Heterostructures via a Solution-Based Anion Exchange in Microcrystalline 2D Layered Metal-Halide Perovskites.

Layered perovskites consist of stacks of inorganic semiconducting metal-halide octahedra lattices sandwiched between organic layers with typically dielectric behavior. The in-plane confinement of electrical carriers in such two-dimensional metal halide perovskites drives a large range of appealing electronic properties, such as strong exciton binding, anisotropic charge diffusion, and polarization-directionality. Heterostructures provide additional control on carrier diffusion and localization, and in-plane heterojunctions are interesting because of the associated high charge mobility.

Mapping emission heterogeneity in layered halide perovskites using cathodoluminescence.

Recent advancements in the fabrication of layered halide perovskites and their subsequent modification for optoelectronic applications have ushered in a need for innovative characterisation techniques. In particular, heterostructures containing multiple phases and consequently featuring spatially defined optoelectronic properties are very challenging to study. Here, we adopt an approach centered on cathodoluminescence, complemented by scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy analysis.

Enhancing charge extraction in inverted perovskite solar cells contacts ultrathin graphene:fullerene composite interlayers.

Improving the perovskite/electron-transporting layer (ETL) interface is a crucial task to boost the performance of perovskite solar cells (PSCs). This is utterly fundamental in an inverted (p-i-n) configuration using fullerene-based ETLs. Here, we propose a scalable strategy to improve fullerene-based ETLs by incorporating high-quality few-layer graphene flakes (GFs), industrially produced through wet-jet milling exfoliation of graphite, into phenyl-C61-butyric acid methyl ester (PCBM).

Stable Sn-Based Hybrid Perovskite-Related Structures with Tunable Color Coordinates via Organic Cations in Low-Temperature Synthesis.

Organic-inorganic Pb-free layered perovskites are efficient broadband emitters and thus are promising materials for lighting applications. However, their synthetic protocols require a controlled atmosphere, high temperature, and long preparation time. This hinders the potential tunability of their emission through organic cations, as is instead common practice in Pb-based structures.

Cell-Membrane-Coated and Cell-Penetrating Peptide-Conjugated Trimagnetic Nanoparticles for Targeted Magnetic Hyperthermia of Prostate Cancer Cells.

Prostate malignancy represents the second leading cause of cancer-specific death among the male population worldwide. Herein, enhanced intracellular magnetic fluid hyperthermia is applied to treat prostate cancer (PCa) cells with minimum invasiveness and toxicity and highly specific targeting. We designed and optimized novel shape-anisotropic magnetic core-shell-shell nanoparticles (i.

Biocomposite Cryogels for Photothermal Decontamination of Water.

An effective and sustainable approach to deal with the scarcity of freshwater is interfacial solar-driven evaporation. Nonetheless, some serious challenges for photothermal materials still need to be considered, such as long-term stability in harsh environments, eco-friendly materials, and cost-effective and simple fabrication processes. Keeping these points in mind, we present a multifunctional silver-coated vegetable waste biocomposite cryogel that not only exhibits high porosity and enhanced wettability and stability but also possesses high light absorption and low thermal conductivity favorable for heat localization, solar steam generation, and efficient photothermal conversion efficiency.

2D Materials-Based Electrochemical Triboelectric Nanogenerators.

The integration of 2D materials in triboelectric nanogenerators (TENGs) is known to increase the mechanical-to-electrical power conversion efficiency. 2D materials are used in TENGs with multiple roles as triboelectric material, charge-trapping fillers, or as electrodes. Here, novel TENGs based on few-layers graphene (FLG) electrodes and stable gel electrolytes composed of liquid phase exfoliated 2D-transition metal dichalcogenides and polyvinyl alcohol are developed.

Robust, High-Performing Maize-Perovskite-Based Solar Cells with Improved Stability.

Herein, we focus on improving the long-term chemical and thermomechanical stability of perovskite solar cells (PSCs), two major challenges currently limiting their commercial deployment. Our strategy incorporates a long-chain starch polymer into the perovskite precursor. The starch polymer confers multiple beneficial effects by forming hydrogen bonds with the methylammonium iodide precursor, templating perovskite growth that results in a compact and homogeneous film deposited in a simple one-step coating (antisolvent-free).

3D printed silicon-few layer graphene anode for advanced Li-ion batteries.

The printing of three-dimensional (3D) porous electrodes for Li-ion batteries is considered a key driver for the design and realization of advanced energy storage systems. While different 3D printing techniques offer great potential to design and develop 3D architectures, several factors need to be addressed to print 3D electrodes, maintaining an optimal trade-off between electrochemical and mechanical performances. Herein, we report the first demonstration of 3D printed Si-based electrodes fabricated using a simple and cost-effective fused deposition modelling (FDM) method, and implemented as anodes in Li-ion batteries.

Phase-Selective Synthesis of Anatase and Rutile TiO Nanocrystals and Their Impacts on Grapevine Leaves: Accumulation of Mineral Nutrients and Triggering the Plant Defense.

Titanium dioxide nanocrystals (TiO NCs), through their photocatalytic activity, are able to generate charge carriers and induce the formation of various reactive oxygen species (ROS) in the presence of O and HO. This special feature makes TiO an important and promising material in several industrial applications. Under appropriate antioxidant balancing, the presence of ROS is crucial in plant growth and development, therefore, the regulated ROS production through the photocatalytic activity of TiO NCs may be also exploited in the agricultural sector.

The Reactivity of CsPbBr Nanocrystals toward Acid/Base Ligands.

The interaction of lead bromide perovskite nanocrystals with charged ligands, such as salts, zwitterions, or acid-base pairs, has been extensively documented over the past few years. On the other hand, little is known about the reactivity of perovskite nanocrystals toward neutral ligands. To fill this gap, in this work we study the interaction of CsPbBr nanocrystals passivated with didodecyldimethylammonium bromide (DDABr) toward a series of exogenous acid/base ligands using a combined computational and experimental approach.

Topochemical Transformation of Two-Dimensional VSe into Metallic Nonlayered VO for Water Splitting Reactions in Acidic and Alkaline Media.

The engineering of the structural and morphological properties of nanomaterials is a fundamental aspect to attain desired performance in energy storage/conversion systems and multifunctional composites. We report the synthesis of room temperature-stable metallic rutile VO (VO (R)) nanosheets by topochemically transforming liquid-phase exfoliated VSe in a reductive Ar-H atmosphere. The as-produced VO (R) represents an example of two-dimensional (2D) nonlayered materials, whose bulk counterparts do not have a layered structure composed by layers held together by van der Waals force or electrostatic forces between charged layers and counterbalancing ions amid them.

Pectin-cellulose nanocrystal biocomposites: Tuning of physical properties and biodegradability.

The fabrication of pectin-cellulose nanocrystal (CNC) biocomposites has been systematically investigated by blending both polysaccharides at different relative concentrations. Circular free-standing films with a diameter of 9 cm were prepared by simple solution of these carbohydrates in water followed by drop-casting and solvent evaporation. The addition of pectin allows to finely tune the properties of the biocomposites.

Alloy CsCd Pb Br Perovskite Nanocrystals: The Role of Surface Passivation in Preserving Composition and Blue Emission.

Various strategies have been proposed to engineer the band gap of metal halide perovskite nanocrystals (NCs) while preserving their structure and composition and thus ensuring spectral stability of the emission color. An aspect that has only been marginally investigated is how the type of surface passivation influences the structural/color stability of AMX perovskite NCs composed of two different M cations. Here, we report the synthesis of blue-emitting Cs-oleate capped CsCd Pb Br NCs, which exhibit a cubic perovskite phase containing Cd-rich domains of Ruddlesden-Popper phases (RP phases).

Hybrid Magnetic Nanovectors Promote Selective Glioblastoma Cell Death through a Combined Effect of Lysosomal Membrane Permeabilization and Chemotherapy.

Glioblastoma multiforme is the most aggressive brain tumor, due to its high invasiveness and genetic heterogeneity. Moreover, the blood-brain barrier prevents many drugs from reaching a therapeutic concentration at the tumor site, and most of the chemotherapeutics lack in specificity toward cancer cells, accumulating in both healthy and diseased tissues, with severe side effects. Here, we present in vitro investigations on lipid-based nanovectors encapsulating a drug, nutlin-3a, and superparamagnetic iron oxide nanoparticles, to combine the proapoptotic action of the drug and the hyperthermia mediated by superparamagnetic iron oxide nanoparticles stimulated with an alternating magnetic field.

Homotypic targeting and drug delivery in glioblastoma cells through cell membrane-coated boron nitride nanotubes.

Glioblastoma multiforme (GBM) is one of the most aggressive types of brain cancer, characterized by rapid progression, resistance to treatments, and low survival rates; the development of a targeted treatment for this disease is still today an unattained objective. Among the different strategies developed in the latest few years for the targeted delivery of nanotherapeutics, homotypic membrane-membrane recognition is one of the most promising and efficient. In this work, we present an innovative drug-loaded nanocarrier with improved targeting properties based on the homotypic recognition of GBM cells.

Melamine Foams Decorated with In-Situ Synthesized Gold and Palladium Nanoparticles.

A versatile and straightforward route to produce polymer foams with functional surface through their decoration with gold and palladium nanoparticles is proposed. Melamine foams, used as polymeric porous substrates, are first covered with a uniform coating of polydimethylsiloxane, thin enough to assure the preservation of their original porous structure. The polydimethylsiloxane layer allows the facile in-situ formation of metallic Au and Pd nanoparticles with sizes of tens of nanometers directly on the surface of the struts of the foam by the direct immersion of the foams into gold or palladium precursor solutions.

Thiocyanate-Treated Perovskite-Nanocrystal-Based Light-Emitting Diodes with Insight in Efficiency Roll-Off.

Light emitting diodes (LED) based on halide perovskite nanocrystals (NC) have received widespread attention in recent years. In particular, LEDs based on CsPbBr NCs were the object of special interest. Here, we report for the first time green LED based on CsPbBr NCs treated with ammonium thiocyanate solution before purification with polar solvent.

Antibacterial Melamine Foams Decorated with in Situ Synthesized Silver Nanoparticles.

A new and straightforward single-step route to decorate melamine foams with silver nanoparticles (ME/Ag) is proposed. Uniform coatings of silver nanoparticles with diameters less than 10 nm are formed in situ directly on the struts surface of the foams, after their dipping in an AgNO solution. We prove that the nanoparticles are stably adhered on the foams, and that their amount can be directly controlled by the concentration of the AgNO solution and the dipping time.

Synthesis of Copper Nanoparticles in Ethylene Glycol by Chemical Reduction with Vanadium (+2) Salts.

Copper nanoparticles have been synthesized in ethylene glycol (EG) using copper sulphate as a precursor and vanadium sulfate as an atypical reductant being active at room temperature. We have described a technique for a relatively simple preparation of such a reagent, which has been electrolytically produced without using standard procedures requiring an inert atmosphere and a mercury cathode. Several stabilizing agents have been tested and cationic capping agents have been discarded owing to the formation of complex compounds with copper ions leading to insoluble phases contaminating the metallic nanoparticles.

Electrospun Fiber Pads of Cellulose Acetate and Essential Oils with Antimicrobial Activity.

The method of electrospinning was used to create nanofibers made of cellulose acetate (CA) and essential oils (EOs). CA polymer at 15% / was dissolved in acetone and then 1% or 5% / of EOs was added to the polymer solution. The utilized essential oils were rosemary and oregano oils.