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ACS Applied Materials & Interfaces Jul 2024Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited...
Electronic devices employing two-dimensional (2D) van der Waals (vdW) transition-metal dichalcogenide (TMD) layers as semiconducting channels often exhibit limited performance (e.g., low carrier mobility), in part, due to their high contact resistances caused by interfacing non-vdW three-dimensional (3D) metal electrodes. Herein, we report that this intrinsic contact issue can be efficiently mitigated by forming the 2D/2D in-plane junctions of 2D semiconductor channels seamlessly interfaced with 2D metal electrodes. For this, we demonstrated the selectively patterned conversion of semiconducting 2D PtSe (channels) to metallic 2D PtTe (electrodes) layers by employing a wafer-scale low-temperature chemical vapor deposition (CVD) process. We investigated a variety of field-effect transistors (FETs) employing wafer-scale CVD-2D PtSe/2D PtTe heterolayers and identified that silicon dioxide (SiO) top-gated FETs exhibited an extremely high hole mobility of ∼120 cm V s at room temperature, significantly surpassing performances with previous wafer-scale 2D PtSe-based FETs. The low-temperature nature of the CVD method further allowed for the direct fabrication of wafer-scale arrays of 2D PtSe/2D PtTe heterolayers on polyamide (PI) substrates, which intrinsically displayed optical pulse-induced artificial synaptic behaviors. This study is believed to vastly broaden the applicability of 2D TMD layers for next-generation, high-performance electronic devices with unconventional functionalities.
PubMed: 38949620
DOI: 10.1021/acsami.4c06540 -
The Journal of Physical Chemistry... Jul 2024To create complementary metal oxide semiconductor compatible molecular devices, more insights into the electrode property regarding its metal/semiconductor doping level...
To create complementary metal oxide semiconductor compatible molecular devices, more insights into the electrode property regarding its metal/semiconductor doping level and creating a functional molecular device are required. In this work, we constructed an EGaIn/alkanethiol/Au-Si molecular diode (with a rectification ratio of 50.70) induced by Schottky barriers within a gold-silicon doped electrode instead of the functional property of molecules. The relationship between the rectification ratio and the number of methylene units in alkanethiol was analyzed, revealing a gradual increase in the ratio from 3.33 for CHS to 50.70 for CHS. The rectification ratio of the junction is well modulated by the temperature due to the change in the Schottky barrier. Such a mechanism is explained by the energy band diagrams of the surface space charge region and a combination of density functional theory and Keldysh-Green formalism calculations.
PubMed: 38949616
DOI: 10.1021/acs.jpclett.4c01351 -
Chemistry, An Asian Journal Jul 2024We report a systematic study on controlling the enzyme activity of a terminal uridylyl transferase (TUTase) called SpCID1, which provides methods to effect site-specific...
We report a systematic study on controlling the enzyme activity of a terminal uridylyl transferase (TUTase) called SpCID1, which provides methods to effect site-specific incorporation of a single modified nucleotide analog at the 3'-end of an RNA oligonucleotide (ON). Responsive heterocycle-modified fluorescent UTP probes that are useful in analyzing non-canonical nucleic acid structures and azide- and alkyne-modified UTP analogs that are compatible for chemoenzymatic functionalization were used as study systems. In the first strategy, we balanced the concentration of essential metal ion cofactors (Mg2+ and Mn2+ ions) to restrict the processivity of the enzyme, which gave a very good control on the incorporation of clickable nucleotide analogs. In the second approach, borate that complexes with 2' and 3' oxygen atoms of a ribose sugar was used as a reversibly binding chelator to block repeated addition of nucleotide analogs. Notably, in the presence of heterocycle-modified fluorescent UTPs, we obtained single-nucleotide incorporated RNA products in reasonable yields, while with clickable nucleotides yields were very good. Further, 3'-end azide- and alkyne-labeled RNA ONs were post-enzymatically functionalized by CuAAC and SPAAC reactions with fluorescent probes. These strategies broaden the scope of TUTase in site-specifically installing modifications of different types onto RNA for various applications.
PubMed: 38949615
DOI: 10.1002/asia.202400475 -
Angewandte Chemie (International Ed. in... Jul 2024Two-dimensional covalent organic frameworks (2D-COFs) have recently emerged as fascinating scaffolds for solar-to-chemical energy conversion because of their...
Two-dimensional covalent organic frameworks (2D-COFs) have recently emerged as fascinating scaffolds for solar-to-chemical energy conversion because of their customizable structures and functionalities. Herein, two tris(triazolo)triazine-based COF materials (namely COF-JLU51 and COF-JLU52) featuring large surface area, high crystallinity, excellent stability and photoelectric properties were designed and constructed for the first time. Remarkably, COF-JLU51 gave an outstanding H2O2 production rate of over 4200 µmol g-1 h-1 with excellent reusability in pure water and O2 under one standard sun light, that higher than its isomorphic COF-JLU52 and most of the reported metal-free materials, owing to its superior generation, separation and transport of photogenerated carriers. Experimental and theoretical researches prove that the photocatalytic process undergoes a combination of indirect 2e- O2 reduction reaction (ORR) and 4e- H2O oxidation reaction (WOR). Specifically, an ultrahigh yield of 7624.7 µmol g-1 h-1 with apparent quantum yield of 18.2% for COF-JLU52 was achieved in a 1:1 ratio of benzyl alcohol and water system. This finding contributes novel, nitrogen-rich and high-quality tris(triazolo)triazine-based COF materials, and also designate their bright future in photocatalytic solar transformations.
PubMed: 38949611
DOI: 10.1002/anie.202411546 -
Organic Letters Jul 2024Minisci-type dehydrogenative coupling of C(sp)-H and N-heteroaromatics was performed with -hydroxysuccinimide as a hydrogen atom transfer catalyst in a...
Minisci-type dehydrogenative coupling of C(sp)-H and N-heteroaromatics was performed with -hydroxysuccinimide as a hydrogen atom transfer catalyst in a photoelectrochemical cell composed of a mesoporous BiVO photoanode and a Pt electrode. In the absence of metal catalysts and chemical oxidants, a range of -heteroarenes (e.g., quinolines, isoquinolines, and quinoxaline) can undergo coupling with various C(sp)-H partners to form the corresponding products in excellent yields.
PubMed: 38949597
DOI: 10.1021/acs.orglett.4c01998 -
The Review of Scientific Instruments Jul 2024With the development of 5G technology, the accurate measurement of the complex permittivity of a printed circuit board (PCB) in the wide frequency range is crucial for...
With the development of 5G technology, the accurate measurement of the complex permittivity of a printed circuit board (PCB) in the wide frequency range is crucial for the design of high-frequency circuits. In this paper, a microwave measurement device and method based on the double-sided parallel-strip line (DSPSL) resonator have been developed to measure the complex permittivity of typical PCBs in the vertical direction. The device includes the DSPSL resonator, the DSPSL coupling probe, a pressure monitor, a Farran C4209 vector network analyzer (100 K to 9 GHz), and a FEV-10-PR-0006 frequency multiplier (75-110 GHz). Based on transmission line theory, the physical model of the DSPSL resonator was established, and the relative permittivity and loss angle tangent value of the dielectric substrate were calculated using conformal transformation. To excite the resonator, the DSPSL coupling probe with a good transmission effect was designed, which consists of DSPSL microstrip line (MSL) transition structure and an MSL-WR10 rectangular waveguide converter. To reduce the air gap between the sample and the metal guide band and dielectric support block, and to improve test accuracy, a mechanical pressure device is added to the top of the DSPSL resonator. Based on the DSPSL resonator, we have used the device to test four typical PCBs, namely, polytetrafluoroethylene, Rogers RT/duroid®5880, Rogers RO3006®, and Rogers RO3010®. The results show that the maximum error of the relative permittivity is less than 3.05%, and the maximum error of the loss angle tangent is less than 1.27 × 10-4.
PubMed: 38949472
DOI: 10.1063/5.0214359 -
Dalton Transactions (Cambridge, England... Jul 2024Lanthanide metal-organic frameworks (Ln-MOFs) have unique advantages in sensing due to their excellent optical properties. In this study, we synthesized a dicarboxylic...
Lanthanide metal-organic frameworks (Ln-MOFs) have unique advantages in sensing due to their excellent optical properties. In this study, we synthesized a dicarboxylic acid ligand with amide groups and successfully synthesized a novel two-dimensional (2D) MOF with the molecular formula CHEuNO (Eu-MOF) by a solvothermal method. Single-crystal X-ray diffraction showed that amide groups are exposed on the outside of the two-dimensional coordination layer, with the possibility of recognizing specific molecules through hydrogen bonding interactions. The ligand's "antenna effect" enables Eu-MOF to emit a strong luminescence characterized by the "f-f" transition. Further studies have revealed that Eu-MOF could be used as a bifunctional fluorescent probe for the selective detection of benzaldehyde and Fe. The sensing mechanism has been analyzed in detail through powder X-ray diffraction (PXRD) analysis, UV-vis spectroscopy, fluorescence lifetime measurement, and density functional (DFT) theory calculation. This design and research can provide a reference for subsequent related work.
PubMed: 38949446
DOI: 10.1039/d4dt01512f -
Small (Weinheim An Der Bergstrasse,... Jul 2024To meet increasing requirement for innovative energy storage and conversion technology, it is urgent to prepare effective, affordable, and long-term stable oxygen...
Bimetal Oxides Anchored on Carbon Nanotubes/Nanosheets as High-Efficiency and Durable Bifunctional Oxygen Catalyst for Advanced Zn-Air Battery: Experiments and DFT Calculations.
To meet increasing requirement for innovative energy storage and conversion technology, it is urgent to prepare effective, affordable, and long-term stable oxygen electrocatalysts to replace precious metal-based counterparts. Herein, a two-step pyrolysis strategy is developed for controlled synthesis of FeO and MnO anchored on carbon nanotubes/nanosheets (FeO-MnO-CNTs/NSs). The typical catalyst has a high half-wave potential (E = 0.87 V) for oxygen reduction reaction (ORR), accompanied with a smaller overpotential (η = 290 mV) for oxygen evolution reaction (OER), showing substantial improvement in the ORR and OER performances. As well, density functional theory calculations are performed to illustrate the catalytic mechanism, where the in situ generated FeO directly correlates to the reduced energy barrier, rather than MnO. The FeO-MnO-CNTs/NSs-based Zn-air battery exhibits a high-power density (153 mW cm) and satisfyingly long durability (1650 charge/discharge cycles/550 h). This work provides a new reference for preparation of highly reversible oxygen conversion catalysts.
PubMed: 38949416
DOI: 10.1002/smll.202402104 -
Small Methods Jul 2024Adverse side reactions and uncontrolled Zn dendrites growth are the dominant factors that have restricted the application of Zn ion batteries. Herein, a 3D...
Adverse side reactions and uncontrolled Zn dendrites growth are the dominant factors that have restricted the application of Zn ion batteries. Herein, a 3D self-supporting porous carbon fibers (denoted as PCFs) host is developed with "trap" effect to adjust the Zn deposition. The unique open structural design of N-doped carbon can act as the zincophilic sites to induce uniform deposition and inhibit adverse side reactions. More importantly, the porous hollow PCFs host with "trap" effect can induce Zn deposition in the fiber by adjusting the local electric field and current density, thereby increasing the specific energy density of the battery and inhibiting dendrite growth. In addition, the 3D open frameworks can regulate Zn flux to enable outstanding cycling performance at ultra-high current densities. As expected, the PCFs framework guarantees the uniform Zn plating and stripping with an outstanding stability over 6000 cycles at the current density of 40 mA cm. And the Zn@PCFs||MnO full battery shows an excellent lifespan over 1300 cycles at 2000 mA g.
PubMed: 38949412
DOI: 10.1002/smtd.202400408 -
Physical Chemistry Chemical Physics :... Jul 2024In this study, using the tight-binding model and Green's function technique, we investigate potential electronic phase transitions in bilayer 6 borophene under the...
In this study, using the tight-binding model and Green's function technique, we investigate potential electronic phase transitions in bilayer 6 borophene under the influence of external stimuli, including a perpendicular electric field, electron-hole coupling between sublayers (excitonic effects), and dopants. Our focus is on key electronic properties such as the band structure and density of states. Our findings reveal that the pristine lattice is metal with Dirac cones around the Fermi level, where their intersection forms a nodal line. The system undergoes transitions to a semiconducting state - elimination of nodal line - with a perpendicular electric field and a semimetallic state - transition from two Dirac cones to a single Dirac cone - with combined electric field and excitonic effects. Notably, with these, the system retains its massless Dirac-like bands characteristic at finite energy. However, introducing a dopant still leads to a metallic phase, but the Dirac-like bands become massive. Considering all these effects, the system ultimately reaches a semiconducting phase with massive Dirac-like bands. These results hold significance for optoelectronic applications.
PubMed: 38949400
DOI: 10.1039/d4cp01484g