Scalability Of Synthesis Research Articles

Biomimetic Synthesis of PANI/Graphitic Oxidized Carbon Nitride for Supercapacitor Applications.

Polyaniline (PANI) composites have gained momentum as supercapacitive materials due to their high energy density and power density. However, some drawbacks in their performance remain, such as the low stability after hundreds of charge-discharge cycles and limitations in the synthesis scalability. Herein, we report for the first time PANI-Graphitic oxidized carbon nitride composites as potential supercapacitor material. The biomimetic polymerization of aniline assisted by hematin, supported by phosphorous and oxygen-modified carbon nitrides (g-POCN and g-OCN, respectively), achieved up to 89% yield. The obtained PAI/g-POCN and PANI/g-OCN show enhanced electrochemical properties, such as conductivity of up to 0.0375 S/cm, specific capacitances (Cs) of up to 294 F/g (at high current densities, 5 A/g) and a stable operation after 500 charge-discharge cycles (at 3 A/g). In contrast, the biomimetic synthesis of Free PANI, assisted by stabilized hematin in cosolvents, exhibited lower performance properties (65%). Due to their structural differences, the electrochemical properties of Free PANI (conductivity of 0.0045 S/cm and Cs of up to 82 F/g at 5 A/g) were lower than those of nanostructured PANI/g-POCN and g-OCN supports, which provide stability and improve the properties of biomimetically synthesized PANI. This work reveals the biomimetic synthesis of PANI, assisted by hematin supported by modified carbon nitrides, as a promising strategy to produce nanostructured supercapacitors with high performance.

Spray‐Stencil Lithography Enabled Large‐Scale Fabrication of Multispectral Colloidal Quantum‐Dot Infrared Detectors

AbstractInfrared HgTe colloidal quantum dots (CQDs) are attracting great interest due to their synthesis scalability, mechanical flexibility, wide spectrum tunability, and excellent photoelectric properties. However, traditional HgTe CQD infrared detector fabrication methods such as drop casting and spin coating cannot achieve spatial control of patterned CQD films, which limits their sensing range to just single waveband and greatly hinders the realization of pixelated or multispectral CQD detectors. In this paper, an efficient spray‐stencil lithography technique is demonstrated for the scalable fabrication of multichannel HgTe CQD infrared detectors that can respond to different spectral ranges. Uniform and smooth CQD films can be deposited on rigid, flexible, and curved substrates up to 4 inch wafer. Both photoconductive and photovoltaic infrared HgTe CQD detectors are fabricated with peak D* above 1011 Jones across short‐wave and mid‐wave regions and show infrared imaging with noise equivalent temperature difference down to 26.7 mK. Flexible multispectral detectors with six channels are fabricated by the proposed spray‐stencil lithography method, and experimentally demonstrate spectral sensing and chemical analysis capability. It is believed that the proposed fabrication method provides a reliable scheme for the production of high‐performance multispectral CQD infrared detector arrays.

Scalable Construction of Hollow Multishell Co3O4 with Mitigated Interface Reconstruction for Efficient Lithium Storage

AbstractTo meet the growing needs for high‐capacity and/or high‐power energy storage systems, designing high‐performance lithium storage materials beyond traditional graphite anodes are crucial for lithium‐ion batteries. Cobalt oxide (Co3O4) as a potential anode material is proved to own a high theoretical capacity, but its practical application is always limited by the conflict between performance comprehensiveness and synthesis scalability. Herein, a uniform hollow multishell Co3O4 with high specific surface area is designed via a simple and scalable route based on inhomogeneous contraction. The mean diameter of precursor and inner structure are influenced by hydrothermal reaction time. Owing to the unique structure, the material exhibits high electrochemical performance for lithium storage. The as‐prepared hollow sphere delivers a high specific capacity of 1012 mAh g−1 at a current density of 445 mA g−1 even after 200 cycles. Moreover, the synthetic strategy is readily extendable for accurate construction of other desired energy storage materials.

Roller-Induced Bundling of Long Silver Nanowire Networks for Strong Interfacial Adhesion, Highly Flexible, Transparent Conductive Electrodes

Silver nanowires (AgNWs) have been the most promising electrode materials for fabrication of flexible transparent touch panel, displays and many other electronics because of their excellent electrical properties, cost effectiveness, synthesis scalability, and suitability for mass production. Although a few literature reports have described the use of short Ag NWs in fabrication of randomly oriented Ag NW network-based electrode, their electrical conductivities are still far lower than that of Ag films. So far, no any literature report was able to provide any simple solution to fabrication of large-area and mass-manufactural ability to address the issues, such as, conductivity, transparency, electrical current withstand, bending stability, and interfacial adhesion. In the current work, we provide a simple solution to conquer the above-mentioned challenges, and report the development of long Ag NW bundle network electrodes on large area PET films that were coated, aligned, and bundled quickly and simply using a steel roller. Our developed AgNWs-bundle networks had superior performance in optoelectronic properties (sheet resistance 5.8 Ω sq−1; optical transmittance 89% at 550 nm wavelength), electrical current withstand up to 500 mA, and bending stability over 5000 bending cycles, and strong interfacial adhesion.

Distinct Chemical and Physical Properties of Janus Nanosheets.

Janus particles have recently garnered significant attention for their distinct properties compared to particles that are homogeneously functionalized. Moreover, high aspect ratio Janus particles that are rod-like or planar (i.e., nanosheets) are especially intriguing considering their interfacial properties as well as their ability to assemble into higher order and hybrid structures. To date, major challenges facing the exploration and utilization of 2D Janus particles are scalability of synthesis, characterization of tailored chemical functionalization, and ability to introduce a diverse set of functionalities. Herein, a facile method to access Janus 2D graphene oxide (GO) nanosheets by combining a Pickering-type emulsion and grafting-from polymerization via ATRP is reported. Janus GO nanosheets bearing PMMA on one face as well as the symmetrically functionalized analogue are prepared, and the chemical, thermal, structural, surface, and interfacial properties of these materials are characterized. Time-of-flight secondary ion mass spectrometry coupled with Langmuir-Blodgett films is shown to be an ideal route to conclusively establish asymmetric functionalization of 2D materials. This work not only provides a facile route for the preparation of Janus nanosheets but also demonstrates the direct visualization of polymer grown from the surface of GO.

Development of a High-Performance Donor–Acceptor Conjugated Polymer: Synergy in Materials and Device Optimization

The development of a high-performance polymer PBDT-BT for bulk heterojunction solar cell devices is summarized. The polymer was first synthesized by Stille polycondensation, and solar cell devices in conventional geometry were optimized through the use of a lithium salt cathode interlayer reaching 6% power conversion efficiency. Improvements were made to the synthesis of the polymer using Suzuki polycondensation giving high-molecular-weight material in the Mn = 100 kg/mol range. Further device optimization in inverted geometry gave power conversion efficiency of over 9%. The synthesis scalability as well as the batch-to-batch reproducibility of the polymer were extensively investigated.

Green Synthesis of Robust, Biocompatible Silver Nanoparticles Using Garlic Extract.

This paper details a facile approach for the synthesis of stable and monodisperse silver nanoparticles performed at ambient/low temperature where Allium sativum (garlic) extract functions as the silver salt reducing agent during nanoparticle synthesis as well as the post-synthesis stabilizing ligands. Varying the synthesis conditions provides control of particle size, size-distribution, and kinetics of particle formation. Infrared spectroscopy, energy dispersive x-ray chemical analysis, and high performance liquid chromatography indicated that the carbohydrates present in the garlic extract are the most likely nanoparticle stabilizing chemistry. The synthesized silver nanoparticles also demonstrate potential for biomeical applications, owing to the 1) enhanced stability in biological media, 2) resistance to oxidation by the addition of H2O2, 3) ease and scalability of synthesis, and 4) lack of harsh chemicals required for synthesis. Cytotoxicity assays indicated no decrease in cellular proliferation for vascular smooth muscle cells and 3T3 fibroblasts at a concentration of 25 μg/ml, confirming that garlic extract prepared silver nanoparticles are ideal candidates for future experimentation and implementation into biomedical applications.