Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction

2024-07-22T20:32:08Z

题名: Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction 作者: Pan, Jiangyang; Gao, Lei; Zhang, Xinyu; Huang, Dubin; Zhu, Jinlong; Wang, Liping; Wei, Yadong; Yin, Wen; Xia, Yuanguang; Zou, Ruqiang; Zhao, Yusheng; Han, Songbai 摘要:

The development of cutting-edge solid-state electrolytes (SSEs) entails a deep understanding of the underlying correlation between the structure and ionic conductivity. Generally, the structure of SSEs encompasses several interconnected crystal parameters, and their collective influence on Li+ transport can be challenging to discern. Here, we systematically investigate the structure-function relationship of halide spinel LixMgCl2+x (2 >= x >= 1) SSEs. A nonmonotonic trend in the ionic conductivity of LixMgCl2+x SSEs has been observed, with the maximum value of 8.69 x 10(-6) S cm(-1) achieved at x = 1.4. The Rietveld refinement analysis, based on neutron diffraction data, has revealed that the crystal parameters including cell parameters, Li+ vacancies, Debye-Waller factor, and Li-Cl bond length assume diverse roles in influencing ionic conductivity of LixMgCl2+x at different stages within the range of x values. Besides, mechanistic analysis demonstrates Li+ transport along three-dimensional pathways, which primarily governs the contribution to ionic conductivity of LixMgCl2+x SSEs. This study has shed light on the collective influence of crystal parameters on Li+ transport behaviors, providing valuable insights into the intricate relationship between the structure and ionic conductivity of SSEs.

Preparation of Si₃N₄-based antimicrobial coatings from suspensions with long-time stability

2024-07-22T20:32:08Z

题名: Preparation of Si₃N₄-based antimicrobial coatings from suspensions with long-time stability 作者: Du, Songmo; Zhang, Jie; Sun, Siyuan; Li, Fei; Chen, Zhanglin; Zhang, Shijia; Zhao, Shuo; Tian, Zhaobo; Ning, Xiaoshan; Chen, Kexin; Cui, Wei; Liu, Guanghua 摘要: A Si3N4-based antimicrobial coating was fabricated from suspensions with long-time stability. The stability of Si3N4 suspension and the antimicrobial performance of coating were investigated. The viscosity of Si3N4 suspension was found to be the key factor affecting both stability and antimicrobial performance. The Si3N4 suspensions were modified with HASE acrylic copolymer, PAA-NH4, and Polyurethane, resulting in an improvement of the stability of Si3N4 suspension from a few hours to six months. The coating produced using the modified Si3N4 suspension exhibited an antibacterial activity of 99.9%. This study highlights the crucial role of modifying the Si3N4 suspension in improving its long-term stability and coating antimicrobial activity.

Development of a One-Step Synthesis of oxa-Spirocyclic Diphosphine Ligands Driven by Their Application in the Industrial Synthesis of Sacubitril

2024-07-22T20:31:20Z

题名: Development of a One-Step Synthesis of oxa-Spirocyclic Diphosphine Ligands Driven by Their Application in the Industrial Synthesis of Sacubitril 作者: Chen, Gen-Qiang; Xiao, Renwei; Ding, Xiaobing; Wang, Jiang; Ma, Baode; Lang, Qiwei; Zhang, Xumu 摘要: Herein we have developed a highly practical and efficient one-step coupling protocol for the synthesis of chiral spiro diphosphine ligands, especially for the oxa-spiro diphosphine ligands O-SDP, which showed excellent reactivity and diastereoselectivity in the asymmetric hydrogenation of a key intermediate of Sacubitril. It should be noted that the one-step coupling protocol could be operated on a kilogram scale, and the resulting ruthenium catalyst of O-SDP could hydrogenate the key intermediate of Sacubitril on an industrial scale.

Solution-Processable Route for Large-Area Uniform 2D Semiconductor Nanofilms

2024-07-22T20:31:20Z

题名: Solution-Processable Route for Large-Area Uniform 2D Semiconductor Nanofilms 作者: Li, Wen-Hua; Li, Nan; Wang, Xiao-Li; Wang, Wenjuan; Zhang, Haobing; Xu, Qiang 摘要: ["The semiconductor thin film engineering technique plays a key role in the development of advanced electronics. Printing uniform nanofilms on freeform surfaces with high efficiency and low cost is significant for actual industrialization in electronics. Herein, a high-throughput colloidal printing (HTCP) strategy is reported for fabricating large-area and uniform semiconductor nanofilms on freeform surfaces. High-throughput and uniform printing rely on the balance of atomization and evaporation, as well as the introduced thermal Marangoni flows of colloidal dispersion, that suppresses outward capillary flows. Colloidal printing with in situ heating enables the fast fabrication of large-area semiconductor nanofilms on freeform surfaces, such as SiO2/Si, Al2O3, quartz glass, poly(ethylene terephthalate) (PET), Al foil, plastic tube, and Ni foam, expanding their technological applications where substrates are essential. The printed SnS2 nanofilms are integrated into thin-film semiconductor gas sensors with one of the fastest responses (8 s) while maintaining the highest sensitivity (Rg/Ra = 21) (toward 10 ppm NO2), as well as an ultralow limit of detection (LOD) of 46 ppt. The ability to print uniform semiconductor nanofilms on freeform surfaces with high-throughput promises the development of next-generation electronics with low cost and high efficiency.","A high-throughput colloidal printing strategy for fabricating large-area and uniform semiconductor nanofilms on freeform surfaces. Uniform deposition relies on the discovery of unprecedented enhanced thermal Marangoni flows of well-dispersed nanosheet colloid during the print-heating process that suppresses outward capillary flows. image"]

Research Progress in Enantioselective Radical Desymmetrization Reactions

2024-07-22T20:31:08Z

题名: Research Progress in Enantioselective Radical Desymmetrization Reactions 作者: Yang, Chang-Jiang; Liu, Lin; Gu, Qiang-Shuai; Liu, Xin-Yuan 摘要: Enantioselective radical desymmetrization is a highly effective approach for rapidly creating enantioenriched molecules, introducing dramatically increased structural complexity from readily available prochiral or meso compound feedstocks. Two strategic modes have been developed for these reactions, which differ in the nature of the stereo-determining steps. The first category deals primarily with the stereoselective desymmetrization of closed-shell radical precursors or functional reagents, whereas the second category achieves desymmetrization by stereoselectively functionalizing open-shell radical species. This mini-review explores the research progress in this growing field, aiming to elucidate mechanistic scenarios related to stereochemical control. Additionally, it offers insights into the challenges and opportunities that lie ahead for further development.

Influence Mechanism of Interfacial Oxidation of Li₃YCl₆ Solid Electrolyte on Reduction Potential

2024-07-22T20:31:08Z

题名: Influence Mechanism of Interfacial Oxidation of Li₃YCl₆ Solid Electrolyte on Reduction Potential 作者: Wang, Xin; Yang, Zhiqiang; Li, Na; Wu, Kang; Gao, Kesheng; Zhao, Enyue; Han, Songbai; Guo, Wenhan 摘要: Halide-based solid electrolytes are promising candidates for all solid-state lithium-ion batteries (ASSLBs) due to their high ionic conductivity, wide electrochemical window, and excellent chemical stability with cathode materials. However, when tested in practice, their intrinsic electrochemical stability windows do not well match the conditions for stable operation of ASSBs. Existing literature reports halide-based ASSBs that still operate well outside the electrochemical stability window, while ASSBs that do not operate within the window are not well studied or the studies are based on the cathode material interface. In this study, we aim to elucidate the mechanism behind all-solid-state battery failure by investigating how the reduction potential of Li3YCl6 solid-state electrolyte itself changes under overcharging conditions. Our findings demonstrate that in Li-In|Li3YCl6|Li3YCl6-C half-cells during the first state of charge, Cl ions participate in charge compensation, resulting in a depletion of ligands. This phenomenon significantly affects the reduction potential of Y3+, causing it to be reduced to Y2Cl3 and ultimately to Y-0 at conditions far exceeding its actual reduction potential. Furthermore, we analyze the interfacial impedance induced by this process and propose a novel perspective on battery failure.

Emergence of Improper Electronic Ferroelectricity and Flat Band in Twisted Bilayer Tl₂S

2024-07-22T20:30:55Z

题名: Emergence of Improper Electronic Ferroelectricity and Flat Band in Twisted Bilayer Tl₂S 作者: Gui, Zhigang; Li, Wei; Huang, Li 摘要: Two-dimensional (2D) ferroelectrics possessing out-of-plane (OP) polarization are highly desirable for applications and fundamental physics. Here, by first-principles calculations, we reveal that large-angle interlayer twisting can efficiently stabilize an unexpected ordering of sizable electric dipoles, producing OP polarization out of the centrosymmetric ground-state structure of Tl2S, in great contrast to the recently proposed interlayer-sliding ferroelectricity. The ferroelectricity originates from a nonlinear coupling between a polar order dominantly contributed by electrons and an unstable phonon mode associated with a commensurate k point (1/3, 1/3, 0) in the two constituent monolayers, therefore indicating an improper and electronic ferroelectric nature. More interestingly, a flat band and a van Hove singularity occur in its electronic structures just below the Fermi level in the large-angle twisted bilayer Tl2S. The unusual coexistence of improper electronic ferroelectricity, a flat band, and a van Hove singularity in one 2D material offers exceptional opportunities for exploring novel physics and applications.

Rhodium-Catalyzed Asymmetric Hydrogenation and Transfer Hydrogenation of 1,3-Dipolar Nitrones

2024-07-22T20:30:55Z

题名: Rhodium-Catalyzed Asymmetric Hydrogenation and Transfer Hydrogenation of 1,3-Dipolar Nitrones 作者: Xu, Liren; Yang, Tilong; Sun, Hao; Zeng, Jingwen; Mu, Shuo; Zhang, Xumu; Chen, Gen-Qiang 摘要: Owing to their distinctive 1,3-dipolar structure, the catalytic asymmetric hydrogenation of nitrones to hydroxylamines has been a formidable and longstanding challenge, characterized by intricate enantiocontrol and susceptibility to N-O bond cleavage. In this study, the asymmetric hydrogenation and transfer hydrogenation of nitrones were accomplished with a tethered TsDPEN-derived cyclopentadienyl rhodium(III) catalyst (TsDPEN: p-toluenesulfonyl-1,2-diphenylethylene-1,2-diamine), the reaction proceeds via a novel 7-membered cyclic transition state, producing chiral hydroxylamines with up to 99 % yield and >99 % ee. The practical viability of this methodology was underscored by gram-scale catalytic reactions and subsequent transformations. Furthermore, mechanistic investigations and DFT calculations were also conducted to elucidate the origin of enantioselectivity.

Enhanced Hydrogen Evolution Catalysis of Pentlandite due to the Increases in Coordination Number and Sulfur Vacancy during Cubic-Hexagonal Phase Transition

2024-07-22T20:30:43Z

题名: Enhanced Hydrogen Evolution Catalysis of Pentlandite due to the Increases in Coordination Number and Sulfur Vacancy during Cubic-Hexagonal Phase Transition 作者: Liu, Yuegao; Cai, Chao; Zhu, Shengcai; Zheng, Zhi; Li, Guowu; Chen, Haiyan; Li, Chao; Sun, Haiyan; Chou, I-Ming; Yu, Yanan; Mei, Shenghua; Wang, Liping 摘要: ["The search for new phases is an important direction in materials science. The phase transition of sulfides results in significant changes in catalytic performance, such as MoS2 and WS2. Cubic pentlandite [cPn, (Fe, Ni)9S8] can be a functional material in batteries, solar cells, and catalytic fields. However, no report about the material properties of other phases of pentlandite exists. In this study, the unit-cell parameters of a new phase of pentlandite, sulfur-vacancy enriched hexagonal pentlandite (hPn), and the phase boundary between cPn and hPn are determined for the first time. Compared to cPn, the hPn shows a high coordination number, more sulfur vacancies, and high conductivity, which result in significantly higher hydrogen evolution performance of hPn than that of cPn and make the non-nano rock catalyst hPn superior to other most known nanosulfide catalysts. The increase of sulfur vacancies during phase transition provides a new approach to designing functional materials.","New mineral: the sulfur-vacancies enriched P63/mmc hexagonal pentlandite (hPn) is discovered. The hydrogen evolution performance of the non-nano rock catalyst hPn is better than that of cPn and most known nanosulfide catalysts. image"]

Photoswitchable Temperature Nanosensors Based on the Chemical Kinetics of Photochromic Naphthopyran for Live Cell Imaging

2024-07-22T20:30:43Z

题名: Photoswitchable Temperature Nanosensors Based on the Chemical Kinetics of Photochromic Naphthopyran for Live Cell Imaging 作者: Cheng, Yu; Wu, Jianhong; Cui, Yunxin; Zhai, Jingying; Wu, Minghui; Xie, Xiaojiang 摘要: Microscopic temperature imaging holds significant importance in various fields, particularly in the development of nanomaterials for photothermal therapy (PTT). In this study, we present an analytical method to probe cellular temperature based on chemical kinetics and additional luminescence quenching by photoswitchable naphthopyrans. Taking advantage of the rapid ring-closing reaction of naphthopyran, temperature sensing was realized with a linear relationship between the logarithmic decay time constant (ln tau) and the reciprocal temperature (T (-1)). To create luminescent temperature nanosensors, we harnessed the ability of ring-opened naphthopyran to quench the luminescence of a semiconducting polymer, resulting in a diverse array of probes. Structural modifications on the naphthopyran also provided a way to fine-tune the sensitivity and response window of the nanosensors. The method allowed cellular temperature imaging on a cost-effective fluorescence microscopic setup. As an application, the temperature increase induced by gold nanorods (AuNRs) in cell lysosomes was successfully monitored, laying the foundation for a new class of photoswitchable nanosensors with promising biological applications.

Exploring the Underlying Correlation between the Structure and Ionic Conductivity in Halide Spinel Solid-State Electrolytes with Neutron Diffraction

Preparation of Si3N4-based antimicrobial coatings from suspensions with long-time stability

Development of a One-Step Synthesis of oxa-Spirocyclic Diphosphine Ligands Driven by Their Application in the Industrial Synthesis of Sacubitril

Solution-Processable Route for Large-Area Uniform 2D Semiconductor Nanofilms

Research Progress in Enantioselective Radical Desymmetrization Reactions

Influence Mechanism of Interfacial Oxidation of Li3YCl6 Solid Electrolyte on Reduction Potential

Emergence of Improper Electronic Ferroelectricity and Flat Band in Twisted Bilayer Tl2S

Rhodium-Catalyzed Asymmetric Hydrogenation and Transfer Hydrogenation of 1,3-Dipolar Nitrones

Enhanced Hydrogen Evolution Catalysis of Pentlandite due to the Increases in Coordination Number and Sulfur Vacancy during Cubic-Hexagonal Phase Transition

Photoswitchable Temperature Nanosensors Based on the Chemical Kinetics of Photochromic Naphthopyran for Live Cell Imaging

Preparation of Si₃N₄-based antimicrobial coatings from suspensions with long-time stability

Influence Mechanism of Interfacial Oxidation of Li₃YCl₆ Solid Electrolyte on Reduction Potential

Emergence of Improper Electronic Ferroelectricity and Flat Band in Twisted Bilayer Tl₂S