Transition-metal dichalcogenide (TMD) nanosheets have become an intensively investigated topic in the field of 2D nanomaterials, especially due to the direct semiconductor nature, and the broken inversion symmetry in the odd-layer number, of some of their family members. These properties make TMDs attractive for different technological applications such as photovoltaics, optoelectronics, valleytronics, and hydrogen evolution reactions. Among them, MoX 2 (X = S and Se) are turned to direct gap when their thickness is thinned down to monolayer, and thus, efforts toward obtaining large-scale monolayer TMDs are crucial for technological applications. Colloidal synthesis of TMDs has been developed in recent years, as it provides a cost-efficient and scalable way to produce few-layer TMDs having homogeneous size and thickness, yet obtaining a monolayer has proven challenging. Here, we present a method for the colloidal synthesis of mono-and few-layer MoX 2 (X = S and Se) using elemental chalcogenide and metal chloride as precursors. Using a synthesis with slow injection of the MoCl 5 precursor under a nitrogen atmosphere, and optimizing the synthesis parameters with a design of experiments approach, we obtained a MoX 2 sample with the semiconducting (1H) phase and optical band gaps of 1.96 eV for 1H−MoS 2 and 1.67 eV for 1H−MoSe 2 , respectively, consistent with a large monolayer yield in the ensemble. Both display photoluminescence at cryogenic and room temperature, paving the way for optical spectroscopy studies and photonic applications of colloidal TMD nanosheets.

In this paper we report on the use of an Ullmann-like aryl halide homocoupling reaction to obtain long Graphyne Molecular Wires (GY MWs) organized in dense, ordered arrays.

The growth of controlled 1D carbon-based nanostructures on metal surfaces is a multistep process whose path, activation energies, and intermediate metastable states strongly depend on the employed substrate. Whereas this process has been extensively studied on gold, less work has been dedicated to silver surfaces, which have a rather different catalytic activity. In this work, we present an experimental and theoretical investigation of the growth of poly-p-phenylene (PPP) chains and subsequent narrow graphene ribbons starting from 4,4″-dibromo-p-terphenyl molecular precursors deposited at the silver surface. By combing scanning tunneling microscopy (STM) imaging and density functional theory (DFT) simulations, we describe the molecular morphology and organization at different steps of the growth process and we discuss the stability and conversion of the encountered species on the basis of calculated thermodynamic quantities. Unlike the case of gold, at the debromination step we observe the appearance of organometallic molecules and chains, which can be explained by their negative formation energy in the presence of a silver adatom reservoir. At the dehydrogenation temperature, the persistence of intercalated Br atoms hinders the formation of well-structured graphene ribbons, which are instead observed on gold, leading only to a partial lateral coupling of the PPP chains. We numerically derive very different activation energies for Br desorption from the Ag and Au surfaces, thereby confirming the importance of this process in defining the kinetics of the formation of molecular chains and graphene ribbons on different metal surfaces.

This work is focused on the structural control of graphene nanoribbons (GNRs) and intermediate polymeric wires [poly­(p-phenylene), PPP] during their thermoactivated bottom-up synthesis from room temperature to 480 °C. The first step of the synthesis relies on the Ullmann coupling between 4,4″-dibromo-p-terphenyl (DBTP) molecular precursor units that lead to PPP wires in the temperature range between 170 and 200 °C. Thermal annealing at higher temperatures (360–480 °C) triggers the PPP lateral fusion to yield GNRs. We systematically studied the deposition of DBTP on the three main low-Miller-index gold surfaces, i.e., Au(100), Au(110), and Au(111), to elucidate the templating effects of such surfaces due to the pronounced anisotropy of their reconstructions via a multitechnique approach (scanning tunneling microscopy, X-ray photoelectron spectroscopy, and low-energy electron diffraction). The best results are obtained on Au(100) in terms of (i) GNR length (up to 80 nm), (ii) narrow width distribution (only 6- and 9-GNRs), (iii) long-range order, and (iv) excellent alignment along the reconstruction. Au(111) produces longer GNRs than Au(100) but poorer molecular ordering. Concerning PPP wires, they are stable within a wide temperature range and exhibit an interesting improvement of the long-range order with increasing temperature on Au(100), but the best overall organization and unidirectionality have been achieved on Au(110).

Prostate malignancy represents the second leading cause of cancer-specific death among the male population worldwide. Herein, enhanced intracellular magnetic fluid hyperthermia is applied in vitro 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.e., trimagnetic nanoparticles - TMNPs) with significant magnetothermal conversion following an exchange coupling effect to an external alternating magnetic field (AMF). The functional properties of the best candidate in terms of heating efficiency (i.e., Fe3O4@Mn0.5Zn0.5Fe2O4@CoFe2O4) were exploited following surface decoration with PCa cell membranes (CM) and/or LN1 cell-penetrating peptide (CPP). We demonstrated that the combination of biomimetic dual CM-CPP targeting and AMF responsiveness significantly induces caspase 9-mediated apoptosis of PCa cells. Furthermore, a downregulation of the cell cycle progression markers and a decrease of the migration rate in surviving cells were observed in response to the TMNP-assisted magnetic hyperthermia, suggesting a reduction in cancer cell aggressiveness.