Andrea Luigi Sorrentino, Lorenzo Poggini, Giulia Serrano, Giuseppe Cucinotta, Brunetto Cortigiani, Luigi Malavolti, Francesca Parenti, Edwige Otero, Marie-Anne Arrio, Philippe Sainctavit, Andrea Caneschi, Andrea Cornia, Roberta Sessoli, Matteo Mannini
The decoration of technologically relevant surfaces, such as metal oxides, with single-molecule magnets (SMMs) constitutes a persistent challenge for the integration of these molecular systems into novel technologies and, in particular, for the development of spintronic and quantum devices. We used UHV thermal sublimation to deposit tetrairon(III) propeller-shaped SMMs (Fe4) as a single layer on a TiO2 ultrathin film grown on Cu(001). The properties of the molecular deposit were studied using a multi-technique approach based on standard topographic and spectroscopic measurements, which demonstrated that molecules remain largely intact upon deposition. Ultralow temperature X-ray Absorption Spectroscopy (XAS) with linearly and circularly polarized light was further employed to evaluate both the molecular organization and the magnetic properties of the Fe4 monolayer. X-ray Natural Linear Dichroism (XNLD) and X-ray Magnetic Circular Dichroism (XMCD) showed that molecules in a monolayer display a preferential orientation and an open magnetic hysteresis with pronounced quantum tunnelling steps up to 900 mK. However, unexpected extra features in the XAS and XMCD spectra disclosed a minority fraction of altered molecules, suggesting that the TiO2 film may be chemically non-innocent. The observed persistence of SMM behaviour on a metal oxide thin film opens new possibilities for the development of SMM-based hybrid systems.
用单分子磁体（SMMs）装饰金属氧化物等技术相关表面，是将这些分子系统集成到新技术，特别是开发自旋电子和量子设备的一项长期挑战。我们利用超高真空热升华技术将四铁（III）螺旋桨形 SMMs（Fe4）作为单层沉积在生长在铜(001)上的二氧化钛超薄薄膜上。在标准形貌和光谱测量的基础上，采用多技术方法对分子沉积物的特性进行了研究，结果表明分子在沉积后基本保持完整。此外，还采用了线性偏振光和圆偏振光的超低温 X 射线吸收光谱（XAS）来评估 Fe4 单层的分子组织和磁性。X 射线自然线性二色性（XNLD）和 X 射线磁性圆二色性（XMCD）显示，单层中的分子显示出优先取向和开放磁滞，量子隧穿阶跃明显，最高可达 900 mK。然而，XAS 和 XMCD 光谱中意想不到的额外特征揭示了改变分子的少数部分，这表明二氧化钛薄膜可能在化学上是非无害的。在金属氧化物薄膜上观察到的 SMM 行为的持续性为开发基于 SMM 的混合系统提供了新的可能性。
{"title":"Assembling Fe4 Single Molecule Magnets on a TiO2 monolayer","authors":"Andrea Luigi Sorrentino, Lorenzo Poggini, Giulia Serrano, Giuseppe Cucinotta, Brunetto Cortigiani, Luigi Malavolti, Francesca Parenti, Edwige Otero, Marie-Anne Arrio, Philippe Sainctavit, Andrea Caneschi, Andrea Cornia, Roberta Sessoli, Matteo Mannini","doi":"10.1039/d4nr02234c","DOIUrl":"https://doi.org/10.1039/d4nr02234c","url":null,"abstract":"The decoration of technologically relevant surfaces, such as metal oxides, with single-molecule magnets (SMMs) constitutes a persistent challenge for the integration of these molecular systems into novel technologies and, in particular, for the development of spintronic and quantum devices. We used UHV thermal sublimation to deposit tetrairon(III) propeller-shaped SMMs (Fe<small><sub>4</sub></small>) as a single layer on a TiO<small><sub>2</sub></small> ultrathin film grown on Cu(001). The properties of the molecular deposit were studied using a multi-technique approach based on standard topographic and spectroscopic measurements, which demonstrated that molecules remain largely intact upon deposition. Ultralow temperature X-ray Absorption Spectroscopy (XAS) with linearly and circularly polarized light was further employed to evaluate both the molecular organization and the magnetic properties of the Fe4 monolayer. X-ray Natural Linear Dichroism (XNLD) and X-ray Magnetic Circular Dichroism (XMCD) showed that molecules in a monolayer display a preferential orientation and an open magnetic hysteresis with pronounced quantum tunnelling steps up to 900 mK. However, unexpected extra features in the XAS and XMCD spectra disclosed a minority fraction of altered molecules, suggesting that the TiO<small><sub>2</sub></small> film may be chemically non-innocent. The observed persistence of SMM behaviour on a metal oxide thin film opens new possibilities for the development of SMM-based hybrid systems.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141496018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The interlayer twist angle has a direct effect on the exciton lifetimes in van der Waals heterostructures. At small angles, the interlayer and intralayer excitons in MoSe2/WS2 heterostructures are hybridized, resulting in hybridized excitons with long lifetimes and strong resonance. However, the study of twist-angle-modulation of hybridized exciton lifetimes is still insufficient, leading to an unclear understanding of the mechanism through which the twist angle between layers influences the lifetime of hybridized excitons. Here, we observed the formation of hybridized excitons by constructing MoSe2/WS2 heterostructures with different twist angles. The exciton lifetime is found to increase from 0.5 ns to 3.3 ns when the twist angle is reduced from 12° to 1°. This work provides a new perspective on the modulation of exciton lifetime, enabling further exploration in improving the efficiency of optoelectronic devices.
{"title":"Twist angle-dependent interlayer hybridized exciton lifetimes in van der Waals heterostructures","authors":"Shihong Chen, Zejun Sun, Huan Liu, Haowen Xu, Chong Wang, Rui Han, Zihao Wang, Shuchun Huang, Xiaolian Zhao, Zekai Chen, Weizhou Li, Dameng Liu","doi":"10.1039/d4nr00661e","DOIUrl":"https://doi.org/10.1039/d4nr00661e","url":null,"abstract":"The interlayer twist angle has a direct effect on the exciton lifetimes in van der Waals heterostructures. At small angles, the interlayer and intralayer excitons in MoSe2/WS2 heterostructures are hybridized, resulting in hybridized excitons with long lifetimes and strong resonance. However, the study of twist-angle-modulation of hybridized exciton lifetimes is still insufficient, leading to an unclear understanding of the mechanism through which the twist angle between layers influences the lifetime of hybridized excitons. Here, we observed the formation of hybridized excitons by constructing MoSe2/WS2 heterostructures with different twist angles. The exciton lifetime is found to increase from 0.5 ns to 3.3 ns when the twist angle is reduced from 12° to 1°. This work provides a new perspective on the modulation of exciton lifetime, enabling further exploration in improving the efficiency of optoelectronic devices.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475300","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashish Kumar Gupta, Eva Zarkadoula, Maxim Ziatdinov, Sergei V. Kalinin, Vikas Reddy Paduri, Jordan A Hachtel, Yanwen Zhang, Christina Trautmann, William J. Weber, Ritesh Sachan
It is widely accepted that the interaction of swift heavy ions with many complex oxides is predominantly governed by the electronic energy loss that gives rise to nanoscale amorphous ion tracks along the penetration direction. The question of how electronic excitation and electron-phonon coupling affect the atomic system through defect production, recrystallization, and strain effects has not yet been fully clarified. To advance the knowledge of the atomic structure of ion tracks, we irradiated single crystalline SrTiO3 with 629 MeV Xe ions and performed comprehensive electron microscopy investigations complemented by molecular dynamics simulations. This study shows discontinuous ion-track formation along the ion penetration path, comprising an amorphous core and a surrounding a few monolayer thick shell of strained/defective crystalline SrTiO3. Using machine-learning-aided analysis of atomic-scale images, we demonstrate the presence of 4-8% strain in the disordered region interfacing with the amorphous core in the initially formed ion tracks. Under constant exposure of the electron beam during imaging, the amorphous part of the ion tracks readily recrystallizes radially inwards from the crystalline-amorphous interface under the constant electron-beam irradiation during the imaging. Cation strain in the amorphous region is observed to be significantly recovered, while the oxygen sublattice remains strained even under the electron irradiation due to the present oxygen vacancies. The molecular dynamics simulations support this observation and suggest that local transient heating and annealing facilitate recrystallization process of the amorphous phase and drive Sr and Ti sublattices to rearrange. In contrast, the annealing of O atoms is difficult, thus leaving a remnant of oxygen vacancies and strain even after recrystallization. This work provides insights for creating and transforming novel interfaces and nanostructures for future functional applications.
人们普遍认为，快速重离子与许多复杂氧化物的相互作用主要受电子能量损耗的支配，电子能量损耗会沿穿透方向产生纳米级非晶离子轨道。至于电子激发和电子-声子耦合如何通过产生缺陷、再结晶和应变效应影响原子系统，这一问题尚未完全阐明。为了增进对离子轨道原子结构的了解，我们用 629 MeV Xe 离子辐照了单晶 SrTiO3，并进行了全面的电子显微镜研究，同时辅以分子动力学模拟。这项研究表明，沿着离子穿透路径形成的离子轨道是不连续的，由无定形核心和周围几单层厚的应变/缺陷晶体 SrTiO3 壳组成。通过对原子尺度图像进行机器学习辅助分析，我们证明在最初形成的离子轨迹中，与无定形内核相接的无序区域存在 4%-8% 的应变。在成像过程中，在电子束的持续照射下，离子轨道的无定形部分很容易从晶体-无定形界面向内径向再结晶。据观察，无定形区域的阳离子应变明显恢复，而氧亚晶格由于存在氧空位，即使在电子辐照下仍保持应变。分子动力学模拟支持这一观察结果，并表明局部瞬态加热和退火促进了无定形相的再结晶过程，并促使 Sr 和 Ti 亚晶格重新排列。与此相反，O 原子的退火却很困难，因此即使在再结晶后也会残留氧空位和应变。这项研究为创建和改造新型界面和纳米结构以实现未来的功能性应用提供了启示。
{"title":"Nanoscale core-shell structure and recrystallization of swift heavy ion tracks in SrTiO3","authors":"Ashish Kumar Gupta, Eva Zarkadoula, Maxim Ziatdinov, Sergei V. Kalinin, Vikas Reddy Paduri, Jordan A Hachtel, Yanwen Zhang, Christina Trautmann, William J. Weber, Ritesh Sachan","doi":"10.1039/d4nr01974a","DOIUrl":"https://doi.org/10.1039/d4nr01974a","url":null,"abstract":"It is widely accepted that the interaction of swift heavy ions with many complex oxides is predominantly governed by the electronic energy loss that gives rise to nanoscale amorphous ion tracks along the penetration direction. The question of how electronic excitation and electron-phonon coupling affect the atomic system through defect production, recrystallization, and strain effects has not yet been fully clarified. To advance the knowledge of the atomic structure of ion tracks, we irradiated single crystalline SrTiO3 with 629 MeV Xe ions and performed comprehensive electron microscopy investigations complemented by molecular dynamics simulations. This study shows discontinuous ion-track formation along the ion penetration path, comprising an amorphous core and a surrounding a few monolayer thick shell of strained/defective crystalline SrTiO3. Using machine-learning-aided analysis of atomic-scale images, we demonstrate the presence of 4-8% strain in the disordered region interfacing with the amorphous core in the initially formed ion tracks. Under constant exposure of the electron beam during imaging, the amorphous part of the ion tracks readily recrystallizes radially inwards from the crystalline-amorphous interface under the constant electron-beam irradiation during the imaging. Cation strain in the amorphous region is observed to be significantly recovered, while the oxygen sublattice remains strained even under the electron irradiation due to the present oxygen vacancies. The molecular dynamics simulations support this observation and suggest that local transient heating and annealing facilitate recrystallization process of the amorphous phase and drive Sr and Ti sublattices to rearrange. In contrast, the annealing of O atoms is difficult, thus leaving a remnant of oxygen vacancies and strain even after recrystallization. This work provides insights for creating and transforming novel interfaces and nanostructures for future functional applications.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the context of catalytic CO2 reduction, the interference from the inherent hydrogen evolution reaction (HER) and the possible selectivity towards CO has posed a significant challenge in the CO2 reduction reaction to formic acid (HCOOH). To address this hurdle, we have investigated the impact of different single atom metal catalysts on tuning the selectivity by employing density functional theory (DFT) to scrutinize the reaction pathway. Single-atom catalyst (SACs) supported on carbon-based systems have proven to be pivotal in altering both the activity and selectivity of the CO2 reduction reaction. In this study, a series of single-atom-metal loaded g-C3N4 monolayers (MCN, M = Ni, Cu, Zn, Ga, Cd, In, Sn, Pb, Ag, Au, Bi, Pd and Pt) were systematically examined. Through detailed DFT calculations, we explored their influence on the reaction selectivity between *COOH and *OCHO intermediates. Notably, NiCN favors the reaction via the *OCHO route with a significantly lower rate-determining potential at 0.36 eV, which is approximately 73.5% lower in comparison to the CN system (1.36 eV). Most importantly, the Ni SACs with smaller atomic radii (0.124 nm) was shifted to the corner position of the carbon nitride forming lower coordination that significantly enhances the CO2 adsorption, promoting the CO2 reduction over HER. Overall, this study provides a theoretical prediction of how the selection of single-atom metal catalysts (SACs), guided by DFT studies, effectively modulates the reaction pathway, thereby offering the potential solution for the high selectivity in CO2 reduction products.
在催化二氧化碳还原方面，内在氢进化反应（HER）的干扰和可能对 CO 的选择性对二氧化碳还原甲酸（HCOOH）反应构成了重大挑战。为了解决这一难题，我们采用密度泛函理论 (DFT) 仔细研究了反应途径，从而研究了不同单原子金属催化剂对调节选择性的影响。事实证明，支持在碳基体系上的单原子催化剂（SAC）在改变二氧化碳还原反应的活性和选择性方面起着关键作用。在本研究中，我们对一系列负载单原子金属的 g-C3N4 单层（MCN，M = Ni、Cu、Zn、Ga、Cd、In、Sn、Pb、Ag、Au、Bi、Pd 和 Pt）进行了系统研究。通过详细的 DFT 计算，我们探讨了它们对 *COOH 和 *OCHO 中间体之间反应选择性的影响。值得注意的是，NiCN 有利于通过 *OCHO 途径进行反应，其速率决定电位为 0.36 eV，比 CN 系统（1.36 eV）低约 73.5%。最重要的是，具有较小原子半径（0.124 nm）的镍 SAC 被转移到了氮化碳的角位置，形成了较低的配位，从而显著增强了对 CO2 的吸附，促进了 CO2 对 HER 的还原。总之，本研究从理论上预测了在 DFT 研究指导下选择单原子金属催化剂 (SAC) 如何有效地调节反应途径，从而为二氧化碳还原产物的高选择性提供了潜在的解决方案。
{"title":"Mechanistic study on the competition between carbon dioxide reduction and hydrogen evolution reaction and selectivity tuning via single-atom catalyst loading on graphitic carbon nitride","authors":"Joel Jie Foo, Sue-Faye Ng, Mo Xiong, Wee-Jun Ong","doi":"10.1039/d4nr01932f","DOIUrl":"https://doi.org/10.1039/d4nr01932f","url":null,"abstract":"In the context of catalytic CO2 reduction, the interference from the inherent hydrogen evolution reaction (HER) and the possible selectivity towards CO has posed a significant challenge in the CO2 reduction reaction to formic acid (HCOOH). To address this hurdle, we have investigated the impact of different single atom metal catalysts on tuning the selectivity by employing density functional theory (DFT) to scrutinize the reaction pathway. Single-atom catalyst (SACs) supported on carbon-based systems have proven to be pivotal in altering both the activity and selectivity of the CO2 reduction reaction. In this study, a series of single-atom-metal loaded g-C3N4 monolayers (MCN, M = Ni, Cu, Zn, Ga, Cd, In, Sn, Pb, Ag, Au, Bi, Pd and Pt) were systematically examined. Through detailed DFT calculations, we explored their influence on the reaction selectivity between *COOH and *OCHO intermediates. Notably, NiCN favors the reaction via the *OCHO route with a significantly lower rate-determining potential at 0.36 eV, which is approximately 73.5% lower in comparison to the CN system (1.36 eV). Most importantly, the Ni SACs with smaller atomic radii (0.124 nm) was shifted to the corner position of the carbon nitride forming lower coordination that significantly enhances the CO2 adsorption, promoting the CO2 reduction over HER. Overall, this study provides a theoretical prediction of how the selection of single-atom metal catalysts (SACs), guided by DFT studies, effectively modulates the reaction pathway, thereby offering the potential solution for the high selectivity in CO2 reduction products.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141495924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Darwin Kurniawan, Francesca Caielli, Karthik Thyagajaran, Kostya Ken Ostrikov, Wei-Hung Chiang, David Z. Pai
Coupling atmospheric-pressure low-temperature plasmas to electrochemical reactors enables the generation of highly reactive species at plasma-liquid interfaces. This type of plasma electrochemical reactor (PEC) has been used to synthesize fluorescent nitrogen-doped graphene quantum dots (NGQDs),1 which are usable for multifunctional applications in a facile, simple, and sustainable way. However, the synthesis mechanism remains poorly understood, as well as the location of synthesis. To research these questions, we present an in situ diagnostics study on liquid phase chemistry during the PEC synthesis of NGQDs from chitosan. Monitoring of the photoluminescence and UV-VIS absorption at different depths in the reaction medium during plasma treatment reveals that the NGQDs are produced at the plasma-liquid interface but accumulate at a few millimetres depth below the interface, where the liquid ceases to flow convectively, as determined by particle image velocimetry. Our study provides insights into the plasma synthesis of fluorescent GQDs/NGQDs from carbon precursors that may prove useful for achieving the scalability of PEC processes up to continuous-flow or array reactors.
{"title":"Operando Time and Space-Resolved Liquid-Phase Diagnostics Reveal the Plasma Selective Synthesis of Nanographenes","authors":"Darwin Kurniawan, Francesca Caielli, Karthik Thyagajaran, Kostya Ken Ostrikov, Wei-Hung Chiang, David Z. Pai","doi":"10.1039/d4nr01280a","DOIUrl":"https://doi.org/10.1039/d4nr01280a","url":null,"abstract":"Coupling atmospheric-pressure low-temperature plasmas to electrochemical reactors enables the generation of highly reactive species at plasma-liquid interfaces. This type of plasma electrochemical reactor (PEC) has been used to synthesize fluorescent nitrogen-doped graphene quantum dots (NGQDs),1 which are usable for multifunctional applications in a facile, simple, and sustainable way. However, the synthesis mechanism remains poorly understood, as well as the location of synthesis. To research these questions, we present an in situ diagnostics study on liquid phase chemistry during the PEC synthesis of NGQDs from chitosan. Monitoring of the photoluminescence and UV-VIS absorption at different depths in the reaction medium during plasma treatment reveals that the NGQDs are produced at the plasma-liquid interface but accumulate at a few millimetres depth below the interface, where the liquid ceases to flow convectively, as determined by particle image velocimetry. Our study provides insights into the plasma synthesis of fluorescent GQDs/NGQDs from carbon precursors that may prove useful for achieving the scalability of PEC processes up to continuous-flow or array reactors.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masud ., Md Aftabuzzaman, Haoran Zhou, Saehyun Kim, Jaekyung Yi, Sarah S Park, Youn Soo Kim, Hwan Kyu Kim
Chemically synthesized PEDOT (poly(3,4-ethylenedioxythiophene)) nanomaterials, having various nanostructured morphology with different intrinsic electrical conductivity and crystallinity, were compared as electrocatalyst for Co (III) reduction in dye-sensitized solar cells (DSSCs). The electrochemical parameters, charge transfer resistance toward electrode/electrolytes interface, catalytic activity for Co (III)-reduction, and diffusion of cobalt redox species greatly depend on the morphology, crystallinity, intrinsic electrical conductivity of chemically synthesized PEDOTs and optimization of fabrication procedure of counter electrodes. Spin-coated DMSO-dispersed PEDOT counter electrode by the ordered 1D structure of PEDOT, having nanosized fiber of average 70 nm diameter and electrical conductivity ~16 S cm-1, exhibit lowest charge transfer resistance, highest diffusion for cobalt redox mediator and superior electrocatalytic ability over traditional Pt-catalyst. The photovoltaic performance of DSSC using chemically synthesized PEDOT exceeds the performance of a Pt-electrode device because of the improvement of current density, which is directly related to the superior electrocatalytic ability of PEDOT toward Co (III)-reduction. This simple spin-coated counter electrode by cheap and scalable chemically synthesized PEDOT can be a potential alternative to the expensive Pt-counter electrode for cobalt and other redox electrolytes in DSSCs and various flexible electronic devices.
{"title":"Chemically synthesized poly(3,4-ethylenedioxythiophene) conducting polymer as a robust electrocatalyst for highly efficient dye-sensitized solar cells","authors":"Masud ., Md Aftabuzzaman, Haoran Zhou, Saehyun Kim, Jaekyung Yi, Sarah S Park, Youn Soo Kim, Hwan Kyu Kim","doi":"10.1039/d4nr00949e","DOIUrl":"https://doi.org/10.1039/d4nr00949e","url":null,"abstract":"Chemically synthesized PEDOT (poly(3,4-ethylenedioxythiophene)) nanomaterials, having various nanostructured morphology with different intrinsic electrical conductivity and crystallinity, were compared as electrocatalyst for Co (III) reduction in dye-sensitized solar cells (DSSCs). The electrochemical parameters, charge transfer resistance toward electrode/electrolytes interface, catalytic activity for Co (III)-reduction, and diffusion of cobalt redox species greatly depend on the morphology, crystallinity, intrinsic electrical conductivity of chemically synthesized PEDOTs and optimization of fabrication procedure of counter electrodes. Spin-coated DMSO-dispersed PEDOT counter electrode by the ordered 1D structure of PEDOT, having nanosized fiber of average 70 nm diameter and electrical conductivity ~16 S cm-1, exhibit lowest charge transfer resistance, highest diffusion for cobalt redox mediator and superior electrocatalytic ability over traditional Pt-catalyst. The photovoltaic performance of DSSC using chemically synthesized PEDOT exceeds the performance of a Pt-electrode device because of the improvement of current density, which is directly related to the superior electrocatalytic ability of PEDOT toward Co (III)-reduction. This simple spin-coated counter electrode by cheap and scalable chemically synthesized PEDOT can be a potential alternative to the expensive Pt-counter electrode for cobalt and other redox electrolytes in DSSCs and various flexible electronic devices.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaying Zheng, Jiwei Ma, Minghuai Yu, Hao Xie, Dongdong Yan, Yihong Dong, Liu Yi, Xiaoyu Wang, Weixiang Ye
Inorganic CsPbI3 perovskite nanocrystals (NCs) exhibit remarkable optoelectronic properties for illumination. However, their poor stability has hindered the development of light-emitting diodes (LEDs) based on these materials. In this study, we propose a facile method to synthesize Mg2+-doped CsPbI3 NCs with enhanced stability and high photoluminescence (PL) intensity under ambient air conditions. Theoretical calculations confirm that the doped NCs possess a stronger formation energy compared to undoped NCs. By partially replacing Pb2+ with Mg2+, the synthesized CsPbI3 NCs emit red light at approximately 620 nm. We optimize the doping ratio to 1/30, which significantly enhances the photoluminescence of single-particle CsPbI3 NC. Subsequently, we fabricate a red LED by combining the CsPbI3 NCs with a blue chip. The resulting LED, based on the doped CsPbI3 NCs, exhibits excellent performance with high luminance of 4902.22 cd/m2 and a stable color coordinate of (0.7, 0.27). This work not only presents a simple process for synthesizing perovskite NCs but also provides a design strategy for developing novel red LEDs for various applications.
{"title":"Efficient Open-Air Synthesis of Mg2+-Doped CsPbI3 Nanocrystals for High-Performance Red LEDs","authors":"Jiaying Zheng, Jiwei Ma, Minghuai Yu, Hao Xie, Dongdong Yan, Yihong Dong, Liu Yi, Xiaoyu Wang, Weixiang Ye","doi":"10.1039/d4nr02005g","DOIUrl":"https://doi.org/10.1039/d4nr02005g","url":null,"abstract":"Inorganic CsPbI3 perovskite nanocrystals (NCs) exhibit remarkable optoelectronic properties for illumination. However, their poor stability has hindered the development of light-emitting diodes (LEDs) based on these materials. In this study, we propose a facile method to synthesize Mg2+-doped CsPbI3 NCs with enhanced stability and high photoluminescence (PL) intensity under ambient air conditions. Theoretical calculations confirm that the doped NCs possess a stronger formation energy compared to undoped NCs. By partially replacing Pb2+ with Mg2+, the synthesized CsPbI3 NCs emit red light at approximately 620 nm. We optimize the doping ratio to 1/30, which significantly enhances the photoluminescence of single-particle CsPbI3 NC. Subsequently, we fabricate a red LED by combining the CsPbI3 NCs with a blue chip. The resulting LED, based on the doped CsPbI3 NCs, exhibits excellent performance with high luminance of 4902.22 cd/m2 and a stable color coordinate of (0.7, 0.27). This work not only presents a simple process for synthesizing perovskite NCs but also provides a design strategy for developing novel red LEDs for various applications.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Doping heterometal atoms into ligand-protected gold superatom nanoclusters (Aun NCs) is proposed to further diversify their geometrical and electronic structures and enhance their photoluminescent properties, which are attributed to the mixing and effects between atoms. However, the fundamental principles that govern the optoelectronic properties of the doped Aun NCs remain elusive. Herein, we systematically explored the two prototypical 8-electron Aun (n = 11, 13) NCs, both with and without Ir dopant atoms, using comprehensive ab initio calculations and real-time nonadiabatic molecular dynamics simulations. These doped Aun NCs maintain their parent geometrical structures and 8-electron superatomic configuration (1S21P6). The strong core-shell (Ir-Aun) electronic coupling significantly expands the energy gap, resulting in a weak nonadiabatic coupling matrix element, which in turn increases carrier lifetime. This increase is mainly governed by the low-frequency vibration mode. We uncovered the relationship between electronic structures, electron vibration, and carrier dynamics for these doped Aun NCs. These calculated results provide crucial insights for the atomically precise design of metal NCs with superior optoelectronic properties.
有人提出在配体保护的金超原子纳米团簇（Aun NCs）中掺杂杂金属原子，以进一步丰富其几何和电子结构，并增强其光致发光特性。然而，支配掺杂 Aun NCs 光电特性的基本原理仍然难以捉摸。在此，我们利用全面的 ab initio 计算和实时非绝热分子动力学模拟，系统地探索了两种原型 8 电子 Aun（n = 11、13）NC，包括掺杂 Ir 原子和不掺杂 Ir 原子。这些掺杂 Aun NCs 保持了母体的几何结构和 8 电子超原子构型 (1S21P6)。强核壳（Ir-Aun）电子耦合显著扩大了能隙，从而产生了弱非绝热耦合矩阵元素，进而延长了载流子寿命。载流子寿命的增加主要受低频振动模式的影响。我们揭示了这些掺杂 Aun NCs 的电子结构、电子振动和载流子动力学之间的关系。这些计算结果为从原子上精确设计具有优异光电特性的金属 NC 提供了重要的启示。
{"title":"Doping-mediated excited states dynamics of diphosphine-protected M@Au12 (M = Au, Ir) superatoms nanocluster","authors":"Wei Pei, Lei Hou, Jing Yang, Si Zhou, Jijun Zhao","doi":"10.1039/d4nr02051k","DOIUrl":"https://doi.org/10.1039/d4nr02051k","url":null,"abstract":"Doping heterometal atoms into ligand-protected gold superatom nanoclusters (Aun NCs) is proposed to further diversify their geometrical and electronic structures and enhance their photoluminescent properties, which are attributed to the mixing and effects between atoms. However, the fundamental principles that govern the optoelectronic properties of the doped Aun NCs remain elusive. Herein, we systematically explored the two prototypical 8-electron Aun (n = 11, 13) NCs, both with and without Ir dopant atoms, using comprehensive ab initio calculations and real-time nonadiabatic molecular dynamics simulations. These doped Aun NCs maintain their parent geometrical structures and 8-electron superatomic configuration (1S21P6). The strong core-shell (Ir-Aun) electronic coupling significantly expands the energy gap, resulting in a weak nonadiabatic coupling matrix element, which in turn increases carrier lifetime. This increase is mainly governed by the low-frequency vibration mode. We uncovered the relationship between electronic structures, electron vibration, and carrier dynamics for these doped Aun NCs. These calculated results provide crucial insights for the atomically precise design of metal NCs with superior optoelectronic properties.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141475311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhua Xu, Jie Li, Mengyun Hu, Zhengying Wu, Yukou Du
The development of efficient alcohol electrooxidation catalysts is of vital importance for the commercialization of direct liquid fuel cells. As emerging advanced catalysts, two-dimensional (2D) noble metal nanomaterials have attracted great research attention due to their intrinsic structural advantages. Herein, we reported the synthesis of petal-like PdAg nanosheets (NSs) with ultrathin 2D structure and jagged edge via a facile wet-chemical approach, combing the doping engineering and morphology tuning. Notably, the highly active sites and Pd-Ag composition endowed PdAg NSs with promoted toxicity tolerance and substantially improved the durability toward ethanol/methanol oxidation reaction (EOR/MOR). Moreover, the electronic effect and synergistic effect significantly enhanced the EOR and MOR activities in comparison with Pd NSs and commercial Pd/C. This work provides efficient catalysts for fuel electrooxidations and deep insight into the rational design and fabrication of novel 2D nanoarchitecture.
{"title":"2D Petal-Like PdAg Nanosheets Promote Efficient Electrocatalytic Oxidation of Ethanol and Methanol","authors":"Yuhua Xu, Jie Li, Mengyun Hu, Zhengying Wu, Yukou Du","doi":"10.1039/d4nr01537a","DOIUrl":"https://doi.org/10.1039/d4nr01537a","url":null,"abstract":"The development of efficient alcohol electrooxidation catalysts is of vital importance for the commercialization of direct liquid fuel cells. As emerging advanced catalysts, two-dimensional (2D) noble metal nanomaterials have attracted great research attention due to their intrinsic structural advantages. Herein, we reported the synthesis of petal-like PdAg nanosheets (NSs) with ultrathin 2D structure and jagged edge via a facile wet-chemical approach, combing the doping engineering and morphology tuning. Notably, the highly active sites and Pd-Ag composition endowed PdAg NSs with promoted toxicity tolerance and substantially improved the durability toward ethanol/methanol oxidation reaction (EOR/MOR). Moreover, the electronic effect and synergistic effect significantly enhanced the EOR and MOR activities in comparison with Pd NSs and commercial Pd/C. This work provides efficient catalysts for fuel electrooxidations and deep insight into the rational design and fabrication of novel 2D nanoarchitecture.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liquid electronics foresee potential applications in soft-robotics, printed electronics, and healable electronics. The intrinsic shortcomings of the solid-state electronics can be offset by liquid conductors. Alloys of gallium have emerged as a transformative material for liquid electronics due to its intrinsic fluidity, conductivity, and low toxicity. However, sculpting liquid metal or its composite into 3D architecture is a challenging task. To tackle the issue, herein, we have explored the interfacial chemistry of metal ions and tannic acid (TA) complexation at liquid-liquid interface. First, we have established that MIII -TA network at liquid-liquid interface could structure liquid in liquid by jamming of the interfacial film. The surface coverage of the droplet largely depends on concentration of metal ions, oxidation state of metal ions and pH of the surrounding environment. Further extending the approach, we have demonstrated that TA functionalized gallium nanoparticles (Ga NPs) are also able to sculpt the liquid droplets in the presence of transition metal ions. Finally, a mold-based free-standing 3D architecture is obtained using the interfacial reaction and interfacial crowding of metal-phenolate network. The conductivity measurement reveals that these liquid constructs can be used for low-voltage electronic application, thus opening a doorway for liquid electronics.
液体电子学有望应用于软机器人、印刷电子学和可愈合电子学。液态导体可以弥补固态电子器件的固有缺陷。镓合金因其固有的流动性、导电性和低毒性，已成为液态电子学的变革性材料。然而，将液态金属或其复合材料雕刻成三维结构是一项具有挑战性的任务。为了解决这个问题，我们在此探讨了金属离子与单宁酸（TA）在液-液界面上的界面化学络合。首先，我们确定了液-液界面上的 MIII -TA 网络可以通过干扰界面膜来构造液中液。液滴的表面覆盖率主要取决于金属离子的浓度、金属离子的氧化状态和周围环境的 pH 值。我们进一步扩展了这一方法，证明了 TA 功能化镓纳米粒子（Ga NPs）也能在过渡金属离子存在的情况下雕刻液滴。最后，我们利用金属-苯酚网络的界面反应和界面排挤作用，获得了一种基于模具的独立三维结构。电导率测量结果表明，这些液体结构可用于低压电子应用，从而为液体电子学打开了一扇大门。
{"title":"Sculpting Liquid Metal Stabilized Interfaces: A Gateway for Liquid Electronics","authors":"Reek Mahapatra, Subhabrata Das, Arshdeep Kaur Gill, Devender Singh, Anvi Sangwan, Kaushik Ghosh, Debabrata Patra","doi":"10.1039/d4nr01836b","DOIUrl":"https://doi.org/10.1039/d4nr01836b","url":null,"abstract":"Liquid electronics foresee potential applications in soft-robotics, printed electronics, and healable electronics. The intrinsic shortcomings of the solid-state electronics can be offset by liquid conductors. Alloys of gallium have emerged as a transformative material for liquid electronics due to its intrinsic fluidity, conductivity, and low toxicity. However, sculpting liquid metal or its composite into 3D architecture is a challenging task. To tackle the issue, herein, we have explored the interfacial chemistry of metal ions and tannic acid (TA) complexation at liquid-liquid interface. First, we have established that MIII -TA network at liquid-liquid interface could structure liquid in liquid by jamming of the interfacial film. The surface coverage of the droplet largely depends on concentration of metal ions, oxidation state of metal ions and pH of the surrounding environment. Further extending the approach, we have demonstrated that TA functionalized gallium nanoparticles (Ga NPs) are also able to sculpt the liquid droplets in the presence of transition metal ions. Finally, a mold-based free-standing 3D architecture is obtained using the interfacial reaction and interfacial crowding of metal-phenolate network. The conductivity measurement reveals that these liquid constructs can be used for low-voltage electronic application, thus opening a doorway for liquid electronics.","PeriodicalId":92,"journal":{"name":"Nanoscale","volume":null,"pages":null},"PeriodicalIF":6.7,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141462717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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