Highly Emissive Colloidal Nanocrystals of a "2.5-Dimensional" Monomethylhydrazinium Lead Bromide.

The ability to control materials at the nanoscale has advanced optoelectronic devices, such as LEDs, displays, and quantum light sources. A new frontier is controlling exciton properties beyond quantum size confinement, achieved through single monolayer heterostructures. In the prototypical example of transition metal dichalcogenide heterostructures and moiré superlattices, excitons with long lifetimes, strong binding energies, and tunable dipole moments have been demonstrated and are ideal for optoelectronics and quantum applications.

Structural and Optical Characterization of Reaction Intermediates during Fast Chiral Nanoparticle Growth.

As nanoparticle morphologies produced by seeded growth expand in number and complexity, tracking their evolution during growth is increasingly important to achieving a mechanistic understanding. However, fast reactions such as chiral growth, in which morphologies change within seconds, remain challenging to monitor at the relevant time scale. We introduce a method based on fast addition of the reducing agent NaBH, enabling interruption of gold nanoparticle growth, as well as access to reaction intermediates for morphological and optical investigations.

Transforming achiral semiconductors into chiral domains with exceptional circular dichroism.

Highly concentrated solutions of asymmetric semiconductor magic-sized clusters (MSCs) of cadmium sulfide, cadmium selenide, and cadmium telluride were directed through a controlled drying meniscus front, resulting in the formation of chiral MSC assemblies. This process aligned their transition dipole moments and produced chiroptic films with exceptionally strong circular dichroism. -factors reached magnitudes as high as 1.

Synthesis and Advanced NMR Characterization of Ordered 3D Reticular Materials with PolySilicate Nodes and Hydrophobic OrganoSilicone Linkers.

This work describes the synthesis of ordered 3D siloxane-silsesquioxane reticular materials with silicate D4R cubes (SiO), harvested from a sacrificial tetrabutylammonium cyclosilicate hydrate (TBA-CySH) precursor, interlinked with octyl and dicyclopentyl (Cp) hydrocarbon functionalities in a one-step synthesis with organodichlorosilanes. Advanced solid-state NMR spectroscopy allowed us to unravel the molecular order of the nodes and their interconnection by the silicone linkers. In the case of octyl-methyl silicone linkers, changing the silane-to-silicate ratio in the synthesis allowed for tuning the length of the linker between the nodes.

Effective Utilization of Nanoporosity and Surface Area Guides Electrosynthesis over Soft-Landed Copper Oxide Catalyst Layers.

Porous nanomaterials find wide-ranging applications in modern medicine, optoelectronics, and catalysis, playing a key role in today's effort to build an electrified, sustainable future. Accurate in situ quantification of their structural and surface properties is required to model their performance and improve their design. In this article, we demonstrate how to assess the porosity, surface area and utilization of a model nanoporous soft-landed copper oxide catalyst layer/carbon interface, which is otherwise difficult to resolve using physisorption or capacitance-based methods.

Phosphorus Oxidation Controls Epitaxial Shell Growth in InP/ZnSe Quantum Dots.

InP/ZnSe/ZnS core/shell/shell quantum dots are the most investigated quantum dot material for commercial applications involving visible light emission. The inner InP/ZnSe interface is complex since it is not charge balanced, and the InP surface is prone to oxidation. The role of oxidative defects at this interface has remained a topic of debate, with conflicting reports of both detrimental and beneficial effects on the quantum dot properties.

Au@TiO Core-Shell Nanoparticles with Nanometer-Controlled Shell Thickness for Balancing Stability and Field Enhancement in Plasmon-Enhanced Photocatalysis.

Plasmonic core-shell nanostructures can make photocatalysis more efficient for several reasons. The shell imparts stability to the nanoparticles, light absorption is expanded, and electron-hole pairs can be separated more effectively, thus reducing recombination losses. The synthesis of metal@TiO core-shell nanoparticles with nanometer control over the shell thickness and understanding its effect on the resulting photocatalytic efficiency still remains challenging.

Additive-Free Synthesis of (Chiral) Gold Bipyramids from Pentatwinned Nanorods.

The production of colloidal metal nanostructures with complex geometries usually involves shape-directing additives, such as metal ions or thiols, which stabilize high-index facets. These additives may however affect the nanoparticles' surface chemistry, hindering applications, e.g.

Self-Matching Assembly of Chiral Gold Nanoparticles Leads to High Optical Asymmetry and Sensitive Detection of Adenosine Triphosphate.

To achieve chiral amplification, life uses small chiral molecules as building blocks to construct hierarchical chiral architectures that can realize advanced physiological functions. Inspired by the chiral amplification strategy of nature, we herein demonstrate that the chiral assembly of chiral gold nanorods (GNRs) leads to enhanced optical asymmetry factors (-factors), up to 0.24.

Pentatwinned AuAg Nanorattles with Tailored Plasmonic Properties for Near-Infrared Applications.

Noble metal nanoparticles, particularly gold and silver nanoparticles, have garnered significant attention due to their ability to manipulate light at the nanoscale through their localized surface plasmon resonance (LSPR). While their LSPRs below 1100 nm were extensively exploited in a wide range of applications, their potential in the near-infrared (NIR) region, crucial for optical communication and sensing, remains relatively underexplored. One primary reason is likely the limited strategies available to obtain highly stable plasmonic nanoparticles with tailored optical properties in the NIR region.

Investigation of the Octahedral Network Structure in Formamidinium Lead Bromide Nanocrystals by Low-Dose Scanning Transmission Electron Microscopy.

Metal halide perovskites (MHP) are highly promising semiconductors. In this study, we focus on FAPbBr nanocrystals, which are of great interest for green light-emitting diodes. Structural parameters significantly impact the properties of MHPs and are linked to phase instability, which hampers long-term applications.

Functionalization of three-dimensional epitaxial graphene with metal nanoparticles.

We demonstrate the first successful functionalization of epitaxial three-dimensional graphene with metal nanoparticles. The functionalization is obtained by immersing three-dimensional graphene in a nanoparticle colloidal solution. This method is versatile and demonstrated here for gold and palladium, but can be extended to other types of nanoparticles.

Quantitative 3D structural analysis of small colloidal assemblies under native conditions by liquid-cell fast electron tomography.

Electron tomography has become a commonly used tool to investigate the three-dimensional (3D) structure of nanomaterials, including colloidal nanoparticle assemblies. However, electron microscopy is typically done under high-vacuum conditions, requiring sample preparation for assemblies obtained by wet colloid chemistry methods. This involves solvent evaporation and deposition on a solid support, which consistently alters the nanoparticle organization.

Rashba-Type Band Splitting Effect in 2D (PEA)PbI Perovskites and Its Impact on Exciton-Phonon Coupling.

Despite a few recent reports on Rashba effects in two-dimensional (2D) Ruddlesden-Popper (RP) hybrid perovskites, the precise role of organic spacer cations in influencing Rashba band splitting remains unclear. Here, using a combination of temperature-dependent two-photon photoluminescence (2PPL) and time-resolved photoluminescence spectroscopy, alongside density functional theory (DFT) calculations, we contribute to significant insights into the Rashba band splitting found for 2D RP hybrid perovskites. The results demonstrate that the polarity of the organic spacer cation is crucial in inducing structural distortions that lead to Rashba-type band splitting.

Organic Molecular Glues to Design Three-Dimensional Cubic Nano-assemblies of Magnetic Nanoparticles.

Self-assembled magnetic nanoparticles offer next-generation materials that allow harnessing of their physicochemical properties for many applications. However, how three-dimensional nanoassemblies of magnetic nanoparticles can be synthesized in one-pot synthesis without excessive postsynthesis processes is still a bottleneck. Here, we propose a panel of small organic molecules that glue nanoparticle crystallites during the growth of particles to form large nanoassembled nanoparticles (NANs).

A robust Fe-based heterogeneous photocatalyst for the visible-light-mediated selective reduction of an impure CO stream.

The transformation of CO into value-added products from an impure CO stream, such as flue gas or exhaust gas, directly contributes to the principle of carbon capture and utilization (CCU). Thus, we have developed a robust iron-based heterogeneous photocatalyst that can convert the exhaust gas from the car into CO with an exceptional production rate of 145 μmol g h. We characterized this photocatalyst by PXRD, XPS, ssNMR, EXAFS, XANES, HR-TEM, and further provided mechanistic experiments, and multi-scale/level computational studies.

Defect Engineering of MoTe via Thiol Treatment for Type III van der Waals Heterojunction Phototransistor.

Molybdenum ditelluride (MoTe) nanosheets have displayed intriguing physicochemical properties and opto-electric characteristics as a result of their tunable and small band gap ( ∼ 1 eV), facilitating concurrent electron and hole transport. Despite the numerous efforts devoted to the development of p-type MoTe field-effect transistors (FETs), the presence of tellurium (Te) point vacancies has caused serious reliability issues. Here, we overcome this major limitation by treating the MoTe surface with thiolated molecules to heal Te vacancies.

Direct visualization of ligands on gold nanoparticles in a liquid environment.

The interactions between gold nanoparticles, their surface ligands and the solvent critically influence the properties of these nanoparticles. Although spectroscopic and scattering techniques have been used to investigate their ensemble structure, a comprehensive understanding of these processes at the nanoscale remains challenging. Electron microscopy makes it possible to characterize the local structure and composition but is limited by insufficient contrast, electron beam sensitivity and the requirement for ultrahigh-vacuum conditions, which prevent the investigation of dynamic aspects.

CsBiBr nanoparticles decorated CN nanotubes composite photocatalyst for highly selective oxidation of benzylic alcohol.

Solar-light driven oxidation of benzylic alcohols over photocatalysts endows significant prospects in value-added organics evolution owing to its facile, inexpensive and sustainable process. However, the unsatisfactory performance of actual photocatalysts due to the inefficient charge separation, low photoredox potential and sluggish surface reaction impedes the practical application of this process. Herein, we developed an innovative Z-Scheme CsBiBr nanoparticles@porous CN tubes (CBB-NP@P-tube-CN) heterojunction photocatalyst for highly selective benzyl alcohol oxidation.

Scaling-Up Microwave-Assisted Synthesis of Highly Defective Pd@UiO-66-NH Catalysts for Selective Olefin Hydrogenation under Ambient Conditions.

The need to develop green and cost-effective industrial catalytic processes has led to growing interest in preparing more robust, efficient, and selective heterogeneous catalysts at a large scale. In this regard, microwave-assisted synthesis is a fast method for fabricating heterogeneous catalysts (including metal oxides, zeolites, metal-organic frameworks, and supported metal nanoparticles) with enhanced catalytic properties, enabling synthesis scale-up. Herein, the synthesis of nanosized UiO-66-NH was optimized via a microwave-assisted hydrothermal method to obtain defective matrices essential for the stabilization of metal nanoparticles, promoting catalytically active sites for hydrogenation reactions (760 kg·m·day space time yield, STY).

High-Throughput Morphological Chirality Quantification of Twisted and Wrinkled Gold Nanorods.

Chirality in gold nanostructures offers an exciting opportunity to tune their differential optical response to left- and right-handed circularly polarized light, as well as their interactions with biomolecules and living matter. However, tuning and understanding such interactions demands quantification of the structural features that are responsible for the chiral behavior. Electron tomography (ET) enables structural characterization at the single-particle level and has been used to quantify the helicity of complex chiral nanorods.

Sampling Real-Time Atomic Dynamics in Metal Nanoparticles by Combining Experiments, Simulations, and Machine Learning.

Even at low temperatures, metal nanoparticles (NPs) possess atomic dynamics that are key for their properties but challenging to elucidate. Recent experimental advances allow obtaining atomic-resolution snapshots of the NPs in realistic regimes, but data acquisition limitations hinder the experimental reconstruction of the atomic dynamics present within them. Molecular simulations have the advantage that these allow directly tracking the motion of atoms over time.