Jinyu Chen, Chao Chen, Chong Zhao, na tu, Yunjing Chen, Nie Xin, Xiaokun Huang, Junming Liu, Xiangping Jiang
To clarify the structural mechanism of high piezoelectric activity of (1-x)BiFeO3-xBaTiO3 ((1-x)BF-xBT) solid solution, the evolution of phase structure and domain configuration and their effects on piezoelectric properties were studied in a wide range of components (0.2 ≤ x ≤ 0.9). XRD refinement results show that with the introduction of BT, the phase structure gradually transforms from rhombohedral (R) to rhombohedral/pseudocubic (R/pC) coexistence and finally to pC, accompanied by the weakening of lattice distortion. The freezing temperature (Tf) of (1-x)BF-xBT decreases with the increment of BT around the morphotropic phase boundary (MPB) (0.3 ≤ x ≤ 0.5). This indicates that the domain structure changes from ferroelectric ordered domains to nanodomains (or polar nanoregions), corresponding to the enhancement of the relaxation state. High piezoelectric properties in 0.7BF-0.3BT are attributed to the unique heterogeneous domain structure and superior domain switching at MPB. The large strain is achieved in 0.6BF-0.4BT, which results from the mutual transformation between relaxor nanodomains and ferroelectric ordered domains.
{"title":"The composition / field-induced octahedral tilt, domain switch and improved piezoelectric properties in BF-BT ceramics across phase transition","authors":"Jinyu Chen, Chao Chen, Chong Zhao, na tu, Yunjing Chen, Nie Xin, Xiaokun Huang, Junming Liu, Xiangping Jiang","doi":"10.1039/d4ta03949a","DOIUrl":"https://doi.org/10.1039/d4ta03949a","url":null,"abstract":"To clarify the structural mechanism of high piezoelectric activity of (1-x)BiFeO3-xBaTiO3 ((1-x)BF-xBT) solid solution, the evolution of phase structure and domain configuration and their effects on piezoelectric properties were studied in a wide range of components (0.2 ≤ x ≤ 0.9). XRD refinement results show that with the introduction of BT, the phase structure gradually transforms from rhombohedral (R) to rhombohedral/pseudocubic (R/pC) coexistence and finally to pC, accompanied by the weakening of lattice distortion. The freezing temperature (Tf) of (1-x)BF-xBT decreases with the increment of BT around the morphotropic phase boundary (MPB) (0.3 ≤ x ≤ 0.5). This indicates that the domain structure changes from ferroelectric ordered domains to nanodomains (or polar nanoregions), corresponding to the enhancement of the relaxation state. High piezoelectric properties in 0.7BF-0.3BT are attributed to the unique heterogeneous domain structure and superior domain switching at MPB. The large strain is achieved in 0.6BF-0.4BT, which results from the mutual transformation between relaxor nanodomains and ferroelectric ordered domains.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431169","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, Chongqing Yang, Xiaobin Fu, Yilong Yang, Senhe Huang, Junbo Hou, Min Yang, Yuezeng Su, Xiaodong Zhuang
The specific performance of two-dimensional conductive metal–organic frameworks (MOFs) in energy storage devices is significantly constrained by the presence of bulky redox-active centers and densely packed interlayers. Herein, we report two semi-conductive MOFs, Fe-MOF and Cr-MOF, using a small aromatic linker, pyrazine (pyz). Both MOFs demonstrated exceptional capacitive properties in an ionic electrolyte. Despite having similar layered AB-stacking geometries and non-porous structures, the single-crystalline Fe-MOF demonstrated weaker redox interactions between Fe2+ and pyz nodes, resulting in typical semiconducting properties with a bandgap of ∼1.07 eV. In contrast, the Cr-MOF exhibited a high conductivity, reaching 9.0 mS cm−1 at 350 K. Remarkably, the Fe-MOF electrode delivered a specific capacitance of 436.7 F g−1 at 0.5 A g−1, almost three times higher than that of the Cr-MOF (123.5 F g−1), despite its larger bandgap. Moreover, a high energy density of 98.2 W h kg−1 and excellent cycling stability (retaining 95.3% after 10 000 cycles) have been achieved in the Fe-MOF electrode. In situ experimental analysis together with theoretical calculations revealed that the superior charge storage capability of the Fe-MOF originated from the participation of both cations and anions in the diffusion-controlled charge storage, even with a non-porous structure. This study enhances our understanding of energy storage mechanisms in non-porous conductive MOFs and provides valuable insights for the development of advanced MOF materials for future energy storage applications.
二维导电金属有机框架（MOFs）在储能设备中的具体性能受到笨重的氧化还原活性中心和密集夹层的严重制约。在此，我们报告了两种半导电 MOF：Fe-MOF 和 Cr-MOF，它们都使用了小型芳香族连接物吡嗪（pyz）。这两种 MOF 在离子电解质中都表现出优异的电容特性。尽管具有相似的层状 AB 堆积几何结构和无孔结构，但单晶铁-MOF 在 Fe2+ 和吡嗪节点之间的氧化还原作用较弱，因此具有典型的半导体特性，带隙为 1.07 eV。相比之下，Cr-MOF 表现出很高的电导率，在 350 K 时达到 9.0 mS cm-1。值得注意的是，在 0.5 A g-1 的条件下，铁-MOF 电极的比电容为 436.7 F g-1，几乎是铬-MOF（123.5 F g-1）的三倍，尽管其带隙更大。此外，Fe-MOF 电极还实现了 98.2 W h kg-1 的高能量密度和出色的循环稳定性（10,000 次循环后保持 95.3%）。现场实验分析和理论计算显示，Fe-MOF 优异的电荷存储能力源于阳离子和阴离子都参与了扩散控制的电荷存储，即使是无孔结构也是如此。这项研究加深了我们对无孔导电 MOF 储能机理的理解，为未来储能应用领域先进 MOF 材料的开发提供了宝贵的启示。
{"title":"Non-porous two-dimensional conducting metal–organic frameworks with enhanced capacitance","authors":"Cheng Chen, Chongqing Yang, Xiaobin Fu, Yilong Yang, Senhe Huang, Junbo Hou, Min Yang, Yuezeng Su, Xiaodong Zhuang","doi":"10.1039/d4ta05484a","DOIUrl":"https://doi.org/10.1039/d4ta05484a","url":null,"abstract":"The specific performance of two-dimensional conductive metal–organic frameworks (MOFs) in energy storage devices is significantly constrained by the presence of bulky redox-active centers and densely packed interlayers. Herein, we report two semi-conductive MOFs, Fe-MOF and Cr-MOF, using a small aromatic linker, pyrazine (pyz). Both MOFs demonstrated exceptional capacitive properties in an ionic electrolyte. Despite having similar layered AB-stacking geometries and non-porous structures, the single-crystalline Fe-MOF demonstrated weaker redox interactions between Fe<small><sup>2+</sup></small> and pyz nodes, resulting in typical semiconducting properties with a bandgap of ∼1.07 eV. In contrast, the Cr-MOF exhibited a high conductivity, reaching 9.0 mS cm<small><sup>−1</sup></small> at 350 K. Remarkably, the Fe-MOF electrode delivered a specific capacitance of 436.7 F g<small><sup>−1</sup></small> at 0.5 A g<small><sup>−1</sup></small>, almost three times higher than that of the Cr-MOF (123.5 F g<small><sup>−1</sup></small>), despite its larger bandgap. Moreover, a high energy density of 98.2 W h kg<small><sup>−1</sup></small> and excellent cycling stability (retaining 95.3% after 10 000 cycles) have been achieved in the Fe-MOF electrode. <em>In situ</em> experimental analysis together with theoretical calculations revealed that the superior charge storage capability of the Fe-MOF originated from the participation of both cations and anions in the diffusion-controlled charge storage, even with a non-porous structure. This study enhances our understanding of energy storage mechanisms in non-porous conductive MOFs and provides valuable insights for the development of advanced MOF materials for future energy storage applications.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431172","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}
Shuangshuang Zhou, Qiqun Liu, Xiaowei Li, Ning Wang, Cheng-Bo Li
Homogeneous molecular catalysts suffer from formidable recycling and instability challenges, preventing their further application. In this paper, we report that thiophene substituted salen metal complexes could work as heterogeneous hydrogen evolution photocatalysts in the water phase after self-assembling into a supramolecular nanobelt by highly ordered π–π stacking, which exhibited semiconductor properties. Compared to the previously reported salen metal catalysts which need photosensitizers and organic solvents, the newly assembled catalyst serves as a photocatalyst in the water phase, and its hydrogen evolution rate is 55 times higher than that of its homogeneous system and 110 times higher than that of metal salen complexes without the thiophene group, and the stability is also greatly improved. The enhanced catalytic activity is revealed to be due to the great improvement of optical absorption, charge separation and interfacial charge transfer rates.
{"title":"A nanobelt structure as a photocatalyst assembled from molecular cobalt complexes boosts hydrogen evolution","authors":"Shuangshuang Zhou, Qiqun Liu, Xiaowei Li, Ning Wang, Cheng-Bo Li","doi":"10.1039/d4ta05432f","DOIUrl":"https://doi.org/10.1039/d4ta05432f","url":null,"abstract":"Homogeneous molecular catalysts suffer from formidable recycling and instability challenges, preventing their further application. In this paper, we report that thiophene substituted salen metal complexes could work as heterogeneous hydrogen evolution photocatalysts in the water phase after self-assembling into a supramolecular nanobelt by highly ordered π–π stacking, which exhibited semiconductor properties. Compared to the previously reported salen metal catalysts which need photosensitizers and organic solvents, the newly assembled catalyst serves as a photocatalyst in the water phase, and its hydrogen evolution rate is 55 times higher than that of its homogeneous system and 110 times higher than that of metal salen complexes without the thiophene group, and the stability is also greatly improved. The enhanced catalytic activity is revealed to be due to the great improvement of optical absorption, charge separation and interfacial charge transfer rates.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431174","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}
MnMoO4 is a barely explored material for electrocatalytic oxygen evolution reaction (OER) and in-situ tracking of the reactive intermediates and final active species during OER in an alkaline pH lacks a sequential study. Herein, in-situ spectroscopic and ex-situ microscopic studies unravel a pH-dependent [MoO4]2- dissolution from MnMoO4 with a kobs of 4.5 s-1 to form α-MnO2 and subsequent potential-driven anodic transformation to δ-MnO2. The electrochemically derived δ-MnO2 delivers a fairly stable current density (15 mA cm-2) at 1.55 V (vs RHE) for over 24 h. However, a thermally stable mixed-phase α/δ-MnO2 species evolved during OER with dominant MnIII content and remains highly reactive toward OER with η10 at 333 K of 239 mV. Temperature-dependent OER study provides an unimolecular reaction order for [OH]- and an anodic transfer coefficient (a) of 0.7. A low activation barrier of 9.77 k J mol-1 and a high exchange current density (j0) of 0.095 mA cm-2 validate that the improved OER activity on α/δ-MnO2 is due to fast electro-kinetics. DFT study on the (21 @#x0305;(1 ) @#x0305;6) surface of the δ-MnO2 concluded that the dissociation of the *O-H bond to form the *O is the rate-limiting for OER and the *O intermediate is stabilized by a weak O—O interaction (1.4 Å) with one lattice-oxygen before forming a hydroperoxide intermediate. Herein, in-situ tracking of the reactive phases generated from the MnMoO4 pre-catalyst, detailed electro-kinetics, and the theoretical study help to unravel the OER mechanism.
锰氧化物（MnMoO4）是一种几乎未被开发的电催化氧进化反应（OER）材料，缺乏对碱性 pH 下 OER 反应过程中反应中间产物和最终活性物种的原位跟踪研究。在本文中，原位光谱和原位显微镜研究揭示了[MoO4]2-从 MnMoO4 中溶解形成 α-MnO2 的过程与 pH 值的关系，其 kobs 为 4.5 s-1，随后电位驱动阳极转化为 δ-MnO2。电化学衍生的 δ-MnO2 在 1.55 V（相对于 RHE）电压下提供了相当稳定的电流密度（15 mA cm-2），持续时间超过 24 小时。然而，在 OER 过程中演化出了一种热稳定的 α/δ-MnO2 混合相，其中 MnIII 含量占主导地位，并且对 OER 仍具有高反应性，η10 在 333 K 时为 239 mV。随温度变化的 OER 研究提供了[OH]- 的单分子反应顺序和 0.7 的阳极转移因子 (a)。9.77 k J mol-1 的低活化势垒和 0.095 mA cm-2 的高交换电流密度 (j0) 证明，α/δ-MnO2 的 OER 活性的提高是由于快速的电动力学。对 δ-MnO2 的 (21 @#x0305;(1 ) @#x0305;6) 表面进行的 DFT 研究得出结论：*O-H 键解离形成 *O 是 OER 的限速过程，*O 中间体在形成过氧化氢中间体之前通过与一个晶格氧的弱 O-O 相互作用（1.4 Å）而稳定下来。在这里，对 MnMoO4 前催化剂生成的反应相进行原位跟踪、详细的电动力学和理论研究有助于揭示 OER 机理。
{"title":"Tracking the Active Phase and Reaction Pathway of OER Mediated by MnMoO4 Microrod Electro(Pre)-catalyst","authors":"Anubha Rajput, Ankita Kumari, Hirak Kumar Basak, Dibyajyoti Ghosh, Biswarup Chakraborty","doi":"10.1039/d4ta05985a","DOIUrl":"https://doi.org/10.1039/d4ta05985a","url":null,"abstract":"MnMoO4 is a barely explored material for electrocatalytic oxygen evolution reaction (OER) and in-situ tracking of the reactive intermediates and final active species during OER in an alkaline pH lacks a sequential study. Herein, in-situ spectroscopic and ex-situ microscopic studies unravel a pH-dependent [MoO4]2- dissolution from MnMoO4 with a kobs of 4.5 s-1 to form α-MnO2 and subsequent potential-driven anodic transformation to δ-MnO2. The electrochemically derived δ-MnO2 delivers a fairly stable current density (15 mA cm-2) at 1.55 V (vs RHE) for over 24 h. However, a thermally stable mixed-phase α/δ-MnO2 species evolved during OER with dominant MnIII content and remains highly reactive toward OER with η10 at 333 K of 239 mV. Temperature-dependent OER study provides an unimolecular reaction order for [OH]- and an anodic transfer coefficient (a) of 0.7. A low activation barrier of 9.77 k J mol-1 and a high exchange current density (j0) of 0.095 mA cm-2 validate that the improved OER activity on α/δ-MnO2 is due to fast electro-kinetics. DFT study on the (21 @#x0305;(1 ) @#x0305;6) surface of the δ-MnO2 concluded that the dissociation of the *O-H bond to form the *O is the rate-limiting for OER and the *O intermediate is stabilized by a weak O—O interaction (1.4 Å) with one lattice-oxygen before forming a hydroperoxide intermediate. Herein, in-situ tracking of the reactive phases generated from the MnMoO4 pre-catalyst, detailed electro-kinetics, and the theoretical study help to unravel the OER mechanism.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142431404","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}
High entropy compound (HEC) nanostructures have attracted considerable attention for various electrocatalysis reactions due to their unique physicochemical features by the adjustable multi-elemental synergy. However, there is a lack of focus on grain boundary engineering in HEC nanomaterials for enhanced electrocatalysis. Herein, wormcast-like PdFeCoNiCu polycrystalline high-entropy nanomaterials (PdFeCoNiCu-pHENs) are synthesized by a facile two-stage potential electrodeposition method. The as-synthesized PdFeCoNiCu-pHENs wormcast-like porous nanostructure enriches grain boundary defects, which exhibit superior electroactivity toward both hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR), as well as the excellent MOR-coupled hydrogen production in alkaline. Benefiting from the electron synergistic effect of multi-element and the full distribution of massive grain boundary defects in novel wormcast-like polycrystalline aggregation, PdFeCoNiCu-pHENs exhibited great MOR (the specific activity of 52.5 mA·cm−2) and HER (the overpotential of 38.4 mV versus RHE at 10 mA·cm−2) electroactivities and efficient MOR-assisted hydrogen generation (the required cell voltage of 1.11 V at 100 mA·cm−2) ability. This study offers a new strategy to develop advantageous high-entropy electrocatalysts for efficient energy-saving hydrogen production.
{"title":"Electrochemical Synthesis Wormcast-like Pd-based Polycrystalline High Entropy Aggregates for Methanol Water Co-electrocatalysis","authors":"Yaxing Liu, Wenhao Ding, Jiaxin Liu, Guizhe zhao, Weiyin Li, Yaqing Liu","doi":"10.1039/d4ta06304j","DOIUrl":"https://doi.org/10.1039/d4ta06304j","url":null,"abstract":"High entropy compound (HEC) nanostructures have attracted considerable attention for various electrocatalysis reactions due to their unique physicochemical features by the adjustable multi-elemental synergy. However, there is a lack of focus on grain boundary engineering in HEC nanomaterials for enhanced electrocatalysis. Herein, wormcast-like PdFeCoNiCu polycrystalline high-entropy nanomaterials (PdFeCoNiCu-pHENs) are synthesized by a facile two-stage potential electrodeposition method. The as-synthesized PdFeCoNiCu-pHENs wormcast-like porous nanostructure enriches grain boundary defects, which exhibit superior electroactivity toward both hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR), as well as the excellent MOR-coupled hydrogen production in alkaline. Benefiting from the electron synergistic effect of multi-element and the full distribution of massive grain boundary defects in novel wormcast-like polycrystalline aggregation, PdFeCoNiCu-pHENs exhibited great MOR (the specific activity of 52.5 mA·cm−2) and HER (the overpotential of 38.4 mV versus RHE at 10 mA·cm−2) electroactivities and efficient MOR-assisted hydrogen generation (the required cell voltage of 1.11 V at 100 mA·cm−2) ability. This study offers a new strategy to develop advantageous high-entropy electrocatalysts for efficient energy-saving hydrogen production.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415565","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}
In an effort to increase the thermomechanical stability of lithium-ion battery separators, thermoset membranes (TM) are a viable alternative to commercial polyolefin separators. We present an efficient and scalable method to produce thin TMs via photopolymerization-induced phase separation (PIPS) in ambient conditions. The pore size is controllable and tuneable by varying the ratio between propylene carbonate (PC) and tetraethylene glycol (TEG) as porogens. The TMs maintain dimensional stability above 200 ○C and sufficient mechanical stiffness. By incorportating a small amount of a thiol monomer, the brittleness of the TMs was supressed, and a high Young’s modulus is achieved (880 MPa). The ionic conductivity of the optimized TMs were around 1 mS cm-2, with a low MacMullin number, NM (4.9). In symmetrical Li/Li cells, the TMs behaved similar to the commerical PE reference, effectively supressing short circuits for 1000+ hours although continous overpotential build up and electrolyte consumption eventually led to cell failure. In LiFePO4/Li half-cells, similar rate capabilities were achieved for the TMs compared to the reference showing its viability as a separator material.
{"title":"Tuneable and efficient manufacturing of Li-ion battery separators using photopolymerization-induced phase separation","authors":"Samuel Emilsson, Göran Lindbergh, Mats Johansson","doi":"10.1039/d4ta03701d","DOIUrl":"https://doi.org/10.1039/d4ta03701d","url":null,"abstract":"In an effort to increase the thermomechanical stability of lithium-ion battery separators, thermoset membranes (TM) are a viable alternative to commercial polyolefin separators. We present an efficient and scalable method to produce thin TMs via photopolymerization-induced phase separation (PIPS) in ambient conditions. The pore size is controllable and tuneable by varying the ratio between propylene carbonate (PC) and tetraethylene glycol (TEG) as porogens. The TMs maintain dimensional stability above 200 ○C and sufficient mechanical stiffness. By incorportating a small amount of a thiol monomer, the brittleness of the TMs was supressed, and a high Young’s modulus is achieved (880 MPa). The ionic conductivity of the optimized TMs were around 1 mS cm-2, with a low MacMullin number, NM (4.9). In symmetrical Li/Li cells, the TMs behaved similar to the commerical PE reference, effectively supressing short circuits for 1000+ hours although continous overpotential build up and electrolyte consumption eventually led to cell failure. In LiFePO4/Li half-cells, similar rate capabilities were achieved for the TMs compared to the reference showing its viability as a separator material.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142415564","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}
Yuanzhu Jiang, Aodong Zhu, Teng Liao, Wang Zhao, Mengmeng Cheng, Xinxin Zhang, Yi-Bing Cheng, Junyan Xiao
The potential risk of lead (Pb) leakage from lead halide perovskite materials poses a significant challenge in the commercialization of perovskite solar cells (PSCs). To address this issue, a viable strategy involves endowing the materials in PSCs with the ability to immobilize Pb. Herein, we introduce a straightforward technique for carbon-based PSCs that utilizes phosphate as a multifunctional additive, which exhibits both bonding and chemical adsorption effects. A playdough-like carbon material can be made by mixing a phosphate aqueous solution with graphite powder, and then be pressed into shape to serve as the top electrode of PSCs. In addition to good compatibility with small-area PSCs and modules, this versatile carbon electrode effectively mitigates the Pb leakage from damaged devices to a safe level.
{"title":"Multifunctional additive enables lead-adsorbing carbon electrodes for perovskite solar cells","authors":"Yuanzhu Jiang, Aodong Zhu, Teng Liao, Wang Zhao, Mengmeng Cheng, Xinxin Zhang, Yi-Bing Cheng, Junyan Xiao","doi":"10.1039/d4ta05429f","DOIUrl":"https://doi.org/10.1039/d4ta05429f","url":null,"abstract":"The potential risk of lead (Pb) leakage from lead halide perovskite materials poses a significant challenge in the commercialization of perovskite solar cells (PSCs). To address this issue, a viable strategy involves endowing the materials in PSCs with the ability to immobilize Pb. Herein, we introduce a straightforward technique for carbon-based PSCs that utilizes phosphate as a multifunctional additive, which exhibits both bonding and chemical adsorption effects. A playdough-like carbon material can be made by mixing a phosphate aqueous solution with graphite powder, and then be pressed into shape to serve as the top electrode of PSCs. In addition to good compatibility with small-area PSCs and modules, this versatile carbon electrode effectively mitigates the Pb leakage from damaged devices to a safe level.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142404956","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}
Zhao Hanyu, Jia Ying, Wang Xiaochun, Sha Xinkang, Zhao Jiali, Cheng Junhao, Chen Guangxue, He Minghui
Ionic conductors are important materials for sensing devices owing to their excellent stretchability, conductivity, and transparency. However, it is extremely challenging to simultaneously achieve high tensile strength, fracture strain, and toughness in a dry ion conductor. In view of this, an acrylic acid (AA) and poly(ethylene glycol) dimethacrylate (PEGMA) based dry ion conductor (ISPSIC) with ultra-high mechanical performance is developed by an efficient one-pot method. By utilizing PEGMA to construct microphase-separated regions within the polymer network of the traditional poly(AA–ChCl) type supramolecular deep eutectic polymer, the ISPSIC can enhance the tensile strength of the dry ion conductor by 252.74% with only 0.43% PEGMA content, with no loss of tensile strain. Benefiting from the advantages of the in situ microphase-separation structure, this dry ion conductor exhibits remarkably high tensile strength (77.77 MPa), tensile strain (505.43%), toughness (232.70 MJ m−3), transparency (>90%), and electrical conductivity (6.7 × 10−5 S m−1). Notably, the relative resistance variations of the ISPSIC are greater than 800% and can be electrohealed up to 98.5% within 0.03 s. This work provides a reliable method for further tuning the microstructure and high performance of ionic conductors during polymerization.
{"title":"Efficient preparation of high-toughness ionic conductors using in situ microphase-separation","authors":"Zhao Hanyu, Jia Ying, Wang Xiaochun, Sha Xinkang, Zhao Jiali, Cheng Junhao, Chen Guangxue, He Minghui","doi":"10.1039/d4ta03238a","DOIUrl":"https://doi.org/10.1039/d4ta03238a","url":null,"abstract":"Ionic conductors are important materials for sensing devices owing to their excellent stretchability, conductivity, and transparency. However, it is extremely challenging to simultaneously achieve high tensile strength, fracture strain, and toughness in a dry ion conductor. In view of this, an acrylic acid (AA) and poly(ethylene glycol) dimethacrylate (PEGMA) based dry ion conductor (ISPSIC) with ultra-high mechanical performance is developed by an efficient one-pot method. By utilizing PEGMA to construct microphase-separated regions within the polymer network of the traditional poly(AA–ChCl) type supramolecular deep eutectic polymer, the ISPSIC can enhance the tensile strength of the dry ion conductor by 252.74% with only 0.43% PEGMA content, with no loss of tensile strain. Benefiting from the advantages of the <em>in situ</em> microphase-separation structure, this dry ion conductor exhibits remarkably high tensile strength (77.77 MPa), tensile strain (505.43%), toughness (232.70 MJ m<small><sup>−3</sup></small>), transparency (>90%), and electrical conductivity (6.7 × 10<small><sup>−5</sup></small> S m<small><sup>−1</sup></small>). Notably, the relative resistance variations of the ISPSIC are greater than 800% and can be electrohealed up to 98.5% within 0.03 s. This work provides a reliable method for further tuning the microstructure and high performance of ionic conductors during polymerization.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142404960","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 significant progress of perovskite solar cells (PSCs) in the past decade has shown enormous potential for industrialization; however, several critical issues such as long-term stability and potential lead leakage still need to be addressed. It is a practical challenge to overcome these issues through one approach. Herein, we introduce an ultraviolet absorbent and conductive passivation agent 4,4′-diaminostilbene-2,2′-disulfonic acid (DSDA) into SnO2 to down-convert ultraviolet light into visible light and enhance the conductivity of SnO2, thereby improving the light-stability and performance of PSCs. The amphoteric DSDA molecule with four functional groups can also passivate defects on the surface of SnO2 films, affect the crystal growth of the perovskite layer, and provide in situ protection against lead leakage. Our results show that the power conversion efficiency (PCE) of the PSCs increases evidently from 22.95% to 25.09% owing to the simultaneous enhancement of the photoelectric properties of SnO2 films and the critical SnO2/perovskite interfaces by adding DSDA into SnO2 films. Importantly, the DSDA-optimized PSCs without encapsulation exhibited enhanced operational and UV-light stability, as well as in situ fixation of leaked lead ions. This simultaneous enhancement of both optical and electrical properties of functional layers via adding a multifunctional organic compound provides an efficient strategy to effectively improve the efficiency and long-term stability of PSCs.
{"title":"Down-converting ultraviolet light using a conductive passivator to enhance the efficiency and stability of perovskite solar cells","authors":"Honglei Yu, Zhengyan He, Xiangheng Liu, Zhiqiang Zhang, Yongjia Li, Shufang Zhang, Qi Zhang, Changlin Yao, Hai Zhong","doi":"10.1039/d4ta05782a","DOIUrl":"https://doi.org/10.1039/d4ta05782a","url":null,"abstract":"The significant progress of perovskite solar cells (PSCs) in the past decade has shown enormous potential for industrialization; however, several critical issues such as long-term stability and potential lead leakage still need to be addressed. It is a practical challenge to overcome these issues through one approach. Herein, we introduce an ultraviolet absorbent and conductive passivation agent 4,4′-diaminostilbene-2,2′-disulfonic acid (DSDA) into SnO<small><sub>2</sub></small> to down-convert ultraviolet light into visible light and enhance the conductivity of SnO<small><sub>2</sub></small>, thereby improving the light-stability and performance of PSCs. The amphoteric DSDA molecule with four functional groups can also passivate defects on the surface of SnO<small><sub>2</sub></small> films, affect the crystal growth of the perovskite layer, and provide <em>in situ</em> protection against lead leakage. Our results show that the power conversion efficiency (PCE) of the PSCs increases evidently from 22.95% to 25.09% owing to the simultaneous enhancement of the photoelectric properties of SnO<small><sub>2</sub></small> films and the critical SnO<small><sub>2</sub></small>/perovskite interfaces by adding DSDA into SnO<small><sub>2</sub></small> films. Importantly, the DSDA-optimized PSCs without encapsulation exhibited enhanced operational and UV-light stability, as well as <em>in situ</em> fixation of leaked lead ions. This simultaneous enhancement of both optical and electrical properties of functional layers <em>via</em> adding a multifunctional organic compound provides an efficient strategy to effectively improve the efficiency and long-term stability of PSCs.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405060","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}
Much effort has been carried out to develop efficient electrochemical catalysts for nitrogen reduction reaction (NRR). However, the activity and selectivity of present catalysts are still limited in their applications. Herein, from the perspective of Lewis acid-base interactions and flexible active center, the positively charged tetrahedron transition metal (TM) clusters were anchored into boron nitride nanotubes (BNNTs) with B-vacancies to design a series of efficient NRR catalysts, meeting the above requirements. Through Density Functional Theory (DFT) calculations, our results uncover that the Mn4/BNNT (6, 6) system exhibits optimal activity characterized by a low limiting potential of only -0.29 V and a high selectivity confirmed by an adsorption energy difference between nitrogen molecules and hydrogen proton (-0.73 eV). Owing to the existence of electron-deficient Lewis acid sites, the adsorption and activation for N2 are strongly enhanced. Simultaneously, the flexible active center destabilizes the N-containing intermediates and upgrades the hydrogenation reaction process, making NH3 easy to desorb or further hydrogenate to NH4+. This innovative approach, employing Lewis acid pair and flexible active center to design efficient NRR catalysts, holds great promise for NH3 synthesis under ambient conditions.
{"title":"Lewis acid sites and flexible active center synergistically boost efficient electrochemical ammonia synthesis","authors":"Libo Chen, Tong-Hui Wang, Xingyou Lang, Qing Jiang","doi":"10.1039/d4ta04884a","DOIUrl":"https://doi.org/10.1039/d4ta04884a","url":null,"abstract":"Much effort has been carried out to develop efficient electrochemical catalysts for nitrogen reduction reaction (NRR). However, the activity and selectivity of present catalysts are still limited in their applications. Herein, from the perspective of Lewis acid-base interactions and flexible active center, the positively charged tetrahedron transition metal (TM) clusters were anchored into boron nitride nanotubes (BNNTs) with B-vacancies to design a series of efficient NRR catalysts, meeting the above requirements. Through Density Functional Theory (DFT) calculations, our results uncover that the Mn4/BNNT (6, 6) system exhibits optimal activity characterized by a low limiting potential of only -0.29 V and a high selectivity confirmed by an adsorption energy difference between nitrogen molecules and hydrogen proton (-0.73 eV). Owing to the existence of electron-deficient Lewis acid sites, the adsorption and activation for N2 are strongly enhanced. Simultaneously, the flexible active center destabilizes the N-containing intermediates and upgrades the hydrogenation reaction process, making NH3 easy to desorb or further hydrogenate to NH4+. This innovative approach, employing Lewis acid pair and flexible active center to design efficient NRR catalysts, holds great promise for NH3 synthesis under ambient conditions.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":11.9,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142405061","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}
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