bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surrounding Media Sensitive Photoluminescence of Boron-Doped Graphene Quantum Dots
Authors: Fan Louzhen 
Published: February 2020

Graphene is a zero-bandgap semiconductor, no optical luminescence is observed in pristine graphene. A bandgap, however, can be engineered into graphene quantum dots (GQDs) due to quantum confinement and edge effects. As a result, luminescent GQDs have attracted great attention as one of highly promising nanomaterials due to their exceptional advantages of low cytotoxicity, excellent solubility, stable photoluminescence (PL), fine biocompatibility as well as low-cost.[
1
] Above these fascinating merits in GQDs distinguish themselves from traditional fluorescent materials, making them perfect alternatives for numerous exciting applications: bioimaging,[
2
] fluorescence sensors,[
3
[ fuel cells,[
4
] photovoltaic devices.[
5]

Doping carbon materials with heteroatoms can effectively tune their intrinsic properties, thus producing new phenomena and unexpected characteristics. Although veriouse heteroatom-doped carbon materials have been reported, doped GQDs have been much less studied. Herein, we report a facile one-pot electrochemical approach for the synthesis of boron(B) doped GQDs (B-GQDs) with B content of 5.24 at %, in which only borax was used as the electrolyte without any other chemical additives. The as obtained water-soluble B-GQDs feature intriguing tunable fluorescence, act as a Al3+fluorescent sensor, cellular imaging and electrocatalysts for the oxygen reduction reaction. With the existence of borax, they show strong green luminescence with a quantum yield as high as 13%. Significantly, green fluorescent crystals were obtained from evaporating the aqueous solution in the presence of borax at room temperature.

Acknowledgements

This work is supported by NSFC (21073018), the Major Research Plan of NSFC (21233003), Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Beijing Normal University.

References

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2010, 22, 734-738; b) J. Peng, W. Gao, B. K. Gupta, Z. Liu, R. Romero-Aburto, L. Ge, L. Song, L. B. Alemany, X. Zhan, G. Gao, S. A. Vithayathil, B. A. Kaipparettu, A. A. Marti, T. Hayashi, J.-J. Zhu, Nano Letters
2012, 12, 844-849; c) L. Tang, R. Ji, X. Cao, J. Lin, H. Jiang, X. Li, K. S. Teng, C. M. Luk, S. Zeng, J. Hao, S. P. Lau, ACS Nano
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6, 5102-5110.
[2] a) S. Zhu, J. Zhang, C. Qiao, S. Tang, Y. Li, W. Yuan, B. Li, L. Tian, F. Liu, R. Hu, H. Gao, H. Wei, H. Zhang, H. Sun, B. Yang, Chem. Commun.
2011, 47, 6858-6860; b) H. Tao, K. Yang, Z. Ma, J. Wan, Y. Zhang, Z. Kang, Z. Liu, Small
2012, 8, 281-290.
[3] Y. Dong, G. Li, N. Zhou, R. Wang, Y. Chi, G. Chen, Anal. Chem.
2012, 84, 8378-8382.
[4] a) Y. Li, Y. Zhao, H. Cheng, Y. Hu, G. Shi, L. Dai, L. Qu, J. Am. Chem. Soc
.
2011, 134, 15-18; b) Q. Li, S. Zhang, L. Dai, L.-s. Li, J. Am. Chem. Soc.
2012, 134, 18932-18935.
[5] a) Y. Li, Y. Hu, Y. Zhao, G. Shi, L. Deng, Y. Hou, L. Qu, Adv.Mater.
2011, 23, 776-780; b) V. Gupta, N. Chaudhary, R. Srivastava, G. D. Sharma, R. Bhardwaj, S. Chand, J. Am. Chem. Soc.
2011, 133, 9960-9963.
(Plenary) High-Performance Photonic BiCMOS – Next Generation More-than-Moore Technology for the Large Bandwidth Era
Authors: Zimmermann Lars 
Published: February 2020

It is a remarkable fact that since the advent of cable telephony we observe a continuous growth of network traffic on a global scale. Despite all economic ups and downs, traffic grows steadily, certainly since the advent of the internet about two decades ago. The similarity to Moore’s law of microelectronics has been pointed out several times, and, as a matter of fact this traffic development would not have happened without the unswerving advance of IC technology. Ubiquitous compute power has changed and will keep changing our world, spanning an unprecedented application space encompassing web 3.0, augmented reality, 3D online gaming and virtual worlds, social media etc.
Looking at the infrastructure underlying all these developments we soon realize that long haul traffic and its growth merely reflect the tip of the iceberg. There is an emerging planetary realm of warehouse-scale data centers hosting a growing fraction of global computing and data storage. Traffic between user and data center is surpassed by traffic created inside the data center leading to Petabit/sec aggregate bandwidth requirements. This inside data center traffic feeds hundreds of individual user services that shape the cloud from the point of view of consumers, therefore stimulating additional traffic in radio access networks, fiber-to-the-home and other networks.
The technology most needed to sustain this positive feedback growth is the interconnect engine. And without any doubt, optical solutions intimately integrated with electronics will be required to satisfy the demand of bandwidth, energy-per-bit, and cost. Eventually, large bandwidth will become ubiquitous. With the migration of photonic systems to ever shorter distances, scalable photonic-electronic IC technologies become a necessity.
At this point it is important to keep in mind that photonic functionality such as reception or transmission can be integrated and the required footprint can shrink. However, photonics cannot shrink anymore by orders of magnitude, simply due to the wavelength used. Therefore, required voltage swings remain similar to discrete solutions, while the ability to go to maximum speed beyond 50Gbit/sec is very important.
Here exists a sweet spot for next generation More-than-Moore technologies, such as high-performance photonic BiCMOS. Going beyond the concept of present More-than-Moore technologies, photonic BiCMOS combines 2 high-performance technology sub-modules (high –performance HBTs and photonics) with a baseline CMOS process. The added complexity pays off with a full set of photonic features fit for broad-band optoelectronic system integration. We shall present IHP’s perspective on a photonic More-than-Moore technology, joining most advanced HBT technology with high-speed photonic devices for electronic-photonic sub-systems for next generation communication networks.
Advanced 3D Imaging and Analysis of Lithium Ion Battery Electrodes
Authors: Biton Moshiel , Tariq Farid , Yufit Vladimir , Shearing Paul R , Kishimoto Masashi , Gelb Jeff , Golodnitsky Diana , Peled Emanuel , Brandon Nigel P. 
Published: February 2020

Meeting increasing energy demands, storage requirements and energy portability will be expedited through an ability to directly image lithium battery material nano/micro structures at high resolutions in 3D. The performance of the battery is dependent on nano/micro-structure as important reactions often occur at porous electrode interfaces. Furthermore, during processing or operation microstructural evolution may degrade electrochemical performance.
Despite their importance, battery electrode microstructures remain poorly understood, limiting current understanding of their failure. Tomographic techniques allow for the direct 3-D imaging and chracterisation of complex microstructures from millimetres down towards nanometers.
Here we present results from 3D x-ray and FIBSEM tomography of battery materials (e.g. Figure 1) down to resolutions of tens of nanometers. Quantitative analysis of critical parameters important for battery materials is evaluated, and these are linked to simulation tools to relate structure to performance characteristics. Both x-ray and FIBSEM tomography can provide this information, facilitating analysis of micro/nano structure, morphology and provide exciting opportunities to study fabrication effects or operating conditions that could cause electrode degradation and failure.
We find this approach is effective in understanding how lithium ion batteries function at high resolutions and consequently that tomography coupled with modeling/experiments can provide new insights into degradation mechanism.
Figure 1 – 3D lithium ion anode structure with MCMB particles
Nano-Structured Silicon Derived from Silica Precursors as Anode Material for Lithium Ion Batteries
Authors: Schrandt Matthew , Kolla Praveen , Rhine Wendell , Koodali Ranjit T , Wu James , Lvovich Vadim , Cook Rob , Smirnova Alevtina 
Published: February 2020

Silicon is valuable as a high energy density anode material for Li-ion battery applications. However, the high lithium storage capacity leads to extreme volume expansion during lithiation and delithiation that can lead to mechanical deterioration and poor cycle life. To improve cyclability, nano-structured materials can be used to facilitate the volume change without deterioration. By using structured SiO2 precursors, the goal is to reduce SiO2 to Si while maintaining the structure and porosity of SiO2 and thus, mitigating degradation effects during cycling.
Nanostructured Si has been synthesized by Mg vapor reduction from SiO2 precursors [1] (e.g. SiO2 microspheres from 3M, SiO2 aerogel, and mesoporous SiO2 [2]). Following the reduction to Si, the materials were chemically treated in HCl and HF to remove remaining MgO and SiO2 respectively. Figures 1 and 2 confirm the presence of Si in reduced samples and successful removal of MgO and SiO2. TGA/DSC has been used to optimize the reduction time and temperature.
CV data (Figure 3) and cyclability tests (Figure 4) demonstrate a specific capacity of up to 2065 mAh/g with a low charge transfer resistance (Figure 3, inset).
SEM, TEM, BET, EDS, XRD, and Raman spectroscopy data will be presented for SiO2 and reduced Si to describe chemical composition and morphology. Structure dependent electrochemical properties such as impedance spectroscopy, cyclic voltammetry, galvanostatic discharge, and cycle stability will be presented and discussed.
References:
[1] R. Cook, M. Schrandt, P. Kolla, W. Rhine, R. Koodali, A. Smirnova, MRS Online Proceedings Library,1643 (2014).
[2] D. Zhao, A. Rodriguez, N. M. Dimitrijevic, T. Rajh and R. T. Koodali, J. Physical Chemistry
C, 114, 15728 (2010)
Invited Presentation: Tailoring Cathode and Morphology of Discharge Products Toward High-Rate and Long-Life Lithium-Oxygenbatteries
Authors: Zhang Xin-Bo , Xu Ji-Jing , Wang Zhong-Li , Xu Dan 
Published: February 2020

The pressing concerns of reducing greenhouse gas emissions and the consumption of non-renewable fossil fuels have led to increased demand for electrochemical energy storage systems with energy densities that far exceed those of the lithium-ion battery. To this end, rechargeable lithium-oxygen (Li-O2) batteries have been the focus of great interest due to their extremely high energy potentiality (up to 2-3 kWh kg-1) because oxygen, the cathode material, is not necessarily stored in the battery, as with convention lithium-ion battery technology, but can be accessed from the environment. However, in practice, the system has presented many scientific and technological challenges since it was introduced in 1996. The decomposition of the organic electrolytes during the discharge and charge processes causes the battery instability and electrolyte depletion. The irregular precipitation of thick film-like or large toroidal-like insoluble discharge product, Li2O2, blocks the void of the O2 cathode and eventually limits the battery performance, including the specific capacity, charge efficiency, and cycle life. The continuous accumulation of Li2CO3 and lithium carboxylates, resulting from side reactions of the Li2O2 and intermediate species, such as LiO2* and O2
-, with the cathode and the electrolyte on cycling, leads to cathode passivation and battery death. The insufficient structural stability of the cathode during Li2O2 formation/decomposition is also a limitation for battery cycle life.
In response, we have designed and fabricated a series of advanced cathodes, which hold many favorable properties including high electronic conductivity, tuned porous structure, and high electrocatlytic activity for both oxygen reduction and evolution reactions, to reduce the discharge/charge overpotentials to alleviate electrolyte decomposition, tailoring the deposition site and morphology of Li2O2 within cathode to enhance the specific capacity, charge efficiency, and cycle life. Finally, a free-standing honeycomb-like palladium-modified hollow spherical carbon deposited onto carbon paper cathode is successfully obtained, which endows a lithium-oxygen battery with high-rate capability (5900 mAh g-1 at a current density of 1.5 A g-1) and long-term (100 cycles at a current density of 300 mA g-1 and a specific capacity limit of 1000 mAh g-1) stability. These superior properties could be explained by the tailored deposition and morphology of the discharge products as well as the alleviated electrolyte decomposition compared with the conventional carbon cathode. The obtained performances provide a promising example and promotethe effort to design more advanced cathode architecture for lithium-oxygen batteries.
Invited Presentation: Ionic Liquid-Based Lithium/oxygen Battery
Authors: Arbizzani Catia , Monaco Simone , Soavi Francesca , Mastragostino Marina 
Published: February 2020

In the last few years, much research effort is being focused on rechargeable lithium–air (O2) batteries which feature a theoretical specific energy comparable to that of gasoline. While these cutting-edge batteries are at their early stage of development with many challenges to be overcome, they are the most promising candidates to power electric vehicles with long driving range. In the frame of the European LABOHR Project we are investigating the use of hydrophobic ionic liquid (IL)-based electrolytes in these batteries. Basic studies of the oxygen redox reaction in N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide at home-made catalyst-free porous carbon electrode demonstrated that O2mass transport in IL becomes crucial at the fastest battery discharge rates, which are of interest for automotive applications. The study also demonstrated that it is possible to overcome this limitation by new flow-cell designs, and the main achievements are reported and discussed.

Acknowledgement

Work funded by the European Commission in the 7th Framework Programme FP7-2010-GC-ELECTROCHEMICAL STORAGE, under contract no. 265971 “Lithium-Air Batteries with split Oxygen Harvesting and Redox processes” (LABOHR). All the partners of the LABOHR Project are acknowledged for the fruitful discussions on Li/O2 batteries with ionic liquids.

References

[1] www.labohr.eu
[2] S. Monaco, A. M. Arangio, F. Soavi, M. Mastragostino, E. Paillard, S. Passerini, Electrochimica Acta 83 (2012) 94–104.
[3] F. Soavi, S. Monaco, M. Mastragostino, Journal of Power Sources 224 (2013) 115 – 119.
[4] S. Monaco, F. Soavi, M. Mastragostino, J. Phys. Chem. Lett. 4 (2013) 1379−1382.
Invited Presentation: Air Batteries with Ionic Liquid Electrolytes: The Abile Project
Authors: Bresser Dominic , Elia Giuseppe Antonio , Hassoun Jusef , Kwak Won Jin , Lamp Peter , Mueller Franziska , Nuernberger Simon , Oberhumer Philipp , Paschos Odysseas , Passerini Stefano , Reiter Jakub , Scrosati Bruno , Sun Yang-Kook , Tsiouvaras Nikolaos 
Published: February 2020

Electrification has been a major focus of BMW and large efforts have been initiated in order to investigate technologies of high potential to be integrated in future electric vehicles. Metal-air and particularly lithium-air batteries [1] are one of the possible solutions that may substantially enhance the electric drive range. The main challenges in Li-air batteries are related to the stability of the electrolyte and safety of the negative electrode. BMW, together with three scientific teams initiated a project focusing on the use of ionic liquids and alternative anodes as potential components for Li-air batteries.
Due to their excellent electrochemical and chemical properties, onium-based ionic liquids [2] were chosen as the first candidates. The presentation will describe the electrochemical behaviour of a Li-air cell comprising such ionic liquid-based electrolytes. The results prove the concept that the chosen ionic liquid may assure the proper lithium-oxygen cell operation and electrochemical stability during cycling.
In this presentation work towards system safety improvement will be also shown [3]. In this field, alternatives to the lithium metal anode were investigated. The latter include: i) tin-carbon composite, ii) carbon-coated Zn1-xFexO [4], iii) SiOx-carbon and SiOx-silicon materials. Electrochemical tests have shown reversible behaviour of all materials both in conventional organic electrolytes as well as in electrolytes based on ionic liquids.
References:

Girishkumar G., McCloskey B., Luntz A.C., Wanson S., Wilcke W.: Lithium-air battery: Promise and Challenges. J. Phys. Chem. Lett., 2010, 1 (14), p. 2193-2203.

Armand M., Endres F., MacFarlane D.R., Ohno H., Scrosati B.: Ionic-liquid materials for the Electrochemical Challenges. Nature Mat., 2009, 8 (8), p. 621-629.

Hassoun J., Jung H.G., Lee D.J., Park J.B., Amine K., Sun Y.K., Scrosati B.: A Metal-Free, Lithium-Ion Oxygen Battery: A Step Forward to Safety in Lithium-Air Batteries. Nano Letters, 2012, 12, p. 5775-5779.

Bresser D., Mueller F., Fiedler M., Krueger S., Kloepsch R., Baither D., Winter M., Paillard E., Passerini S.: Transition-Metal-Doped Zinc Oxide Nanoparticles as a New Lithium-Ion Anode Material. Chemistry of Materials, 2013, 25 (24), p. 4977-4985.
Anodic Tin Oxide Thin Films with Nano-Channeled Structure for Lithium Battery Anode
Authors: Kim Eun-Ji , Shin Heon-Cheol 
Published: February 2020

One-dimensional (1-D) nano-channeled structure has attracted attention as electrode design for the high performance electrochemical devices. This is mainly because its 1-D nano porous structure would allow for the fast ionic transport through it and rapid interfacial reactions. One of the conventional preparation methods of 1-D nano-channeled structure is anodic oxidation. Since the first introduction of anodic aluminum oxide (AAO), different anodic metal oxides with 1-D structure have been reported for the past few decades.
Among the various 1-D metallic oxides reported in the literature, tin oxide might be utilized for various applications, such as catalysis, gas sensing, and electrochemical energy storage. In particular, when the nano-channeled tin oxide is used as the anode of the lithium battery, both of the lithia(Li2O) network and nano-channeled structure accommodate the volume change of the tin-lithium phase during the charging/discharging cycles. Although there are some attempts to use the anodic tin oxide thin film as the electrode material for lithium battery, the active material on the substrate was not pure tin oxide but tin - tin oxide bilayer. Since the tin layer underneath anodic tin oxide undergoes a significant reaction-induced volume change, 1-D structure of bilayer collapses during the cycling,
In this work, pure anodic tin oxide with well-defined 1-D structure was prepared for the use as the anode for rechargeable lithium battery. Anodic tin oxides with different pore sizes and wall thicknesses were fabricated under various anodizing conditions and their electrochemical properties were characterized by cyclic voltammetry and charge-discharge experiment.
In this presentation, cycling stability and rate capability of anodic tin oxides with different porous structures will be presented. Moreover, the feasibility of creating 1-D tin-based anodic oxide composite will be discussed for the further improvement of cycling stability.
High Voltage Pyrophosphate Cathodes for Li- and Na-Ion Batteries: Atomic-Scale Insights into Defects and Diffusion
Authors: Islam M. Saiful , Clark John , Barpanda Prabeer , Yamada Atsuo 
Published: February 2020

Major advances in rechargeable batteries for electronics, electric vehicles and grid storage requires the development of new materials. Recently, it has been proposed that the pyrophosphate framework may provide a new platform for important electrode research. Li2FeP2O7 displays reversible reaction at 3.5 V vs Li/Li+ without nanosizing or carbon coating, which is the highest voltage for any Fe-based phosphate cathode [1]. There is growing interest in sodium-ion batteries largely due to the natural abundance of sodium and cost issues for grid-storage. The sodium pyrophosphate, Na2FeP2O7, has been found to be electrochemically active (3V vs Na/Na+) [2], which is the first pyrophosphate-type of cathode for Na-ion batteries.
This presentation highlights recent studies of both Li2FeP2O7 and Na2FeP2O7 using atomistic simulation techniques [3] to provide detailed insights into defect, dopant and ion migration properties relevant to their electrochemical behaviour [4]. Li/Fe and Na/Fe antisites were found to be the most favourable intrinsic defects suggesting significant disorder, which would be sensitive to synthesis conditions. In contrast to 1D diffusion in LiFePO4, fast Li+ transport in Li2FeP2O7 is predicted to be through a 2D network. Interestingly, the Na2FeP2O7 structure appears to support quasi-3D Na+ diffusion. Hence, a significant result is that alkali-ion diffusion within this framework is found to be either 2D or 3D with low energy barriers, which are important for good rates of charge/discharge.
References

[1] S. Nishimura, M. Nakamura, R. Natsui, A. Yamada, J. Am. Chem. Soc.
2010, 132, 13596.

[2] P. Barpanda, T. Ye, S. Nishimura, S.C. Chung, Y. Yamada, M. Okubo, H.S. Zhou, A. Yamada, Electrochem. Commun.
2012, 24, 116.

[3] M.S. Islam and C.A.J. Fisher, Chem. Soc. Rev.
2014, 43, 185.

[4] J.M. Clark, S.-I. Nishimura, A. Yamada, M.S. Islam, Angew. Chem. Int. Ed.
2012, 51, 13149.