Synthetic Metals最新文献

In this research, we have synthesized a thiophene Schiff base from 5-phenyl thiophene-2-carboxaldehyde and 2-thiophene carboxylic acid hydrazide and characterized by using FT-IR NMR, HRMS and SC-XRD analysis techniques. The probe exhibited a selective turn-on fluorescence response for Cu²⁺ over 20 other common metal ions in a CH₃CN (9:1, v/v) solution. The Job’s plot represents a 1:1 binding complexation mode and further DFT study was carried out to aid in understanding the geometric structure and interaction of the ligand and Cu²⁺. The detection limit (LOD) and limit of quantification (LOQ) were found to be 20 nM and 69 nM respectively. Furthermore, the probe’s sensing ability was tested in HeLa cells and their fluorescence imaging also supported the effective turn-on response towards Cu²⁺ ion.

This study explores how nitrogen substitution and gold electrodes collectively influence the electronic characteristics of naphthalenediimide (NDI) molecules (M = 1, 2, and 3) through theoretical analysis. Utilizing ELF, LOL, QTAIM, and NCI analyses, we reveal significant alterations in NDI's electronic structure and interactions upon bonding with gold electrodes (Au-M-Au). Both ELF and LOL analyses demonstrate increased electron localization and delocalization on the NDI surface due to gold electrodes, with a stronger effect on nitrogen-doped molecules (M = 2, 3). QTAIM analysis confirms favorable non-covalent interactions, including evident hydrogen bonding, between NDI molecules and gold electrodes, notably intensified in doped molecules, especially the Au…O interaction. NCI analysis provides insight into the diverse interactions within the molecular system. Overall, this research highlights the crucial role of gold electrodes and nitrogen substitution in fine-tuning NDI molecules' electronic properties. The observed modulation of electron behavior and formation of beneficial interactions with gold electrodes hint at promising applications for doped NDI-gold systems requiring efficient charge transport mechanisms.

This study explored the integration of polyethylene glycol (PEG) into InP-based quantum dot (QD) light-emitting diodes (LEDs). By 5 wt% of PEG 400 blended into the QD emission layer (EML), we achieved an enhancement in both current efficiency (100 %) and external quantum efficiency (91 %). X-ray reflectivity revealed significant morphological changes in the QD EML upon PEG incorporation, primarily manifesting as increased thickness in the dense surface region without affecting the total thickness. This adjustment influenced electron density distribution, impacting hole and electron flow. Overall, the addition of PEG not only improved the electrical properties of QD LEDs but also reshaped the internal morphology of the QD EML. Notably, the efficiency improvements observed rival those achieved by integrating traditional hole transport materials into QD EMLs.

As the pixel size continues to shrink, conventional display devices are unable to satisfy the increasing demand. Therefore, a novel light-emitting device has garnered significant attention. This device emitted light under an alternating current (AC) electric field and blocked the injection of external carriers by using the insulating layer. However, at the same time, this approach leads to a reduction in brightness. In this paper, we have realized the performance enhancement of AC-driven QLEDs by incorporating Au NPs of different sizes in PEDOT:PSS. Our investigation reveals that Au NPs of greater size exhibit a notable enhancement of the brightness, rising from 5512 cd/m² to 7234 cd/m², representing a substantial increase of approximately 31.2 %. It demonstrates the great potential of the "far-field" effect in AC-driven QLEDs.

A series of thieno[3,2-b]thiophene (TT) flanked para-azaquinodimethane (p-AQM) based quinoidal conjugated polymers PAQM2TT-T, PAQM2TT-BT and PAQM3TT were designed in a strategy to extend the aromatic-quinoidal π-system. The three polymers were synthesized by Stille polycondensation, and their opto-electronic properties and device performance in field-effect transistors have been explored. From absorption spectroscopy, the polymers show low bandgaps (1.54–1.57 eV) and high HOMO energy levels. They exhibit typical p-type behavior according to the results of the characterization of the field-effect transistors with average charge carrier mobilities of 0.08 cm² V⁻¹ s⁻¹ for PAQM2TT-T, 0.12 cm² V⁻¹ s⁻¹ for PAQM2TT-BT and 0.05 cm² V⁻¹ s⁻¹ for PAM3TT. This report presents an alternative π-extended quinoidal-donor strategy to control the molecular design and properties of new p-AQM-based conjugated polymers.

Electrochromic fabric was formed by interfacial polymerization of polyaniline (PANI) and multi-walled carbon nanotubes (MWCNTs) on the surface of cotton cloth. The morphology and properties of the composite films were controlled by changing the content of multi-walled carbon nanotubes. The electrochromic properties of the fabric and its application in the field of near-infrared thermal shielding were studied. It is found that the electrochromic fabrics with MWCNTs have better electrochemical and color-changing properties. Electrochromic fabrics achieve color changes from light yellow to yellow-green to dark green in the voltage range of −1.0–1.2 V, and maintain a fast color switching time (2.15 s for coloring, 1.89 s for bleaching) after 600 cycles. The reflection contrast (ΔR) at 500 nm is 23.01 %. Moreover, the electrochromic devices are assembled with fabrics. The device has obvious discoloration and good bending stability. In addition, the thermal shielding is realized by using their reflection characteristics in the visual-near-infrared region. The results show that the electrochromic device has a low surface temperature at different environmental condition, and the thermal reduction from the original state to the bleached state is up to 3.8 ° C, indicating the potential application of the device in thermal regulation.

In this study, we prepared an electrode material from biowaste residue for hybrid supercapacitor application. Bagasse from brewery residue was treated by oxidative calcination at 300 °C. The carbonized material was impregnated using different concentrations of potassium hydroxide (KOH), followed by thermal annealing at 850 °C to obtain activated carbon (AC). The AC obtained was used to prepare a composite with poly(3,4-ethylenedioxythiophene) (PEDOT) via in-situ polymerization process using iron (III) tosylate as oxidizing agent. Pure activated carbon attained a specific surface area (SSA) of 625 m² g⁻¹, and specific capacitance of 80.38 F g⁻¹ at 5 mV s⁻¹ while the AC-PEDOT composite presents 201 F g⁻¹ at the same scan rate, given about 250 % improvement to the specific capacitance. Likewise, the AC presented an energy density of 10.88 Wh Kg⁻¹ and a power density of 9411.59 W Kg⁻¹ at 0.5 A g⁻¹ while the AC-PEDOT composite showed energy density of 25.92 Wh Kg⁻¹ and power density of 4836.44 W Kg⁻¹ at 0.5 A g⁻¹. The results confirm the properties of AC as a supercapacitive material and a battery-like behavior for the AC-PEDOT composite, demonstrating potential for hybrid supercapacitors application.

In this work, composites of Co-Pt nanoparticles/carbon nanotubes (Co-Pt NPs/CNTs) were prepared by loading binary nanoparticles Co-Pt nanoparticles onto carbon nanotubes. These composites were utilized as highly efficient catalysts for the methanol electrocatalytic oxidation reaction (MOR). The morphology of the materials was analyzed using transmission electron microscopy (TEM), Spherical Aberration Corrected Scanning (AC-STEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results revealed that the 5.54 nm diameter Co-Pt nanoparticles were evenly distributed on the surface of carbon nanotubes. Chronoamperometry (CA), linear scanning voltammetry (LSV), and cyclic voltammetry (CV) techniques were employed to assess the activity and stability of Co-Pt NPs/CNTs composites. Various Co-Pt NPs/CNTs composites were prepared by adjusting the ratio of Co-Pt. Through analysis of MOR performance, it was found that the Co₃Pt₁ NPs/CNTs composites exhibited superior catalytic activity with a mass activity of 4411 mA·mg⁻¹_Pt, which was 2.45 times higher than that of commercial Pt/C catalysts. This study introduced a novel approach for the preparation of high-performance Co-Pt bimetallic nanoparticles catalysts.

In this work, the role of a high boiling point green solvent additive Diphenyl ether (DPE) in device recombination processes in organic solar cell, fabricated using ultrasonic spray coating method is investigated. Without DPE and with 2.4 % DPE, the device series resistance was high of the order of 10⁴ Ω. With 0.3 %, 0.6 %, 1.2 % DPE, series resistance was less. Transient studies show that, for these contents, the rise and decay times of photocurrent was less than 5 µs. For 0.3 % DPE, nearly 3/4th photovoltage decayed with 51.4 µs lifetime and the remaining decays with 4.6 µs lifetime. With higher DPE content (1.2 %), 97 % photovoltage decay was with a longer lifetime 46.1 µs, and remaining with 1.6 µs. With further more DPE content (2.4 %), only 1 % TPV decays with shorter lifetime of 11.6 µs and 99 % decay is in longer time scale of 672 µs. In addition, a longer lifetime of over 1000 µs was also observed for this case, indicating the presence of deep traps, in addition to the shallow traps and bimolecular recombination. Morphology studies show that for 0 % and 0.3 % DPE content, stacked structure of droplets was formed in the film, but with 0.6 % and higher content, the progressively impinging droplets intermix with each other, providing more time for the film to dry. It was shown that the contribution of trap assisted recombination for varying DPE content was due to disordered PTB7 or PC₇₁BM phases, indicating a competition between PTB7 aggregation and PC₇₁BM dispersion in the coated film.

Hyperphosphorescent organic light-emitting diodes (HPOLEDs) are drawing increased attention, as the efficient Förster resonance energy transfer (FRET) from phosphorescent sensitizer to the narrowband fluorescent terminal emitter may give improved performances. In this work, we reported a class of Ir(III) phosphors based on the di-trifluoromethyl (CF₃) substituted imidazo[4,5-c]pyridin-2-ylidene chelates; i.e., (L_6F) and (L_6FB). The f-isomers exhibited efficient blue emission with peak max. 443 − 462 nm, while m-counterparts exhibited green emission between 501 – 512 nm in degassed toluene solution. The theoretical calculation indicates divergent MLCT, LLCT and ILCT contributions for distinctive isomers. OLEDs based on dopant m-Ir(L_6FB)₃ exhibited green luminescence at 505 nm, EQE_max of 20.3 % and CIE_x,y of (0.277, 0.462), while respective HPOLEDs with terminal emitter ν-DABNA showed blue hyperphosphorescence peaking at 468 nm, EQE_max of 25.2 %, CIE_x,y of (0.174, 0.204) and EQE of 22.7 % at 1000 cd·m^-2. Therefore, our finding demonstrates the effective conversion of the green electrophosphorescence to blue hyperphosphorescence via the rapid FRET process.