The chemical bulk reductive covalent functionalization of thin‐layer black phosphorus (BP) using BP intercalation compounds has been developed. Through effective reductive activation, covalent ...functionalization of the charged BP by reaction with organic alkyl halides is achieved. Functionalization was extensively demonstrated by means of several spectroscopic techniques and DFT calculations; the products showed higher functionalization degrees than those obtained by neutral routes.
The reductive covalent functionalization of thin‐layer black phosphorus (BP) proceeds via BP intercalation compounds. Following the reductive activation of BP, the resulting charged BP reacts with alkyl halides and undergoes covalent functionalization. The BP lattice shows unprecedented opening and a higher degree of functionalization than that obtained by neutral routes.
The solid‐state synthesis of pure sodium‐black phosphorus intercalation compounds (Na‐BPICs) has been optimized in bulk for two stoichiometric ratios. Specifically, in‐situ X‐Ray diffraction (XRD) ...allowed the precise identification of the optimal temperature range for the formation of Na‐BPICs: 94 °C–96 °C. Moreover, as the undesired formation of Na3P takes place at this very same range, we succeeded in introducing a new synthetic route based on a fast‐thermal ball milling implementation that results in the bulk production of BPIC without Na3P in 9 out of 10 cases. Finally, by combining XRD, Raman spectroscopy, and DFT calculations we developed a new structural model for Na‐based BPICs showing an increase of BP's unit cell with Na atoms incorporated in every second layer. These results will pave the way for the large‐scale synthesis and application of pure BPICs, which are of great interest in fields such as optoelectronics or energy storage.
Bulk production: The formation of the sodium/black phosphorus intercalated (BPIC) phase via solid‐state reaction was followed in‐situ using X‐ray diffraction. Parameters of this reaction were used to introduce a synthesis procedure that uses ball milling at elevated temperatures and results in the formation of a mixed BPIC/black phosphorus phase without intermetallic phases.
The Cover Feature shows the structure of a stage 2 sodium‐black phosphorus intercalated compound (Na‐BPIC) in front of its X‐ray diffraction pattern that has been instrumental for its determination. ...The compound was successfully synthesized without containing intermetallic phases from pure black phosphorus (in the background) and pure sodium via ball‐milling. The image was designed by Rafal Konkol at the Universität Wien graphics department. More information can be found in the Communication by K. Werbach and co‐workers.
Eine chemisch‐reduktive Volumen‐Funktionalisierung von dünnlagigem schwarzem Phosphor (BP) wurde unter Verwendung von BP‐Interkalationsverbindungen entwickelt. Durch effektive reduktive Aktivierung ...wurde die kovalente Funktionalisierung des geladenen BP mit Alkylhalogeniden erreicht. Die kovalente Funktionalisierung wurde umfassend mit mehreren spektroskopischen Methoden sowie DFT‐Rechnungen nachgewiesen; es liegt ein höherer Funktionalisierungsgrad als bei neutralen Funktionalisierungsreaktionen vor.
Eine chemisch‐reduktive Volumen‐Funktionalisierung von dünnlagigem schwarzem Phosphor (BP) gelang unter Verwendung von BP‐Interkalationsverbindungen. Durch eine effektive reduktive Aktivierung wurde die kovalente Funktionalisierung des geladenen BP mit Alkylhalogeniden erzielt, wobei eine Öffnung des BP‐Gitters und ein höherer Funktionalisierungsgrad als bei neutralen Reaktionsrouten resultieren.
Abstract
Eine chemisch‐reduktive Volumen‐Funktionalisierung von dünnlagigem schwarzem Phosphor (BP) wurde unter Verwendung von BP‐Interkalationsverbindungen entwickelt. Durch effektive reduktive ...Aktivierung wurde die kovalente Funktionalisierung des geladenen BP mit Alkylhalogeniden erreicht. Die kovalente Funktionalisierung wurde umfassend mit mehreren spektroskopischen Methoden sowie DFT‐Rechnungen nachgewiesen; es liegt ein höherer Funktionalisierungsgrad als bei neutralen Funktionalisierungsreaktionen vor.
Black phosphorus intercalation compounds (BPICs) with alkali metals (namely: K and Na) have been synthesized in bulk by solid‐state as well as vapor‐phase reactions. By means of a combination of in ...situ X‐ray diffraction, Raman spectroscopy, and DFT calculations the structural behavior of the BPICs at different intercalation stages has been demonstrated for the first time. Our results provide a glimpse into the very first steps of a new family of intercalation compounds, with a distinct behavior as compared to its graphite analogues (GICs), showing a remarkable structural complexity and a dynamic behavior.
Nuancen von Schwarz: Interkalationsverbindungen von schwarzem Phosphor (BPICs) mit den Alkalimetallen K und Na (im Bild als dunkle Kugeln dargestellt) zeigen eine komplexe strukturelle Dynamik. In‐situ‐Raman‐Spektroskopie und Dichtefunktionalrechnungen liefern Vergleichsdaten zur Identifizierung dieser Interkalationsverbindungen.
The chemical bulk reductive covalent functionalization of thin layer black phosphorus (BP) using BP intercalation compounds has been developed. Through effective reductive activation, covalent ...functionalization of the charged BP is achieved by organic alkyl halides. Functionalization was extensively demonstrated by means of several spectroscopic techniques and DFT calculations, showing higher functionalization degrees than the neutral routes.
Micro- and nanoscale mechanical resonators have recently emerged as ubiquitous devices for use in advanced technological applications, for example in mobile communications and inertial sensors, and ...as novel tools for fundamental scientific endeavors. Their performance is in many cases limited by the deleterious effects of mechanical damping. Here, we report a significant advancement towards understanding and controlling support-induced losses in generic mechanical resonators. We begin by introducing an efficient numerical solver, based on the "phonon-tunneling" approach, capable of predicting the design-limited damping of high-quality mechanical resonators. Further, through careful device engineering, we isolate support-induced losses and perform the first rigorous experimental test of the strong geometric dependence of this loss mechanism. Our results are in excellent agreement with theory, demonstrating the predictive power of our approach. In combination with recent progress on complementary dissipation mechanisms, our phonon-tunneling solver represents a major step towards accurate prediction of the mechanical quality factor.
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