Monthly Archives: March 2024

Interfacial Activity of Janus Particle: Unity of Molecular Surfactant and Homogeneous Particle

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Interfacial Activity of Janus Particle: Unity of Molecular Surfactant and Homogeneous Particle

Janus particles, which combine the amphiphilicity of molecular surfactants and the Pickering effect of homogeneous particles, have gained significant attention in recent years. In this review, synthesis methods, stabilization mechanism and the applications in interfacial engineering of Janus particles are discussed.


Abstract

Janus particles with different compositions and properties segmented to different regions on the surface of one objector provide more opportunities for interfacial engineering. As a novel interfacial active material, Janus particles integrate the amphiphilic properties of molecular surfactants and the Pickering effect of homogeneous particles. In this research, the outstanding properties of Janus particles on various interfaces are examined from both theoretical and practical perspectives, and the advantages of Janus particles over molecular surfactants and homogeneous particle surfactants are analyzed. We believe that Janus particles are ideal tools for interface regulation and functionalization in the future.

Modulation of the Structure‐function Relationship of the “nano‐greenhouse effect” towards Optimized Supra‐photothermal Catalysis

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Modulation of the Structure-function Relationship of the “nano-greenhouse effect” towards Optimized Supra-photothermal Catalysis

The structure-function relationship of the “nano-greenhouse effect” was investigated in a prototypical Ni@SiO2 core-shell catalyst towards photothermal CO2 catalysis. This work deepens the understandings on the contributing factor of the “nano-greenhouse effect” towards enhanced photothermal conversion. It also provides insights on the design principles of an ideal photothermal catalyst in balancing heat management and mass transport processes.


Abstract

Photothermal catalytic CO2 hydrogenation holds great promise for relieving the global environment and energy crises. The “nano-greenhouse effect” has been recognized as a crucial strategy for improving the heat management capabilities of a photothermal catalyst by ameliorating the convective and radiative heat losses. Yet it remains unclear to what degree the respective heat transfer and mass transport efficiencies depend on the specific structures. Herein, the structure-function relationship of the “nano-greenhouse effect” was investigated and optimized in a prototypical Ni@SiO2 core-shell catalyst towards photothermal CO2 catalysis. Experimental and theoretical results indicate that modulation of the thickness and porosity of the SiO2 nanoshell leads to variations in both heat preservation and mass transport properties. This work deepens the understandings on the contributing factor of the “nano-greenhouse effect” towards enhanced photothermal conversion. It also provides insights on the design principles of an ideal photothermal catalyst in balancing heat management and mass transport processes.

High Performance Organic Solar Cells Prepared with Bi‐Triangular Pyramidal Organic Phosphonium Interface Material

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High Performance Organic Solar Cells Prepared with Bi-Triangular Pyramidal Organic Phosphonium Interface Material

Double-dipole bi-tetraphenylphosphonium bromide exhibits excellent cathode modification effect for organic solar cell, HOMO level down to −7.32 eV.


Abstract

Nowadays, amine containing electrode interface material destroy the non-fullerene acceptor becomes a hard nut to crack for organic solar cells. Developing water-soluble interface material which is no chemical reaction with non-fullerene acceptor is an important research theme. Here, we report two bi-triangular pyramidal electronic configuration organic-phosphonium bromides as non-amine cathode interfacial layer for fabricating high-efficiency stable organic solar cells. The power conversion efficiency (PCE) of inverted device structure with PBDB-T/ITIC as active layer is up to 11.58 % which is great larger than control device PCE (9.35 %). Same device structure with PM6/Y6 as active layer, the PCE is up to 15.26 % and also is dramatically higher than the referred device PCE 14.36 %. Meanwhile, the devices show greatly improved stability by organic-phosphonium bromide interlayer.

Nanoparticle‐Based Cryogels from Colloidal Aqueous Dispersion: Synthesis, Properties and Applications

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Nanoparticle-Based Cryogels from Colloidal Aqueous Dispersion: Synthesis, Properties and Applications

This review focuses on cryogels derived from inorganic nanocrystals, prepared using a simple and versatile method of freezing and freeze-drying an aqueous nanoparticle colloid. We explore how factors like freezing temperature and nanoparticle composition can influence the cryogel structure. We discuss the properties and applications, along with the challenges and future directions for this promising material.


Abstract

Cryogels have morphological features that make them interesting for several applications such as catalysis, sensing or tissue engineering. Their interconnected network and open porous structure, build up by primary particles (such as inorganic nanocrystals or polymers), provide these materials with unique physical properties and high specific surface areas. While the library of cryogels is endless, widely used in the polymer chemistry field, in this review we will summarize the structure and properties, applications and challenges of inorganic nanocrystal-based cryogels obtained by freezing and freeze-drying an aqueous nanoparticle colloid. This fast, easy and versatile gelation method will be outlined, along with the corresponding macro-, micro- and nano-structures and gel morphologies that can be obtained, for example, by changing the freezing temperature or by using one nanoparticle system or nanoparticle mixtures. Their applications towards electrocatalysis, photocatalysis and photoelectrochemical sensing will be highlighted, as well as the challenges and prospects of these materials.

Pd‐Catalyzed Oxidative C−H Arylation of (Poly)fluoroarenes with Aryl Pinacol Boronates and Experimental and Theoretical Studies of its Reaction Mechanism

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Pd-Catalyzed Oxidative C−H Arylation of (Poly)fluoroarenes with Aryl Pinacol Boronates and Experimental and Theoretical Studies of its Reaction Mechanism

A simple catalytic process for the C−H arylation of (poly)flluoroarenes with aryl pinacol boronates mediated by a Pd/Ag system without added ligand is reported. This reaction can be carried out in air, generating unsymmetric biaryl products in up to 98 % yield. DFT calculations indicate that the presence of an electron-rich aryl ligand at Pd(II) intermediate reduces the energy barrier for the CMD process with C6F5H to give [Pd(DMF)2(Ar)(C6F5)], and thus the desired cross-coupling product is obtained.


Abstract

We report the synergistic combination of Pd(OAc)2 and Ag2O for the oxidative C−H arylation of (poly)fluoroarenes with aryl pinacol boronates (Ar-Bpin) in DMF as the solvent. This procedure can be conducted easily in air, and without using additional ligands, to afford the fluorinated unsymmetrical biaryl products in up to 98 % yield. Experimental studies suggest that the formation of [PdL2(C6F5)2] in DMF as coordinating solvent does not take place under the reaction conditions as it is stable to reductive elimination and thus would deactivate the catalyst. Thus, the intermediate [Pd(DMF)2(ArF)(Ar)] must be formed selectively to give desired arylation products. DFT calculations predict a low barrier (5.87 kcal/mol) for the concerted metalation deprotonation (CMD) process between C6F5H and the Pd(II) species formed after transmetalation between the Pd(II)X2 complex and aryl-Bpin which forms a Pd-Arrich species. Thus a Pd(Arrich)(Arpoor) complex is generated selectively which undergoes reductive elimination to generate the unsymmetrical biaryl product.

Anodization as a scalable nanofabrication method to engineer mechanobactericidal nanostructures on complex geometries

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Anodization as a scalable nanofabrication method to engineer mechanobactericidal nanostructures on complex geometries

Disconnected nanotubular topography generated using electrochemical anodization in organic electrolytes demonstrates excellent mechanobactericidal effect, similar to nanopillars found on insect wings. The structures are mechanically robust and durable enough to sustain forces experienced in daily handling and can be generated even on complx 3D geometries, which commonly used top-down nanofabrication methods are incapable of.


Abstract

Bacterial contamination of implant surfaces is one of the primary causes of their failure, and this threat has been further exacerbated due to the emergence of drug-resistant bacteria. Nanostructured mechanobactericidal surfaces that neutralize bacteria via biophysical forces instead of traditional biochemical routes have emerged as a potential remedy against this issue. Here, we report on the bactericidal activity of titania nanotubes (TNTs) prepared by anodization, a well-established and scalable method. We investigate the differences in bacterial behavior between three different topographies and demonstrate the applicability of this technique on complex three-dimensional (3D) geometries. It was found that the metabolic activity of bacteria on such surfaces was lower, indicative of disturbed intracellular processes. The differences in deformations of the cell wall of Gram-negative and positive bacteria were investigated from electron micrographs Finally, nanoindentation experiments show that the nanotubular topography was durable enough against forces typically experienced in daily life and had minimal deformation under forces exerted by bacteria. Our observations highlight the potential of the anodization technique for fabricating mechanobactericidal surfaces for implants, devices, surgical instruments, and other surfaces in a healthcare setting in a cheap, scalable way.

Recent Advancements on Sustainable Electrochemical Water Splitting Hydrogen Energy Applications Based on Nanoscale Transition Metal Oxide (TMO) Substrates

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Recent Advancements on Sustainable Electrochemical Water Splitting Hydrogen Energy Applications Based on Nanoscale Transition Metal Oxide (TMO) Substrates

Nanoscale transition metal oxides (TMO) is a promising contender for generating clean and sustainable hydrogen production from water with exceptional efficiency using water splitting approach. This review article specifically examines the use of TMO as active catalysts and current generator with this technique. It discusses the crucial component that governs the regulation of catalytic activity due to large active surface area of nanoscale TMO. The ultimate goal with the evolution of nanoscale TMO substrate is to produce a clean energy sources from environmental available water for future research to achieve the cost-effective, efficient, and environmentally friendly hydrogen production using water splitting approach.


Abstract

The development of green hydrogen generation technologies is increasingly crucial to meeting the growing energy demand for sustainable and environmentally acceptable resources. Many obstacles in the advancement of electrodes prevented water electrolysis, long thought to be an eco-friendly method of producing hydrogen gas with no carbon emissions, from coming to fruition. Because of their great electrical conductivity, maximum supporting capacity, ease of modification in valence states, durability in hard environments, and high redox characteristics, transition metal oxides (TMOs) have recently captured a lot of interest as potential cathodes and anodes. Electrochemical water splitting is the subject of this investigation, namely the role of transition metal oxides as both active and supportive sites. It has suggested various approaches for the logical development of electrode materials based on TMOs. These include adjusting the electronic state, altering the surface structure to control its resistance to air and water, improving the flow of energy and matter, and ensuring the stability of the electrocatalyst in challenging conditions. In this comprehensive review, it has been covered the latest findings in electrocatalysis of the Oxygen Evolution Reaction (OER) and Hydrogen Evaluation Reaction (HER), as well as some of the specific difficulties, opportunities, and current research prospects in this field.

Reaction Mechanisms of Fe‐dependent Fatty Acid Decarboxylases

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The escalating demand for fossil fuels has raised environmental concerns, urging the exploration of biosynthetic pathways for renewable hydrocarbon fuels. Terminal alkenes (α-alkenes) emerge as "drop-in" compatible fuels and chemicals, holding the potential to replace traditional fossil fuels. Fatty acid decarboxylases present a promising route for converting fatty acids into α-alkenes, underscoring the imperative need for comprehending the catalytic mechanisms governing these enzymes in the quest for renewable biofuel production. The reported fatty acid decarboxylases entail the involvement of heme and non-heme iron cofactors in the redox process. In this review, we summarize the reaction mechanisms of four iron-dependent fatty acid decarboxylases (OleTJE, OleTPRN, UndA, and UndB), providing a critical analysis of the factors influencing chemical selectivity and catalytic performance.