bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Peroxide Electrosynthesis via Selective Oxygen Reduction Reactions Through Interfacial Reaction Microenvironment Engineering
Authors: Tian Qiang , Jing Lingyan , Wang Wenyi , Ye Xieshu , Chai Xiaoyan , Zhang Xue , Hu Qi , Yang Hengpan , He Chuanxin
Published: November 2024

The electrochemical two‐electron oxygen reduction reaction (2e− ORR) offers a compelling alternative for decentralized and on‐site H2O2 production compared to the conventional anthraquinone process. To advance this electrosynthesis system, there is growing interest in optimizing the interfacial reaction microenvironment to boost electrocatalytic performance. This review consolidates recent advancements in reaction microenvironment engineering for the selective electrocatalytic conversion of O2 to H2O2. Starting with fundamental insights into interfacial electrocatalytic mechanisms, an overview of various strategies for constructing the favorable local reaction environment, including adjusting electrode wettability, enhancing mesoscale mass transfer, elevating local pH, incorporating electrolyte additives, and employing pulsed electrocatalysis techniques is provided. Alongside these regulation strategies, the corresponding analyses and technical remarks are also presented. Finally, a summary and outlook on critical challenges, suggesting future research directions to inspire microenvironment engineering and accelerate the practical application of H2O2 electrosynthesis is delivered.
Soft Sputtering of Large‐Area 2D MoS2 Layers Using Isolated Plasma Soft Deposition for Humidity Sensors
Authors: Youn Hye‐Young , Choi Tae‐Yang , Shim Junoh , Park Se Young , Kwon Min‐Ki , Kim Sunkook , Kim Han‐Ki
Published: November 2024

2D transition‐metal dichalcogenides are emerging as key materials for next‐generation semiconductor technologies owing to their tunable bandgaps, high carrier mobilities, and exceptional surface‐to‐volume ratios. Among them, molybdenum disulfide (MoS2) has garnered significant attention. However, scalable wafer‐level deposition methods that enable uniform layer‐controlled synthesis remain a critical challenge. In this paper, a novel fabrication approach—isolated plasma soft deposition (IPSD) followed by sulfurization—for the scalable production of 2D MoS2 with precise layer control is introduced. The IPSD system employs a scanning‐based deposition method combined with plasma surface pretreatment, achieving large‐area, high‐quality 2D MoS2 layers. Comprehensive characterizations using Raman, UV–vis, and photoluminescence spectroscopy, and transmission electron microscopy confirmed the successful synthesis of crystalline mono‐ to tetralayer 2D MoS2 on 6‐inch SiO2/Si substrates. Furthermore, respiration sensors fabricated using the IPSD‐grown 2D MoS2 layers demonstrated fast response times (≈1 s) and high response to relative humidity levels between 30% and 60%. This study offers significant advancements in the scalable synthesis of 2D MoS2 and opens new avenues for its application in advanced sensing and electronic devices.
Investigating Impacts of Local Pressure and Temperature on CVD Growth of Hexagonal Boron Nitride on Ge(001)/Si
Authors: Franck Max , Dabrowski Jarek , Schubert Markus Andreas , Vignaud Dominique , Achehboune Mohamed , Colomer Jean‐François , Henrard Luc , Wenger Christian , Lukosius Mindaugas
Published: November 2024

The chemical vapor deposition (CVD) growth of hexagonal boron nitride (hBN) on Ge substrates is a promising pathway to high‐quality hBN thin films without metal contaminations for microelectronic applications, but the effect of CVD process parameters on the hBN properties is not well understood yet. The influence of local changes in pressure and temperature due to different reactor configurations on the structure and quality of hBN films grown on Ge(001)/Si is studied. Injection of the borazine precursor close to the sample surface results in an inhomogeneous film thickness, attributed to an inhomogeneous pressure distribution at the surface, as shown by computational fluid dynamics simulations. The additional formation of nanocrystalline islands is attributed to unfavorable gas phase reactions due to the radiative heating of the injector. Both issues are mitigated by increasing the injector‐sample distance, leading to an 86% reduction in pressure variability on the sample surface and a 200 °C reduction in precursor temperature. The resulting hBN films exhibit no nanocrystalline islands, improved thickness homogeneity, and high crystalline quality (Raman FWHM = 23 cm−1). This is competitive with hBN films grown on other non‐metal substrates but achieved at lower temperature and with a low thickness of only a few nanometers.
Pressure‐Induced Unusual Transition of Luminescence Mechanics from Self‐Trapped Exciton to Free Exciton Emission in Lead Bromide Perovskitoids
Authors: Rong Yan , Wang Lingrui , Wang Yongheng , Wang Wenxin , Wang Jiaxiang , Yuan Yifang , Shahzadi Urooj , Chen Junnian , Zhang Lei , Wang Kai , Guo Haizhong
Published: November 2024

Understanding the luminescence mechanics of metal halide perovskites is the key to uncovering the detailed pathways responsible for remarkable photophysical properties and engineering materials with enhanced optoelectronic properties. In this work, high pressure is employed to reveal the self‐trapped exciton (STE) emission features of a 1D lead bromide perovskitoid (HM)Pb2Br6. Upon compression, a remarkable 42‐fold enhancement in the intensity compared to the initial emission, along with exciton transfer from STE emission to narrow free exciton emission, is achieved in (HM)Pb2Br6. These phenomena are related to the anisotropic compression of (HM)Pb2Br6, which results in enhanced structural stiffness and a significant reduction in the distances of Pb─Pb bond lengths between inter‐[Pb2Br6]2− chains, as well as Pb─Br bond lengths within the three basic intra‐[Pb2Br6]2− octahedra. These results provide essential insights into the intriguing photophysics of STEs and shed new light on the dramatic exciton transfer to control and enhance the optical properties of the metal halide perovskites.
Pressure‐Induced Excitation‐Dependent Emission Color Tuning and Enhancement in 1D Zigzag Edge‐Sharing Perovskites (C6H10N2)PbX4 (X = Br, Cl)
Authors: Wu Xueqian , Sun Yiyang , Wang Lingrui , Huang Yijia , Wang Jiaxiang , Yuan Yifang , Shahzadi Urooj , Fu Ruijing , Wang Kai , Guo Haizhong
Published: November 2024

1D zigzag edge‐sharing perovskites have generated intense research interest due to their unique structures and optoelectronic properties. Recent efforts have focused on refining these structures to enhance their efficiency across various applications. Herein, high‐pressure is utilized to modulate the properties of two Pb‐based perovskites, (AMP)PbCl4 and (AMP)PbBr4 (where AMP2+ = C6H10N22+), characterized by 1D zigzag edge‐sharing [PbX4]2−∞ chains linked by AMP through hydrogen bonding. An inverse excitation‐dependent emission phenomenon and emission enhancement are observed in these two perovskites, attributed to the contraction of inhomogeneously coordinated [PbX6]4− octahedra. Pressure‐induced lattice contraction promotes the overlap of Pb and X orbitals, resulting in a decrease in the bandgap. Concurrently, pressure‐induced phase transitions, due to the distortion of [PbX6]4− octahedra, lead to discontinuous decreases in the bandgap. These high‐pressure optical and structural explorations facilitate the systematic design of halide perovskites with desired characteristics.
Heater‐Embedded Visible‐Light Phototransistor Based on Cd‐Doped IGZO Film Fabricated through Microwave‐Assisted Sol–Gel Process
Authors: Kim Eun‐Ha , Ha Tae‐Jun
Published: November 2024

A phototransistor with a sol–gel‐based Cd‐doped indium‐gallium‐zinc‐oxide (IGZO) photoactive sensing channel on a dual‐purpose indium‐tin‐oxide (ITO) substrate (gate electrode and embedded transparent heater) is reported for the first time. The Cd‐doped IGZO layer is fabricated in situ by a one‐step microwave‐assisted sol–gel process with reduced temperature (<125 °C) and time (<15 min). Despite the wide bandgap of the IGZO (≈3.83 eV) channel, visible‐light (≈2 eV) photosensing is achieved in the developed phototransistor upon Cd doping owing to the reduced bandgap (≈3.71 eV) and increased density of subgap states associated with oxygen vacancies in the metal–oxygen bonding structure. In addition, the Cd‐doped IGZO phototransistor exhibits excellent operational stability (up to 10 000 cycles) and long‐term reliability (up to 30 days). Finally, the embedded Joule heater, based on the inherent transparent ITO substrate, significantly improves the recovery characteristics of the IGZO phototransistor owing to relaxation of the photoexcited charges at the oxygen‐vacancy‐related trap states upon heating, resulting in 100% recovery in a significantly reduced timeframe (≈10 s). These findings pave the way for the development of high‐performance, stable, and reliable visible‐light phototransistors based on wide‐bandgap IGZO active sensing channels with fast and full recovery, expanding their practical applicability of optoelectronics.
PEA2SnI4 Perovskite Thin Films for Photonics: Linear and Nonlinear Optical Properties and Waveguided Photoluminescence
Authors: Suárez Isaac , Sánchez‐Díaz Jesús , Pashaei Adl Hamid , Mora‐Seró Iván , Martínez‐Pastor Juan P
Published: November 2024

In this work, 2D PEA2SnI4 (PEA: 2‐phenylethanaminium) perovskite thin films, formed with the reducing agent NaBH4 to control the Sn+4 defects are investigated. Optical characterization of the films reveals idoneous properties for the development of photon sources, particularly an extraordinarily high absorption coefficient at the exciton resonance > 10 µm−1, the ability to enhance the light‐matter interaction due to the high refractive index. These linear optical properties are complemented with impressive nonlinear optical characteristics, involving a giant nonlinear absorption β = 7–10 cm MW−1 and a remarkably high nonlinear refractive coefficient, n2 = 1.5–4 cm2 GW−1. The integration of PEA2SnI4 films into rigid and flexible waveguides further enhances the generation of waveguided photoluminescence (PL), which is also obtained under the two‐photon absorption mechanism. The efficient generation of PL is validated by the reabsorption effect, resulting in the propagation of recycled photons over distances longer than 3 mm with an increased effective lifetime from 3 to 8.5 ns. These findings pave the way for the development of novel photonic functionalities based on these innovative low‐dimensional semiconductors.
2D Transition Metal Carbo‐Chalcogenide Nb2CSe2: A Combination of Transition Metal Dichalcogenide and MXene for Ultrafast Photonics Application
Authors: Ren Ke , Pan Zhongben , Tu Xueyang , Pan Han , Gao Kong , Li Zongsheng , Chu Hongwei , Fang Yuqiang , Li Dechun
Published: November 2024

Transition metal carbo‐chalcogenides (TMCCs), a novel class of 2D materials, combining the distinctive properties of transition metal dichalcogenides (TMDs) and MXenes, eliciting considerable interest for their excellent properties across various fields. However, TMCCs' optical properties and potential in ultrafast photonics remain unexplored. This study investigates Nb2CSe2, a novel developed TMCC, which exhibits superior optical properties and robust environmental stability. Density functional theory calculations reveal solid near‐infrared absorption and a high density of states near the Fermi level in Nb2CSe2, indicative of high carrier mobility and robust optical responses. The nonlinear absorption coefficient of Nb2CSe2 is measured as 0.431 cm GW−1, significantly outperforming most TMDs and MXenes. Its fastest relaxation lifetime of excited carriers is on the order of hundreds of femtoseconds. The wavelength‐dependent transition of carrier dynamics and excitation intensity‐dependent transition of absorption mechanism is observed. For the first time, a TMCC‐based saturable absorber is integrated into an erbium‐doped fiber laser cavity, the evolution from Q‐switched operation to conventional soliton operation with sub‐picoseconds pulse width and dual‐wavelength complex soliton dynamics are realized, underscoring the material's superior capabilities in enhancing ultrafast laser performance. This research provides a promising platform for fundamental studies and practical applications of TMCCs in ultrafast photonics.
High‐Efficiency Luminescence and Robust Thermal Quenching Resistance in Organic–Inorganic Hybrid Indium‐Based Metal Halides
Authors: Tang Zhe , Wang Xiaochen , Bai Tianxin , Liu Siyu , Wang Shuyue , Wei Qingfeng , Fan Binbin , Chen Junsheng
Published: November 2024

Low‐dimensional lead‐free metal halide perovskites have attracted considerable attention for the development of multifunctional optoelectronic materials owing to their extensive structural diversity and adjustable optical properties. However, organic cation‐based low‐dimensional metal halides often exhibit limited thermal stability, while inorganic cations‐based ones have a poor solution processability. To address these challenges, this study proposes a hybrid organic–inorganic cation approach by utilizing both 4,4‐difluoropiperidine (DFPD) and cesium (Cs+) to prepare low‐dimensional metal halides: (DFPD)2CsInCl6. Two isostructural metal halides are developed: α‐(DFPD)2CsInCl6 and β‐(DFPD)2CsInCl6, which exhibit different space group symmetries. This strategy ensures both thermal stability and introduces structural diversity. Doping (DFPD)2CsInCl6 with antimony (Sb3+) enhances its PLQY from 0% to 100%. The emission centers of both materials exhibit temperature‐insensitive behavior and maintain efficient and stable PL emission even at high temperatures (up to 400 K), making them excellent candidates as thermally stable phosphor materials for solid‐state lighting applications. This work thus expands the scope of developing multifunctional low‐dimensional metal halides.
Intrinsic Room‐Temperature Phosphorescent Hydrogel Driven by Phase Separation and Glass Transition
Authors: Fan Xinzhen , Gao Lu , Jin Yijie , Qiu Tian , Banquy Xavier , Zhu Xiao‐Xia , Zhao Chuanzhuang
Published: November 2024

Designing room‐temperature phosphorescent (RTP) hydrogels presents a unique challenge in comparison to RTP polymeric films and powders, due to the quenching of phosphorescence by water molecules within the hydrogel and their inherent softness. This study presents the first example of intrinsic RTP hydrogels without doping by luminophores or stiffening agents. The hydrogel is synthesized by copolymerizing acrylamide (Am) with N‐acryloyl‐aminoundecanoic acid (NAUA). The hydrophobic NAUA induces phase separation in the hydrogel network and the glass transition of the hydrophobic phase can stiffen the structure and constrain the mobility of water molecules and chain segments. Under such condition, the clustering of amide and carboxylic acid groups triggers the emission of RTP with a persistent afterglow exceeding 1.5 s, which is as good as the reported RTP hydrogels with dopants. When the hydrogel is heated above its glass transition temperature, its modulus drops quickly from 20.0 to 0.026 MPa within 2 s and RTP also diminishes. Taking advantage of the temperature‐switchable rigidity and RTP behavior, the hydrogels are endowed with functions such as shape memory, temperature‐sensing, and information concealment.
Unveiling Ultrafast Spin‐Valley Dynamics and Phonon‐Mediated Charge Transfer in MoSe2/WSe2 Heterostructures
Authors: Wagner Julian , Bernhardt Robin , Rieland Lukas , Abdul‐Aziz Omar , Li Qiuyang , Zhu Xiaoyang , Dal Conte Stefano , Cerullo Giulio , van Loosdrecht Paul H. M. , Hedayat Hamoon
Published: November 2024

Helicity‐resolved ultrafast transient absorption spectroscopy is used to study spin‐valley polarization dynamics in a vertically stacked MoSe2/WSe2 heterostructure. The experimental findings reveal details of interlayer charge transfer on ultrafast timescales, showing that the spin‐valley polarized state of photoexcited carriers is conserved during the charge transfer and formation of interlayer excitons. These results confirm that phonon scattering mediates the interlayer charge transfer process, while a high phonon population at elevated temperatures causes a significant decrease in spin‐valley selective charge transfer. Moreover, the experimental findings demonstrate the possibility that interlayer excitons and their spin‐valley polarization can be probed in the optical response of intralayer excitons. These findings pave the way for ultrafast detection, control, and manipulation of spin‐valley polarized excitons in transition metal dichalcogenide‐based 2D heterostructures.
Suppress Dark‐Current for High‐Photoresponse MoS2 Transistor
Authors: Zhang Chunchi , Liu Jinxiu , Wu Haijuan , Tan Chao , Hao Xin , Wang Zegao
Published: November 2024

Due to the atomic thickness of 2D MoS2 film, the electronic structure is easily tunable by electric field and exhibits abundant property. However, due to the limit capacitance of inorganic dielectric, the tunability is still not well exhibited. Herein, a MoS2 phototransistor with large tunability driven by ion‐gel film is fabricated. To improve the interface and reduce the dark current, the passivation layer is used to hinder the leakage current. With the passivation layer, there will be a specific barrier height on the interface of metal electrodes and ion‐gel membrane. Under effect of the PVA (polyvinyl alcohol) passivation layer, the current on/off radio can reach 107 and the mobility can reach 6.54 cm2/(Vs) superior to the one without passivation layer. There is an abnormal behavior in the transistor including positive and negative photoresponse due to the coupling of the photogating effect and the adsorption of negative ion. The photoresponsivity can increase by 29 times which can reach 603.48 A W−1 at 400 nm illumination. Furthermore, the flexible transistor based on ion‐gel can be demonstrated and it found that the transistor still has a considerable photoresponse with strain of 0.49%. This work provides a new solution for flexible wearable electronic and photoelectronic detection field.
From the Bulk to the Nanoscale: Strong Evolution in the Structure and Chiroptical Properties of Chiral Halide Double Perovskites
Authors: Maniadi Maria , Tieriekhov Kostiantyn , Ségut Olivier , Mercier Nicolas , Abhervé Alexandre
Published: November 2024

In the quest for lead‐free chiral metal‐halide materials, 2D double perovskites appear as very promising candidates especially for spintronic applications. However, compared to highly crystalline Pb2+ compounds, the more challenging synthetic procedure for compounds based on Ag+ and Bi3+/Sb3+ so far limited the number of these chiral materials to very few reported examples, as highlighted by the absence of crystal structure based on the extensively used (S/R)‐1‐phenylethylammonium (S/R‐MBA) cations in chiral metal halides. This study presents the successful preparation and characterization of a complete series of 2D bromide‐based and iodide‐based double perovskites based on the cations (S/R)‐1‐(4‐bromophenyl)ethylammonium (S/R‐4BrMBA), which allows to describe their structures, thin film processing, and resulting chiroptical properties. The strong modulation of the structure and circular dichroism (CD) properties at the nanoscale is unprecedented, since the thin films of (S/R‐4BrMBA)4AgBiBr8 strongly evolve from a single‐phase compound with small intrinsic CDiso to a polymorphic material showing a strong increase in the CD signal due to macroscopic effects.
Selective Enzymatic C−H‐Oxyfunctionalization for the Efficient Synthesis of Grevillic Acid
Authors: Cziegler Clemens , Baumert Benjamin , Badenhorst Christoffel P. S. , Siems Karsten , Bornscheuer Uwe T.
Published: November 2024

In this study, a selective C−H‐oxyfunctionalization using an unspecific peroxygenase (UPO) enabled an efficient biosynthetic route for the synthesis of grevillic acid (GA), a natural antioxidant. The route commenced with the release of o‐coumaric acid (oCA) from trans‐2‐coumaric acid glucoside (trans‐CAG) using commercially available β‐glucosidase from almonds. In addition, a cis‐to‐trans photoisomerization of cis‐CAG was implemented to increase the synthetic access of oCA. The key step, the para‐hydroxylation relative to the existing hydroxyl group of oCA, was accomplished by an UPO with full conversion and 93% isolated yield. Despite its name, the UPO turned out to exhibit excellent regioselectivity in this C−H functionalization, requiring only H2O2 as a cosubstrate.
Micro/Nanofibers for Flexible, Stretchable, and Strain‐Insensitive Wearable Electronics‐ A Review
Authors: Hanif Adeela , Kim Dong Sung
Published: November 2024

The development of flexible and stretchable wearable electronics has significantly advanced smart fabrics, biomedical devices, and healthcare technologies. However, these devices often face challenges from mechanical deformations that disrupt signals, emphasizing the need for strain‐insensitive architectures to maintain functionality under varying strain conditions. Progress in this field relies on multifunctional, strain‐insensitive microfibers and nanofibers (NFs) to ensure consistent performance while minimizing signal interference caused by mechanical stress. This review highlights the advantages of fibers for flexible, stretchable, and strain‐insensitive wearable electronics, analyzing materials, fabrication methods, and design strategies that optimize strain insensitivity in single free‐standing microfibers (SFMs) and NF‐based devices. It emphasizes maintaining mechanical and electrical stability under large strains through strategic material selection, advanced fiber spinning techniques, and innovative structural designs. While emphasizing SFMs, this review also provides a concise exploration of the role of NFs within this context. The applications of SFMs in wearable electronics, particularly as conductors, sensors, and components in smart textiles, are discussed with an emphasis on strain insensitivity. The review concludes by addressing challenges in this evolving field of wearable electronics and outlining future research directions, offering insights to drive innovations in fiber‐based wearable electronics for reliable, lightweight, breathable, user‐friendly, and high‐performance wearable devices.
Uncovering the Nanoscopic Humidity Ingression in Multifunctional Addivated Halide Perovskites
Authors: Kazim Samrana , Huang Junyi , Haris Muhammed P.U. , Li Xiongjie , Shi Xiaotang , Zhang Zhiguo , Berger Rüdiger , Buffeteau Thierry , Bassani Dario M. , Wang Mingkui , Ahmad Shahzada
Published: November 2024

Sulfur‐based multifunctional additives are attractive for increasing not only the device power conversion efficiency but also the moisture stability of perovskite solar cells. The stability of the device against external and internal stress plays a pivotal role in the commercial endeavor of emerging technologies such as perovskite photovoltaics. However, the potential of sulfur‐based additives remains largely unexplored for perovskite solar cell fabrication. Here, a mechanism is deduced for the local nanoscopic humidity ingression into a multifunctional additiviated formamidinium‐loaded halide perovskites. By tuning the iodide and bromide tails of the additives, the influence of sulfur heteroatom containing ammonium‐amidinium salts on the photo‐physical and device properties of a formamidinium‐rich perovskite absorber is uncovered. In addition, the process of strong water adsorption is excluded through the proton‐migration mechanism, thereby significantly improving the moisture resistance of perovskite films. The high crystallinity and long lifetime decay allow a higher PCE of 25.14% to be achieved compared to the control at 22.49%, along with improved long‐term stability by retaining 99.6% of the initial PCE after 1000 h.
High H2 permeability in F‐doped BaZr0.7Ce0.2Y0.1O3−δ perovskite membranes via thermodynamic controlled sintering
Authors: Gu Zhenbin , Tan Jinkun , Zhou Haoli , Liu Zhengkun , Ge Lin , Zhang Guangru , Jin Wanqin
Published: November 2024

A raw hydrogen mixture frequently results in a reduction in conversion efficiency and the generation of undesired by‐products. The application of advanced membrane technology has the potential to offer an economically viable solution for the recovery of hydrogen from such mixtures. BaZr1−x−yCexYyO3−δ is increasingly regarded as an optimal perovskite hydrogen permeable membrane. Nevertheless, the main drawback to its use in a larger scale is the extremely low hydrogen permeability and stability. An original perovskite material is proposed in this study, BaZr0.7Ce0.2Y0.1O3−δ‐Fx. A thermodynamic‐controlled sintering strategy (TCS) has been employed to inhibit the evaporation of metals from ceramic solids. The TCS directly caused the hydrogen permeation flux to reach 1.07 ml·min−1 cm−2, representing a fourfold improvement. Furthermore, F‐doping demonstrated enhanced performance at low and medium temperatures. The aforementioned successful strategy provides an effective path for the tailoring of perovskite materials and promotes its application for the industrial‐scale separation of hydrogen.
Stabilisierung eines Strontiumhydridkomplexes mit einem Einzähnigen Carbazolylliganden und Dessen Reaktivität
Authors: Winkler Lucas , Hinz Alexander
Published: November 2024

Der Strontiumhydridkomplex 2 [(dtbpCbz)SrH(L)]2 (L=Benzol, Toluol) wurde isoliert und konnte durch einen sterisch anspruchsvollen Carbazolylliganden (dtbpCbz=1,8‐bis(3,5‐ditertbutylphenyl)‐3,6‐ditertbutylcarbazolyl) stabilisiert werden. Verbindung 2 wurde durch Reaktion des Amids (dtbpCbz)SrN(SiMe3)2 mit Phenysilan dargestellt und durch 1H NMR‐Spektroskopie, Einkristallröntgenstrukturanalyse und schwingungsspektroskopische Methoden charakterisiert. Wir untersuchten die Reaktivität von 2 gegenüber Kohlenstoffmonoxid, Azobenzol sowie Trimethylsilylacetylen, wobei sich drei verschiedene Reaktivitätsarten zeigten: Addition, Reduktion und Deprotonierung. Die Reaktion von 2 mit Kohlenstoffmonoxid lieferte den Ethendiolat‐Komplex 4 durch Addition an die C−O Bindung, wohingegen bei der Umsetzung mit Azobenzol die Reduktion der N−N Doppelbindung sowie Eliminierung von Wasserstoff beobachtet wurde, welche zu einem heteroleptischen Strontiumkomplex mit einem radikalischen Azobenzenylliganden führte (5). Das terminale Alkin wird durch das Hydrid deprotoniert, wodurch der Acetylidkomplex 6 entstand.
A Chemically Powered Rotary Molecular Motor Based on Reversible Oxazepine Formation
Authors: Han Tian‐Jiao , Ke Xin‐Yan , Wang Min‐Can , Ni Shao‐Fei , Mei Guang‐Jian
Published: November 2024

While biological machines are powered mainly by chemical transformations, chemically driven artificial rotary motor systems are very limited. Here, we report an aniline‐phenol‐based rotary molecular motor that operates via an information ratchet mechanism. The 360° directional rotation about a single covalent bond can be chemically driven by reversible oxazepine formation. Both the oxazepine formation and hydrolysis steps are kinetically gated via dynamic kinetic resolution, arising from the kinetic bias of chiral catalysts for enantiomers. Given the 95 % ee (97.5 : 2.5) and 88 % ee (94 : 6) of the individual gating steps of motor analogues, the overall directionality ratio could be calculated to be 91.7 : 8.3 (97.5 %×94 %≈91.7 %), which means that the motor will make one mistake (backward rotation) approximately every 11 to 12 turns.
Structural and Functional Characterization of an Amidase Targeting a Polyurethane for Sustainable Recycling
Authors: Rotilio Laura , Bayer Thomas , Meinert Hannes , Teixeira Luis M. C. , Johansen Martin B. , Sommerfeldt Andreas , Petersen Allan R. , Sandahl Alexander , Keller Malene B. , Holck Jesper , Paiva Pedro , Otzen Daniel E. , Bornscheuer Uwe T. , Wei Ren , Fernandes Pedro A. , Ramos Maria J. , Westh Peter , Morth J. Preben
Published: November 2024

Global plastic production exceeded 400 million tons in 2022, urgently demanding improved waste management and recycling strategies for a circular plastic economy. While the enzymatic hydrolysis of polyethylene terephthalate (PET) has become feasible on industrial scales, efficient enzymes targeting other hydrolyzable plastic types, such as polyurethanes (PURs), are lacking. Recently, enzymes of the amidase signature (AS) family, capable of cleaving urethane bonds in a polyether‐PUR analog and a linear polyester‐PUR, have been identified. Herein, we present high‐resolution crystal structures of the AS enzyme UMG‐SP3 in three states: ligand‐free, bound with a suicidal inhibitor mimicking the transition state, and bound with a monomeric PUR degradation product. Besides revealing the conserved core and catalytic triad akin to other AS family members, the UMG‐SP3 structures show remarkable flexibility of loop regions. Particularly, Arg209 in loop 3 adopts two induced‐fit conformations upon ligand binding. Through structure‐guided kinetic studies and enzyme engineering, we mapped structural key elements that determine the enhanced hydrolysis of urethane and amide bonds in various small molecules, including a linear PUR fragment analog. Our findings contribute critical insights into urethanase activity, aiding PUR degradation campaigns and sustainable plastic recycling efforts in the future.
Bridged Carbolong Modulating Interfacial Charge Transfer Enhancement for High‐Performance Inverted Perovskite Solar Cells
Authors: Yang Yang , Chen Shiyan , Dai Zhiyuan , Wei Hang , Wan Shuyuan , Chen Yan , Sun Jinhan , Liu Zhe , Ding Liming , Xia Haiping , Chen Ruihao , Wang Hongqiang
Published: November 2024

Efficient regulation of perovskite/C60 interface is crucial to improving the long‐term stability of the inverted perovskite solar cells (PSCs). However, precise methods for controlling the perovskite/C60 interface have yet to be thoroughly explored. Herein, we develop a carbolong chemical manipulation strategy to improve the interface contact of perovskite/C60 due to versatile functional groups and excellent optoelectronic properties of carbolong metallaaromatics. And constructing an electron‐transfer bridge enhances the interfacial interaction and accelerates interfacial electron transfer. The carbolong manipulation results in optimized energy level alignment, suppressed nonradiative recombination, and improved electronic contact. An impressive efficiency of 25.80% is demonstrated, with open‐circuit voltage and fill factor of 1.19 V and 84.53 %, respectively. The unsealed devices retain more than 98 % of their original efficiency after 1400 h of maximum power point tracking under illumination and demonstrate remarkable thermal stability, maintaining 93 % of their initial efficiency after 2500 h at 85 °C in a nitrogen atmosphere. And the encapsulated carbolong‐modified module achieved a high efficiency of 20.72 % (active area of 25.25 cm2) with robust operation stability.
Better Together: Photoredox/Copper Dual Catalysis in Atom Transfer Radical Polymerization
Authors: Sobieski Julian , Gorczyński Adam , Jazani Arman Moini , Yilmaz Gorkem , Matyjaszewski Krzysztof
Published: November 2024

Photomediated Atom Transfer Radical Polymerization (photoATRP) is an activator regeneration method, which allows for the controlled synthesis of well‐defined polymers via light irradiation. Traditional photoATRP is often limited by the need for high‐energy ultraviolet or violet light. These could negatively affect the control and selectivity of the polymerization, promote side reactions, and may not be applicable to biologically relevant systems. This drawback can be circumvented by an introduction of the catalytic amount of photocatalysts, which absorb visible and/or NIR light and, therefore, controlled, regenerative ATRP can be performed with the dual‐catalytic cycle. Herein, a critical summary of recent developments in the field of dual‐catalysis concerning Cu‐catalyzed ATRP is provided. Contributions of involved species are examined mechanistically, followed by challenges and future directions towards the next generation of advanced functional macromolecular materials.
Single‐Cell Secretome Profiling Enabled by Selective Enrichment and NanoLC‐MS/MS Analysis
Authors: He Yingyun , Liu Xinxin , Zhu Fengjiao , Dai Zhongpeng , Li Xiao , Li Linmei , Zhao Baofeng , Yuan Huiming , Lu Yao , Liang Zhen , Zhang Yukui , Zhang Lihua
Published: November 2024

Recent advances in single‐cell proteomics enable the direct profiling of thousands of proteins from a single mammalian cell. However, due to the bottlenecks in detecting low‐abundance secreted proteins and extracellular vesicle (EV) proteins (collectively referred to as the secretome) against a background of high‐abundance proteins in serum‐containing culture medium, the comprehensive investigation of the secretome at the single‐cell level using nanoLC‐MS/MS still remains challenging. Herein, we report a novel single‐cell secretome profiling (SCSP) method by integrating the metabolic labeling of newly synthesized proteins, click chemistry‐based enrichment, and in situ digestion of the labeled secretome in an alkyne‐functionalized capillary micro‐reactor, followed by nanoLC‐MS/MS analysis. By this method, an average of 389 protein groups were quantified from the secretome of single HeLa cells (n=17), with a total of 752 protein groups confidently identified in the single‐cell secretome, which is a significant increase compared to the previously reported targeted analysis limited to dozens of secreted proteins by antibody recognition. These results indicated that our developed SCSP method would provide a powerful tool to gain insights into secretion heterogeneity and intercellular communication at the single‐cell level.
Stabilisation of a Strontium Hydride with a Monodentate Carbazolyl Ligand and its Reactivity
Authors: Winkler Lucas , Hinz Alexander
Published: November 2024

The molecular strontium hydride 2 [(dtbpCbz)SrH(L)]2 (L=benzene, toluene) was isolated and stabilized by employing a sterically demanding carbazole ligand (dtbpCbz=1,8‐bis(3,5‐ditertbutylphenyl)‐3,6‐ditertbutylcarbazolyl). Compound 2 was synthesized via phenylsilane metathesis with the corresponding amide (dtbpCbz)SrN(SiMe3)2 and characterized by 1H NMR, XRD and vibrational spectroscopy methods. We further investigated the stoichiometric reactivity of 2 towards carbon monoxide, azobenzene and trimethylsilylacetylene, showing three distinct reactivity pathways: addition, reduction and deprotonation. The reaction of 2 with carbon monoxide yields the ethenediolate complex 4 via addition, while with azobenzene reduction of the N−N double bond and release of hydrogen were observed, affording a heteroleptic strontium complex with a radical azobenzenyl ligand (5). The terminal alkyne is deprotonated by the hydride moiety to give the acetylide complex 6.
Functional Characterization and Molecular Basis of a Multi‐Site Halogenase in Naphthacemycin Biosynthesis
Authors: Hu Yu , Peng Shu‐Ya , Ma Xueyang , Chen Hongwei , Nie Qiu‐Yue , He Jun‐Bin , Chen Qianqian , Zhou Qiang , Lu Xin‐Hua , Hua Qiang , Yang Donghui , Liang Yong , Ma Ming , Tang Gong‐Li
Published: November 2024

Halogenases are spurring a growing interest in the fields of biosynthesis and biocatalysis. Although various halogenases have been identified in numerous natural product biosynthetic pathways, the mechanisms for multiple halogenations and site‐selectivity remain largely unclear. In this study, we biochemically characterized FasV, a flavin‐dependent halogenase (FDH) that catalyzes five successive chlorinations in the biosynthesis of the naphthacene‐containing aromatic polyketide naphthacemycin. This multiple halogenation reaction was elucidated to occur in an orderly fashion, as evidenced by enzyme kinetics, time‐course assays, and computational simulations. Crystallographic analyses and mutagenesis studies revealed previously unrecognized amino acid residues, including T53, L81, F93, and I212, that are crucial for controlling regioselectivity and substrate specificity. Based on this, a I212T mutant was generated to exclusively catalyze selective monohalogenation. We propose a novel dual‐activation mechanism and demonstrate that the larger binding pocket of FasV makes it a valuable biocatalyst for other substrates with diverse structures. Therefore, this study provides new insight into multi‐site polyhalogenases and highlights the potential for engineering FasV‐like FDHs for biocatalytic applications.
Enhancing Mechanical Durability and Long‐Term Stability in Organic Solar Cells via Flexible Linker‐Sequential Block Copolymerized Donors
Authors: Lin Congqi , Peng Ruixiang , Song Wei , Gao Jiangwei , Feng Tingting , Bai Yongqi , Liu Quan , Yang Mengjin , Zhang Jianfeng , Ge Ziyi
Published: November 2024

Multi‐component copolymerized donors (MCDs) hold great promise for improving both the efficiency and mechanical robustness of flexible organic solar cells (f‐OSCs) owing to their facile molecular tunability and advantageous one‐pot copolymerization. However, despite the excellent crystallinity imparted by their highly conjugated polymer backbone, MCDs often struggle to retain photovoltaic performance under large external deformations, limiting their applicability in wearable devices. Herein, we developed a novel series of flexible linker‐sequential block MCDs (Fs‐MCDs), specifically PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTB, PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTH, and PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD, by precisely incorporating flexible functional groups into the conjugated polymer skeleton. This design strategy introduced highly effective tensile active sites, resulting in remarkable mechanical durability, with PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD achieving crack‐onset strain (COS) values of 49.88 % in pristine films and 31.29 % in blends. The nearly 50 % COS in pristine films represents one of the highest values reported for Fs‐MCD‐based OSCs, marking a significant milestone in advancing f‐OSC. Additionally, PM6‐Cl0.8‐b‐D18‐Cl0.2‐BTD demonstrated excellent photovoltaic performance, with efficiencies of 18.09 % in rigid binary and 19.05 % in ternary, as well as 16.63 % in flexible OSCs. It also showed impressive device stability in invert OSC (T80=9,078 h). This unique molecular design strategy provides a promising avenue for synergistically improving the photovoltaic performance, mechanical properties, and device stability of f‐OSCs.
Lignin‐Based Type I Macromolecular Photoinitiator for Fabricating UV‐Blocking Films
Authors: Qi Yujie , Zhai Haoqi , Huang Xing , Shi Mengquan , Zhang Yuxi , Zhao Yuxia
Published: November 2024

As the largest renewable source of aromatic feedstock in nature, lignin has good thermal stability, strong ultraviolet (UV) absorption, and mechanical reinforcing property. In this study, a lignin‐based Type I macromolecular photoinitiator (macro PI) named DAL‐11ene‐TPO is designed and synthesized through covalently grafting 10‐undecenoyl chloride (11ene) and 2,4,6‐trimethylbenzoyl‐ethoxy‐phenylphosphine oxide (TPO‐L, a commercial small molecular PI) into dealkaline lignin (DAL) skeleton. A series of characterizations were performed to prove that DAL‐11ene‐TPO was synthesized successfully, including 1H NMR, FTIR, UV–vis, 31P NMR, GPC (gel permeation chromatography). The formed active free radicals were monitored by electron spin resonance (ESR). DAL‐11ene‐TPO can high‐efficiently initiate the monomers polymerization upon the irradiation of 405 nm LED. The resulting polymer films showed strong UV‐blocking performance and good visible light transmittance. Moreover, the elongation at break of the polymer film containing 0.5% DAL‐11ene‐TPO is improved by 50% compared with that of TPO‐L control group. Furthermore, DAL‐11ene‐TPO has polymerizable groups, which can be bonded into the network of the polymers, resulting in a high biosafety of the end products. The results indicate that DAL‐11ene‐TPO can be used as a high‐efficient bio‐based macro PI for preparing high performance UV‐blocking films.
Substitution of Glutamic Acid at Position 71 of DRβ1*04:01 and Collagen‐Specific Tolerance Without Alloreactivity
Authors: Jha Vibha , Freed Brian M. , Sunderhaus Elizabeth R. , Lee Jessica E. , Prage Edward B. , Miglani Manjula , Rosloniec Edward F. , Matsuda Jennifer L. , Coulombe Marilyne G. , McKee Amy S. , Roark Christina L.
Published: November 2024

Objective

The DRB1 locus is strongly associated with both susceptibility and resistance to rheumatoid arthritis (RA). DRB1 alleles encoding the VKA or VRA epitope in positions 11, 71, and 74 confer the highest risk of developing RA, whereas the allele encoding VEA is protective. We therefore investigated the feasibility of creating antigen‐specific tolerance without inducing alloreactivity by replacing lysine with glutamic acid at position 71 in DRβ1*04:01.

Methods

Individual DRB1 alleles and the DRB1*04:01K71E allele were cloned into T2 cell lines to measure binding of biotinylated peptides. Transgenic animals expressing DRB1*04:01, DRB1*01:01, or DRB1*04:01K71E were injected with collagen to measure T cell proliferation. Skin and bone marrow transplants between DRB1*04:01K71E and DRB1*04:01 mice were performed to determine if the single amino acid change at position 71 would be recognized as foreign. DRB1*04:01 mice transplanted with DRB1*04:01K71E bone marrow were injected with collagen to test if resistance to collagen sensitization could be transferred.

Results

Replacing lysine (K) at position 71 in DRβ1*04:01 with glutamic acid (E) blocked collagen peptide binding and rendered the DRB1*04:01K71E mice resistant to collagen sensitization. Skin and bone marrow transplants from DRB1*04:01K71E mice were not rejected by DRB1*04:01 mice, suggesting the single E71 difference was not recognized as allogeneic. Bone marrow from DRB1*04:01K71E mice adoptively transferred antigen‐specific tolerance to collagen to DRB1*04:01 mice.

Conclusion

These studies demonstrate that editing a single amino acid in DRβ1*04:01 blocks collagen peptide binding without inducing alloreactivity and could therefore represent a gene therapy approach to induce antigen‐specific passive tolerance.
A Facile and Efficient Synthesis of BODIPY‐Based Fluorescent Probes for Selective Detection of Hydrazine
Authors: Saraf Prakriti , Shrivastava Pragati , Sarkar Madhushree , Kumar Dalip
Published: November 2024

A facile and ratiometric BODIPY‐based fluorescent probe 4 was developed for the selective detection of hydrazine in solution phase. The BODIPY‐based fluorophores 3 and 4 were easily prepared in high yields from the L‐proline catalyzed reaction between α/β‐formyl BODIPY 1 a/1 b and 3‐cyanoacetylindole 2. Use of easily accessible substrates, benign solvent, catalytic amount of L‐proline and high product yields are the advantageous features of the developed protocol. Prepared BODIPYs 3 (536 nm) and 4 (567 nm) showed bathochromic shifts (36–67 nm) in UV‐Visible absorption maxima when compared to parent BODIPY (500 nm) in dichloromethane (DCM). The stable and economical BODIPY‐based probe 4 exhibited rapid response and remarkable selectivity towards hydrazine when compared to other commonly occurring analytes. At low concentration, the BODIPY probe 4 (10 μΜ) is non‐fluorescent, however, a significant enhancement in fluorescent (turn‐on) was observed with the increasing concentration of hydrazine (0–100 μΜ). This change in fluorescent behaviour may be ascribed to intramolecular charge transfer (ICT) effect as supported by density functional theory (DFT) calculations. With a 4.3 μM detection limit, the BODIPY probe 4 was also found to be useful in detecting hydrazine in real environmental samples.
Photoresponsive Luminescent Silica Nanoparticles as Additive for 3D Printing and Electrospinning
Authors: Lorberg Rick Y. , Nair Sailaja Sidharth Thulaseedharan , Terlau Fabian , Victoria Cappellari Maria , Schmiedtchen Marco , Galstyan Anzhela , Strassert Cristian A. , Giese Michael , Voskuhl Jens
Published: November 2024

In this study, we present the synthesis and a versatile way to incorporate photoresponsive organic luminophores into polymeric materials using mesoporous silica nanoparticles (MSNs). The encapsulated thioethers within the MSNs were employed in polyvinyl alcohol (PVA) films, resin‐based stereolithography, and electrospinning. Due to light‐induced cyclisation to dibenzothiophenes (DBTs), mmOC12 loaded materials were used to inscribe images using UV light. The DBTs formed from mmOC12 (mmDBTA/B) exhibit a long phosphorescence afterglow, which was investigated by steady‐state and time‐resolved photoluminescence spectroscopy. In addition, scanning electron microscopy (SEM) imaging, including energy dispersive X‐ray spectroscopy (EDX), revealed the well‐dispersed and intact MSNs in the polymeric materials. This approach shows a general way to incorporate non‐polar organic luminophores into polymeric materials while retaining their unique emission properties.
Regulation of classical zinc fingers for neuronal signaling in the central nervous system
Authors: Hwang Yunha , Park Soyeon , Kim Hyunyong , Park Yerim , Kang Hyun Goo , Lee Dong‐Heon , Lee Seung Jae
Published: November 2024

Zinc finger (ZF) proteins are well‐known for their regulatory functions in the central dogma, and their structural domains serve as promising scaffolds for the study of neurodegenerative diseases. These proteins often contain multiple ZF domains, enabling interactions with target molecules that regulate transcription and translation. The Cys2His2 (C2H2) type ZF domains, found in the brain, are associated with long‐ and short‐term memory, neuronal differentiation and development, and other physiological processes. The classical C‐X2‐C‐X12‐H‐X3‐H type ZF domains have been detected in studies of Parkinson's disease (PD) and are closely linked to biological pathways involved in a wide range of neurodegenerative diseases. In this review, we introduce three ZF proteins expressed in the brain: Parkin‐interacting substrate (PARIS), zinc finger and BTB domain‐containing 20 (ZBTB20), and zinc finger protein 18 (ZNF18). We explore the structural and functional roles of these ZF proteins in the brain. Each of these proteins contains more than four ZF domains, as well as functional domains such as KRAB, BTB, and SCAN, which perform modular roles independently of the ZF domains. Biophysical studies of PARIS have demonstrated that its classical three‐ZF domain, PARIS(ZF2–4), forms hydrogen bonds with insulin response sequences (IRSs) with high specificity (Kd = 38.9 ± 2.4 nM). Metal coordination studies showed that PARIS binds Co2+ with high affinity (Kd = 49.1 ± 7.7 nM), more strongly than other ZF domains, and it also coordinates with other xenobiotic metal ions such as Fe2+ and Ni2+. Although Zn2+–PARIS(ZF2–4) binds specifically to IRSs, Fe2+–, Fe3+– or Co2+–PARIS(ZF2–4) cannot, due to distortions in the ZF domain structure that disrupt hydrogen bonding. These brain‐specific ZF domains exhibit common patterns, with similar numbers of ZF domains and sequence homology at the C‐terminus, whereas both the ZF domains and N‐terminal protein–protein interaction domains contribute to their functional versatility. Elucidating the structure and function of these classical ZF proteins offers promising avenues for the treatment of diverse brain disorders, including Alzheimer's disease, PD, and autism spectrum disorder.