyzed electrochemical CO2 reduction reaction (CO2RR) under ambient conditions is both fundamentally interesting and technologically important for selective CO2RR to hydroca...
- Published
- 2019
- Full Text
- View/download PDF
35. Ultrasensitive Detection and Binding Mechanism of Cocaine in an Aptamer‐based Single‐molecule Device
- Author
-
Chenguang Zhou, Xinjiani Chen, and Xuefeng Guo
- Subjects
Mechanism (biology) ,Chemistry ,Aptamer ,Biophysics ,Molecule ,General Chemistry - Published
- 2019
- Full Text
- View/download PDF
36. Reactive Template-Derived CoFe/N-Doped Carbon Nanosheets as Highly Efficient Electrocatalysts toward Oxygen Reduction, Oxygen Evolution, and Hydrogen Evolution
- Author
-
Bin Zhao, Panpan Hao, Shanyong Chen, Xuefeng Guo, Kun Xiang, Muhong Li, Yu Zhang, and Feifei Bi
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Doped carbon ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Oxygen reduction ,Energy storage ,0104 chemical sciences ,Sustainable energy ,Metal ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,Environmental Chemistry ,Water splitting ,Hydrogen evolution ,0210 nano-technology - Abstract
The increasing need for clean and sustainable energy inspires researchers to explore low-cost nonprecious metal electrocatalysts for advanced energy storage and conversion. Herein, we develop a rea...
- Published
- 2019
- Full Text
- View/download PDF
37. Multistep nucleation and growth mechanisms of organic crystals from amorphous solid states
- Author
-
Fei Zhang, Yujie Sun, Xiaoge Wang, Chunhui Gu, Zhe Wang, Zheyu Lu, Xuefeng Guo, Junsheng Yang, Mingliang Li, W Zhang, Wenguang Zhu, Junliang Sun, and Hongliang Chen
- Subjects
0301 basic medicine ,Ostwald ripening ,Materials science ,Electronic materials ,Spinodal decomposition ,Science ,Nucleation ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,Crystal engineering ,Article ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,symbols.namesake ,Scanning probe microscopy ,Molecular self-assembly ,lcsh:Science ,Multidisciplinary ,General Chemistry ,Organic molecules in materials science ,021001 nanoscience & nanotechnology ,Amorphous solid ,Organic semiconductor ,030104 developmental biology ,symbols ,lcsh:Q ,0210 nano-technology - Abstract
Molecular self-assembly into crystallised films or wires on surfaces produces a big family of motifs exhibiting unique optoelectronic properties. However, little attention has been paid to the fundamental mechanism of molecular crystallisation. Here we report a biomimetic design of phosphonate engineered, amphiphilic organic semiconductors capable of self–assembly, which enables us to use real-time in-situ scanning probe microscopy to monitor the growth trajectories of such organic semiconducting films as they nucleate and crystallise from amorphous solid states. The single-crystal film grows through an evolutionary selection approach in a two-dimensional geometry, with five distinct steps: droplet flattening, film coalescence, spinodal decomposition, Ostwald ripening, and self-reorganised layer growth. These sophisticated processes afford ultralong high-density microwire arrays with high mobilities, thus promoting deep understanding of the mechanism as well as offering important insights into the design and development of functional high-performance organic optoelectronic materials and devices through molecular and crystal engineering., Little attention has been paid to the fundamental mechanism of molecular self-assembly into crystallised films or wires on surfaces. Here the authors use real time in-situ scanning probe microscopy to monitor the growth trajectories of organic semiconducting films as they crystallize from an amorphous solid state under ambient conditions.
- Published
- 2019
- Full Text
- View/download PDF
38. The promoted catalytic hydrogenation performance of bimetallic Ni–Co–B noncrystalline alloy nanotubes
- Author
-
Xiaojuan Guo, Xuefeng Guo, Mingjiang Xie, Min Mo, and Weiping Ding
- Subjects
Materials science ,General Chemical Engineering ,Alloy ,chemistry.chemical_element ,Nanoparticle ,02 engineering and technology ,General Chemistry ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Nickel ,chemistry ,Chemical engineering ,Specific surface area ,engineering ,Lamellar structure ,0210 nano-technology ,Bimetallic strip ,Cobalt - Abstract
A noncrystalline Ni–B alloy in the shape of nanotubes has demonstrated its superior catalytic performance for some hydrogenation reactions. Remarkable synergistic effects have been observed in many reactions when bimetallic catalysts were used; however, bimetallic noncrystalline alloy nanotubes are far less investigated. Here, we report a simple acetone-assisted lamellar liquid crystal approach for synthesizing a series of bimetallic Ni–Co–B nanotubes and investigate their catalytic performances. The dilution effect of acetone on liquid crystals was characterized by small-angle X-ray diffraction (SAXRD) and scanning electron microscopy (SEM). The Ni/Co molar ratio of the catalyst was varied to study the composition, porous structure, electronic interaction, and catalytic efficiency. In the liquid-phase hydrogenation of p-chloronitrobenzene, the as-prepared noncrystalline alloy Ni–Co–B nanotubes exhibited higher catalytic activity and increased stability as compared to Ni–B and Co–B alloy nanotubes due to electronic interactions between the nickel and cobalt. The excellent hydrogenation performance of the Ni–Co–B nanotubes was attributed to their high specific surface area and the characteristic confinement effects, compared with Ni–Co–B nanoparticles.
- Published
- 2019
- Full Text
- View/download PDF
39. Molecule-Based Transistors: From Macroscale to Single Molecule
- Author
-
Xuefeng Guo, Li Peihui, and Chuancheng Jia
- Subjects
Organic electronics ,Materials science ,010405 organic chemistry ,Information storage ,General Chemical Engineering ,Transistor ,LIGHT STIMULATION ,Nanotechnology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,law.invention ,law ,Materials Chemistry ,Molecule ,Field-effect transistor - Abstract
Molecule-based field-effect transistors (FETs) are of great significance as they have a wide range of application prospects, such as logic operations, information storage and sensor monitoring. This account mainly introduces and reviews our recent work in molecular FETs. Specifically, through molecular and device design, we have systematically investigated the construction and performance of FETs from macroscale to nanoscale and even single molecule. In particular, we have proposed the broad concept of molecular FETs, whose functions can be achieved through various external controls, such as light stimulation, and other physical, chemical or biological interactions. In the end, we tend to focus the discussion on the development challenges of single-molecule FETs, and propose prospects for further breakthroughs in this field.
- Published
- 2020
40. CuPd Nanoparticles as a Robust Catalyst for Electrochemical Allylic Alkylation
- Author
-
Honghong Lin, Kecheng Wei, Zhouyang Yin, Shouheng Sun, Mengqi Shen, Chao Yu, Paul G. Williard, Huan Pang, Michelle Muzzio, and Xuefeng Guo
- Subjects
chemistry.chemical_classification ,Green chemistry ,Allylic rearrangement ,Materials science ,010405 organic chemistry ,General Medicine ,General Chemistry ,010402 general chemistry ,Electrocatalyst ,Electrochemistry ,Electrosynthesis ,01 natural sciences ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,Tsuji–Trost reaction ,chemistry ,Alkyl - Abstract
An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 m KHCO3 solution at room temperature. The Pd catalysis was Pd/Cu composition-dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross-coupling of alkyl halides and allylic halides to form C-C hydrocarbons with product yields reaching up to 99 %. This NP-catalyzed electrochemical allylic alkylation expands the synthetic scope of cross-coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.
- Published
- 2020
41. Revealing the direct effect of individual intercalations on DNA conductance toward single-molecule electrical biodetection
- Author
-
Xuefeng Guo, Li Gao, Bo Liang, Xin Li, and Xiaolong Wang
- Subjects
Mechanism (biology) ,Chemistry ,Drug discovery ,Biomedical Engineering ,Direct observation ,Structural integrity ,Conductance ,Nanotechnology ,General Chemistry ,General Medicine ,Molecular dynamics ,chemistry.chemical_compound ,Molecule ,General Materials Science ,DNA - Abstract
Monitoring complex interactions of biological systems at the molecular level provides new opportunities to uncover fundamental details of the basic processes of life, of crucial importance to biology, diagnosis and drug discovery. Here, we detailed a reliable single-molecule electrical approach for achieving label-free, ultrasensitive electrical detection of DNA functions, using DNA intercalations by individual EB/SGs as a representative, based on DNA-functionalized molecular junctions. The analysis principle relies on the distortion mechanism of intercalative binding on the structural integrity of DNAs at the single-event level, resulting in significant step-wise changes in DNA charge transport. Such an understanding led to direct, rapid intercalator detection with subfemtomolar sensitivity. This single-molecule electrical approach provides a foundation for future molecular dynamics studies with single-molecule sensitivity, which will lead to direct observation of new effects and fundamental discoveries of the details of the most basic processes of life.
- Published
- 2020
42. Organoamine-assisted biomimetic synthesis of faceted hexagonal hydroxyapatite nanotubes with prominent stimulation activity for osteoblast proliferation
- Author
-
Heyun Zhang, Weiping Ding, Liang Yu, Xuefeng Guo, Xiangke Guo, Luming Peng, and Lanhua Chen
- Subjects
musculoskeletal diseases ,medicine.anatomical_structure ,Materials science ,Hexagonal crystal system ,Biomimetic synthesis ,Biomedical Engineering ,medicine ,General Materials Science ,Osteoblast ,Nanotechnology ,General Chemistry ,General Medicine ,Bone healing - Abstract
Uniform single-crystalline hydroxyapatite nanotubes with hexagonal facets are synthesized via a distinctive organoamines-assisted biomimetic route. These novel HA nanotubes exhibit exceptional performance in stimulating osteoblast proliferation, which gives them intriguing potential for bone repair.
- Published
- 2020
43. Frontispiece: Morphology‐Reserved Synthesis of Discrete Nanosheets of CuO@SAPO‐34 and Pore Mouth Catalysis for One‐Pot Oxidation of Cyclohexane
- Author
-
Xiangke Guo, Mengxia Xu, Minyi She, Yan Zhu, Taotao Shi, Zhaoxu Chen, Luming Peng, Xuefeng Guo, Ming Lin, and Weiping Ding
- Subjects
General Chemistry ,Catalysis - Published
- 2020
- Full Text
- View/download PDF
44. Template ion-exchange synthesis of Co-Ni composite hydroxides nanosheets for supercapacitor with unprecedented rate capability
- Author
-
Xuan Wang, Haoyu Song, Shenglan Ma, Muhong Li, Gaoxiong He, Mingjiang Xie, and Xuefeng Guo
- Subjects
General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2022
- Full Text
- View/download PDF
45. Crown ether induced assembly to γ-Al2O3 nanosheets with rich pentacoordinate Al3+ sites and high ethanol dehydration activity
- Author
-
Shanyong Chen, Panpan Hao, Xuefeng Guo, Mingjiang Xie, Yu Zhang, Kun Xiang, Weiping Ding, Tingting Qu, Luming Peng, and J. Chen
- Subjects
chemistry.chemical_classification ,Ethylene ,Chemistry ,General Physics and Astronomy ,Nanoparticle ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,medicine.disease ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Catalysis ,chemistry.chemical_compound ,Chemical engineering ,Yield (chemistry) ,medicine ,Dehydration ,0210 nano-technology ,Crown ether ,Nanosheet ,Space velocity - Abstract
Two-dimensional (2D) materials have attracted great attention due to their unique physical and chemical properties derived from the dimensionality effect and modulation in their band structure. Herein, an important industrial catalytic material, gamma alumina (γ-Al2O3) with well-defined two-dimensional nanosheet structure was fabricated by a designed crown ether induced assembly approach. The obtained γ-Al2O3 nanosheets with a thickness of ∼4 nm possess high surface area (351 m2/g) and 16% pentacoordinate Al3+ sites which are the main catalytic active sites for ethanol dehydration to ethylene, compared to almost no pentacoordinate Al3+ sites for the commercial γ-Al2O3 nanoparticles. Furtherly, systematical investigation reveals that the crown ether plays the key role in the assembly of nanosheet structure. As a catalyst for ethanol dehydration to ethylene, the obtained alumina nanosheets with easily-accessible surface and more active sites, exhibit a superior catalytic performance to the commercial alumina with a much higher yield at large space velocity.
- Published
- 2018
- Full Text
- View/download PDF
46. Trimetallic (Co/Ni/Cu) Hydroxyphosphate Nanosheet Array as Efficient and Durable Electrocatalyst for Oxygen Evolution Reaction
- Author
-
Shanyong Chen, Xiangke Guo, Feifei Bi, Panpan Hao, Yu Zhang, Xuefeng Guo, Muhong Li, Tingting Qu, and Mingjiang Xie
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,General Chemical Engineering ,Oxygen evolution ,02 engineering and technology ,General Chemistry ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrocatalyst ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,Environmental Chemistry ,0210 nano-technology ,Nanosheet - Abstract
The construction of earth-abundant and non-noble-metal-based oxygen evolution reaction (OER) electrocatalysts that could work effectively with long-term stability in alkaline electrolyte is of prim...
- Published
- 2018
- Full Text
- View/download PDF
47. Towards single-molecule optoelectronic devices
- Author
-
Lijue Chen, Dong Xiang, Xuefeng Guo, Junyang Liu, Wenjing Hong, Maoning Wang, and Anni Feng
- Subjects
Materials science ,Molecular junction ,business.industry ,Molecular electronics ,02 engineering and technology ,General Chemistry ,Visible radiation ,Electroluminescence ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,symbols.namesake ,Photon emission ,symbols ,Molecule ,Optoelectronics ,0210 nano-technology ,Raman spectroscopy ,business ,Plasmon - Abstract
Benefiting from the development of molecular electronics and molecular plasmonics, the interplay of light and electronic transport in molecular junctions has attracted growing interest among researchers in both fields, leading to a new research direction of “single-molecule optoelectronics”. Here, we review the latest developments of photo-modulated charge transport, electroluminescence and Raman spectroscopy from single-molecule junctions, and suggest future directions for single-molecule optoelectronics.
- Published
- 2018
- Full Text
- View/download PDF
48. Reduction-oxidation pretreatment enhanced catalytic performance of Co3O4/Al2O3 over CO oxidation
- Author
-
Yan Zhu, Jia Guo, Jing Gu, Yibo Wang, Tao Wang, Luming Peng, Jie Yang, Weiping Ding, Xuefeng Guo, and Nianhua Xue
- Subjects
Chemistry ,Oxide ,General Physics and Astronomy ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Oxidation Activity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Redox ,Lower temperature ,0104 chemical sciences ,Surfaces, Coatings and Films ,Catalysis ,Metal ,chemistry.chemical_compound ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology - Abstract
The present work investigated the effect of reduction-oxidation(R-O) pretreatment on the CO oxidation activity of Co3O4/Al2O3 catalyst. After the reduction-oxidation treatment, the crystalline size of Co3O4 supported on the Al2O3 decreased and it exposed more Co3+, resulting in the improvement of CO oxidation activity. Compared with the as-prepared conventional Co3O4/Al2O3 catalyst, the Co3O4/Al2O3-R-O catalyst is easy to be reduced at lower temperature. The surface reconstruction occurred during the reduction-oxidation pretreatment accounting for the improvement of the catalytic activity. This study reveals the importance of R-O pretreatment as a strategy for the improvement of supported metal oxide catalyst with advanced catalytic performance.
- Published
- 2018
- Full Text
- View/download PDF
49. Comparison of the luminescent properties of warm-toned long-lasting phosphorescent composites: SiO2/red-emitting color converter@SrAl2O4:Eu2+, Dy3+ and PMMA/red-emitting color converter@SrAl2O4:Eu2+, Dy3+
- Author
-
Mingqiao Ge, Zhi Chen, Yanan Zhu, Mengjuan Li, and Xuefeng Guo
- Subjects
010302 applied physics ,chemistry.chemical_classification ,Materials science ,Biophysics ,Phosphor ,02 engineering and technology ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Atomic and Molecular Physics, and Optics ,Spectral line ,Afterglow ,chemistry ,0103 physical sciences ,Emission spectrum ,Chromaticity ,Composite material ,0210 nano-technology ,Phosphorescence ,Luminescence - Abstract
Two kinds of warm-toned (yellow/orange-emitting) long-lasting phosphorescent composites, namely, SiO2/red-emitting color converter@SrAl2O4:Eu2+, Dy3+ (SiO2/RECC@SAOED) and PMMA/red-emitting color converter@SrAl2O4:Eu2+, Dy3+ (PMMA/RECC@SAOED), were prepared in this study. Their morphological and luminescent properties were compared with those of the uncoated SAOED phosphor and analyzed in detail. SiO2/RECC@SAOED and PMMA/RECC@SAOED particles presented a coarse surface with an increased diameter of 12 µm. In addition to the first emission peak at 525 nm similar to that of the uncoated SAOED, an emission peak occurred in the emission spectra of SiO2/RECC@SAOED and PMMA/RECC@SAOED at 610 and 612 nm, respectively. The chromaticity coordinates of SiO2/RECC@SAOED and PMMA/RECC@SAOED moved to the yellow (x = 0.3769, y = 0.5006) and orange (x = 0.4647, y = 0.4671) areas compared with those of the uncoated SAOED in the green area (x = 0.2781, y = 0.5777). The afterglow decay curve revealed that the afterglow property of SiO2/RECC@SAOED was better than that of PMMA/RECC@SAOED.
- Published
- 2018
- Full Text
- View/download PDF
50. Crystal-Facet Effect of γ-Al2O3 on Supporting CrOx for Catalytic Semihydrogenation of Acetylene
- Author
-
Weiping Ding, Luming Peng, Rongtian Gu, Jie Yang, Yan Zhu, Nianhua Xue, Xuefeng Guo, and Yibo Wang
- Subjects
Facet (geometry) ,Materials science ,010405 organic chemistry ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Crystal ,chemistry.chemical_compound ,Crystallography ,Acetylene ,chemistry - Abstract
With the successful preparation of γ-alumina with high-energy external surfaces such as {111} facets, the crystal-facet effect of γ-Al2O3 on surface-loaded CrOx has been explored for semihydrogenat...
- Published
- 2018
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.