35 results on '"Xianzhong Yang"'
Search Results
2. Emerging strategies for steering orientational deposition toward high-performance Zn metal anodes
- Author
-
Yuhan Zou, Xianzhong Yang, Lin Shen, Yiwen Su, Ziyan Chen, Xiang Gao, Jiang Zhou, and Jingyu Sun
- Subjects
Nuclear Energy and Engineering ,Renewable Energy, Sustainability and the Environment ,Environmental Chemistry ,Pollution - Abstract
Obtaining smooth plating layers by steering Zn orientational deposition is the key to achieving longevous Zn anodes. The design strategies of inducing orientational deposition and relating mechanistic insights are reviewed.
- Published
- 2022
- Full Text
- View/download PDF
3. In situ separator modification via CVD-derived N-doped carbon for highly reversible Zn metal anodes
- Author
-
Xianzhong Yang, Guojie Sun, Xuedong Bai, Jiaze Lv, Yiwen Su, Xuezeng Tian, Zixiong Shi, Xueyu Lian, Jingyu Sun, Yanyan Shao, Aomiao Zhi, Zhongfan Liu, and Weiping Li
- Subjects
Battery (electricity) ,Materials science ,Nucleation ,chemistry.chemical_element ,Chemical vapor deposition ,Overpotential ,Condensed Matter Physics ,Depth of discharge ,Atomic and Molecular Physics, and Optics ,Anode ,chemistry ,Chemical engineering ,General Materials Science ,Electrical and Electronic Engineering ,Carbon ,Separator (electricity) - Abstract
Attention toward aqueous zinc-ion battery has soared recently due to its operation safety and environmental benignity. Nonetheless, dendrite formation and side reactions occurred at the anode side greatly hinder its practical application. Herein, we adopt direct plasma-enhanced chemical vapor deposition strategy to in situ grow N-doped carbon (NC) over commercial glass fiber separator targeting a highly stabilized Zn anode. The strong zincophilicity of such a new separator would reduce the nucleation overpotential of Zn and enhance the Zn-ion transference number, thereby alleviating side reactions. Symmetric cells equipped with NC-modified separator harvest a stable cycling for more than 1,100 h under 1 mA·cm−2/1 mAh·cm−2. With the assistance of NC, the depth of discharge of Zn anode reaches as high as 42.7%. When assembled into full cells, the zinc-ion battery based on NC-modified separator could maintain 79% of its initial capacity (251 mAh·g−1) at 5 A·g−1 after 1,000 cycles.
- Published
- 2021
- Full Text
- View/download PDF
4. Synchronous Dual Electrolyte Additive Sustains Zn Metal Anode with 5600 h Lifespan
- Author
-
Xianzhong Yang, Weiping Li, Ziyan Chen, Meng Tian, Jun Peng, Jinrong Luo, Yiwen Su, Yuhan Zou, Gao Weng, Yuanlong Shao, Shixue Dou, and Jingyu Sun
- Subjects
General Medicine ,General Chemistry ,Catalysis - Published
- 2023
- Full Text
- View/download PDF
5. Identifying the Evolution of Selenium‐Vacancy‐Modulated MoSe 2 Precatalyst in Lithium–Sulfur Chemistry
- Author
-
Yifan Ding, Xianzhong Yang, Zixiong Shi, Zhongti Sun, Menglei Wang, Chaohui Wei, Haina Ci, Lin Shen, and Jingyu Sun
- Subjects
Chemistry ,Vacancy defect ,Physical chemistry ,General Medicine ,Catalysis - Published
- 2021
- Full Text
- View/download PDF
6. Identifying the Evolution of Selenium‐Vacancy‐Modulated MoSe 2 Precatalyst in Lithium–Sulfur Chemistry
- Author
-
Yifan Ding, Chaohui Wei, Haina Ci, Menglei Wang, Xianzhong Yang, Lin Shen, Jingyu Sun, Zixiong Shi, and Zhongti Sun
- Subjects
Battery (electricity) ,Chemistry ,chemistry.chemical_element ,General Chemistry ,Electrolyte ,Sulfur ,Catalysis ,symbols.namesake ,Chemical engineering ,Vacancy defect ,symbols ,Moiety ,Lithium ,Raman spectroscopy - Abstract
Witnessing compositional evolution and identifying the catalytically active moiety of electrocatalysts is of paramount importance in Li-S chemistry. Nevertheless, this field remains elusive. We report the scalable salt-templated synthesis of Se-vacancy-incorporated MoSe2 architecture (SeVs-MoSe2 ) and reveal the phase evolution of the defective precatalyst in working Li-S batteries. The interaction between lithium polysulfides and SeVs-MoSe2 is probed to induce the transformation from SeVs-MoSe2 to MoSeS. Furthermore, operando Raman spectroscopy and ex situ X-ray diffraction measurements in combination with theoretical simulations verify that the effectual MoSeS catalyst could help promote conversion of Li2 S2 to Li2 S, thereby boosting the capacity performance. The Li-S battery accordingly exhibits a satisfactory rate and cycling capability even with and elevated sulfur loading and lean electrolyte conditions (7.67 mg cm-2 ; 4.0 μL mg-1S ). This work elucidates the design strategies and catalytic mechanisms of efficient electrocatalysts bearing defects.
- Published
- 2021
- Full Text
- View/download PDF
7. Artificial Interphase Layer for Stabilized Zn Anodes: Progress and Prospects
- Author
-
Qihui Zhang, Yiwen Su, Zixiong Shi, Xianzhong Yang, and Jingyu Sun
- Subjects
Biomaterials ,Zinc ,Electric Power Supplies ,Water ,General Materials Science ,General Chemistry ,Lithium ,Electrodes ,Interphase ,Biotechnology - Abstract
The burgeoning Li-ion battery is regarded as a powerful energy storage system by virtue of its high energy density. However, inescapable issues concerning safety and cost aspects retard its prospect in certain application scenarios. Accordingly, strenuous efforts have been devoted to the development of the emerging aqueous Zn-ion battery (AZIB) as an alternative to inflammable organic batteries. In particular, the instability from the anode side severely impedes the commercialization of AZIB. Constructing an artificial interphase layer (AIL) has been widely employed as an effective strategy to stabilize the Zn anode. This review specializes in the state-of-the-art of AIL design for Zn anode protection, encompassing the preparation methods, mechanism investigations, and device performances based on the classification of functional materials. To begin with, the origins of Zn instability are interpreted from the perspective of electrical field, mass transfer, and nucleation process, followed by a comprehensive summary with respect to functions of AIL and its designing criteria. In the end, current challenges and future outlooks based upon theoretical and experimental considerations are included.
- Published
- 2022
8. Directly Grown Universally Doped Ultrathin Nanocrystalline Carbon Overlayer Sustains Pragmatic Zinc Metal Anodes
- Author
-
Xianzhong Yang, Jiaze Lv, Cai Cheng, Zixiong Shi, Jun Peng, Ziyan Chen, Xueyu Lian, Weiping Li, Yuhan Zou, Yu Zhao, Mark H. Rümmeli, Shixue Dou, and Jingyu Sun
- Abstract
Rechargeable Zn-ion battery has emerged as a promising alternative to Li-ion battery owing to the high safety and environmental benignity. Nevertheless, dendritic formation and side reaction occurred at the anode side greatly handicap its practical advance. Here, we put forward an effective maneuver to sustain practical Zn anode by optimizing the anode/electrolyte interface, which deals with the direct growth of an ultrathin nitrogen and oxygen co-doped carbon (NOC) overlayer over Zn foil via a scalable plasma enhanced chemical vapor deposition. Thus-designed NOC overlayer can guide the stable Zn deposition along Zn (002) because of the favorable adsorption by dopant atoms and cultivation effect of nanocrystalline carbons, thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth and side reaction are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling (1125 h at 10.0 mA cm− 2/1.0 mAh cm− 2; 136 h at 30.0 mA cm− 2/30.0 mAh cm− 2). Assembled full battery further realizes elongated lifespans under stringent conditions. This strategy marks a new avenue for the in-situ construction of ultrathin protective coating to optimize the Zn deposition electrochemistry toward pragmatic Zn anode.
- Published
- 2022
- Full Text
- View/download PDF
9. Ambipolar two-dimensional bismuth nanostructures in junction with bismuth oxychloride
- Author
-
Nan Wu, Jun Peng, Xianzhong Yang, Yifan Huang, Shengnan Lu, Chao Zhang, Hung-Ta Wang, Congcong Wu, Xiangchen Hu, and Yi Yu
- Subjects
Coalescence (physics) ,Materials science ,Nanostructure ,Ambipolar diffusion ,chemistry.chemical_element ,Heterojunction ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Bismuth ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Phase (matter) ,Microscopy ,Bismuth oxychloride ,General Materials Science ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
Despite the unique properties of bismuth (Bi), there is a lack of two-dimensional (2D) heterostructures between Bi and other functional 2D materials. Here, a coherent strategy is reported to simultaneously synthesize rhombohedral phase Bi nanoflakes and bismuth oxychloride (BiOCl) nanosheets. The delicate balance between several reactions is mediated mainly for the reduction and chlorination in the chemical vapor transport (CVT) process. The Bi-BiOCl lateral heterostructures have been constructed via the coalescence of the two different 2D nanostructures. The characteristics of ambipolar conducting Bi and insulator-like BiOCl are elaborated by scanning microwave impedance microscopy (sMIM). This work demonstrates a way to construct a 2D Bi nanostructure in junction with its oxyhalide.
- Published
- 2020
- Full Text
- View/download PDF
10. Strengthening ion uptake and mitigating volume change via bimetallic telluride heterojunction for ultrastable K-ion hybrid capacitors
- Author
-
Zhihan Zeng, Wenqi Zhang, Hao Ma, Yuyang Yi, Xueyu Lian, Xianzhong Yang, Ran Cai, Wen Zhao, and Jingyu Sun
- Subjects
General Chemical Engineering ,Environmental Chemistry ,General Chemistry ,Industrial and Manufacturing Engineering - Published
- 2023
- Full Text
- View/download PDF
11. Mosaic Nanocrystalline Graphene Skin Empowers Highly Reversible Zn Metal Anodes
- Author
-
Xianzhong Yang, Jiaze Lv, Cai Cheng, Zixiong Shi, Jun Peng, Ziyan Chen, Xueyu Lian, Weiping Li, Yuhan Zou, Yu Zhao, Mark H. Rümmeli, Shixue Dou, and Jingyu Sun
- Subjects
General Chemical Engineering ,General Engineering ,General Physics and Astronomy ,Medicine (miscellaneous) ,General Materials Science ,Biochemistry, Genetics and Molecular Biology (miscellaneous) - Abstract
Constructing a conductive carbon-based artificial interphase layer (AIL) to inhibit dendritic formation and side reaction plays a pivotal role in achieving longevous Zn anodes. Distinct from the previously reported carbonaceous overlayers with singular dopants and thick foreign coatings, a new type of N/O co-doped carbon skin with ultrathin feature (i.e., 20 nm thickness) is developed via the direct chemical vapor deposition growth over Zn foil. Throughout fine-tuning the growth conditions, mosaic nanocrystalline graphene can be obtained, which is proven crucial to enable the orientational deposition along Zn (002), thereby inducing a planar Zn texture. Moreover, the abundant heteroatoms help reduce the solvation energy and accelerate the reaction kinetics. As a result, dendrite growth, hydrogen evolution, and side reactions are concurrently mitigated. Symmetric cell harvests durable electrochemical cycling of 3040 h at 1.0 mA cm
- Published
- 2022
- Full Text
- View/download PDF
12. A Universal Graphene‐Selenide Heterostructured Reservoir with Elevated Polysulfide Evolution Efficiency for Pragmatic Lithium–Sulfur Battery
- Author
-
Menglei Wang, Yujie Zhu, Yingjie Sun, Yu Zhao, Xianzhong Yang, Xiaojing Wang, Yingze Song, Haina Ci, and Jingyu Sun
- Subjects
Biomaterials ,Electrochemistry ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2022
- Full Text
- View/download PDF
13. Crystalline tetra-aniline with chloride interactions towards a biocompatible supercapacitor
- Author
-
Hui Wei, Yuanlong Shao, Chaohui Wei, Shuo Li, Yanyan Shao, Cheng-Wei Lin, Zhihui Chen, Dongzi Yang, Jingyu Sun, Yihan Zhu, Xianzhong Yang, Fei Shen, Guan Sheng, Wei Zhang, Richard B. Kaner, and Xiaoling Tong
- Subjects
Supercapacitor ,chemistry.chemical_classification ,Conductive polymer ,Materials science ,Aniline Compounds ,Process Chemistry and Technology ,Nanotechnology ,Electrolyte ,Polymer ,Electrochemistry ,Electric Capacitance ,Energy storage ,chemistry.chemical_compound ,Electrolytes ,chemistry ,Chlorides ,Mechanics of Materials ,Electrode ,Polyaniline ,General Materials Science ,Electrical and Electronic Engineering ,Electrodes - Abstract
Recent advances in wearable and implantable electronics have increased the demand for biocompatible integrated energy storage systems. Conducting polymers, such as polyaniline (PANi), have been suggested as promising electrode materials for flexible biocompatible energy storage systems, based on their intrinsic structural flexibility and potential polymer chain compatibility with biological interfaces. However, due to structural disorder triggering insufficient electronic conductivity and moderate electrochemical stability, PANi still cannot fully satisfy the requirements for flexible and biocompatible energy storage systems. Herein, we report a biocompatible physiological electrolyte activated flexible supercapacitor encompassing crystalline tetra-aniline (c-TANi) as the active electrode material, which significantly enhances the specific capacitance and electrochemical cycling stability with chloride electrochemical interactions. The crystallization of TANi endows it with sufficient electronic conductivity (8.37 S cm-1) and a unique Cl- dominated redox charge storage mechanism. Notably, a fully self-healable and biocompatible supercapacitor has been assembled by incorporating polyethylene glycol (PEG) with c-TANi as a self-healable electrode and a ferric-ion cross-linked sodium polyacrylate (Fe3+-PANa)/0.9 wt% NaCl as a gel electrolyte. The as-prepared device exhibits a remarkable capacitance retention even after multiple cut/healing cycles. With these attractive features, the c-TANi electrode presents a promising approach to meeting the power requirements for wearable or implantable electronics.
- Published
- 2021
14. Interfacial Manipulation via In Situ Grown ZnSe Cultivator toward Highly Reversible Zn Metal Anodes
- Author
-
Yiwen Su, Xianzhong Yang, Shuai Yang, Rong Huang, Bingzhi Liu, Zixiong Shi, Chao Li, Menglei Wang, Zhongti Sun, Yuhan Wu, Shi Xue Dou, Shuo Li, and Jingyu Sun
- Subjects
Materials science ,Mechanical Engineering ,Electrolyte ,Chemical vapor deposition ,engineering.material ,Redox ,Cathode ,Anode ,Overlayer ,law.invention ,Coating ,Chemical engineering ,Mechanics of Materials ,law ,Plating ,engineering ,General Materials Science - Abstract
Zn metal anode has garnered growing scientific and industrial interest owing to its appropriate redox potential, low cost, and high safety. Nevertheless, the instability of Zn anode caused by dendrite formation, hydrogen evolution, and side reactions has greatly hampered its commercialization. Herein, an in situ grown ZnSe overlayer is crafted over one side of commercial Zn foil via chemical vapor deposition in a scalable manner, aiming to achieve optimized electrolyte/Zn interfaces with large-scale viability. Impressively, thus-derived ZnSe coating functions as a cultivator to guide oriented growth of Zn (002) plane at the infancy stage of stripping/plating cycles, thereby inhibiting the formation of Zn dendrites and the occurrence of side reactions. As a result, high cyclic stability (1530 h at 1.0 mA cm-2 /1.0 mAh cm-2 ; 172 h at 30.0 mA cm-2 /10.0 mAh cm-2 ) in symmetric cells is harvested. Meanwhile, when paired with V2 O5 based cathode, assembled full cell achieves an outstanding capacity (194.5 mAh g-1 ) and elongated lifespan (a capacity retention of 84% after 1000 cycles) at 5.0 A g-1 . The reversible Zn anode enabled by the interfacial manipulation strategy via ZnSe cultivator is anticipated to satisfy the demand of commercial use.
- Published
- 2021
15. Identifying the Evolution of Selenium-Vacancy-Modulated MoSe
- Author
-
Menglei, Wang, Zhongti, Sun, Haina, Ci, Zixiong, Shi, Lin, Shen, Chaohui, Wei, Yifan, Ding, Xianzhong, Yang, and Jingyu, Sun
- Abstract
Witnessing compositional evolution and identifying the catalytically active moiety of electrocatalysts is of paramount importance in Li-S chemistry. Nevertheless, this field remains elusive. We report the scalable salt-templated synthesis of Se-vacancy-incorporated MoSe
- Published
- 2021
16. Manipulating Electrocatalytic Li
- Author
-
Zixiong, Shi, Zhongti, Sun, Jingsheng, Cai, Xianzhong, Yang, Chaohui, Wei, Menglei, Wang, Yifan, Ding, and Jingyu, Sun
- Abstract
Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage, yet they are plagued by the notorious polysulfide shuttle effect and sluggish redox kinetics. While rationally designed redox mediators can facilitate polysulfide conversion, favorable bidirectional sulfur electrocatalysis remains a formidable challenge. Herein, selective dual-defect engineering (i.e., introducing both N-doping and Se-vacancies) of a common MoSe
- Published
- 2021
17. Interfacial Manipulation via In-Situ Grown ZnSe Overlayer toward Highly Reversible Zn Metal Anodes
- Author
-
Xianzhong Yang, Chao Li, Zhongti Sun, Shuai Yang, Zixiong Shi, Rong Huang, Bingzhi Liu, Shuo Li, Yuhan Wu, Menglei Wang, Yiwen Su, Shi Xue Dou, and Jingyu Sun
- Abstract
Zn metal anode has garnered growing scientific and industrial interest owing to its appropriate redox potential, low cost and good safety. Nevertheless, the instability of Zn metal, caused by dendrite formation, hydrogen evolution and side reactions, gives rise to poor electrochemical stability and unsatisfactory cycling life, greatly hampering large-scale utilization. Herein, an in-situ grown ZnSe layer with controllable thickness is crafted over one side of commercial Zn foil via chemical vapor deposition, aiming to achieve optimized interfacial manipulation between aqueous electrolyte/Zn anode. Thus-derived ZnSe overlayer not only prevents water penetration and restricts Zn2+ two-dimensional diffusion, but also homogenizes the electric field at the interface and facilitates favorable (002) plane growth of Zn. As a result, dendrite-free and homogeneous Zn deposition is obtained; side reactions are concurrently inhibited. In consequence, a high Coulombic efficiency of 99.2% and high cyclic stability for 860 cycles at 1.0 mA cm–2 in symmetrical cells is harvested. Meanwhile, when paired with V2O5 cathode, assembled full cell achieves an outstanding initial capacity (200 mAh g–1) and elongated lifespan (a capacity retention of 84% after 1000 cycles) at 5.0 A g–1. Our highly reversible Zn anode enabled by the interfacial manipulation strategy is anticipated to satisfy the demand of industrial and commercial use.
- Published
- 2021
- Full Text
- View/download PDF
18. An Anode‐Free Potassium‐Metal Battery Enabled by a Directly Grown Graphene‐Modulated Aluminum Current Collector
- Author
-
Yu Zhao, Bingzhi Liu, Yuyang Yi, Xueyu Lian, Menglei Wang, Shuo Li, Xianzhong Yang, and Jingyu Sun
- Subjects
Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
Potassium (K)-metal batteries have emerged as a promising energy-storage device owing to abundant K resources. An anode-free architecture that bypasses the need for anode host materials can deliver an elevated energy density. However, the poor efficiency of K plating/stripping on potassiophobic anode current collectors results in rapid K inventory loss and a short cycle life. Herein, commercial Al foils are decorated with an ultrathin graphene-modified layer (Al@G) through roll-to-roll plasma-enhanced chemical vapor deposition. By harnessing strong adhesion (10.52 N m
- Published
- 2022
- Full Text
- View/download PDF
19. Printing‐Scalable Ti 3 C 2 T x MXene‐Decorated Janus Separator with Expedited Zn 2+ Flux toward Stabilized Zn Anodes
- Author
-
Yiwen Su, Bingzhi Liu, Qihui Zhang, Jun Peng, Chaohui Wei, Shuo Li, Weiping Li, Zaikun Xue, Xianzhong Yang, and Jingyu Sun
- Subjects
Biomaterials ,Electrochemistry ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials - Published
- 2022
- Full Text
- View/download PDF
20. Inorganic Low
- Author
-
Jun, Peng, Weiwen, Pu, Shengnan, Lu, Xianzhong, Yang, Congcong, Wu, Nan, Wu, Zhaoru, Sun, and Hung-Ta, Wang
- Abstract
For the interlayer dielectric in microelectronics, light element compounds are preferably accepted due to less electronic polarization. Here, the nontrivial dielectric nature of the Sb
- Published
- 2020
21. Regulating Interfacial Ion Migration via Wool Keratin Mediated Biogel Electrolyte toward Robust Flexible Zn‐Ion Batteries (Small 10/2022)
- Author
-
Yanyan Shao, Jin Zhao, Wenguang Hu, Zhou Xia, Jinrong Luo, Yijing Zhou, Liang Zhang, Xianzhong Yang, Ning Ma, Dongzi Yang, Qiuwei Shi, Jingyu Sun, Lei Zhang, Jingshu Hui, and Yuanlong Shao
- Subjects
Biomaterials ,General Materials Science ,General Chemistry ,Biotechnology - Published
- 2022
- Full Text
- View/download PDF
22. Synergizing Conformal Lithiophilic Granule and Dealloyed Porous Skeleton toward Pragmatic Li Metal Anodes
- Author
-
Zixiong Shi, Zhongti Sun, Xianzhong Yang, Chen Lu, Shuo Li, Xiaoyu Yu, Yifan Ding, Ting Huang, and Jingyu Sun
- Published
- 2022
- Full Text
- View/download PDF
23. Regulating Interfacial Ion Migration via Wool Keratin Mediated Biogel Electrolyte toward Robust Flexible Zn‐Ion Batteries
- Author
-
Yanyan Shao, Jin Zhao, Wenguang Hu, Zhou Xia, Jinrong Luo, Yijing Zhou, Liang Zhang, Xianzhong Yang, Ning Ma, Dongzi Yang, Qiuwei Shi, Jingyu Sun, Lei Zhang, Jingshu Hui, and Yuanlong Shao
- Subjects
Biomaterials ,Electrolytes ,Zinc ,Electric Power Supplies ,Wool ,Animals ,Keratins ,General Materials Science ,General Chemistry ,Biotechnology - Abstract
Aqueous Zn-ion batteries (ZIBs) have emerged as a promising energy supply for next-generation wearable electronics, yet they are still impeded by the notorious growth of zinc dendrite and uncontrollable side reaction. While the rational design of electrolyte composition or separator decoration can effectively restrain zinc dendrite growth, synchronously regulating the interfacial electrochemical performance by tackling the physical delamination venture between electrode and electrolyte remains a major obstacle for high-performance wearable aqueous ZIB. Herein, a category of hybrid biogel electrolyte containing carrageenan and wool keratin (CWK) is put forward to regulate the interfacial electrochemistry in aqueous ZIB. Systematic electrochemical kinetics analyses and ex situ scanning electrochemical microscopy (SECM) characterizations achieve comprehensive understanding of the keratin enhanced interfacial Zn
- Published
- 2022
- Full Text
- View/download PDF
24. Teachers’ continuous vs. intermittent presence in procedural knowledge instructional videos
- Author
-
Tian Yi, Jiumin Yang, Lei Huang, Zhongling Pi, and Xianzhong Yang
- Subjects
020205 medical informatics ,Instructional design ,05 social sciences ,050301 education ,Cognition ,Sample (statistics) ,02 engineering and technology ,Academic achievement ,Procedural knowledge ,Education ,Presentational and representational acting ,Interpersonal relationship ,ComputingMilieux_COMPUTERSANDEDUCATION ,0202 electrical engineering, electronic engineering, information engineering ,Mathematics education ,Psychology ,0503 education ,Cognitive load - Abstract
Massive Open Online Courses (MOOCs) have become increasingly common in recent years. As the main component of MOOCs, instructional videos play a significant role in students’ learning. This study builds on the extant research on multimedia learning by testing the impact of teachers’ continuous vs. intermittent presence in procedural knowledge instructional videos. Students’ outcomes were assessed in terms of achievement, learning satisfaction, social presence, and cognitive load. Using a quasi-experimental design, 120 Chinese undergraduate students from four undergraduate classes, were randomly assigned to one of two video conditions based on whether the instructor had a continuous or intermittent presence in an instructional video teaching procedural knowledge. A series of independent sample t tests revealed that a teacher’s intermittent presentational approach improved learning achievement and satisfaction, and created less cognitive load relative to a continuous presentational approach. Results...
- Published
- 2018
- Full Text
- View/download PDF
25. Carbon nanomaterials for highly stable Zn anode: Recent progress and future outlook
- Author
-
Jingyu Sun, Qihui Zhang, Xianzhong Yang, Yiwen Su, and Zhongfan Liu
- Subjects
Battery (electricity) ,Chemistry ,General Chemical Engineering ,Electrochemistry ,Nanotechnology ,Carbon nanomaterials ,Energy storage ,Analytical Chemistry ,Corrosion ,Anode - Abstract
Aqueous zinc-ion battery has readily showed its cutting edges as one of the most promising energy storage systems due to high theoretical capacity and good environmental benignancy. Issues in particular at the anode side encompassing rampant dendrite growth, severe corrosion and side reactions otherwise impede the pragmatic applications. Carbon nanomaterials have been widely employed to protect Zn anode benefiting from their collective merits. Nevertheless, there has been a lack of comprehensive reviews thus far on covering the strategic solutions of Zn anode stabilization with the aid of nano-carbons. This article summarizes the state-of-the-art knowledge in designing concepts, mechanism investigations and device performances of Zn anode protection strategies based on carbon nanomaterials. Future perspectives and key challenges in this emerging field are included at the end.
- Published
- 2022
- Full Text
- View/download PDF
26. Self-assembly of Au@Ag core–shell nanocuboids into staircase superstructures by droplet evaporation
- Author
-
Zhigao Dai, Jing Li, Liyan Zhou, Jianfang Wang, Xianzhong Yang, Wenjie Liang, Chunming Jiang, Mengtao Sun, Jianhua Yang, Xiao Guo, Yuxin Zhao, Liu Quanzhen, and Shanjun Mu
- Subjects
Materials science ,business.industry ,Finite-difference time-domain method ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Nanomaterials ,symbols.namesake ,Monolayer ,symbols ,Optoelectronics ,General Materials Science ,Self-assembly ,0210 nano-technology ,business ,Raman spectroscopy ,Layer (electronics) ,Raman scattering ,Plasmon - Abstract
Plasmonic nanomaterials, along with their assemblies, provide numerous applications due to their profound optical properties. In this work, we report the self-assembly of Au@Ag core-shell nanocuboids (NCs) into staircase superstructures in both vertical and horizontal orientations through two-stage droplet evaporation. Each stair is composed of a uniform well-aligned monolayer of NCs. The gap distance between NCs can be greatly shrunk to boost the corresponding surface-enhanced Raman scattering (SERS) performance using an ethanol wash method. The SERS performance of the assembled NCs is calculated by finite-difference time-domain (FDTD) simulation, and studied against the step number using 4-mercaptobenzoic acid as a Raman reporter molecule. The increasing EF with the increase of layer number proves that the plasmon mode propagates well in our uniformly aligned assemblies.
- Published
- 2018
- Full Text
- View/download PDF
27. Manipulating Electrocatalytic Li 2 S Redox via Selective Dual‐Defect Engineering for Li–S Batteries
- Author
-
Jingsheng Cai, Chaohui Wei, Xianzhong Yang, Zixiong Shi, Zhongti Sun, Yifan Ding, Jingyu Sun, and Menglei Wang
- Subjects
Battery (electricity) ,Materials science ,Mechanical Engineering ,Defect engineering ,Nanotechnology ,Electrochemistry ,Electrocatalyst ,Redox ,Energy storage ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Pouch cell ,General Materials Science ,Polysulfide - Abstract
Lithium-sulfur (Li-S) batteries are promising candidates for next-generation energy storage, yet they are plagued by the notorious polysulfide shuttle effect and sluggish redox kinetics. While rationally designed redox mediators can facilitate polysulfide conversion, favorable bidirectional sulfur electrocatalysis remains a formidable challenge. Herein, selective dual-defect engineering (i.e., introducing both N-doping and Se-vacancies) of a common MoSe2 electrocatalyst is used to manipulate the bidirectional Li2 S redox. Systematic theoretical prediction and detailed electrokinetic analysis reveal the selective electrocatalytic effect of the two types of defects, thereby achieving a deeper mechanistic understanding of the bidirectional sulfur electrochemistry. The Li-S battery using this electrocatalyst exhibits excellent cyclability, with a low capacity decay rate of 0.04% per cycle over 1000 cycles at 2.0 C. More impressively, the potential for practical applications is highlighted by a high areal capacity (7.3 mAh cm-2 ) and the construction of a flexible pouch cell. Such selective electrocatalysis created by dual-defect engineering is an appealing approach toward working Li-S systems.
- Published
- 2021
- Full Text
- View/download PDF
28. Physical mechanism on exciton-plasmon coupling revealed by femtosecond pump-probe transient absorption spectroscopy
- Author
-
En Cao, Tõnu Pullerits, Jing Li, Wenjie Liang, Xuefeng Xu, Mengtao Sun, Weihua Lin, Xianzhong Yang, and Ying Shi
- Subjects
Materials science ,Physics and Astronomy (miscellaneous) ,Scattering ,Exciton ,Physics::Optics ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Condensed Matter::Materials Science ,Monolayer ,Femtosecond ,Ultrafast laser spectroscopy ,General Materials Science ,Surface plasmon resonance ,0210 nano-technology ,Spectroscopy ,Energy (miscellaneous) - Abstract
The unclear mechanism of exciton-plasmon coupling interaction in monolayer MoS2-Ag nanoparticles hybrid, as a longstanding target in molecular nanotechnology and catalysis, is systemically investigated with transmission spectra and femtosecond pump-probe transient absorption spectroscopy in this paper. The properties of exciton in monolayer MoS2 are strongly enhanced due to the local surface plasmon resonance (LSPR) induced by Ag nanoparticles, and manifested by obvious changes in transmission spectra. Furthermore, we discuss the dynamic processes of exciton-plasmon coupling interaction with the femtosecond transient absorption spectroscopy, which indicates that there are three lifetimes, Auger scattering, electron-electron interaction and electron-phonon interaction, and illustrate the reason of the enlarged lifetime in hybrid system. Meanwhile, the intensity of A excitonic state in femtosecond transient absorption spectroscopy is significantly enhanced by LSPR, instead of excitonic state B. In conclusion, our study can promote the deeper understanding and illustrate the unique merits of the exciton-plasmon coupling interaction in the monolayer MoS2-Ag nanoparticles hybrid system.
- Published
- 2017
- Full Text
- View/download PDF
29. Plasmon-exciton coupling of monolayer MoS2-Ag nanoparticles hybrids for surface catalytic reaction
- Author
-
Xianzhong Yang, Tõnu Pullerits, Hua Yu, Xiao Guo, Qianqian Ding, Wenjie Liang, Mengtao Sun, Rongming Wang, and Guangyu Zhang
- Subjects
Materials science ,Photoluminescence ,Renewable Energy, Sustainability and the Environment ,Materials Science (miscellaneous) ,Energy Engineering and Power Technology ,Substrate (chemistry) ,Nanoparticle ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Fuel Technology ,Nuclear Energy and Engineering ,Monolayer ,Photocatalysis ,Surface plasmon resonance ,0210 nano-technology ,Plasmon - Abstract
The optical properties of monolayer molybdenum disulfide (MoS2)/Ag nanoparticle (NP) hybrids and their application to surface catalytic reactions were studied by transmission, photoluminescence (PL) and Raman spectroscopies. The local surface plasmon resonance (LSPR) of Ag nanoparticles was tuned to better match the exciton energy of monolayer MoS2. The PL of the hybrids was enhanced by more than 50 times when the local surface plasmon resonance (LSPR) peak was tuned systematically from 438 nm to 532 nm, indicating a stronger coupling and higher energy transfer rate between the plasmon of the Ag NPs and the excitons of the MoS2. Additionally, photocatalytic reactions of 4-nitrobenzenethiol (4NBT) were performed on the MoS2, the Ag nanoparticles, and the hybrid MoS2 with Ag nanoparticles. On the MoS2 substrate alone, there is no photocatalytic reaction. With a low laser intensity, the probability of a chemical reaction occurring for molecules directly adsorbed onto the Ag NPs is much lower than the probability of a reaction involving those molecules adsorbed onto the MoS2/Ag substrate. At a higher power, although the electric field was reduced by approximately 30% by the MoS2 layer, there is better efficiency for the plasmon-exciton co-driven surface catalytic reactions on the MoS2/Ag substrate compared to the Ag substrate alone. Our findings illustrate the potential to control hot carriers for better surface catalytic reactions by tuning the exciton-plasmon coupling between the 2D transition metal dichalcogenides (TMDCs) and Ag NPs.
- Published
- 2017
- Full Text
- View/download PDF
30. Non-symmetric hybrids of noble metal-semiconductor: Interplay of nanoparticles and nanostructures in formation dynamics and plasmonic applications
- Author
-
Xianzhong Yang, Haofei Zhao, Yinghui Sun, and Rongming Wang
- Subjects
Nanostructure ,Materials science ,Non symmetric ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,engineering.material ,010402 general chemistry ,01 natural sciences ,Coating ,Noble metal ,lcsh:TA401-492 ,General Materials Science ,Plasmon ,business.industry ,Semiconductor ,021001 nanoscience & nanotechnology ,Hybrid ,0104 chemical sciences ,Quantum dot ,engineering ,lcsh:Materials of engineering and construction. Mechanics of materials ,0210 nano-technology ,business - Abstract
Noble metal-semiconductor hybrids have been employed as fundamental structures in modern technologies. In these hybrids, their cooperative multiple functions attract much attention in recent years because of the interplay of nanoparticles and nanostructures. In this review, we summarize the interplay of nanoparticles and nanostructures in specific kinds of noble metal-semiconductor hybrids, termed as non-symmetric hybrids of noble metal-semiconductor. It particularly refers to metal nanoparticles (or semiconducting quantum dots) at 1-dimensinal (1D) and 2-dimensional (2D) semiconductor (or metal) nanostructures, in contrast to the core/shell and heterodimer nanostructures. First, we discuss the formation dynamics, especially in chemical growth and assembly as well as physical coating and deposition, of non-symmetric noble metal-semiconductor hybrids with nanoparticles on nanostructures. Second, we introduce the plasmon-related applications of these hybrids in heterogeneous catalysis, optoelectronic or photovoltaic devices, all-optical devices, and surface detection or modulation. This review not only provides a comprehensive understanding of the formation mechanisms of the non-symmetric metal-semiconductor hybrid nanostructures, but also may inspire new ideas of novel functional devices and applications based on these systems.
- Published
- 2017
- Full Text
- View/download PDF
31. Surface plasmon-driven photocatalysis in ambient, aqueous and high-vacuum monitored by SERS and TERS
- Author
-
Xianzhong Yang, Ping Xu, Zhenglong Zhang, Wenjie Liang, and Mengtao Sun
- Subjects
Materials science ,Quantitative Biology::Molecular Networks ,Organic Chemistry ,Surface plasmon ,Ultra-high vacuum ,Physics::Optics ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Chemical reaction ,Catalysis ,0104 chemical sciences ,symbols.namesake ,Physics::Atomic and Molecular Clusters ,symbols ,Photocatalysis ,Water splitting ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,0210 nano-technology ,Plasmon ,Raman scattering - Abstract
•We reviewed plasmon-driven photocatalytic reactions in different environments.•Plasmon-driven photocatalytic reactions in ambient monitored by SERS and TERS.•Plasmon-driven photocatalytic reactions in aqueous monitored by SERS and TERS.•Plasmon-driven photocatalytic reactions in high-vacuum monitored by SERS and TERS.AbstractsThere has been an explosion of interests and activities on plasmon-driven catalytic reactions currently, which has been expanded photonic catalysis to plasmonic catalysis. Particularly, plasmonic catalysis, with activation energy provided by plasmon-induced hot electrons, can exhibit a giant catalytic action on the surface of silver or gold nanostructures, thus breaking the longstanding limitation of photonic catalysis that needs UV light generality. This new surface catalysis has been revealed in various chemical reactions by using surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS), which are the two representative techniques supporting the hot electrons (holes) generated from plasmon-decay on plamonic nanostructures’ surface. In this review, we fully explore the principle of plamonic catalysis, and especially review the advances of plasmon-driven surface catalytic reactions monitoring by SERS and TERS in atmosphere, aqueous and high-vacuum environments. These approaches significantly broaden the applications of plasmonic catalysis such as dissociation of hydrogen, water splitting and hydrocarbon conversion.
- Published
- 2016
- Full Text
- View/download PDF
32. Plasmon-driven catalysis in aqueous solutions probed by SERS spectroscopy
- Author
-
Peijie Wang, Yingqi Qu, Lin Cui, Wenjie Liang, Xianzhong Yang, Mengtao Sun, and Xin Ren
- Subjects
Aqueous solution ,Chemistry ,Surface plasmon ,Inorganic chemistry ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,symbols.namesake ,symbols ,General Materials Science ,Spectral analysis ,Surface plasmon resonance ,0210 nano-technology ,Raman spectroscopy ,Spectroscopy ,Plasmon - Abstract
Since 2010, the plasmon-driven catalysis using surface-enhanced Raman spectroscopy (SERS) in atmospheric environment has been experimentally reported. Recent experimental results since 2014 revealed that catalysis under aqueous condition is much better than that in atmospheric environment. In this paper, we review plasmon-driven catalysis using SERS under aqueous condition. First, the experimental apparatus developed by ourselves is introduced in detail. Second, we demonstrate the advantages of plasmon-driven catalysis using SERS under aqueous condition compared to that in atmospheric environment. Third, we review recent experimental results using this measurement method in different experimental settings under aqueous condition. The manipulation of reaction environment effectively provided the possibility to reveal the mechanism of surface plasmon catalysis for different reactions. This method has great potential to apply on ultrasensitive spectral analysis for SERS, catalysis, sensor and biology system under aqueous condition. Copyright © 2016 John Wiley & Sons, Ltd.
- Published
- 2016
- Full Text
- View/download PDF
33. Prospect for 100TW/90fs X-ray driver using optical parametric chirped pulse amplifiers
- Author
-
S.Q. Jin, Jinan Wang, Zhaoxiang Zhang, Xianzhong Yang, Jiahui Peng, Yongbin Leng, and Z.Z. Xu
- Subjects
Physics ,Chirped pulse amplification ,Optical amplifier ,business.industry ,Preamplifier ,Amplifier ,Bandwidth (signal processing) ,General Physics and Astronomy ,Laser ,Optical parametric amplifier ,law.invention ,Optics ,law ,Ultrafast laser spectroscopy ,business - Abstract
The optical parametric chirped pulse amplification (OPCPA) technique is promising for constructing a 100-TW/90-fs laser system. This laser system consists of a diode-pumped Nd:phosphate oscillator, two LBO preamplifiers and a final power KDP amplifier. A noncollinear BBO-I optical parametric amplifier pumped by a Q-switched and frequency-doubled Nd:YAG laser has been demonstrated. The temporally-stretched chirped signal laser pulses with a bandwidth of 36nm(FWHM) are amplified without limitation in bandwidth and distortion in the spectrum. The gain bandwidth is very sensitive to the pump-signal angle. Variation of this angle of ∼1 5mrad can significantly reduce the amplified bandwidth and results in a significant distortion of the amplified spectrum.
- Published
- 2001
- Full Text
- View/download PDF
34. Recent progress in table-top multi-terawatt laser systems at siom
- Author
-
Xianzhong Yang, Zhaoxiang Zhang, L.H. Lin, Wei Wang, Haihe Lu, D.J. Ying, Z.Z. Xu, S.Q. Jin, Wenfu Zhang, Yongbin Leng, Y. H. Jiang, and Rihong Li
- Subjects
Chirped pulse amplification ,Femtosecond pulse shaping ,Distributed feedback laser ,Materials science ,business.industry ,Ti:sapphire laser ,Laser ,Q-switching ,Optical parametric amplifier ,law.invention ,Optics ,law ,Optoelectronics ,business ,Ultrashort pulse - Abstract
We present a 10-Hz, 23-TW Ti: sapphire laser system based on chirped pulse amplification and a 16.7-TW laser system based on optical parametric chirped pulse amplification for high-field laser physics research at SIOM, CAS.
- Published
- 2004
- Full Text
- View/download PDF
35. 3.6-TW laser system based on optical parametric chirped pulse amplification
- Author
-
L.H. Lin, Z.Z. Xu, Yongbin Leng, Zhaoxiang Zhang, Haihe Lu, Bing Tang, Dinjun Yin, Rihong Li, S.Q. Jin, Jiahui Peng, Wenfu Zhang, and Xianzhong Yang
- Subjects
Femtosecond pulse shaping ,Chirped pulse amplification ,Materials science ,business.industry ,Laser pumping ,Laser ,Optical parametric amplifier ,law.invention ,Optical pumping ,Optics ,law ,Ultrafast laser spectroscopy ,Optoelectronics ,business ,Ultrashort pulse - Abstract
A compact 3.6 TW/155 fs laser system based on optical parametric chirped pulse amplification is demonstrated. The system consists of a femtosecond Ti:sapphire oscillator, a pulse stretcher, a Nd:YAG/Nd:glass amplifier chain as pump laser, an OPA chain and a compressor. The pulses were amplified from 20 pJ to 900 mJ. After compression, a final output of 570 mJ/155 fs was obtained.
- Published
- 2003
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.