The photoactive properties and effectiveness of a selected group of ten terminated MXenes —Sc2CT2, Y2CT2 (T = Cl, Br, S, and Se), Y2CI2 and Zr2CO2— has been deeply studied by means of density functional theory (DFT). Here it is demonstrated that the studied MXenes exhibit robust energetic and dynamical stability, having all an indirect bandgap, while most of them with values within the visible spectrum, and also exhibiting suitable band alignment for the water splitting reaction. The charge density distribution of the valence band maximum (VBM) and conduction band minimum (CBM) is found to be separated across different layers with low overlaps, below 30%. Most MXenes present high charge carrier mobilities with favourable electron-hole disparities, with Sc2CBr2 also presenting directional charge carrier transport. Additionally, these materials show strong optical absorption (~105 cm–1) in the visible spectrum, translating to promising solar-to-hydrogen (STH) efficiency theoretical limits, up to 23%. Overall, the combination of all these features positions MXenes among the optimal materials for efficient photocatalytic water splitting.
{"title":"Exploring the Photoactive Properties of Promising MXenes for Water Splitting","authors":"Diego Ontiveros, Francesc Viñes, Carmen Sousa","doi":"10.1039/d4ta06852a","DOIUrl":"https://doi.org/10.1039/d4ta06852a","url":null,"abstract":"The photoactive properties and effectiveness of a selected group of ten terminated MXenes —Sc<small><sub>2</sub></small>CT<small><sub>2</sub></small>, Y<small><sub>2</sub></small>CT<small><sub>2</sub></small> (T = Cl, Br, S, and Se), Y<small><sub>2</sub></small>CI<small><sub>2</sub></small> and Zr<small><sub>2</sub></small>CO<small><sub>2</sub></small>— has been deeply studied by means of density functional theory (DFT). Here it is demonstrated that the studied MXenes exhibit robust energetic and dynamical stability, having all an indirect bandgap, while most of them with values within the visible spectrum, and also exhibiting suitable band alignment for the water splitting reaction. The charge density distribution of the valence band maximum (VBM) and conduction band minimum (CBM) is found to be separated across different layers with low overlaps, below 30%. Most MXenes present high charge carrier mobilities with favourable electron-hole disparities, with Sc<small><sub>2</sub></small>CBr<small><sub>2</sub></small> also presenting directional charge carrier transport. Additionally, these materials show strong optical absorption (~105 cm<small><sup>–1</sup></small>) in the visible spectrum, translating to promising solar-to-hydrogen (STH) efficiency theoretical limits, up to 23%. Overall, the combination of all these features positions MXenes among the optimal materials for efficient photocatalytic water splitting.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"25 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cheng Chen, Rendang Yang, Yang Wang, Xiaohui Guo, Jie Sheng
Inherently insulating and thermally stable nanocellulose membranes are prone to forming three-dimensional porous structure, conducive to store large amounts of electrolyte and providing ion migration pathways. However, the infiltration of polar electrolytes can compromise the mechanical strength of the nanocellulose membrane by disrupting hydrogen bonding, leading to suboptimal interface and cycling stability of the batteries. This study effectively improves the mechanical strength and electrochemical performance of bacterial cellulose (BC) based separators by in situ constructing a dual-network structure polymerized from poly (ethylene glycol) diacrylate (PEGDA) and acrylic acid (AA). The distinctive dual-network structure not only significantly enhances the wet strength of the BC separator but also introduces a polymer-coordination transport mechanism, building upon the original lithium-ion pore transport system. The transport of lithium ions is regulated by the ether, ester and carboxyl groups in the polymer network, so that they are uniformly deposited on the surface of the lithium metal negative electrode, and finally form a SEI layer dominated by LiF, which greatly reduces the side reactions between the electrolyte and the electrode. The assembled lithium symmetric battery exhibits stable lithium deposition/stripping behavior, and the cycle stability and rate performance far superior to commercial PP separators.
本身具有绝缘性和热稳定性的纳米纤维素膜容易形成三维多孔结构，有利于储存大量电解质并提供离子迁移通道。然而，极性电解质的渗入会破坏氢键，从而影响纳米纤维素膜的机械强度，导致电池的界面和循环稳定性不理想。本研究通过原位构建由聚（乙二醇）二丙烯酸酯（PEGDA）和丙烯酸（AA）聚合而成的双网络结构，有效提高了基于细菌纤维素（BC）的隔膜的机械强度和电化学性能。这种独特的双网络结构不仅大大增强了 BC 分离器的湿强度，还在原有锂离子孔隙传输系统的基础上引入了聚合物配位传输机制。锂离子的传输受聚合物网络中醚基、酯基和羧基的调控，从而均匀地沉积在金属锂负极表面，最终形成以 LiF 为主的 SEI 层，大大降低了电解液与电极之间的副反应。组装后的锂对称电池表现出稳定的锂沉积/剥离行为，其循环稳定性和速率性能远远优于商用聚丙烯隔膜。
{"title":"Dual-network bacterial cellulose-based separators with high wet strength and dual ion transport mechanism for uniform lithium deposition","authors":"Cheng Chen, Rendang Yang, Yang Wang, Xiaohui Guo, Jie Sheng","doi":"10.1039/d4ta06151a","DOIUrl":"https://doi.org/10.1039/d4ta06151a","url":null,"abstract":"Inherently insulating and thermally stable nanocellulose membranes are prone to forming three-dimensional porous structure, conducive to store large amounts of electrolyte and providing ion migration pathways. However, the infiltration of polar electrolytes can compromise the mechanical strength of the nanocellulose membrane by disrupting hydrogen bonding, leading to suboptimal interface and cycling stability of the batteries. This study effectively improves the mechanical strength and electrochemical performance of bacterial cellulose (BC) based separators by in situ constructing a dual-network structure polymerized from poly (ethylene glycol) diacrylate (PEGDA) and acrylic acid (AA). The distinctive dual-network structure not only significantly enhances the wet strength of the BC separator but also introduces a polymer-coordination transport mechanism, building upon the original lithium-ion pore transport system. The transport of lithium ions is regulated by the ether, ester and carboxyl groups in the polymer network, so that they are uniformly deposited on the surface of the lithium metal negative electrode, and finally form a SEI layer dominated by LiF, which greatly reduces the side reactions between the electrolyte and the electrode. The assembled lithium symmetric battery exhibits stable lithium deposition/stripping behavior, and the cycle stability and rate performance far superior to commercial PP separators.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"13 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyelectrolyte hydrogels, combining the conductivity of polyelectrolytes with the flexibility of hydrogels, become a popular candidate for flexible sensors, soft robotics, and electronic skins due to their remarkable stability in electrical conductivity. However, their mechanical properties and adhesive strength are limited because of their single-type bonding interaction. This work introduces a double-networked (DN) polyelectrolyte hydrogel formed through polymer chain entanglements, chemical crosslinking, and the incorporation of multiple strong and/or weak bonding interactions. The first network is a chemically crosslinked polyacrylamide (PAAm). The second network consists of polyelectrolytes (poly(diallyldimethylammonium chloride) (PDDA) and poly(methacrylic acid sodium salt) (PMAANa)), which form numerous weak and/or strong ionic bonds. Weak and/or strong hydrogen bonds are present within and between two networks. The mechanical properties and adhesive strength of the polyelectrolyte DN hydrogel can be tailored through modulating the content of PAAm, polyelectrolytes, and co-solvents. The optimal compositions have a tensile modulus of 10.8 kPa, tensile fracture strain of 1000%, and adhesive strength of 37.8 kPa. The hydrogel sensors are successfully applied to flexible electrodes for various devices for detecting human motion, handwriting recognition, and continuous monitoring of electrophysiological signals. The distinctive solvent-adjustable transparency of the gel also allows for its utilization in information encryption and decryption.
{"title":"Multi-Interaction Conductive Double-Network Polyelectrolyte Hydrogel with High Stretchability, Self-Adhesion, and Tunable Transparency for Bioelectronic Sensing and Information Encryption","authors":"Dongdong Lu, Zilong Zhu, Mingning Zhu, Peng Zhang, X. D. Xiang","doi":"10.1039/d4ta05293e","DOIUrl":"https://doi.org/10.1039/d4ta05293e","url":null,"abstract":"Polyelectrolyte hydrogels, combining the conductivity of polyelectrolytes with the flexibility of hydrogels, become a popular candidate for flexible sensors, soft robotics, and electronic skins due to their remarkable stability in electrical conductivity. However, their mechanical properties and adhesive strength are limited because of their single-type bonding interaction. This work introduces a double-networked (DN) polyelectrolyte hydrogel formed through polymer chain entanglements, chemical crosslinking, and the incorporation of multiple strong and/or weak bonding interactions. The first network is a chemically crosslinked polyacrylamide (PAAm). The second network consists of polyelectrolytes (poly(diallyldimethylammonium chloride) (PDDA) and poly(methacrylic acid sodium salt) (PMAANa)), which form numerous weak and/or strong ionic bonds. Weak and/or strong hydrogen bonds are present within and between two networks. The mechanical properties and adhesive strength of the polyelectrolyte DN hydrogel can be tailored through modulating the content of PAAm, polyelectrolytes, and co-solvents. The optimal compositions have a tensile modulus of 10.8 kPa, tensile fracture strain of 1000%, and adhesive strength of 37.8 kPa. The hydrogel sensors are successfully applied to flexible electrodes for various devices for detecting human motion, handwriting recognition, and continuous monitoring of electrophysiological signals. The distinctive solvent-adjustable transparency of the gel also allows for its utilization in information encryption and decryption.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"69 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Unique physicochemical properties of non-Ti-MXenes have attracted prominent attention in various fields. Doping/substitution and surface modification of non-Ti-MXenes have also started gaining interest because of their enhanced efficiency and targeted application. Recently, the flexibility of non-Ti-MXenes has started becoming popular in wearable electronics. The state-of-the-art research progress on non-Ti-MXenes and their doped/substituted or surface-modified counterparts is systematically reviewed in this article as well as their flexibility and recent utilization in wearable and portable electronic devices. Theoretical and experimental research on synthesis strategies, unique properties, and electrochemical efficiency of the most studied 10 non-Ti-MXenes have been discussed in this review. Also, doping/substitution and surface functionalization of non-Ti-MXenes have been reviewed regarding their characteristics, synthesis techniques, and benefits. The introduction of flexibility using different techniques and their recent utilization in various flexible and wearable electronic devices have also been systematically reviewed. Moreover, the challenges and outlook of this area are also enlightened for future opportunities. The novelty of this article is depicted by addressing the less-investigated category of MXenes that is non-Ti-MXenes. This is the first review covering doping and surface modification of non-Ti-MXenes for implementation in flexible and wearable electronics.
{"title":"Doped and Functionalized Non-Ti-MXene for Flexible and Wearable Electronic Devices","authors":"Shrabani De, Bishnu Bastakoti","doi":"10.1039/d4ta07376b","DOIUrl":"https://doi.org/10.1039/d4ta07376b","url":null,"abstract":"Unique physicochemical properties of non-Ti-MXenes have attracted prominent attention in various fields. Doping/substitution and surface modification of non-Ti-MXenes have also started gaining interest because of their enhanced efficiency and targeted application. Recently, the flexibility of non-Ti-MXenes has started becoming popular in wearable electronics. The state-of-the-art research progress on non-Ti-MXenes and their doped/substituted or surface-modified counterparts is systematically reviewed in this article as well as their flexibility and recent utilization in wearable and portable electronic devices. Theoretical and experimental research on synthesis strategies, unique properties, and electrochemical efficiency of the most studied 10 non-Ti-MXenes have been discussed in this review. Also, doping/substitution and surface functionalization of non-Ti-MXenes have been reviewed regarding their characteristics, synthesis techniques, and benefits. The introduction of flexibility using different techniques and their recent utilization in various flexible and wearable electronic devices have also been systematically reviewed. Moreover, the challenges and outlook of this area are also enlightened for future opportunities. The novelty of this article is depicted by addressing the less-investigated category of MXenes that is non-Ti-MXenes. This is the first review covering doping and surface modification of non-Ti-MXenes for implementation in flexible and wearable electronics.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"18 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xian-Chen Meng, Jian Luan, Yi Liu, Yu-Shu Sheng, Fu-Yu Guo, Peng Zheng, Wen-Long Duan, Wenze Li
Metal-organic frameworks (MOFs) and their derivatives have multiple advantages, such as controlled morphology and uniform distribution of elements, which can be served as a kind of excellent electrocatalyst. It is significant to balance the relationship between activity, conductivity and stability of catalyst for oxygen evolution reaction (OER). The construction of interface in composite materials is an important strategy for the preparation of catalyst for OER. In this paper, a novel Co-MOF (Co-MOF-NH2) was synthesized by hydrothermal method, which was mixed with melamine phosphate (P-MA) and calcined to obtain AIP-PMA composite material. For the first time, a one-step pyrolysis method was used to embed CoP nanoparticles into the Co3O4 shell and load them on the N-doped graphene layer. As a result, the unique morphology offered more dispersed active site and larger specific surface area, and demonstrated the highest catalytic activity and electrical conductivity. Density functional theory (DFT) calculation also showed that the formation of the interface between CoP and Co3O4 made the center of the d band of Co in AIP-PMA far away from the Fermi level, thus reducing the energy barrier released by O2 and resulting as excellent OER performance with 1.55 V potential at a current density of 10 mA cm-2. Furthermore, the graphene coating effectively shielded the catalyst, allowing it to remain stable over time.
金属有机框架（MOFs）及其衍生物具有形态可控、元素分布均匀等多重优点，可作为一种优良的电催化剂。平衡氧进化反应（OER）催化剂的活性、导电性和稳定性之间的关系意义重大。在复合材料中构建界面是制备氧进化反应催化剂的重要策略。本文采用水热法合成了一种新型 Co-MOF（Co-MOF-NH2），并将其与磷酸三聚氰胺（P-MA）混合后煅烧得到 AIP-PMA 复合材料。该研究首次采用一步热解法将 CoP 纳米粒子嵌入 Co3O4 外壳，并将其负载在掺杂 N 的石墨烯层上。因此，这种独特的形态提供了更分散的活性位点和更大的比表面积，并表现出最高的催化活性和导电性。密度泛函理论（DFT）计算还表明，CoP 与 Co3O4 之间形成的界面使 AIP-PMA 中 Co 的 d 带中心远离费米级，从而降低了 O2 释放的能量势垒，使其在 10 mA cm-2 电流密度下具有 1.55 V 电位，从而实现了出色的 OER 性能。此外，石墨烯涂层还能有效屏蔽催化剂，使其长期保持稳定。
{"title":"Co-MOF-derived core-shell CoP@Co3O4 nanoparticle loaded N-doped graphene: An efficient catalyst for oxygen evolution reaction","authors":"Xian-Chen Meng, Jian Luan, Yi Liu, Yu-Shu Sheng, Fu-Yu Guo, Peng Zheng, Wen-Long Duan, Wenze Li","doi":"10.1039/d4ta07696f","DOIUrl":"https://doi.org/10.1039/d4ta07696f","url":null,"abstract":"Metal-organic frameworks (MOFs) and their derivatives have multiple advantages, such as controlled morphology and uniform distribution of elements, which can be served as a kind of excellent electrocatalyst. It is significant to balance the relationship between activity, conductivity and stability of catalyst for oxygen evolution reaction (OER). The construction of interface in composite materials is an important strategy for the preparation of catalyst for OER. In this paper, a novel Co-MOF (Co-MOF-NH2) was synthesized by hydrothermal method, which was mixed with melamine phosphate (P-MA) and calcined to obtain AIP-PMA composite material. For the first time, a one-step pyrolysis method was used to embed CoP nanoparticles into the Co3O4 shell and load them on the N-doped graphene layer. As a result, the unique morphology offered more dispersed active site and larger specific surface area, and demonstrated the highest catalytic activity and electrical conductivity. Density functional theory (DFT) calculation also showed that the formation of the interface between CoP and Co3O4 made the center of the d band of Co in AIP-PMA far away from the Fermi level, thus reducing the energy barrier released by O2 and resulting as excellent OER performance with 1.55 V potential at a current density of 10 mA cm-2. Furthermore, the graphene coating effectively shielded the catalyst, allowing it to remain stable over time.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"1 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenzhu Zhao, Mulin Sun, Fang Xiang, Xuefei Wu, Zachary Fink, Zongming Huang, Junyao Gao, Honghe Ding, Pengju Tan, Chengjian Yuan, Yuqian Yang, Nikita A Emelianov, Lyubov A. Frolova, Zhengguo Xiao, Pavel Troshin, Thomas P. Russell, Junfa Zhu, Yu Li, Qin Hu
Tin-based perovskites have become the most promising non-lead perovskites due to their ideal band gap and low toxicity. Although the open circuit voltage of tin-based perovskite solar cells (TPSCs) continues to approach the theoretical value, the short-circuit current is still far from the theoretical value. Here, we describe an interface modification method by regulating the property of hole transport layer, PEDOT: PSS, which improves the surface molecular morphology and improves the energy level alignment of PEDOT: PSS/perovskite interface. Advanced GIWAXSand IR-SNOM characterization are conducted to achieve multi-dimensional characterization ofnanoscale surface morphology and chemical distribution of PEDOT: PSS. With the multi-attributeoptimization, charge carrier extraction and non-radiative recombination are also improved. Theresultant TPSCs exhibit a higher power conversion efficiency of 13.32% in compared with the control device of 10.50%, accompanied with an increase in the short-circuit current from 18.10 to 20.50 mA cm-2 and FF from 68.23% to 76.43%. This work demonstrates a reliable strategy for improving charge carrier extraction and device performance for lead-free TPSCs.
{"title":"Enhanced charge carrier extraction and transport with interface modification for efficient tin-based perovskite solar cells","authors":"Zhenzhu Zhao, Mulin Sun, Fang Xiang, Xuefei Wu, Zachary Fink, Zongming Huang, Junyao Gao, Honghe Ding, Pengju Tan, Chengjian Yuan, Yuqian Yang, Nikita A Emelianov, Lyubov A. Frolova, Zhengguo Xiao, Pavel Troshin, Thomas P. Russell, Junfa Zhu, Yu Li, Qin Hu","doi":"10.1039/d4ta06046f","DOIUrl":"https://doi.org/10.1039/d4ta06046f","url":null,"abstract":"Tin-based perovskites have become the most promising non-lead perovskites due to their ideal band gap and low toxicity. Although the open circuit voltage of tin-based perovskite solar cells (TPSCs) continues to approach the theoretical value, the short-circuit current is still far from the theoretical value. Here, we describe an interface modification method by regulating the property of hole transport layer, PEDOT: PSS, which improves the surface molecular morphology and improves the energy level alignment of PEDOT: PSS/perovskite interface. Advanced GIWAXSand IR-SNOM characterization are conducted to achieve multi-dimensional characterization ofnanoscale surface morphology and chemical distribution of PEDOT: PSS. With the multi-attributeoptimization, charge carrier extraction and non-radiative recombination are also improved. Theresultant TPSCs exhibit a higher power conversion efficiency of 13.32% in compared with the control device of 10.50%, accompanied with an increase in the short-circuit current from 18.10 to 20.50 mA cm-2 and FF from 68.23% to 76.43%. This work demonstrates a reliable strategy for improving charge carrier extraction and device performance for lead-free TPSCs.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"11 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Changyu Weng, Hongmei Yuan, Jie Wang, Longlong Ma, Jianguo Liu
COFs have garnered widespread attention and demonstrated significant potential in energy storage and conversion, attributed to their predesigned structures, high surface areas, and excellent stability. However, designing and preparing COFs with high-performance Li-ion storage capabilities among different types of linkages remains challenging. In this work, we synthesized two types of COFs with distinct linkages through linkage engineering. The COFs@BOA, incorporating oxazole linkages, and COFs@IM, incorporating imine linkages, both exhibited fine crystallinity and stability. Due to the semiconductor properties of the COFs, we employed an in-situ growth approach to deposit the COFs onto the surface of carbon nanotubes. The resulting COFs@BOA-30 and COFs@IM-30 composites demonstrated highly reversible capacity, with the latter exhibiting a superior capacity of up to 1100.3 mAh g-1 under 100 mA g-1. The capacity contribution of COFs@IM was calculated to be 1696.0 mAh g-1 in the COFs@IM-30 composite, while COFs@BOA contributed only 925.8 mAh g-1. DFT calculations suggest that the discrepancy in capacities may be attributed to the lower LUMO-HOMO gap of COFs@IM. Additionally, electrical conductivity measurements indicate that COFs@IM has better conductivity than COFs@BOA, highlighting the superior performance of COFs@IM. This study underscores the significance of linkage engineering in designing COFs to improve the performance of organic electrodes in LIBs.
{"title":"Linkage engineering regulated π-conjugated covalent organic frameworks (COFs)-based anode for high-performance LIBs","authors":"Changyu Weng, Hongmei Yuan, Jie Wang, Longlong Ma, Jianguo Liu","doi":"10.1039/d4ta06789d","DOIUrl":"https://doi.org/10.1039/d4ta06789d","url":null,"abstract":"COFs have garnered widespread attention and demonstrated significant potential in energy storage and conversion, attributed to their predesigned structures, high surface areas, and excellent stability. However, designing and preparing COFs with high-performance Li-ion storage capabilities among different types of linkages remains challenging. In this work, we synthesized two types of COFs with distinct linkages through linkage engineering. The COFs@BOA, incorporating oxazole linkages, and COFs@IM, incorporating imine linkages, both exhibited fine crystallinity and stability. Due to the semiconductor properties of the COFs, we employed an in-situ growth approach to deposit the COFs onto the surface of carbon nanotubes. The resulting COFs@BOA-30 and COFs@IM-30 composites demonstrated highly reversible capacity, with the latter exhibiting a superior capacity of up to 1100.3 mAh g-1 under 100 mA g-1. The capacity contribution of COFs@IM was calculated to be 1696.0 mAh g-1 in the COFs@IM-30 composite, while COFs@BOA contributed only 925.8 mAh g-1. DFT calculations suggest that the discrepancy in capacities may be attributed to the lower LUMO-HOMO gap of COFs@IM. Additionally, electrical conductivity measurements indicate that COFs@IM has better conductivity than COFs@BOA, highlighting the superior performance of COFs@IM. This study underscores the significance of linkage engineering in designing COFs to improve the performance of organic electrodes in LIBs.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"22 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142670781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kee-Sun Sohn, Byung Do Lee, Deepak S. Gavali, Heejeong Kim, Seonghwan Kim, Min Young Cho, Kyunglim Pyo, Young-Kook Lee, Woon Bae Park
In surveying an extensive library of 4,375 hypothetical Na-based Argyrodites, we underscore the value of computational screening, noting that no Na-based Argyrodite solid-state electrolyte has been successfully synthesized. We introduce a robust approach using density functional theory (DFT) calculations to identify thermodynamically and electrochemically stable candidates. By evaluating energy above the hull (Eh), formation energy (Ef), band gap (Eg), and electrochemical stability window (Vw), we narrow the set to 15 compounds via a 4-dimensional Pareto frontier. Competing materials for Eh and Vw calculations are sourced from the Materials Project, ICSD, and Google DeepMind. Connectivity-optimized graph networks validate the reliability of our calculations. Ab-initio molecular dynamics (AIMD) calculations assess the room-temperature sodium ion conductivity (σRT) of the 15 selected entries, ultimately identifying the top 5 with promising σRT. This discovery of multi-compositional virtual Argyrodites advances the challenge of synthesizing Na-based Argyrodites.
在对包含 4,375 种假设 Na 基 Argyrodites 的庞大资料库进行调查时，我们强调了计算筛选的价值，并指出目前还没有成功合成任何 Na 基 Argyrodite 固态电解质。我们介绍了一种利用密度泛函理论（DFT）计算来确定热力学和电化学上稳定的候选物质的稳健方法。通过评估壳上能量 (Eh)、形成能 (Ef)、带隙 (Eg) 和电化学稳定性窗口 (Vw)，我们通过四维帕累托边界将候选化合物的范围缩小到 15 种。用于 Eh 和 Vw 计算的竞争材料来自材料项目、ICSD 和 Google DeepMind。连接性优化图网络验证了我们计算的可靠性。非线性分子动力学（AIMD）计算评估了 15 个入选条目的室温钠离子电导率（σRT），最终确定了具有良好σRT 的前 5 个条目。这一多成分虚拟氩离子的发现推动了合成钠基氩离子的挑战。
{"title":"Discovering Virtual Na-based Argyrodites as Solid-State Electrolytes Using DFT, AIMD, and Machine Learning Techniques","authors":"Kee-Sun Sohn, Byung Do Lee, Deepak S. Gavali, Heejeong Kim, Seonghwan Kim, Min Young Cho, Kyunglim Pyo, Young-Kook Lee, Woon Bae Park","doi":"10.1039/d4ta06927g","DOIUrl":"https://doi.org/10.1039/d4ta06927g","url":null,"abstract":"In surveying an extensive library of 4,375 hypothetical Na-based Argyrodites, we underscore the value of computational screening, noting that no Na-based Argyrodite solid-state electrolyte has been successfully synthesized. We introduce a robust approach using density functional theory (DFT) calculations to identify thermodynamically and electrochemically stable candidates. By evaluating energy above the hull (E<small><sub>h</sub></small>), formation energy (E<small><sub>f</sub></small>), band gap (E<small><sub>g</sub></small>), and electrochemical stability window (V<small><sub>w</sub></small>), we narrow the set to 15 compounds via a 4-dimensional Pareto frontier. Competing materials for E<small><sub>h</sub></small> and V<small><sub>w</sub></small> calculations are sourced from the Materials Project, ICSD, and Google DeepMind. Connectivity-optimized graph networks validate the reliability of our calculations. Ab-initio molecular dynamics (AIMD) calculations assess the room-temperature sodium ion conductivity (σ<small><sub>RT</sub></small>) of the 15 selected entries, ultimately identifying the top 5 with promising σ<small><sub>RT</sub></small>. This discovery of multi-compositional virtual Argyrodites advances the challenge of synthesizing Na-based Argyrodites.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"22 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fan Yang, Minhao Xiao, Sangsuk Lee, Javier Alan Quezada Rentería, Xinyi Wang, Minju Cha, Anya Rose Dickinson-Cove, Sungsoon Kim, Guy Z. Ramon, Gaurav Sant, Eric M. V. Hoek, David Jassby, Igor M De Rosa
The emerging process of CO2 capture and sequestration will likely require large volumes of caustic. The fossil fuel demand and carbon footprint of transporting liquid caustic is self-defeating, and hence, there is a need for energy-efficient, on-site caustic production for carbon capture projects. Caustic production is dominated by the well-established “chlor-alkali” processes. This process requires highly concentrated (~25 wt.%) and pure (>99.5 wt.%) NaCl feed brines, uses high-cost ion-exchange membranes and high operating temperatures (90 C), and generates a highly-concentrated (>33%) caustic stream that can be further concentrated using thermal evaporation. This highly concentrated caustic is then shipped to customers, where it is typically diluted to the required level. We have developed a flow-through membrane/cathode electrolysis process that produces a caustic solution (pH 10.22-12.26) at a specific energy consumption (SEC) of 1.71 kWhe/kg NaOH at room temperature using a 3.5% NaCl solution as feed, while achieving pure H2 generation without the use of ion exchange membranes. We demonstrate that the SEC is strongly dependent on the flow rate through the cathode, reaching a minimum at a high rate of 1,200 L/m2/hr. Electrochemical impedance spectroscopy, confocal microscopy, and finite element modeling show that the SEC is lowered through a combination of enhanced mass transport (of H+ and OH- ions) to and from the cathode surface and H2 gas stripping, both facilitated by the high flow rates. This technology offers the opportunity for the on-site production of dilute caustic streams (potentially from softened seawater) at a significantly reduced energy cost (compared to conventional chlor-alkali processes that consume >2.1 kWhe/kg NaOH).
{"title":"Efficient Caustic and Hydrogen Production Using a Pressurized Flow-Through Cathode","authors":"Fan Yang, Minhao Xiao, Sangsuk Lee, Javier Alan Quezada Rentería, Xinyi Wang, Minju Cha, Anya Rose Dickinson-Cove, Sungsoon Kim, Guy Z. Ramon, Gaurav Sant, Eric M. V. Hoek, David Jassby, Igor M De Rosa","doi":"10.1039/d4ta04680c","DOIUrl":"https://doi.org/10.1039/d4ta04680c","url":null,"abstract":"The emerging process of CO2 capture and sequestration will likely require large volumes of caustic. The fossil fuel demand and carbon footprint of transporting liquid caustic is self-defeating, and hence, there is a need for energy-efficient, on-site caustic production for carbon capture projects. Caustic production is dominated by the well-established “chlor-alkali” processes. This process requires highly concentrated (~25 wt.%) and pure (>99.5 wt.%) NaCl feed brines, uses high-cost ion-exchange membranes and high operating temperatures (90 C), and generates a highly-concentrated (>33%) caustic stream that can be further concentrated using thermal evaporation. This highly concentrated caustic is then shipped to customers, where it is typically diluted to the required level. We have developed a flow-through membrane/cathode electrolysis process that produces a caustic solution (pH 10.22-12.26) at a specific energy consumption (SEC) of 1.71 kWhe/kg NaOH at room temperature using a 3.5% NaCl solution as feed, while achieving pure H2 generation without the use of ion exchange membranes. We demonstrate that the SEC is strongly dependent on the flow rate through the cathode, reaching a minimum at a high rate of 1,200 L/m2/hr. Electrochemical impedance spectroscopy, confocal microscopy, and finite element modeling show that the SEC is lowered through a combination of enhanced mass transport (of H+ and OH- ions) to and from the cathode surface and H2 gas stripping, both facilitated by the high flow rates. This technology offers the opportunity for the on-site production of dilute caustic streams (potentially from softened seawater) at a significantly reduced energy cost (compared to conventional chlor-alkali processes that consume >2.1 kWhe/kg NaOH).","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"6 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The off-centering phenomenon manifests as locally distorted configurations with broken symmetry in a crystal structure due to the displacement of constituent atoms from their ideal coordination centers within the lattice. In contrast to the anticipated formation of anionic solid solutions of Mg3(Sb1−x−yBixGey)2, herein we report β-Mg3(Sb, Bi)2 based superionic phase formation (space group – Ia, 206) with off-centering of the dominant trigonal α-Mg3(Sb, Bi)2 phase and segregation of nanophase Mg3Ge upon equiatomic (Bi, Ge) alloying. The discordant nature of Ge is unveiled within the layered α-Mg3(Sb, Bi)2 structure and is assessed employing (3 + 1) dimensional superspace to reveal an off-centering (dz) along the z direction for the constituent atoms in the range of ±0–0.02 Å. The (Bi, Ge) alloying results in favourable tuning of the desired p-type conduction for attaining higher power factors by band engineering and synergistic reduction of lattice thermal conductivity. The stable superionic polymorph co-existing in an anionic solid solution of Mg3(Sb, Bi)2 provides a renewed basis for understanding the crystal structure and its transformation in CaAl2Si2-type Zintl compounds.
{"title":"Alloying induced superionic β-phase formation in Mg3Sb2 based Zintl compounds","authors":"Nagendra Singh Chauhan, Takao Mori","doi":"10.1039/d4ta06173j","DOIUrl":"https://doi.org/10.1039/d4ta06173j","url":null,"abstract":"The off-centering phenomenon manifests as locally distorted configurations with broken symmetry in a crystal structure due to the displacement of constituent atoms from their ideal coordination centers within the lattice. In contrast to the anticipated formation of anionic solid solutions of Mg<small><sub>3</sub></small>(Sb<small><sub>1−<em>x</em>−<em>y</em></sub></small>Bi<small><sub><em>x</em></sub></small>Ge<small><sub><em>y</em></sub></small>)<small><sub>2</sub></small>, herein we report β-Mg<small><sub>3</sub></small>(Sb, Bi)<small><sub>2</sub></small> based superionic phase formation (space group – <em>I</em>a<img alt=\"[3 with combining macron]\" border=\"0\" src=\"https://www.rsc.org/images/entities/char_0033_0304.gif\"/>, 206) with off-centering of the dominant trigonal α-Mg<small><sub>3</sub></small>(Sb, Bi)<small><sub>2</sub></small> phase and segregation of nanophase Mg<small><sub>3</sub></small>Ge upon equiatomic (Bi, Ge) alloying. The discordant nature of Ge is unveiled within the layered α-Mg<small><sub>3</sub></small>(Sb, Bi)<small><sub>2</sub></small> structure and is assessed employing (3 + 1) dimensional superspace to reveal an off-centering (dz) along the <em>z</em> direction for the constituent atoms in the range of ±0–0.02 Å. The (Bi, Ge) alloying results in favourable tuning of the desired p-type conduction for attaining higher power factors by band engineering and synergistic reduction of lattice thermal conductivity. The stable superionic polymorph co-existing in an anionic solid solution of Mg<small><sub>3</sub></small>(Sb, Bi)<small><sub>2</sub></small> provides a renewed basis for understanding the crystal structure and its transformation in CaAl<small><sub>2</sub></small>Si<small><sub>2</sub></small>-type Zintl compounds.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"18 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142665394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
![[3 with combining macron]](https://www.rsc.org/images/entities/char_0033_0304.gif)
, 206) with off-centering of the dominant trigonal α-Mg3(Sb, Bi)2 phase and segregation of nanophase Mg3Ge upon equiatomic (Bi, Ge) alloying. The discordant nature of Ge is unveiled within the layered α-Mg3(Sb, Bi)2 structure and is assessed employing (3 + 1) dimensional superspace to reveal an off-centering (dz) along the z direction for the constituent atoms in the range of ±0–0.02 Å. The (Bi, Ge) alloying results in favourable tuning of the desired p-type conduction for attaining higher power factors by band engineering and synergistic reduction of lattice thermal conductivity. The stable superionic polymorph co-existing in an anionic solid solution of Mg3(Sb, Bi)2 provides a renewed basis for understanding the crystal structure and its transformation in CaAl2Si2-type Zintl compounds.
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