73 results on '"Yunxuan Zhao"'
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2. Layered Double Hydroxide Engineering for the Photocatalytic Conversion of Inactive Carbon and Nitrogen Molecules
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Peng Miao, Jiaqi Zhao, Run Shi, Zhenhua Li, Yunxuan Zhao, Chao Zhou, and Tierui Zhang
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General Medicine - Published
- 2022
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3. Quantifying the Contribution of Hot Electrons in Photothermal Catalysis: A Case Study of Ammonia Synthesis over Carbon‐supported Ru Catalyst
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Xuanang Bian, Yunxuan Zhao, Geoffrey I. N. Waterhouse, Yingxuan Miao, Chao Zhou, Li‐Zhu Wu, and Tierui Zhang
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General Medicine ,General Chemistry ,Catalysis - Published
- 2023
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4. Selective Photocatalytic Oxidative Coupling of Methane via Regulating Methyl Intermediates over Metal/ZnO Nanoparticles
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Pu Wang, Run Shi, Yunxuan Zhao, Zhenhua Li, Jiaqing Zhao, Jiaqi Zhao, Geoffrey I. N. Waterhouse, Li‐Zhu Wu, and Tierui Zhang
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General Medicine ,General Chemistry ,Catalysis - Published
- 2023
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5. Low-dissipation optimization of the prefrontal cortex in the −12° head-down tilt position: A functional near-infrared spectroscopy study
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Tingting, Lun, Dexin, Wang, Li, Li, Junliang, Zhou, Yunxuan, Zhao, Yuecai, Chen, Xuntao, Yin, Shanxing, Ou, Jin, Yu, and Rong, Song
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General Psychology - Abstract
IntroductionOur present study set out to investigate the instant state of the prefrontal cortex (PFC) in healthy subjects before and after placement in the -12°head-down tilt (HDT) position in order to explore the mechanism behind the low-dissipation optimization state of the PFC.Methods40 young, right-handed healthy subjects (male: female = 20: 20) were enrolled in this study. Three resting state positions, 0°initial position, -12°HDT position, and 0°rest position were sequentially tested, each for 10 minutes. A continuous-wave functional near-infrared spectroscopy (fNIRS) instrument was used to assess the resting state hemodynamic data of the PFC. After preprocessing the hemodynamics data, we evaluated changes in resting-state functional connectivity (rsFC) level and beta values of PFC. The subjective visual analogue scale (VAS) was applied before and after the experiment. The presence of sleep changes or adverse reactions were also recorded.ResultsPairwise comparisons of the concentrations of oxyhemoglobin (HbO), deoxyhemoglobin (HbR), and hemoglobin (HbT) revealed significant differences in the aforementioned positions. Specifically, the average rsFC of PFC showed a gradual increase throughout the whole process. In addition, based on graph theory, the topological properties of brain network, such as small-world network and nodal degree centrality were analyzed. The results show that global efficiency and small-world sigma (σ) value were differences between 0°initial and 0°rest.DiscussionIn this study, placement in the -12°HDT had a significant effect on PFC function, mainly manifested as self-inhibition, decreased concentration of HbO in the PFC, and improved rsFC, which may provide ideas to the understanding and explanation of neurological diseases.
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- 2022
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6. Enhancing the Supply of Activated Hydrogen to Promote Photocatalytic Nitrogen Fixation
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Tierui Zhang, Xuanang Bian, Shuai Zhang, Yunxuan Zhao, Li-Zhu Wu, Run Shi, Dong Li, and Chao Zhou
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Hydrogen ,Chemistry ,General Chemical Engineering ,Biomedical Engineering ,Nitrogen fixation ,Photocatalysis ,chemistry.chemical_element ,General Materials Science ,Photochemistry - Published
- 2021
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7. Pt Single Atoms on CrN Nanoparticles Deliver Outstanding Activity and CO Tolerance in the Hydrogen Oxidation Reaction
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Zhaojun Yang, Chaoqiu Chen, Yunxuan Zhao, Qing Wang, Jiaqi Zhao, Geoffrey I. N. Waterhouse, Yong Qin, Lu Shang, and Tierui Zhang
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
The large-scale application of proton exchange membrane fuel cells is currently hampered by high cost of commercial Pt catalysts and their susceptibility to poisoning by CO impurities in H
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- 2022
8. Accelerating Electron-Transfer Dynamics by TiO
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Dong, Li, Yunxuan, Zhao, Yingxuan, Miao, Chao, Zhou, Li-Ping, Zhang, Li-Zhu, Wu, and Tierui, Zhang
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Photocatalysis as a sustainable technology is expected to provide a novel sight for the green synthesis of urea directly using N
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- 2022
9. Revealing Ammonia Quantification Minefield in Photo/Electrocatalysis
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Junwang Tang, Chao Zhou, Li-Zhu Wu, Yingxuan Miao, Tierui Zhang, Yunxuan Zhao, Fan Wu, Run Shi, and Ning Xu
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Ammonia production ,Ammonia ,chemistry.chemical_compound ,Materials science ,Aqueous medium ,chemistry ,Inorganic chemistry ,General Medicine ,General Chemistry ,Electrocatalyst ,Catalysis ,Volume concentration - Abstract
Photo/electrocatalytic ammonia synthesis has recently developed fast while the ammonia yields over state-of-the-art photo/electrocatalysts are still very moderate. Such low concentration of synthesized NH3 brings about a challenge to the reliable quantification of the product in photo/electrocatalysis. Notably, we found that the quantitative detection of ammonia concentration below 0.2 ppm is error-prone, which is likely the case happening in the majority of photo/electrocatalytic NH3 synthesis, thus arising concerns about the rationality and accuracy for low-concentration ammonia quantification in these processes. Herein, we discuss the methodology used and analyze the reliability of various detection methods for the detection of trace ammonia in aqueous media. The challenges facing the detection of low concentration of ammonia in photo/electrocatalysis can be overcome by integration with multiple detection methods. According to the data presented, we also propose an effective criterion for precise quantification of ammonia, avoiding the unreasonable comparisons in photo/electrocatalytic ammonia synthesis.
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- 2021
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10. Room-temperature electrochemical acetylene reduction to ethylene with high conversion and selectivity
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Bikun Zhang, Zhimei Sun, Chuan Xia, Run Shi, Yunxuan Zhao, Haotian Wang, Zhenhua Li, Geoffrey I. N. Waterhouse, Tierui Zhang, and Zeping Wang
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Ethylene ,Materials science ,Hydrogen ,Process Chemistry and Technology ,Energy conversion efficiency ,chemistry.chemical_element ,Bioengineering ,Polyethylene ,Electrocatalyst ,Biochemistry ,Catalysis ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Acetylene ,Faraday efficiency - Abstract
The selective hydrogenation of acetylene to ethylene in ethylene-rich gas streams is an important process in the manufacture of polyethylene. Conventional thermal hydrogenation routes require temperatures above 100 °C and excess hydrogen to achieve a satisfactory C2H2 conversion efficiency. Here, we report a room-temperature electrochemical acetylene reduction system based on a layered double hydroxide (LDH)-derived copper catalyst that offers an ethylene Faradaic efficiency of up to ~80% and inhibits alkane and hydrogen formation. The system affords an acetylene conversion of over 99.9% at a flow rate of 50 ml min−1 in a simulated gas feed, yielding high-purity ethylene with an ethylene/acetylene volume ratio exceeding 105 and negligible residual hydrogen (0.08 vol.%). These acetylene conversion metrics are superior to most other state-of-the-art strategies. The findings therefore conclusively demonstrate an electrochemical strategy as a viable alternative to current technologies for acetylene-to-ethylene conversions with potential advantages in energy and atom economies. The selective semihydrogenation of acetylene in ethylene-rich gas streams is an important process in the manufacture of polyethylene, which is traditionally performed thermocatalytically. Now, a room-temperature electrochemical acetylene reduction system with excellent performance is presented.
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- 2021
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11. Understanding Aerobic Nitrogen Photooxidation on Titania through In Situ Time-Resolved Spectroscopy
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Shuai Zhang, Yunxuan Zhao, Yingxuan Miao, Yanjun Xu, Jingrun Ran, Zhuan Wang, Yuxiang Weng, and Tierui Zhang
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General Chemistry ,General Medicine ,Catalysis - Abstract
Nitrate is an important raw material for chemical fertilizers, but it is industrially manufactured in multiple steps at high temperature and pressure, urgently motivating the design of a green and sustainable strategy for nitrate production. We report the photosynthesis of nitrate from N
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- 2022
12. Polarized Cu-Bi Site Pairs for Non-Covalent to Covalent Interaction Tuning toward N
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Jun, Di, Chao, Chen, Yao, Wu, Yunxuan, Zhao, Chao, Zhu, Yi, Zhang, Changda, Wang, Hailong, Chen, Jun, Xiong, Manzhang, Xu, Jiexiang, Xia, Jiadong, Zhou, Yuxiang, Weng, Li, Song, Shuzhou, Li, Wei, Jiang, and Zheng, Liu
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A universal atomic layer confined doping strategy is developed to prepare Bi
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- 2022
13. Unveiling the critical role of TiO2-supported atomically dispersed Cu species for enhanced photofixation of N2 to nitrate
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Dong Li, Yunxuan Zhao, Chao Zhou, Li-Ping Zhang, Junwang Tang, and Tierui Zhang
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Multidisciplinary - Published
- 2022
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14. Exploiting Ru‐Induced Lattice Strain in CoRu Nanoalloys for Robust Bifunctional Hydrogen Production
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Kan Zhang, Tierui Zhang, Mingzi Sun, Yunxuan Zhao, Weidong Li, Geoffrey I. N. Waterhouse, Yuan Liu, Siyu Lu, and Bolong Huang
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Materials science ,Hydrogen ,010405 organic chemistry ,Ammonia borane ,chemistry.chemical_element ,General Chemistry ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Ruthenium ,chemistry.chemical_compound ,Hydrogen storage ,chemistry ,Physical chemistry ,Bifunctional ,Hydrogen production - Abstract
Designing bifunctional catalysts capable of driving the electrochemical hydrogen evolution reaction (HER) and also H2 evolution via the hydrolysis of hydrogen storage materials such as ammonia borane (AB) is of considerable practical importance for future hydrogen economies. Herein, we systematically examined the effect of tensile lattice strain in CoRu nanoalloys supported on carbon quantum dots (CoRu/CQDs) on hydrogen generation by HER and AB hydrolysis. By varying the Ru content, the lattice parameters and Ru-induced lattice strain in the CoRu nanoalloys could be tuned. The CoRu0.5 /CQDs catalyst with an ultra-low Ru content (1.33 wt.%) exhibited excellent catalytic activity for HER (η=18 mV at 10 mA cm-2 in 1 M KOH) and extraordinary activity for the hydrolysis of AB with a turnover frequency of 3255.4 mol ( H 2 ) mol-1 (Ru) min-1 or 814.7 mol ( H 2 ) mol-1 (cat) min-1 at 298 K, respectively, representing one of the best activities yet reported for AB hydrolysis over a ruthenium alloy catalyst. Moreover, the CoRu0.5 /CQDs catalyst displayed excellent stability during each reaction, including seven alternating cycles of HER and AB hydrolysis. Theoretical calculations revealed that the remarkable catalytic performance of CoRu0.5 /CQDs resulted from the optimal alloy electronic structure realized by incorporating small amounts of Ru, which enabled fast interfacial electron transfer to intermediates, thus benefitting H2 evolution kinetics. Results support the development of new and improved catalysts HER and AB hydrolysis.
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- 2020
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15. Exploiting Ru‐Induced Lattice Strain in CoRu Nanoalloys for Robust Bifunctional Hydrogen Production
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Weidong Li, Yunxuan Zhao, Yuan Liu, Mingzi Sun, Geoffrey I. N. Waterhouse, Bolong Huang, Kan Zhang, Tierui Zhang, and Siyu Lu
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General Medicine - Published
- 2020
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16. Sub‐3 nm Ultrafine Cu 2 O for Visible Light Driven Nitrogen Fixation
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Yuxiang Weng, Run Shi, Shuai Zhang, Geoffrey I. N. Waterhouse, Tierui Zhang, Yunxuan Zhao, Zhuan Wang, and Chao Zhou
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Materials science ,010405 organic chemistry ,business.industry ,chemistry.chemical_element ,General Medicine ,General Chemistry ,Electron ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Copper ,Catalysis ,0104 chemical sciences ,Semiconductor ,chemistry ,Photocatalysis ,Nitrogen fixation ,High activity ,business ,Visible spectrum - Abstract
Cu2 O, a low-cost, visible light responsive semiconductor photocatalyst represents an ideal candidate for visible light driven photocatalytic reduction of N2 to NH3 from the viewpoint of thermodynamics, but it remains unexplored. Reported here is the successful synthesis of uniformly sized and ultrafine Cu2 O platelets, with a lateral size of Cu 2 O -1 h-1 at λ>400 nm), with the origin of the high activity being long-lived photoexcited electrons in trap states, an abundance of exposed active sites, and the underlying support structure. This work guides the future design of ultrafine catalysts for NH3 synthesis and other applications.
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- 2020
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17. Selective photocatalytic CO2 reduction over Zn-based layered double hydroxides containing tri or tetravalent metals
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Yunxuan Zhao, Run Shi, Xuyang Xiong, Wenjin Yin, Yufei Zhao, Tierui Zhang, and Geoffrey I. N. Waterhouse
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Multidisciplinary ,Chemistry ,Fermi level ,Inorganic chemistry ,Layered double hydroxides ,engineering.material ,010502 geochemistry & geophysics ,01 natural sciences ,Metal ,symbols.namesake ,chemistry.chemical_compound ,Adsorption ,visual_art ,visual_art.visual_art_medium ,Photocatalysis ,symbols ,engineering ,Water splitting ,Hydroxide ,Selectivity ,0105 earth and related environmental sciences - Abstract
Photocatalytic CO2 reduction holds promise as a future technology for the manufacture of fuels and commodity chemicals. However, factors controlling product selectivity remain poorly understood. Herein, we compared the performance of a homologous series of Zn-based layered double hydroxide (ZnM-LDH) photocatalysts for CO2 reduction. By varying the trivalent or tetravalent metal cations in the ZnM-LDH photocatalysts (M = Ti4+, Fe3+, Co3+, Ga3+, Al3+), the product selectivity of the reaction could be precisely controlled. ZnTi-LDH afforded CH4 as the main reduction product; ZnFe-LDH and ZnCo-LDH yielded H2 exclusively from water splitting; whilst ZnGa-LDH and ZnAl-LDH generated CO. In-situ diffuse reflectance infrared measurements, valence band XPS and density function theory calculations were applied to rationalize the CO2 reduction selectivities of the different ZnM-LDH photocatalysts. The analyses revealed that the d-band center (ed) position of the M3+ or M4+ cations controlled the adsorption strength of CO2 and thus the selectivity to carbon-containing products or H2. Cations with d-band centers relatively close to the Fermi level (Ti4+, Ga3+ and Al3+) adsorbed CO2 strongly yielding CH4 or CO, whereas metal cations with d-band centers further from the Fermi level (Fe3+ and Co3+) adsorbed CO2 poorly, thereby yielding H2 only (from water splitting). Our findings clarify the role of trivalent and tetravalent metal cations in LDH photocatalysts for the selective CO2 reduction, paving new ways for the development of improved LDH photocatalyst with high selectivities to specific products.
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- 2020
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18. Two-dimensional photocatalyst design: A critical review of recent experimental and computational advances
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Yunxuan Zhao, Shuai Zhang, Geoffrey I. N. Waterhouse, Junwang Tang, Tierui Zhang, and Run Shi
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Materials science ,business.industry ,Charge carrier mobility ,Band gap ,Mechanical Engineering ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,N2 Fixation ,Semiconductor ,Mechanics of Materials ,Photocatalysis ,Solar energy conversion ,Water splitting ,General Materials Science ,0210 nano-technology ,business ,Nanosheet - Abstract
In recent years, two-dimensional (2D) semiconductor photocatalysts have been widely applied in water splitting, CO2 reduction, N2 fixation, as well as many other important photoreactions. Photocatalysts in the form of 2D nanosheet possess many inherent advantages over traditional 3D nanopowder photocatalysts, including improved light absorption characteristics, shorter electron and hole migration paths to the photocatalysts’ surface (thus minimizing undesirable electron-hole pair recombination), and abundant surface defects which allow band gap modulation and facilitate charge transfer from the semiconductor to adsorbates. When synergistically exploited and optimized, these advantages can impart 2D photocatalysts with remarkable activities relative to their 3D counterparts. Accordingly, a wide range of experimental approaches is now being explored for the synthesis of 2D photocatalysts, with computational methods increasingly being used for identification of promising new 2D photocatalytic materials. Herein, we critically review recent literatures related to 2D photocatalyst development and design. Particular emphasis is placed on 2D photocatalyst synthesis and the importance of computational studies for the fundamental understanding of 2D photocatalyst electronic structure, band gap structure, charge carrier mobility and reaction pathways. We also explore the practical challenges of using 2D photocatalysts, such as their difficulty to synthesize in large quantity and also their characterization. The overarching aim of this review is to provide a snapshot of recent work targeting high-performance 2D photocatalysts for efficient solar energy conversion, thus laying a firm base for future advancements in this rapidly expanding area of photocatalysis research.
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- 2020
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19. Engineered extracellular vesicles and their mimetics for cancer immunotherapy
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Chunping Liu, Yichao Wang, Longmei Li, Dongyue He, Jiaxin Chi, Qin Li, Yixiao Wu, Yunxuan Zhao, Shihui Zhang, Lei Wang, Zhijin Fan, and Yuhui Liao
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Extracellular Vesicles ,Neoplasms ,Nucleic Acids ,Pharmaceutical Science ,Humans ,Immunotherapy ,Lipids ,Biomarkers - Abstract
Extracellular vesicles (EVs) are heterogeneous membranous vesicles secreted by living cells that are involved in many physiological and pathological processes as intermediaries for intercellular communication and molecular transfer. Recent studies have shown that EVs can regulate the occurrence and development of tumors by transferring proteins, lipids and nucleic acids to immune cells as signaling molecules. As a new diagnostic biomarker and drug delivery system, EVs have broad application prospects in immunotherapy. In addition, the breakthrough of nanotechnology has promoted the development and exploration of engineered EVs for immune-targeted therapy. Herein, we review the uniqueness of EVs in immune regulation and the engineering strategies used for immunotherapy and highlight the logic of their design through typical examples. The present situation and challenges of clinical transformation are discussed, and the development prospects of EVs in immunotherapy are proposed. The goal of this review is to provide new insights into the design of immune-regulatory EVs and expand their application in cancer immunotherapy.
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- 2022
20. Acupuncture for children with autism spectrum disorder: A systematic review and meta-analysis
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Tingting Lun, Shaoping Lin, Yuecai Chen, Yunxuan Zhao, Dexin Wang, Li Li, and Jin Yu
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General Medicine - Published
- 2023
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21. Defect Engineering in Photocatalytic Nitrogen Fixation
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Tierui Zhang, Yunxuan Zhao, Shuai Zhang, Geoffrey I. N. Waterhouse, and Run Shi
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Energy demand ,010405 organic chemistry ,Chemistry ,chemistry.chemical_element ,Defect engineering ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Nitrogen ,Catalysis ,0104 chemical sciences ,Ammonia production ,Ammonia ,chemistry.chemical_compound ,Chemical engineering ,Photocatalysis ,Nitrogen fixation - Abstract
Approximately 2% of the energy consumed by humans each year is used to make nitrogen-based fertilizers, with ammonia (NH3) production being the most significant contributor to this energy demand. C...
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- 2019
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22. Exploiting Single Atom Iron Centers in a Porphyrin-like MOF for Efficient Cancer Phototherapy
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Yunxuan Zhao, Xiaozhong Qu, Hong Yan, Li Wang, Shanyue Guan, Shuyun Zhou, Yangziwan Weng, and Geoffrey I. N. Waterhouse
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Porphyrins ,Materials science ,medicine.medical_treatment ,Photodynamic therapy ,02 engineering and technology ,010402 general chemistry ,Photochemistry ,01 natural sciences ,chemistry.chemical_compound ,Neoplasms ,Tumor Microenvironment ,medicine ,Humans ,General Materials Science ,Irradiation ,Absorption (electromagnetic radiation) ,Metal-Organic Frameworks ,Singlet oxygen ,fungi ,Photothermal therapy ,021001 nanoscience & nanotechnology ,Porphyrin ,0104 chemical sciences ,Models, Chemical ,Photochemotherapy ,Triplet oxygen ,chemistry ,Density functional theory ,0210 nano-technology ,HeLa Cells - Abstract
In recent years, single-atom catalysts (SACs) have attracted enormous attention due their effectiveness in promoting a variety of catalytic reactions. However, the ability of SACs to enhance cancer phototherapies has received little attention to date. Herein, we synthesized a metal organic framework (MOF) rich in porphyrin-like single atom Fe(III) centers (denoted herein as porphyrin-MOF or P-MOF) and then evaluated the performance of the P-MOF for cancer treatment by photodynamic therapy (PDT) and photothermal therapy (PTT) under NIR (808 nm) irradiation, as well as photoacoustic imaging (PAI) of tumors. On acccount of the abundance of single atom Fe(III) centers, the P-MOF material demonstrated excellent performance for modulation of the hypoxic tumor microenvironment of Hela cell tumors in mice, while also demonstrating good properties as a photoacoustic imaging (PAI) agent. Density functional theory (DFT) calculations were used to elucidate the superior performance of P-MOF in these applications relative to Fe2O3 (a Fe(III) reference compound). The calculations revealed that the narrow band gap energy of P-MOF (1.31 eV) enabled strong absorption of NIR photons, thereby inducing nonradiative transitions that converted incident light into heat to promote PTT. Further, a facile change of the spin state of the single atom Fe(III) centers in P-MOF under NIR irradiation transformed coordinated triplet oxygen (3O2) to singlet oxygen (1O2), benefiting PDT. This work demonstrates the great future potential of both SACs and MOFs as multifunctional agents for cancer treatment and tumor imaging.
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- 2019
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23. Ultrafine monolayer Co-containing layered double hydroxide nanosheets for water oxidation
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Chen-Ho Tung, Xiaodan Jia, Run Shi, Geoffrey I. N. Waterhouse, Li-Zhu Wu, Jiaqing Zhao, Xin Zhang, Yufei Zhao, Tierui Zhang, and Yunxuan Zhao
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Materials science ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,Catalysis ,chemistry.chemical_compound ,Fuel Technology ,chemistry ,Chemical engineering ,Monolayer ,Electrochemistry ,Hydroxide ,0210 nano-technology ,Energy (miscellaneous) - Abstract
For many two-dimensional (2D) materials, low coordination edges and corner sites offer greatly enhanced catalytic performance compared to basal sites, motivating the search for new synthetic approaches towards ultrathin and ultrafine 2D nanomaterials with high specific surface areas. To date, the synthesis of catalysts that are both ultrathin (monolayer) and ultrafine (lateral size
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- 2019
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24. Accelerating Electron‐Transfer Dynamics by TiO 2 ‐Immobilized Reversible Single‐Atom Copper for Enhanced Artificial Photosynthesis of Urea
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Dong Li, Yunxuan Zhao, Yingxuan Miao, Chao Zhou, Li‐Ping Zhang, Li‐Zhu Wu, and Tierui Zhang
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2022
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25. Polarized Cu–Bi Site Pairs for Non‐Covalent to Covalent Interaction Tuning toward N 2 Photoreduction
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Jun Di, Chao Chen, Yao Wu, Yunxuan Zhao, Chao Zhu, Yi Zhang, Changda Wang, Hailong Chen, Jun Xiong, Manzhang Xu, Jiexiang Xia, Jiadong Zhou, Yuxiang Weng, Li Song, Shuzhou Li, Wei Jiang, and Zheng Liu
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Published
- 2022
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26. Vacancy‐Rich MXene‐Immobilized Ni Single Atoms as a High‐Performance Electrocatalyst for the Hydrazine Oxidation Reaction
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Shiqi Zhou, Yunxuan Zhao, Run Shi, Yucheng Wang, Anumol Ashok, Frédéric Héraly, Tierui Zhang, and Jiayin Yuan
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
Single-atom catalysts (SACs), on account of their outstanding catalytic potential, are currently emerging as high-performance materials in the field of heterogeneous catalysis. Constructing a strong interaction between the single atom and its supporting matrix plays a pivotal role. Herein, Ti
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- 2022
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27. A Reliable and Precise Protocol for Urea Quantification in Photo/Electrocatalysis
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Dong Li, Ning Xu, Yunxuan Zhao, Chao Zhou, Li‐Ping Zhang, Li‐Zhu Wu, and Tierui Zhang
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Reproducibility of Results ,Urea ,General Materials Science ,General Chemistry - Abstract
To comply with the trend toward green and sustainable development of the fine chemical industry, multitudinous promising technologies (e.g., photocatalysis and electrocatalysis) are beginning to dabble in the green synthesis of fine chemicals, particularly urea synthesis. Whilst numerous advances are made in mechanistic understanding, the low yield reported so far also imposes more stringent requirements on the reliability and anti-interference of the detection method. Herein, the applicability of frequently used methods for urea quantification is methodically compared. In terms of the experimental results, a precise and methodical protocol for urea quantification or evaluation in photo/electrocatalysis is explored and established, with emphasis on screening quantitative methods under specific conditions and indispensable isotopic tracing experiments. The budding urea photo/electrosynthesis urgently demands a rigorous protocol, including the rapid isotopic identification and evaluation criteria, capable of promoting healthy development in the future.
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- 2022
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28. Strain Engineering: A Boosting Strategy for Photocatalysis
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Yingxuan Miao, Yunxuan Zhao, Shuai Zhang, Run Shi, and Tierui Zhang
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
Whilst the photocatalytic technique is considered to be one of the most significant routes to address the energy crisis and global environmental challenges, the solar-to-chemical conversion efficiency is still far from satisfying practical industrial requirements, which can be traced to the suboptimal bandgap and electronic structure of photocatalysts. Strain engineering is a universal scheme that can finely tailor the bandgap and electronic structure of materials, hence supplying a novel avenue to boost their photocatalytic performance. Accordingly, to explore promising directions for certain breakthroughs in strained photocatalysts, an overview on the recent advances of strain engineering from the basics of strain effect, creations of strained materials, as well as characterizations and simulations of strain level is provided. Besides, the potential applications of strain engineering in photocatalysis are summarized, and a vision for the future controllable-electronic-structure photocatalysts by strain engineering is also given. Finally, perspectives on the challenges for future strain-promoted photocatalysis are discussed, placing emphasis on the creation and decoupling of strain effect, and the modification of theoretical frameworks.
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- 2022
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29. Sub-3 nm Ultrafine Cu
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Shuai, Zhang, Yunxuan, Zhao, Run, Shi, Chao, Zhou, Geoffrey I N, Waterhouse, Zhuan, Wang, Yuxiang, Weng, and Tierui, Zhang
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Cu
- Published
- 2020
30. Interfacial wettability and mass transfer characterizations for gas–liquid–solid triple‐phase catalysis
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Run Shi, Lu Shang, Chao Zhou, Yunxuan Zhao, and Tierui Zhang
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- 2022
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31. Designer Functional Nanomedicine for Myocardial Repair by Regulating the Inflammatory Microenvironment
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Chunping Liu, Zhijin Fan, Dongyue He, Huiqi Chen, Shihui Zhang, Sien Guo, Bojun Zheng, Huan Cen, Yunxuan Zhao, Hongxing Liu, and Lei Wang
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Pharmaceutical Science - Abstract
Acute myocardial infarction is a major global health problem, and the repair of damaged myocardium is still a major challenge. Myocardial injury triggers an inflammatory response: immune cells infiltrate into the myocardium while activating myofibroblasts and vascular endothelial cells, promoting tissue repair and scar formation. Fragments released by cardiomyocytes become endogenous “danger signals”, which are recognized by cardiac pattern recognition receptors, activate resident cardiac immune cells, release thrombin factors and inflammatory mediators, and trigger severe inflammatory responses. Inflammatory signaling plays an important role in the dilation and fibrosis remodeling of the infarcted heart, and is a key event driving the pathogenesis of post-infarct heart failure. At present, there is no effective way to reverse the inflammatory microenvironment in injured myocardium, so it is urgent to find new therapeutic and diagnostic strategies. Nanomedicine, the application of nanoparticles for the prevention, treatment, and imaging of disease, has produced a number of promising applications. This review discusses the treatment and challenges of myocardial injury and describes the advantages of functional nanoparticles in regulating the myocardial inflammatory microenvironment and overcoming side effects. In addition, the role of inflammatory signals in regulating the repair and remodeling of infarcted hearts is discussed, and specific therapeutic targets are identified to provide new therapeutic ideas for the treatment of myocardial injury.
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- 2022
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32. Artificial photocatalytic nitrogen fixation: Where are we now? Where is its future?
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Yunxuan Zhao, Yingxuan Miao, Chao Zhou, and Tierui Zhang
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Process Chemistry and Technology ,Physical and Theoretical Chemistry ,Catalysis - Published
- 2022
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33. A simple post-synthesis conversion approach to Zn(OH)F and the effects of fluorine and hydroxyl on the photodegradation properties of dye wastewater
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Yiran Teng, Hao Yang, An Zhang, Wenhao Gu, Fei Teng, Zhe Liu, Zailun Liu, and Yunxuan Zhao
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Environmental Engineering ,Band gap ,Chemistry ,Health, Toxicology and Mutagenesis ,Radical ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Pollution ,0104 chemical sciences ,chemistry.chemical_compound ,Fluorine ,Photocatalysis ,Environmental Chemistry ,Degradation (geology) ,0210 nano-technology ,Electronic band structure ,Photodegradation ,Waste Management and Disposal ,Methylene blue - Abstract
In this work, Zn(OH)F is prepared by an initiative, simple post-synthesis method, in which the molar ratio of F/Zn (R F ) was varied to investigate the effect of the NH 4 F amounts added on the samples. Further, we have mainly investigated their energy bands and photochemical properties. Under UV light irradiation (λ£420 nm), the samples (R F = 0,1,2) show the high degradation activities of methylene blue (MB) dye, namely, 80% of MB can be degraded after 8 min. It is found that the hydroxyl and fluorine have greatly down shifted the conduction band (CB, 0.99 eV) and valence band (VB, 4.17 eV) of Zn(OH)F, compared with ZnO (CB = −0.31 eV, VB = 2.89 eV), but with the nearly same band gap. For the degradation of MB dye, the main oxidative species are holes and hydroxyl radicals for ZnO and Zn(OH)F, respectively. This study suggests that this simple post-synthesis fluorination approach could be extended to develop the other photocatalysts; moreover, we can facilely tune the band structure and photocatalytic activity by introducing or removing hydroxyl and fluorine, which could benefit to develop new photocatalysts.
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- 2017
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34. Graphene with Atomic-Level In-Plane Decoration of h-BN Domains for Efficient Photocatalysis
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Gang Hu, Jinglin Xie, Nanhong Xie, Ding Ma, Junwang Tang, Mengzhu Li, Pei Tang, Yiou Wang, Yufei Zhao, Yunxuan Zhao, Tierui Zhang, and Xi Liu
- Subjects
Materials science ,Graphene ,Band gap ,General Chemical Engineering ,Doping ,Heteroatom ,Rational design ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,Boron nitride ,law ,Materials Chemistry ,Photocatalysis ,0210 nano-technology ,Hydrogen production - Abstract
Band gap opening and engineering make up one of the primary goals of developing novel materials for photocatalytic hydrogen generation. We report here a facile synthesis of graphene decorated with in-plane boron nitride domains via control of both the doping sequence of heteroatoms and the oxygen content of the graphene precursor, showing significant differences in the doping pattern compared with B and/or N singly doped or co-doped graphene. We uncover that the formation of BN domains in graphene is critical for engineering the band gap and delivering an improved activity for photocatalytic hydrogen generation in the absence of any photosensitizer. This work paves the way for the rational design and construction of graphene-based photocatalysts for efficient photocatalysis.
- Published
- 2017
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35. Dynamic changes of single-atom Pt-C3N4 photocatalysts
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Tierui Zhang and Yunxuan Zhao
- Subjects
Crystallography ,Multidisciplinary ,Materials science ,Atom (order theory) - Published
- 2020
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36. The Construction of Chinese Wisdom in Hollywood Animated Films
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Yunxuan Zhao
- Subjects
Hollywood ,media_common.quotation_subject ,Art ,media_common ,Visual arts - Published
- 2020
- Full Text
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37. Electrochemical performances of asymmetric super capacitor fabricated by one-dimensional CoMoO4 nanostructure
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Du Qian, Zailun Liu, Fei Teng, Yiran Teng, Jingjing Xu, and Yunxuan Zhao
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Supercapacitor ,Nanostructure ,business.industry ,General Physics and Astronomy ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Capacitance ,0104 chemical sciences ,Anode ,Electrode ,Optoelectronics ,Nanorod ,Physical and Theoretical Chemistry ,0210 nano-technology ,business ,Current density ,Power density - Abstract
We have prepared the CoMoO4 nanorods (NR) electrode with a specific capacitance (89.5 F g−1) at a current density of 1 mA cm−2. Moreover, the asymmetric supercapacitor (ASC) has been fabricated by using CoMoO4 NR as positive electrode and activated carbon (AC) as negative electrode. At a power density of 80 mW cm−3, the ASC can deliver an energy density of 0.226 mW h cm−3 in the voltage range of 0–1.6 V. In addition, the CoMoO4 NR-based ASC device still remains a high energy density (84.07%) after 5000 cycles, demonstrating that one-dimensional nanostructures could be promising to achieve the high-energy-density materials.
- Published
- 2016
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38. Recent Progress on Two-Dimensional Materials
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Zhanxi Fan, Lain-Jong Li, Hui Zhang, Zhongming Wei, Tianyou Zhai, Cheng Chang, Xin Wang, Zhongfan Liu, Li Song, Shuo Sun, Jie Xiong, Feng Ding, Chaoliang Tan, Chongyi Ling, Kian Ping Loh, Peng Yin, Yu Chen, Zhiyong Tang, Andrew T. S. Wee, Zhiyuan Zeng, Haibo Zeng, Han Zhang, Yi Chen, Yu Zhou, Mingfei Shao, Wei Huang, Xing Zhou, Wei Ji, Nan Liu, Hong Jin Fan, Yuan Huang, Qichun Zhang, Minghua Liu, Kai-Ge Zhou, Zhong-Shuai Wu, Qiyuan He, Yongji Gong, Sheng Hu, Xinran Wang, Xiang Zhang, Cheng Gong, Huan Wang, Wei Chen, Meiting Zhao, Dehui Li, Xun Hong, Li Lin, Jinlan Wang, Chunhai Fan, Qiang Li, Dingsheng Wang, Zhuang Liu, Qihua Xiong, Hongwei Zhu, Weigao Xu, Hua Zhang, Shao Su, Li-Dong Zhao, Jianmin Ma, Tierui Zhang, Hailin Peng, Yunxuan Zhao, Weijie Zhao, Yonghua Chen, Yuen Wu, Feng Miao, and Weida Hu
- Subjects
Materials science ,Physical and Theoretical Chemistry - Published
- 2021
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39. Underwater superaerophobic Ni nanoparticle-decorated nickel–molybdenum nitride nanowire arrays for hydrogen evolution in neutral media
- Author
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Run Shi, Tierui Zhang, Lu Shang, Yunxuan Zhao, Liping Wen, Xiang-Yu Kong, and Geoffrey I. N. Waterhouse
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Materials science ,Hydrogen ,Renewable Energy, Sustainability and the Environment ,Nanowire ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,Overpotential ,Nitride ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,0104 chemical sciences ,chemistry ,Chemical engineering ,Electrode ,Water splitting ,General Materials Science ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
Electrochemical water splitting into hydrogen and oxygen in neutral electrolytes has great significance for future energy supply security, potentially offering a pathway for H2 generation from seawater. However, the electrocatalytic hydrogen evolution reaction (HER) generally occurs at low rates in neutral solutions due to the low proton concentration in such media. Herein, we fabricated a novel HER catalyst capable of efficient H2 evolution in water at neutral pH, comprising a nickel-molybdenum nitride nanowire array modified with metallic Ni nanoparticles (Ni/NiMoN). The entire Ni/NiMoN array was supported on a Cu foam. The Ni nanoparticles promoted the dissociation of adsorbed water to enhance the supply of protons in the neutral electrolyte, whilst the nanowire array imparted the electrode surface with underwater superaerophobic properties, thus allowing H2 gas bubbles to detach from the electrode in a facile manner. On the basis of the synergies realized between the different electrode components, the Ni/NiMoN nanowire array electrode offered exceptional HER performance, with an overpotential of only 37 mV at a current density of 10 mA cm−2 in a neutral electrolyte. Results guide the development of next-generation earth-abundant element electrocatalysts for HER in neutral media.
- Published
- 2020
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40. Porous Ni5P4 as a promising cocatalyst for boosting the photocatalytic hydrogen evolution reaction performance
- Author
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Xiaohui Yu, Tierui Zhang, Yunxuan Zhao, Hua Tang, Xin Liu, Qinqin Liu, Youyong Li, and Xiaofei Yang
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Materials science ,Process Chemistry and Technology ,chemistry.chemical_element ,Protonation ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Phosphide compound ,0104 chemical sciences ,Nickel ,chemistry ,Chemical engineering ,Photocatalysis ,Charge carrier ,Hydrogen evolution ,0210 nano-technology ,Porosity ,General Environmental Science ,Visible spectrum - Abstract
Nonmetallic cocatalysts have demonstrated unprecedented potential for accelerating photocatalytic hydrogen evolution reaction (HER). In this study, a nickel phosphide compound, namely Ni5P4, with porous carnation-like superstructure has been target-synthesized and then employed as HER cocatalyst to in-situ build a hybrid with protonated g-C3N4 nanosheets via an electrostatic self-assembly method. Owing to the synergistic advantages of the excellent metallic conductivity and porous carnation-like superstructure of Ni5P4, the as-obtained HCN/Ni5P4 Schottky-junction with abundant active sites, low H* atom adsorption energy and efficient charge carrier transport channel, affords the photocatalytic H2 production rate of 1157.5 μmol g−1 h−1 when exposed to visible light (λ > 420 nm). This photocatalytic H2 production rate was much higher than those of the corresponding reference cocatalysts, namely Ni2P and NiS2 (169.1 and 593.1 μmol g−1 h−1, respectively), both of which were derived from the same Ni(OH)2 precursor. This study provides a new idea for the design of highly active noble-metal-free materials for the photocatalytic HER.
- Published
- 2020
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41. Alkali Etching of Layered Double Hydroxide Nanosheets for Enhanced Photocatalytic N 2 Reduction to NH 3
- Author
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Run Shi, Xuanang Bian, Xingzhong Cao, Lirong Zheng, Shuai Zhang, Fan Wu, Yunxuan Zhao, Tierui Zhang, and Geoffrey I. N. Waterhouse
- Subjects
Reduction (complexity) ,chemistry.chemical_compound ,Materials science ,chemistry ,Chemical engineering ,Renewable Energy, Sustainability and the Environment ,Etching (microfabrication) ,Photocatalysis ,Hydroxide ,General Materials Science ,Alkali metal - Published
- 2020
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42. Pd Single-Atom Catalysts on Nitrogen-Doped Graphene for the Highly Selective Photothermal Hydrogenation of Acetylene to Ethylene
- Author
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Lu Shang, Tierui Zhang, Yunxuan Zhao, Lirong Zheng, Geoffrey I. N. Waterhouse, Run Shi, Shiqi Zhou, and Yu-Cheng Huang
- Subjects
Materials science ,Ethylene ,Graphene ,Mechanical Engineering ,chemistry.chemical_element ,02 engineering and technology ,Photothermal therapy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Nitrogen ,0104 chemical sciences ,Catalysis ,law.invention ,chemistry.chemical_compound ,Acetylene ,chemistry ,Mechanics of Materials ,law ,General Materials Science ,Irradiation ,0210 nano-technology ,Selectivity - Abstract
The selective hydrogenation of acetylene to ethylene in an ethylene-rich gas stream is an important process in the chemical industry. Pd-based catalysts are widely used in this reaction due to their excellent hydrogenation activity, though their selectivity for acetylene hydrogenation and durability need improvement. Herein, the successful synthesis of atomically dispersed Pd single-atom catalysts on nitrogen-doped graphene (Pd1 /N-graphene) by a freeze-drying-assisted method is reported. The Pd1 /N-graphene catalyst exhibits outstanding activity and selectivity for the hydrogenation of C2 H2 with H2 in the presence of excess C2 H4 under photothermal heating (UV and visible-light irradiation from a Xe lamp), achieving 99% conversion of acetylene and 93.5% selectivity to ethylene at 125 °C. This remarkable catalytic performance is attributed to the high concentration of Pd active sites on the catalyst surface and the weak adsorption energy of ethylene on isolated Pd atoms, which prevents C2 H4 hydrogenation. Importantly, the Pd1 /N-graphene catalyst exhibits excellent durability at the optimal reaction temperature of 125 °C, which is explained by the strong local coordination of Pd atoms by nitrogen atoms, which suppresses the Pd aggregation. The results presented here encourage the wider pursuit of solar-driven photothermal catalyst systems based on single-atom active sites for selective hydrogenation reactions.
- Published
- 2019
43. The Journey toward Low Temperature, Low Pressure Catalytic Nitrogen Fixation
- Author
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Geoffrey I. N. Waterhouse, Tierui Zhang, Xuerui Zhang, Yunxuan Zhao, and Run Shi
- Subjects
Ammonia production ,Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Photocatalysis ,Nitrogen fixation ,General Materials Science ,Electrocatalyst ,Catalysis - Published
- 2020
- Full Text
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44. No imprinted XIST expression in pigs: biallelic XIST expression in early embryos and random X inactivation in placentas
- Author
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Xuguang Du, Du Weihua, Sen Wu, Zhao Xueming, Hui-Ying Zou, Yunping Dai, Hao Haisheng, Yun-Wei Pang, Ning Li, Dawei Yu, Yunxuan Zhao, Lei Chen, Yang-Yang Wang, Jing Wang, Yan Liu, Shan-Jiang Zhao, Huitao Xu, and Hua-Bin Zhu
- Subjects
Swine ,Placenta ,X-inactivation ,Andrology ,Histones ,Cellular and Molecular Neuroscience ,Genomic Imprinting ,Mice ,Pregnancy ,X Chromosome Inactivation ,Dosage Compensation, Genetic ,Gene expression ,Animals ,Molecular Biology ,Alleles ,Cells, Cultured ,Pharmacology ,Dosage compensation ,biology ,Embryogenesis ,Embryo ,Cell Biology ,Methylation ,DNA Methylation ,Histone ,Blastocyst ,embryonic structures ,biology.protein ,Molecular Medicine ,XIST ,Female ,RNA, Long Noncoding - Abstract
Dosage compensation, which is achieved by X-chromosome inactivation (XCI) in female mammals, ensures balanced X-linked gene expression levels between the sexes. Although eutherian mammals commonly display random XCI in embryonic and adult tissues, imprinted XCI has also been identified in extraembryonic tissues of mouse, rat, and cow. Little is known about XCI in pigs. Here, we sequenced the porcine XIST gene and identified an insertion/deletion mutation between Asian- and Western-origin pig breeds. Allele-specific analysis revealed biallelic XIST expression in porcine ICSI blastocysts. To investigate the XCI pattern in porcine placentas, we performed allele-specific RNA sequencing analysis on individuals from reciprocal crosses between Duroc and Rongchang pigs. Our results were the first to reveal that random XCI occurs in the placentas of pigs. Next, we investigated the H3K27me3 histone pattern in porcine blastocysts, showing that only 17-31.8% cells have attained XCI. The hypomethylation status of an important XIST DMR (differentially methylated region) in gametes and early embryos demonstrated that no methylation is pre-deposited on XIST in pigs. Our findings reveal that the XCI regulation mechanism in pigs is different from that in mice and highlight the importance of further study of the mechanisms regulating XCI during early porcine embryo development.
- Published
- 2018
45. Tuning Oxygen Vacancies in Ultrathin TiO
- Author
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Yunxuan, Zhao, Yufei, Zhao, Run, Shi, Bin, Wang, Geoffrey I N, Waterhouse, Li-Zhu, Wu, Chen-Ho, Tung, and Tierui, Zhang
- Abstract
Dinitrogen reduction to ammonia using transition metal catalysts is central to both the chemical industry and the Earth's nitrogen cycle. In the Haber-Bosch process, a metallic iron catalyst and high temperatures (400 °C) and pressures (200 atm) are necessary to activate and cleave NN bonds, motivating the search for alternative catalysts that can transform N
- Published
- 2018
46. In situ hydrothermal fabrication of a MnO2@CoMoO4@Ni nanohybrid electrode and ultrahigh energy density of ASCs
- Author
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Chao Chang, Zhengyang Zhao, Yang Yang, Yunxuan Zhao, Yingzheng Fan, Fei Teng, Yongfa Zhu, Zailun Liu, and Wenqing Yao
- Subjects
Supercapacitor ,Nanostructure ,Fabrication ,Materials science ,General Chemical Engineering ,Nanowire ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Capacitance ,0104 chemical sciences ,law.invention ,law ,Electrode ,0210 nano-technology ,Power density ,Light-emitting diode - Abstract
It still remains a big challenge to fabricate a high-energy-density supercapacitor (SC). Herein, an in situ hydrothermal method is developed to fabricate the high-performance MnO2@CoMoO4@Ni electrode, in which the high capacitance of MnO2 and the high electrical conductivity of CoMoO4 nanowires are fully utilized through the closely-contacted core@shell nanostructure. Amazingly, a flexible AC@Ni//MnO2@CoMoO4@Ni asymmetric supercapacitor (ASC) has been fabricated, which delivers an ultrahigh energy density (2.63 mW h cm−3) at a power density of 4 mW cm−3; after being charged for 10 s, the device assembled in series by two ASCs can efficiently power 15 light emitting diodes (LEDs, 5 mm-diameter red) for more than 5 minutes. Moreover, the ASC still retains 91.28% capacitance after 10000 cycles. We hold that a hybrid nanostructure from a high-energy-density material with a high-electric-conductivity material is a promising strategy to acquire high-performance SCs.
- Published
- 2016
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47. Controllable synthesis of 'L'-shaped V2O5and the improved adsorption capacity by fluorine
- Author
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Yandong Kan, Yang Yang, Juan Xu, Liming Yang, Du Xi, Ren Ming, Wenhao Gu, Yunxuan Zhao, and Fei Teng
- Subjects
Diffuse reflectance infrared fourier transform ,Scanning electron microscope ,Chemistry ,Analytical chemistry ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Adsorption ,Electron diffraction ,Transmission electron microscopy ,General Materials Science ,Selected area diffraction ,0210 nano-technology ,Spectroscopy ,High-resolution transmission electron microscopy - Abstract
In this work, V2O5 with an interesting “L”-shape is successfully prepared by a simple hydrothermal method without using any surfactant or template. The formation mechanism of “L”-shaped V2O5 has been proposed. We have also investigated the effect of fluoride on the morphology, crystal structure and adsorption ability of the samples. The samples are characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) with select area electron diffraction (SAED), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-DRS), photoluminescence (PL) spectroscopy and N2 sorption isotherms. It is found that the addition of fluoride can restrain the formation of “L”-shaped V2O5, resulting in the high-energy {010} facets being exposed and an increased number of oxygen vacancies. Density functional theory (DFT) calculations and PL spectra further confirm the results above. As a result, F-doped V2O5 shows a significantly improved adsorption capacity for methylene blue (MB) compared to the undoped one. The adsorption kinetics follows well a pseudo-second-order model, with correlation coefficients (R) higher than 0.99.
- Published
- 2016
- Full Text
- View/download PDF
48. A newly discovered BiF3 photocatalyst with a high positive valence band
- Author
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Chao Chang, Fei Teng, Yunxuan Zhao, Feng Chenkai, Zailun Liu, Shurong Wang, Mindong Chen, Wenqing Yao, and Yongfa Zhu
- Subjects
Chemistry ,Process Chemistry and Technology ,Ab initio ,chemistry.chemical_element ,Photochemistry ,Catalysis ,Valence band ,Fluorine ,Photocatalysis ,Direct and indirect band gaps ,Density functional theory ,Irradiation ,Physical and Theoretical Chemistry - Abstract
Herein, we, for the first time, introduce BiF3 as a new photo catalyst. The ab initio density functional theory (DFT) calculation has been carried out to insight the electronic structures of BiF3. It is amazing that BiF3 has a highly positive valence band and a wide direct band gap of 3.94 eV. It is further found that the high-electronegativity fluorine (χ = 10.41 eV) significantly contributes to a highly positive valence band. Under UV-light irradiation (λ
- Published
- 2015
- Full Text
- View/download PDF
49. Dispersing Pt and Pd atoms on Au nanoparticles deposited on n-GaN substrates for formic acid oxidation
- Author
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Guoxing Pan, Fei Peng, Yunxuan Zhao, Xuejuan Chen, and Songlv Qin
- Subjects
Atomic layer deposition ,Chemistry ,General Chemical Engineering ,mental disorders ,Inorganic chemistry ,Nanoparticle ,General Chemistry ,Electrochemistry ,Mass activity ,Redox ,Formic acid oxidation - Abstract
Au nanoparticles, with an ultra low-loading of Pt and Pd atoms, supported on n-GaN were prepared using electrochemical atomic layer deposition and surface-limited redox replacement. The as-prepared electrocatalysts showed an enhanced performance for formic acid oxidation, and the mass activity reached 3.5 mA μgPtPd−1. The active sites of the PtChem-O species were found to play a key role in formic acid oxidation.
- Published
- 2015
- Full Text
- View/download PDF
50. Effect of the molecular structure and surface charge of a bismuth catalyst on the adsorption and photocatalytic degradation of dye mixtures
- Author
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Fei Teng, Yunxuan Zhao, and Shurong Wang
- Subjects
chemistry.chemical_compound ,Adsorption ,Diffuse reflectance infrared fourier transform ,Chemistry ,Scanning electron microscope ,General Chemical Engineering ,Inorganic chemistry ,Photocatalysis ,Methyl orange ,Ultraviolet light ,General Chemistry ,Surface charge ,High-resolution transmission electron microscopy - Abstract
[Bi6O6(OH)3](NO3)3·1.5H2O plates were prepared by a facile hydrothermal method. The effect of the pH value, hydrothermal temperature, reaction time, and concentration of Bi(III) ion and additives on the morphology and properties of the samples were investigated. The as-synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET) surface area and UV-vis diffuse reflectance spectroscopy (UV-DRS). It was found that under ultraviolet light irradiation (≤420 nm), the sample prepared at pH = 0.72 displays a higher photocatalytic activity than those prepared at higher pH values, which has been mainly ascribed to the promoted oxygen adsorption at low pH values. Moreover, we investigated the effects of the molecular structure and surface charge on the adsorption and photocatalytic degradation of dye mixtures (methyl orange (MO)–methylene blue (MB) and MO–rhodamine B (RhB)). The results show that in the MB–MO mixture, the adsorption and degradation of both MO and MB are promoted greatly by electrostatic forces; while in the RhB–MO mixture, the degradation of RhB is greatly reduced by MO due to competitive adsorption. These findings help us to understand degradation processes for real wastewater samples containing more than one pollutant.
- Published
- 2015
- Full Text
- View/download PDF
Catalog
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