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Abstract: Several nanostructures composed of fine ZnS nanoparticles was prepared at the air–water interface via reactions between Zn2+ and H2S under monolayers of 5,10,15,20-tetra-4-oxy(2-stearic acid) phenyl porphyrin (TSPP) at room temperature and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–vis and fluorescent spectroscopy. It was found that networks and round rings were formed under different conditions, and belts appear in the pores of the networks. After ripening at 60°C, the belts preserve with improved crystallinity of the nanoparticles. After treated at 300°C, the belts preserve, too. The formation of the rings at room temperature should be attributed to the templating effect of liquid films formed by TSPP molecules at the interface, the formation of the belts should be attributed to the attachment of the cubic zinc blende ZnS nanoparticles possibly under the direction of linear supramolecules of TSPP. [Copyright &y& Elsevier]

Abstract: One-dimensional (1D) silver oxide nanoparticle arrays were synthesized by illuminating the composite Langmuir–Blodgett monolayers of porphyrin derivatives/Ag+ and n-hexadecyl dihydrogen phosphate (n-HDP)/Ag+ deposited on carbon-coated copper grids with daylight and then exposing them to air. Transmission electron microscopy (TEM) observation shows that the nanoparticle size is around 3 nm, with the separation of about 2–3 nm. High-resolution TEM (HRTEM) investigation indicates that the particles are made up of Ag2O. Ag nanorods with the width of 15–35 nm and the length of several hundreds of nanometers were synthesized by irradiating the composite Langmuir monolayers of porphyrin derivatives/Ag+ and n-HDP/Ag+ by UV-light directly at the air/water interface at room temperature. HRTEM image and selected-area electron diffraction (SAED) pattern indicate that the nanorods are single crystals with the (110) face of the face-centered cubic (fcc) silver parallel to the air/water interface. The formation of the 1D arrays and the nanorods should be attributed to the templating effect of the linear supramolecules formed by porphyrin derivative or n-HDP molecules in Langmuir monolayers through non-covalent interactions. [Copyright &y& Elsevier]

Monolayer transition metal dichalcogenides (TMDs) have drawn significant attention for their potential applications in electronics and optoelectronics. To achieve consistent electronic properties and high device yield, uniform large monolayer crystals are crucial. In this report, we describe the growth of high-quality and uniform monolayer WSe2 film using chemical vapor deposition on polycrystalline Au substrates. This method allows for the fabrication of continuous large-area WSe2 film with large-size domains. Additionally, a novel transfer-free method is used to fabricate field-effect transistors (FETs) based on the as-grown WSe2. The exceptional metal/semiconductor interfaces achieved through this fabrication method result in monolayer WSe2 FETs with extraordinary electrical performance comparable to those with thermal deposition electrodes, with a high mobility of up to ≈62.95 cm2 V−1 s−1 at room temperature. In addition, the as-fabricated transfer-free devices can maintain their original performance after weeks without obvious device decay. The transfer-free WSe2-based photodetectors exhibit prominent photoresponse with a high photoresponsivity of ~1.7 × 104 A W−1 at Vds = 1 V and Vg = −60 V and a maximum detectivity value of ~1.2 × 1013 Jones. Our study presents a robust pathway for the growth of high-quality monolayer TMDs thin films and large-scale device fabrication. [ABSTRACT FROM AUTHOR]

Abstract: Regular one-dimensional (1D) parallel chains composed of CdS nanoparticles with cubic zinc blende crystal structure were prepared at the air/water interface via one-step synthesis and assembly process. These nanostructures were produced through an interfacial reaction between Cd2+ ions in the aqueous solution of cadmium acetate and H2S in the gaseous phase under Langmuir monolayers of 10,12-pentacosadiynoic acid (PDA). It was demonstrated that PDA molecules self-assembled into parallelly aligned linear supermolecules at the air/water interface with the aid of π–π interactions and acted as templates for the formation of the superstructures. The experimental conditions including temperature and reaction time have great influences on the superstructure formation and the parameters of the parallel chains. [Copyright &y& Elsevier]

Abstract: Silver dendritic nanostructures and nanoplates were prepared at the solid/liquid interfaces via electroless deposition. Langmuir monolayers of 5,10,15,20-tetra-4-oxy(2-stearic acid) phenyl porphyrin (TSPP) and arachidic acid (AA) were formed at the air/AgNO3 aqueous solution interface. These nanostructures were produced when carbon-coated copper grids were covered on the Langmuir monolayers at lower (<20°C) and higher (20–50°C) temperature, respectively, and the branches are composed of parallel aligned nanobelts with their (110) face parallel to the interface. The formation of the nanostructures should be attributed to the galvanic reduction of Ag+ ions by copper, the electronic conductivity of the carbon layer, the templating effect of the Langmuir monolayer, and the non-equilibrium growth and aggregation of silver nanoparticles at the interface. This is a convenient avenue to produce metal nanostructures. [Copyright &y& Elsevier]

Abstract: Molecular assemblies and nanoparticles of chiral coordination polymers composed of connector of K2PdCl4 and linkers of bisdentate binaphthyl-bis(amidopyridyl) (BNBAPy) ligands have been constructed at the air–water interface. The chiral S- and R-BNBAPy ligands showed similar surface pressure–area isotherms on the K2PdCl4 subphase surface, with the limited molecular area of about 1.2nm2, which suggested that the ligands were nearly parallel to the subphase surface. The X-ray photoelectron spectra for the Langmuir–Blodgett (LB) films of the coordination polymers revealed that the films were composed of Cl, C, Pd and N elements. These Pd-(R-/S-)BNBAPy coordination polymers formed round nanoparticles at the interface with average diameters of 15–20nm. It was found that the chirarity of ligands was almost remained in the LB films of Pd-(R-/S-)BNBAPy coordination polymers, indicating there was little influence on the orientation or arrangement of the ligand chiral center after the formation of their coordination polymer LB films. The present method could provide a facile way to construct chiral molecular and nanostructural materials. [Copyright &y& Elsevier]

Abstract: Ternary europium complexes were formed at the air–water interface mediated by monolayers of 4,4′-dinonyl-2,2′-dipyridyl (DNDPy) and 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine (MPTPy). A saturated Eu(TTA)3 (TTA: theonyltrifluoroacetone) aqueous solution was used as subphase, on the surface of which condensed DNDPy and MPTPy monolayers could be stabilized. The DNDPy-/MPTPy–Eu(TTA)3 layers were transferred onto either hydrophobic or hydrophilic substrate surfaces by Langmuir–Blodgett (LB) method. Fluorescence spectra showed several sharp peaks corresponding to Eu3+ emissions from 5D1 → 7F1 (535nm) and 5D0 → 7F0,1,2,3 (580, 595, 612 and 650nm). A relative stronger emission from 5D1 → 7F1 to that from 5D0 → 7F2 was recorded for the LB films of DNDPy–Eu(TTA)3 complex. Compared with that in solution, longer fluorescence lifetime was observed for the complexes in the LB films. [Copyright &y& Elsevier]