W. Qian, Xiuwen Xu, Jian Wang, Yangbing Xu, Jianwei Chen, Yongshuai Ge, Jun Chen, Shuang Xiao, Shihe Yang
Medical X-ray computed tomography requires fast imaging at a low dose rate and in a large area. Halide perovskites have shown high potential for X-ray detection, but a pressing challenge is the current lack of low-cost methods for large-scale fabrication of high-quality thick perovskite films. Here we demonstrate and elucidate an aerosol-liquid-solid process to enable continuous growth of uniform halide perovskites films at low temperature over a large area of 100 cm2, which are vertically monolithic and monocrystalline, and thus beneficial to carrier transport. Direct conversion X-ray detectors based on the representative CsPbI2Br films in conjunction with a deliberated, interface-engineered C-electrode have realized an unprecedented sensitivity (≥1.48×105 μC Gyair−1cm−2). We have further demonstrated the high-resolution radiographic imaging capability of these films. These results lay the groundwork for large scale application of halide perovskites in radiation detectors.
{"title":"An Aerosol-Liquid-Solid Process for the General Synthesis of Halide Perovskite Thick Films for Direct Conversion X-Ray Detectors","authors":"W. Qian, Xiuwen Xu, Jian Wang, Yangbing Xu, Jianwei Chen, Yongshuai Ge, Jun Chen, Shuang Xiao, Shihe Yang","doi":"10.2139/ssrn.3737815","DOIUrl":"https://doi.org/10.2139/ssrn.3737815","url":null,"abstract":"Medical X-ray computed tomography requires fast imaging at a low dose rate and in a large area. Halide perovskites have shown high potential for X-ray detection, but a pressing challenge is the current lack of low-cost methods for large-scale fabrication of high-quality thick perovskite films. Here we demonstrate and elucidate an aerosol-liquid-solid process to enable continuous growth of uniform halide perovskites films at low temperature over a large area of 100 cm2, which are vertically monolithic and monocrystalline, and thus beneficial to carrier transport. Direct conversion X-ray detectors based on the representative CsPbI2Br films in conjunction with a deliberated, interface-engineered C-electrode have realized an unprecedented sensitivity (≥1.48×105 μC Gyair−1cm−2). We have further demonstrated the high-resolution radiographic imaging capability of these films. These results lay the groundwork for large scale application of halide perovskites in radiation detectors.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"232 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127533214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Donghwan Kim, Eunchan Kim, Sohyun Park, Seungah Kim, B. Min, H. Yoon, K. Kwak, M. Cho
Understanding the graphene-water interaction, referred to as ‘wettability,’ is important for various applications, such as water desalination, filtration, energy storage, and catalysis. However, most studies on graphene's wettability have been performed with either macroscopic water contact angle measurements or molecular dynamics simulations. The detailed hydrogen-bonding network structure of water molecules at the graphene-water interface has not been fully understood at the molecular level. Here, using vibrational sum frequency generation (VSFG) spectroscopy, we elucidate the interfacial water structure and graphene hydrophobicity at a multilayer graphene-water interface. As the number of graphene layers increases, water molecules with dangling OH group become more populated. We compare the contact angles of water on the multilayer graphene surfaces with VSFG results. An excellent correlation between water adhesion energy of graphene and fraction of dangling OH groups estimated from the water OH stretch VSFG spectrum is established. This observation suggests that the VSFG could be an incisive technique for measuring water's adhesion energy on any spatially confined or blocked surface where the water contact angle cannot be measured. We further anticipate that the VSFG result on the transition from wetting transparency to translucency upon increasing the number of graphene layers will be used to understand the wettability of low-dimensional materials and the role of water structure on electric double layers of graphene-based electrodes.
{"title":"Wettability of Graphene and Interfacial Water Structure","authors":"Donghwan Kim, Eunchan Kim, Sohyun Park, Seungah Kim, B. Min, H. Yoon, K. Kwak, M. Cho","doi":"10.2139/ssrn.3737814","DOIUrl":"https://doi.org/10.2139/ssrn.3737814","url":null,"abstract":"Understanding the graphene-water interaction, referred to as ‘wettability,’ is important for various applications, such as water desalination, filtration, energy storage, and catalysis. However, most studies on graphene's wettability have been performed with either macroscopic water contact angle measurements or molecular dynamics simulations. The detailed hydrogen-bonding network structure of water molecules at the graphene-water interface has not been fully understood at the molecular level. Here, using vibrational sum frequency generation (VSFG) spectroscopy, we elucidate the interfacial water structure and graphene hydrophobicity at a multilayer graphene-water interface. As the number of graphene layers increases, water molecules with dangling OH group become more populated. We compare the contact angles of water on the multilayer graphene surfaces with VSFG results. An excellent correlation between water adhesion energy of graphene and fraction of dangling OH groups estimated from the water OH stretch VSFG spectrum is established. This observation suggests that the VSFG could be an incisive technique for measuring water's adhesion energy on any spatially confined or blocked surface where the water contact angle cannot be measured. We further anticipate that the VSFG result on the transition from wetting transparency to translucency upon increasing the number of graphene layers will be used to understand the wettability of low-dimensional materials and the role of water structure on electric double layers of graphene-based electrodes.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127153005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna Depetris, H. Peter, A. Bordoloi, Hippolyte Bernard, A. Niayifar, M. Kühl, Pietro de Anna, T. Battin
Biofilms are structured microbial communities with a spatial configuration that influences their emergent properties and ecological success. Using flume experiments and automated optical coherence tomography, we studied the morphogenesis of phototrophic biofilms along a gradient of hydraulic conditions characteristic for small streams. A compact and coalescent biofilm formed under fast flow, whereas protruding clusters separated by troughs formed under slow flow. While the experimentally imposed hydraulic conditions drove this remarkable morphological differentiation, amplicon sequencing did not reveal significant differences in biofilm community composition. Biofilm morphogenesis was linked to flow-induced displacement and reciprocal interactions between biofilm structure and local hydraulics. Automated profiling with microsensors in combination with optical coherence tomography mapped oxygen mass transfer within and around biofilm structures, providing evidence for the local alteration of the mass transfer regime. Overall, these findings evidence the strong coupling between architectural plasticity, efficient mass transfer and mechanical resistance to shear in a phototrophic biofilm.
{"title":"Morphogenesis of Phototrophic Biofilms is Controlled by Hydraulic Constraints and Enabled by Architectural Plasticity","authors":"Anna Depetris, H. Peter, A. Bordoloi, Hippolyte Bernard, A. Niayifar, M. Kühl, Pietro de Anna, T. Battin","doi":"10.2139/ssrn.3681993","DOIUrl":"https://doi.org/10.2139/ssrn.3681993","url":null,"abstract":"Biofilms are structured microbial communities with a spatial configuration that influences their emergent properties and ecological success. Using flume experiments and automated optical coherence tomography, we studied the morphogenesis of phototrophic biofilms along a gradient of hydraulic conditions characteristic for small streams. A compact and coalescent biofilm formed under fast flow, whereas protruding clusters separated by troughs formed under slow flow. While the experimentally imposed hydraulic conditions drove this remarkable morphological differentiation, amplicon sequencing did not reveal significant differences in biofilm community composition. Biofilm morphogenesis was linked to flow-induced displacement and reciprocal interactions between biofilm structure and local hydraulics. Automated profiling with microsensors in combination with optical coherence tomography mapped oxygen mass transfer within and around biofilm structures, providing evidence for the local alteration of the mass transfer regime. Overall, these findings evidence the strong coupling between architectural plasticity, efficient mass transfer and mechanical resistance to shear in a phototrophic biofilm.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131456418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhikai Le, Wei Zhang, Wenwu Li, Jianpin Tan, Ruiqing Li, Xuebin Wang, Y. V. Kaneti, Xiangfen Jiang, J. Chu, Y. Yamauchi, Ming Hu
Direct manufacturing from powder to final component is of great significance for industry. However, it remains a challenge to develop a one-pot “powder to product” strategy to produce gradient hybrid component with combined structure-function advantages. In this work, we report a metal-organic powder thermochemical solid-vapor architectonics to direct zeolitic imidazolate framework powder into gradient cobalt/carbon monolith with atomically doped nitrogen, encapsulated cobalt nanoparticles, nanotubes arrays, and well-interconnected grains. The in situ generated H 2 vapor (non-uniform distribution) and Co nanoparticles (uniformly distributed) combines a chemical vapor deposition/growth and a solids-state welding together, leading to formation of the unique gradient monolith. The gradient carbon monolith is of good mechanical stability, therefore is directly used as a freestanding working electrode for hydrogen evolution reaction (HER) in a seawater battery. This catalyst shows a low overpotential of 84 mV at a current density of 10 mA cm-2 as well as good stability for HER at a constant overpotential of 200 mV for 5 h. Furthermore, a stable power generation of over 168 h in seawater has been realized.
从粉末到最终部件的直接制造对工业具有重要意义。然而，如何制定一锅式的“粉末到产品”策略来生产具有结构功能综合优势的梯度杂化元件仍然是一个挑战。在这项工作中，我们报告了一种金属有机粉末热化学固-气结构，将沸石咪唑盐框架粉末引导成具有原子掺杂氮、封装钴纳米颗粒、纳米管阵列和良好互连颗粒的梯度钴/碳单体。原位生成的h2蒸汽(非均匀分布)和Co纳米颗粒(均匀分布)结合了化学气相沉积/生长和固态焊接在一起，形成了独特的梯度整体。梯度碳单体具有良好的机械稳定性，可直接用作海水电池析氢反应的独立工作电极。该催化剂在电流密度为10 mA cm-2时具有84 mV的低过电位，在200 mV恒定过电位下具有5 h的良好稳定性，并且在海水中实现了超过168 h的稳定发电。
{"title":"Metal-Organic Powder Thermochemical Solid-Vapor Architectonics Towards Gradient Hybrid Monolith with Combined Structure-Function Features","authors":"Zhikai Le, Wei Zhang, Wenwu Li, Jianpin Tan, Ruiqing Li, Xuebin Wang, Y. V. Kaneti, Xiangfen Jiang, J. Chu, Y. Yamauchi, Ming Hu","doi":"10.2139/ssrn.3582691","DOIUrl":"https://doi.org/10.2139/ssrn.3582691","url":null,"abstract":"Direct manufacturing from powder to final component is of great significance for industry. However, it remains a challenge to develop a one-pot “powder to product” strategy to produce gradient hybrid component with combined structure-function advantages. In this work, we report a metal-organic powder thermochemical solid-vapor architectonics to direct zeolitic imidazolate framework powder into gradient cobalt/carbon monolith with atomically doped nitrogen, encapsulated cobalt nanoparticles, nanotubes arrays, and well-interconnected grains. The in situ generated H 2 vapor (non-uniform distribution) and Co nanoparticles (uniformly distributed) combines a chemical vapor deposition/growth and a solids-state welding together, leading to formation of the unique gradient monolith. The gradient carbon monolith is of good mechanical stability, therefore is directly used as a freestanding working electrode for hydrogen evolution reaction (HER) in a seawater battery. This catalyst shows a low overpotential of 84 mV at a current density of 10 mA cm-2 as well as good stability for HER at a constant overpotential of 200 mV for 5 h. Furthermore, a stable power generation of over 168 h in seawater has been realized.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129116125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xianyun Peng, Yuying Mi, Shunzheng Zhao, Xijun Liu, Defeng Qi, Jiaqiang Sun, Yifan Liu, Haihong Bao, Di Qu, L. Zhuo, Junqiang Ren, Jun Luo, Xiaoming Sun
Development of cost-effective, active trifunctional catalysts for acidic oxygen reduction (ORR) as well as hydrogen- and oxygen-evolution reactions (HER and OER, respectively) is highly desirable, albeit challenging. Herein, single-atomic Ru sites anchored onto Ti3C2Tx MXene nanosheets are first reported to serve as trifunctional electrocatalysts for simultaneously catalyzing acidic HER, OER, and ORR. A half-wave potential of 0.80 V for ORR and small overpotentials of 290 mV and 70 mV for OER and HER, respectively, at 10 mA cm−2 are achieved. Hence, a low cell voltage of 1.56 V is required for the acidic overall water splitting. The maximum power density of an H2–O2 fuel cell using the as-prepared catalyst can reach as high as 941 mW cm−2. Theoretical calculations revealed that isolated Ru–O2 sites can effectively optimize the adsorption of reactants/intermediates and lower the energy barriers for the potential-determining steps, thereby accelerating the HER, ORR, and OER kinetics.
{"title":"Trifunctional Single-Atomic Ru Sites Enable Efficient Overall Water Splitting and Oxygen Reduction in Acidic Media","authors":"Xianyun Peng, Yuying Mi, Shunzheng Zhao, Xijun Liu, Defeng Qi, Jiaqiang Sun, Yifan Liu, Haihong Bao, Di Qu, L. Zhuo, Junqiang Ren, Jun Luo, Xiaoming Sun","doi":"10.2139/ssrn.3517557","DOIUrl":"https://doi.org/10.2139/ssrn.3517557","url":null,"abstract":"Development of cost-effective, active trifunctional catalysts for acidic oxygen reduction (ORR) as well as hydrogen- and oxygen-evolution reactions (HER and OER, respectively) is highly desirable, albeit challenging. Herein, single-atomic Ru sites anchored onto Ti<sub>3</sub>C<sub>2</sub>T<sub>x</sub> MXene nanosheets are first reported to serve as trifunctional electrocatalysts for simultaneously catalyzing acidic HER, OER, and ORR. A half-wave potential of 0.80 V for ORR and small overpotentials of 290 mV and 70 mV for OER and HER, respectively, at 10 mA cm<sup>−2</sup> are achieved. Hence, a low cell voltage of 1.56 V is required for the acidic overall water splitting. The maximum power density of an H<sub>2</sub>–O<sub>2</sub> fuel cell using the as-prepared catalyst can reach as high as 941 mW cm<sup>−2</sup>. Theoretical calculations revealed that isolated Ru–O<sub>2</sub> sites can effectively optimize the adsorption of reactants/intermediates and lower the energy barriers for the potential-determining steps, thereby accelerating the HER, ORR, and OER kinetics.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116775052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthew Y. Lu, R. Scipioni, B. Park, Tianrang Yang, Yvonne A. Chart, S. Barnett
Recent developments in solid oxide cells focus on decreasing operating temperatures below 600 °C for improved cost and electrochemical stability in order to improve viability for commercialization. In this work, we improve the performance and stability of La0.6Sr0.40.2Fe0.8O3-δ (LSCF) and a recently developed electrode material, SrTi0.3Fe0.55Co0.15O3-δ (STFC), with addition of PrOx nanoparticles. Single-step PrOx infiltration improves performance of both LSCF and STFC across all tested temperatures (450 to 650 °C) with the most significant enhancements at lower temperatures. STFC modified with PrOx yields the best overall performance and stability, with the initial polarization resistance of 0.20 Ω·cm2 at 550 °C increasing over ~ 800 hours before stabilizing at 0.27 Ω·cm2. This represents a factor of ~ 10 resistance decrease compared to the LSCF electrode at 550 °C. A distribution of relaxation timesanalysis sheds light on the electrochemical mechanisms impacted by PrOx.
{"title":"Mechanisms of PrO x Performance Enhancement of Oxygen Electrodes for Low Temperature Solid Oxide Cells","authors":"Matthew Y. Lu, R. Scipioni, B. Park, Tianrang Yang, Yvonne A. Chart, S. Barnett","doi":"10.2139/ssrn.3419214","DOIUrl":"https://doi.org/10.2139/ssrn.3419214","url":null,"abstract":"Recent developments in solid oxide cells focus on decreasing operating temperatures below 600 °C for improved cost and electrochemical stability in order to improve viability for commercialization. In this work, we improve the performance and stability of La<sub>0.6</sub>Sr<sub>0.40.2</sub>Fe<sub>0.8</sub>O<sub>3-δ</sub> (LSCF) and a recently developed electrode material, SrTi<sub>0.3</sub>Fe<sub>0.55</sub>Co<sub>0.15</sub>O<sub>3-δ</sub> (STFC), with addition of PrO<sub>x</sub> nanoparticles. Single-step PrOx infiltration improves performance of both LSCF and STFC across all tested temperatures (450 to 650 °C) with the most significant enhancements at lower temperatures. STFC modified with PrO<sub>x</sub> yields the best overall performance and stability, with the initial polarization resistance of 0.20 Ω·cm<sup>2</sup> at 550 °C increasing over ~ 800 hours before stabilizing at 0.27 Ω·cm<sup>2</sup>. This represents a factor of ~ 10 resistance decrease compared to the LSCF electrode at 550 °C. A distribution of relaxation timesanalysis sheds light on the electrochemical mechanisms impacted by PrO<sub>x</sub>.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132321239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract First-principles density functional theory method is employed with experimental techniques to investigate the redox properties and charge storage performance of seven quinone derivatives and to assess their potential as cathodes in sodium-ion batteries. The computed redox properties are comprehensively correlated with other properties, namely, electron affinity (EA), solvation energy, charge storage capacity, and energy density. The correlations are further verified to be applied not only to quinones but also to other organic molecules. The established universal correlations highlight three main conclusions. First, EA and solvation energy need to be cooperatively tuned to achieve a specific redox potential. Second, the exceptionally high performance of anthraquinone-2,6-dicarboxylic acid can be explained by the correlation of the redox potential with EA and solvation energy. Third, the differences in the performance between the calculated and experimental values for the other six quinone derivatives mainly result from the Na binding configurations, highlighting the experimental charge capacity is extraordinarily enhanced by metastable Na binding scenarios.
{"title":"Unveiled Correlations between Electron Affinity and Solvation in Redox Potential of Quinone-Based Sodium-Ion Batteries","authors":"Ki Chul Kim, Tianyuan Liu, Seung Woo Lee, S. Jang","doi":"10.2139/ssrn.3217190","DOIUrl":"https://doi.org/10.2139/ssrn.3217190","url":null,"abstract":"Abstract First-principles density functional theory method is employed with experimental techniques to investigate the redox properties and charge storage performance of seven quinone derivatives and to assess their potential as cathodes in sodium-ion batteries. The computed redox properties are comprehensively correlated with other properties, namely, electron affinity (EA), solvation energy, charge storage capacity, and energy density. The correlations are further verified to be applied not only to quinones but also to other organic molecules. The established universal correlations highlight three main conclusions. First, EA and solvation energy need to be cooperatively tuned to achieve a specific redox potential. Second, the exceptionally high performance of anthraquinone-2,6-dicarboxylic acid can be explained by the correlation of the redox potential with EA and solvation energy. Third, the differences in the performance between the calculated and experimental values for the other six quinone derivatives mainly result from the Na binding configurations, highlighting the experimental charge capacity is extraordinarily enhanced by metastable Na binding scenarios.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132327995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this research, spherical sandwich Pt/Au@Pd@UIO-67@UIO-n (n = 66, 67, 69) core–shell catalysts were assembled. Au nanoparticles (NPs) were used as the core for the epitaxial growth of Pd shells, and the resulting Au@Pd core–shell NPs were successfully encapsulated at the center of monodispersed Au@Pd@UIO-67 nanospheres. Well-dispersed Pt NPs were fully fixed on their surfaces to fabricate Pt/Au@Pd@UIO-67 composites with a UIO-n coating, resulting in Pt NPs sandwiched between an inner Au@Pd@UIO-67 core and an outer UIO-n shell. The synthesized Au@Pd core–shell NPs efficiently controlled the morphology and structure of the UIO-67 and enhanced the CO selectivity of the catalyst, the Pt NPs boosted the CO2 conversion, and the UIO-n component effectively regulated the reverse water–gas shift (RWGS) reaction.
{"title":"Spherical Sandwich Pt/Au@Pd@UIO-67@UIO-N (N = 66, 67, 69) Core–Shell Catalysts: Zr-Based Metal–Organic Framework Effectively Regulating the Reverse Water–Gas Shift Reaction","authors":"Haitao Xu, Xikuo Luo, Jiajia Wang, Yuqun Yuqun Su, Yansong Li, Zhen-liang Xu","doi":"10.2139/ssrn.3257349","DOIUrl":"https://doi.org/10.2139/ssrn.3257349","url":null,"abstract":"In this research, spherical sandwich Pt/Au@Pd@UIO-67@UIO-n (n = 66, 67, 69) core–shell catalysts were assembled. Au nanoparticles (NPs) were used as the core for the epitaxial growth of Pd shells, and the resulting Au@Pd core–shell NPs were successfully encapsulated at the center of monodispersed Au@Pd@UIO-67 nanospheres. Well-dispersed Pt NPs were fully fixed on their surfaces to fabricate Pt/Au@Pd@UIO-67 composites with a UIO-n coating, resulting in Pt NPs sandwiched between an inner Au@Pd@UIO-67 core and an outer UIO-n shell. The synthesized Au@Pd core–shell NPs efficiently controlled the morphology and structure of the UIO-67 and enhanced the CO selectivity of the catalyst, the Pt NPs boosted the CO2 conversion, and the UIO-n component effectively regulated the reverse water–gas shift (RWGS) reaction.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"2625 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128494611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiao Zhang, Suting Weng, Gaojing Yang, Yejing Li, Hong Li, Dong Su, Lin Gu, Zhaoxiang Wang, Xuefeng Wang, Liquan Chen
Solid electrolyte interphase (SEI) is regarded as the most important but the least understood part in rechargeable lithium (Li) batteries. It was formed inevitably by reacting and decomposing electrolytes on the discharged/charged anode. The interplay between the SEI and anode materials governs the charge transfer and Li+ transport, thus determining the reaction kinetic and electrochemical performance of the batteries. Having a comprehensive understanding of the SEI nature and especially its interplay with the active materials during cycling is crucial for both fundamental and applied research of rechargeable batteries. Herein, the dynamic interplay between SEI and Si anode during cycling and long-term cycles was revealed quantitively and qualitatively by titration gas chromatography (TGC), cryogenic transmission electron microscopy (cryo-TEM), and other advanced techniques in terms of charge transfer, nanostructure, and equilibrium. The results show that the SEI electrochemically forms before and through Li-Si alloy reaction, and decomposes during delithiation processes. It consumes more than 10% charges and triggers to form the inactive LixSi by isolating it from the electrical network. It is hard to construct an equilibrium interplay between the SEI and LixSi alloy due to the intrinsic instability of some SEI components (e.g., Li2O and carbonates) and the pulverization of Si anode, resulting in the continuous formation of the SEI and inactive LixSi and thus capacity drop. Therefore, constructing and maintaining an equilibrium interplay between SEI and LixSi is essential to achieve high-performance and high-energy batteries via interfacial engineering, for example, LiF-rich interphase.
{"title":"Interplay Between Solid-Electrolyte Interphase and (In)Active Li xSi in Silicon Anode","authors":"Xiao Zhang, Suting Weng, Gaojing Yang, Yejing Li, Hong Li, Dong Su, Lin Gu, Zhaoxiang Wang, Xuefeng Wang, Liquan Chen","doi":"10.2139/ssrn.3928096","DOIUrl":"https://doi.org/10.2139/ssrn.3928096","url":null,"abstract":"Solid electrolyte interphase (SEI) is regarded as the most important but the least understood part in rechargeable lithium (Li) batteries. It was formed inevitably by reacting and decomposing electrolytes on the discharged/charged anode. The interplay between the SEI and anode materials governs the charge transfer and Li+ transport, thus determining the reaction kinetic and electrochemical performance of the batteries. Having a comprehensive understanding of the SEI nature and especially its interplay with the active materials during cycling is crucial for both fundamental and applied research of rechargeable batteries. Herein, the dynamic interplay between SEI and Si anode during cycling and long-term cycles was revealed quantitively and qualitatively by titration gas chromatography (TGC), cryogenic transmission electron microscopy (cryo-TEM), and other advanced techniques in terms of charge transfer, nanostructure, and equilibrium. The results show that the SEI electrochemically forms before and through Li-Si alloy reaction, and decomposes during delithiation processes. It consumes more than 10% charges and triggers to form the inactive LixSi by isolating it from the electrical network. It is hard to construct an equilibrium interplay between the SEI and LixSi alloy due to the intrinsic instability of some SEI components (e.g., Li2O and carbonates) and the pulverization of Si anode, resulting in the continuous formation of the SEI and inactive LixSi and thus capacity drop. Therefore, constructing and maintaining an equilibrium interplay between SEI and LixSi is essential to achieve high-performance and high-energy batteries via interfacial engineering, for example, LiF-rich interphase.","PeriodicalId":244417,"journal":{"name":"Cell Press","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121950899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Costa, J. Barbosa, H. Castro, R. Gonçalves, S. Lanceros‐Méndez
Energy and environmental issue are among the most relevant challenges to be solved in the near future. Electrical vehicles (EV) will play a key role in the solution by positively contributing to these two issues. Further, they represent an important contribution to reduce the impact of greenhouse gases emissions. To achieve that it is still needed to increase their autonomy through improved lithium-ion batteries.The EV market grew in last years in more than 2 million vehicles worldwide, with vehicles with an autonomy between 200 km and 500 km. Base on this growing market and in comparison with the internal combustion vehicles (ICE), a relevant questions arise: to what extent are EVs eco-friendly and cost effective in comparison with ICE vehicles?This work presents a comparative study of EV from different European countries, with special focus on the economic and ecological impact.It is shown that in the European Countries, the economical payback time is achieved in an average of 10 years, ranging from 1 (France) to 24 years (Germany). The environmental benefit is reached in relatively low time (~3-4 years), being more evenly distributed when compared to the economical payback.It is concluded that it is necessary to reduce the price of the electric vehicles to make them more competitive in the automotive market. Further, it is important to combine both economic and environmental benefits by adopting policies within the European Union to reach a more uniform reality among the different countries, with more levelled prices and revenues (incentives, fees and taxes).
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