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Semiconductor nanocrystals (NCs) are emerging luminescent materials with superior optical properties. However, the light-conversion application of NCs is restricted by reabsorption-induced fluorescent quenching. Here, a NC-NC Forster resonance energy transfer (FRET) system is developed by employing large CsPbBr3 NCs as donors and CdSe/CdS NCs as acceptors. The FRET systems using toluene and octadecene as solvents show decreases of 10% and 14%, respectively, in the integrated photoluminescence (PL) intensity, far below the reabsorption loss observed in concentrated CdSe/CdS NCs (>30%) at the same color purity. Notably, we demonstrate by transient absorption measurements that the styrene-mediated FRET system involves a Dexter energy transfer process, which enables the harvesting of triplet excitons and leads to an additional PL enhancement at system level by a maximum of 40% instead of fluorescence quenching. The remarkably improved light-conversion efficiency and antiquenching property make the proposed NC-NC system superior in light down-conversion applications.

Mesoporous ceria nanoparticles (MCNs) have many superiorities such as higher surface area and more active reaction sites over their solid counterparts. However, the correlation between their structure and catalytic activity is poorly understood due to the lack of methods to synthesize MCNs with variable and well-defined structure parameters. In this study, a MCNs synthesis platform featured with strong structure parameter tuning capacity was established to synthesize plenty of MCNs for exploring their structure-catalytic activity relationship. The platform was composed of Ce(NO3)3·6H2O precursor, trioctylphosphine oxide (TOPO) ligand, and ethanol and octadecene (ODE) solvent. Through altering ligand/precursor ratio, ligand-precursor addition manner and reaction temperature, three groups of MCNs, totally twelve nanoparticles, were synthesized on the platform. The structure parameters of the synthesized MCNs were collected, and their catalytic activities including oxygen storage capacity (OSC), oxidase mimetic activity and photocatalytic activity were evaluated. The MCNs demonstrated wide range of nanoparticle diameter (40–115 nm), pore diameter (2.09–4.17 nm), pore volume (0.20–0.40 cm3 g−1), surface area (119.2–202.8 m2 g−1), and crystallite size (8.8–9.95 nm). These parameters played different roles in controlling different catalytic reactions, where pore size and crystallite size determined the oxygen storage capacity (OSC), pore size regulated the enzyme mimetic activity, and surface area dominated the photocatalytic activity. This study provided important insights into the correlation between structure and catalytic activity of MCNs, which was critical to the fabrication of MCNs based catalytic reactions.

The fluorescent poly(maleic anhydride-alt-octadecene-arylmethoxypyridine) (PMAOA) and poly(maleic anhydride-alt-octadecene-arylchloropyridine) (PMAOB) polymers were synthesized and characterized by FTIR, 1H & 13C NMR spectroscopy. The thermal stability of polymers was measured by TGA-DTA in the range 100-700 ºC. The fluorescence properties of the synthesized PMAOA and PMAOB polymers were studied by UV-Vis spectroscopy and fluorescence spectra and showed notable report due to influence of pyridine grafted to the malelic anhydride ring derivatives. The fluorescent polymers, PMAOA and PMAOB shows high efficacy of antimicrobial activity against Candida albicans, Aspergillusniger, Staphylococcus aureus and Escherichia coli pathogens.

Summary Designing materials that combine surface superhydrophobicity, high surface areas, large and uniform pore sizes, and excellent stability is a very challenging area for synthetic chemists. Here, we demonstrate a bioinspired encapsulation-rearrangement strategy to construct superhydrophobic mesoporous metal-organic framework (MOF) systems by selectively modifying the external surface of an internal lattice-rearranged mesoporous MOF. The surface of a defective MOF with limited porosity named AlTz-53 is initially modified by hydrophobic alkyl chains through click reactions. Subsequently, the internal framework undergoes lattice rearrangement upon solvent desorption, leading to a significantly improved internal porosity and material crystallinity. Functionalizing the surface of AlTz-68 with octadecene (AlTz-68-C18) induces superhydrophobicity with a water contact angle of 173.6°. AlTz-68-C18 also exhibits one of the largest Brunauer-Emmett-Teller (BET) surface areas among all reported superhydrophobic framework materials. Furthermore, we illustrate that both superhydrophobic AlTz-68-C18 and the corresponding modified sponge exhibit excellent performance toward oil/water separation.

The CdSе/ZnS nanostructures of Core-Shell type, that have multi-wave emission, are described and a scheme of possible energy transitions in the studied system is presented. CdSe nuclei were synthesized by mixing cadmium and selenium precursors without creating an inert atmosphere. The cadmium complex with sulphanilamide was used as a cadmium precursor and simultaneously as a stabilizing ligand. To grow the shell, zinc stearate and thiourea were gradually added to the solution of cadmium selenide nuclei in octadecene at 200°C. TEM studies show that the obtained CdSe/ZnS nanoparticles have the shape close to tetrahedral with an effective diameter up to 10 nm. The thickness of the ZnS shell is about 3-4 nm. From the absorption spectra of the CdSe/ZnS nanoparticles, it is clear that the shell growth leads to a sharp increase in the absorption in the short wavelentgh area, which means the formation of a wide gap ZnS material. The obtained CdSe/ZnS nanostructures emit three fluorescence peaks in the visible range. They are attributed to exciton transitions in the nucleus, recombination at defects of the boundary between the core and the shell, and recombination at defects of the shell. Such property provides CdSe/ZnS nanocrystals with a wide range of functionalities.

is an interesting shell material for β-NaREF4 particles of the lighter lanthanides (RE = Ce, Pr, Nd), as variation of its strontium content x allows to vary its lattice parameters and match those of the core material. It crystallizes in the hexagonal gagarinite structure (NaCaYF6) which is closely related to the hexagonal structure of β-NaREF4, known from the upconversion host lattices β-NaYF4 and β-NaGdF4. Here, we studied the formation of nanocrystals over the entire range 0 ≤ x ≤ 1. Heating of a solution of the metal oleates in oleic acid/octadecene in the presence of NH4F results in the formation of small (≈3 nm) particles as the first product. For x ≤ 0.2, these particles mainly consist of the hexagonal gagarinite phase whereas for x > 0.2 most particles crystallize in a cubic lattice resembling the structure of α-NaGdF4. Further heating at 320 °C leads to dissolution of the cubic phase and formation of larger particles of the hexagonal phase. Both the time required for complete dissolution as well as the final size of the particles systematically grows with increasing strontium content x, showing that high values of x decrease the number of hexagonal seeds formed. The lattice parameters of the hexagonal phase are found to increase linearly with x and become, for high values of x, similar to those of the hexagonal phase of NaCeF4, NaPrF4, and NaNdF4. Small particles of the cubic phase of NaGdSrF6 are shown to be suitable precursors to form a gagarinite shell on β-NaCeF4:25% Tb particles.

We report the synthesis of three lead(II) bis(acylselenoureato) complexes (1a–3a), which were prepared by the reaction of the respective acylselenourea compounds ArC(O)NHC(Se)NR2 [Ar = 4-MeC6H4, R = Et (1); 4-ClC6H4, R = nBu (2), iBu (3)] with Pb(OAc)2. All three compounds were confirmed by NMR spectroscopy, elemental analysis and single crystal X-ray diffraction. Furthermore, the lead(II) complex 3a was transformed into PbSe nanostructures in a microwave-assisted synthesis using either a mixture of trioctylphosphine (TOP), octadecene (ODC) and the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIm][NTf2], a mixture of [BMIm][NTf2] and propylene carbonate (PC), pure [BMIm][NTf2] or pure PC. The analyses of the resulting particle dispersions indicated formation of either small PbSe nanoparticles of 19 nm, PbSe submicro-cubes between 178 nm and 366 nm as well as strongly intergrown structures depending on the stabilizing reagent used during the synthesis. The prepared PbSe particle suspensions were characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray spectrocopy (EDX) as well as by selected area electron diffraction (SAED).

We report the synthesis and characterisation of novel CuZn2InTe4 quantum dots (QDs) suitable for various optoelectronic applications. The nanostructures grown are technologically important due to their Cd and Pb-free composition. The synthesis was maintained “green” by using a phosphine free organometallic procedure utilizing octadecene as the coordinating solvent. The structural properties of the nanocrystals (NCs) were analyzed using high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The composition was verified using X-ray photoelectron spectroscopy (XPS), inductive coupled plasma-optical emission spectroscopy (ICP-OES) and energy dispersive X-ray spectroscopy (EDX). The optical studies were performed using UV-VIS-NIR spectroscopy and photoluminescence (PL) spectroscopy and the band gap value obtained was verified using cyclic voltammetry (CV). The nanostructures grown were spherical with a size of about 5 nm possessing appreciable monodispersity.

Nitrogen-free multi-wall carbon nanotubes (MWCNTs) and N-doped bamboo-like carbon nanotubes (BCNTs) were synthesized by using catalytic vapor deposition (CVD) and used as catalyst support materials. Pd, Rh, Ru, and Ir have been deposited onto the nanotubes to achieve metal/nanotube catalysts. The catalytic activity of the samples was fine-tuned by changing the type of support. BCNT supported Pd and Rh (Pd/BCNT, Rh/MWCNT) catalysts were found to be the most active for liquid phase hydrogenation of octadecene amongst these samples. The initial olefin hydrogenation rate of the Pd/BCNT sample was slightly higher than the corresponding MWCNT-supported catalyst. Based on the hydrogenation reaction, the performance of these catalyst had been ranked as follows: Pd/BCNT ≈ Rh/MWCNT > Pd/MWCNT > Rh/BCNT > > Ir/MWCNT > Ru/BCNT > Ir/BCNT > Ru/MWCNT. The structural properties of chemisorbed Pd on MWCNT and N- BCNT were also characterized by means of computational chemical methods in order to shed some light on the nature of metal binding properties of N-doped and undoped surfaces. The calculations shown preference towards the edges of the surfaces which is in good agreement with the experimental findings.

Highly stable nanosized water droplets in diesel nanoemulsions were prepared in the presence of polyoxyethylene alkenyl succinate as a gemini emulsifier. This nonionic gemini emulsifier was prepared through three stages. The addition reaction of octadecene to the double bond of maleic anhydride was the prime step. The second step includes the ring-opening reaction between 2 mol of alkenylsuccinic anhydride with diethylene glycol as a spacer, and the third step was the esterification reaction between the said products with 2 mol of polyethylene glycol 200 to produce polyoxyethylene alkenyl succinate gemini emulsifier abbreviated as GE. FT-IR and 1H NMR spectroscopies were utilized to justify the chemical formula of the synthesized emulsifier. Four water-in-diesel nanoemulsions were formulated under 5 wt % water content and (2, 4, 6, and 8 wt %) surfactant concentrations of the overall nanoemulsion’s weight. The prepared emulsifier’s dynamic interfacial tension mensuration and also its thermodynamic paramet...

The right choice of synthesis route for upconverting nanoparticles (UCNPs) is crucial for obtaining a well-defined product with a specific application capability. Thus we decided to compare the physicochemical, cytotoxic, and temperature-sensing properties of UCNPs obtained from different rare earth (RE) ions, which has been made for the first time in a single study. The core/shell NaYF4:Yb3+,Er3+/NaYF4 UCNPs were obtained by reaction in a mixture of oleic acid and octadecene, and their highly stable water colloids were prepared using the ligand-free modification method. Both oleate-capped and ligand-free UCNPs exhibited a bright upconversion emission upon 975 nm excitation. Moreover, slope values, emission quantum yields, and luminescence lifetimes confirmed an effective energy transfer between the Yb3+ and Er3+ ions. Additionally, the water colloids of the UCNPs showed temperature-sensing properties with a good thermal sensitivity level, higher than 1 % K−1 at 358 K. Evaluation of the cytotoxicity profiles of the obtained products indicated that cell viability was decreased in a dose-dependent manner in the analyzed concentration range.

Nanoparticles (NPs) based on host compound NaYF4 with core@shell structures were synthesised by the precipitation reaction in high-boiling point octadecene/oleic acid solvent. Four laser wavelengths were used (808, 975, 1208, or 1532 nm) for excitation of the obtained NPs. The resulting emission and mechanisms responsible for spectroscopic properties were studied in detail. Depending on NP compositions, i.e. type of doping ion (Er3+, Tm3+, or Yb3+) or presence of dopants in the same or different phases, adjustable up-conversion (UC) could be obtained with emission peaks covering the visible to near-infrared range (475 to 1625 nm). The presented results demonstrated multifunctionality of the prepared NPs. NaYF4:2%Tm3+@NaYF4 NPs exhibited emission at 700 and 1450 nm under 808 nm laser excitation or 800 and 1625 nm emission under 1208 nm laser radiation, as a result of ground- and excited-state absorption processes (GSA and ESA, respectively). However, NaYF4:5%Er3+,2%Tm3+@NaYF4 NPs showed the most interesting properties, as they can convert all studied laser wavelengths due to the absorption of Tm3+ (808, 1208 nm) or Er3+ ions (808, 975, 1532 nm), revealing a photon avalanche process under 1208 nm laser excitation, as well as GSA and ESA at other excitation wavelengths. The NaYF4:2%Tm3+@NaYF4:5%Er3+ NPs revealed the resultant emission properties, as the dopant ions were separated within core and shell phases. The NaYF4:18%Yb3+,2%Tm3+@NaYF4 and NaYF4:18%Yb3+,2%Tm3+@NaYF4:5%Er3+ samples showed the brightest emission, around 800 nm, under 975 nm excitation, though other laser wavelengths allowed for observation of luminescence, as well, especially in NPs with Er3+ in the outer shell, capable of UC under 1532 nm. The presented results highlight the unique and universal properties of lanthanide ions for designing luminescent NPs for a variety of potential applications, such as confocal microscopy.

In order to achieve a significant size reduction to get ultrasmall upconverting nanoparticles (UCNPs) following a thermal coprecipitation pathway, we identified two critical points: the UCNP precursor mixing and high-temperature heating steps. Significant differences could be observed according to the way the inorganic sodium and fluoride sources were mixed to the rare-earth oleate before the high-temperature heating step. More interestingly, accurate monitoring of the high-temperature heating step using microwave (MW) dielectric heating yielded major improvement toward ultrasmall UCNPs. Thus, hexagonal, Tm-doped sub-5-nm UCNPs with an unusual Na(Yb-Gd)F4 matrix with 53% Yb were produced, displaying satisfactory luminescence. Noticeably, MW heating was achieved in a weakly MW-absorbing oleic acid (OA)/octadecene mixture, and the influence of the OA content composition on the MW heating efficiency is discussed in this report.

Nanoparticles of nickel phosphide are finding wide ranging utility as catalysts for hydrodesulfurization, hydrogen evolution reaction, and hydrodeoxygenation of bio-oils. Herein, we present a methodology to tailor monodisperse nickel phosphide nanoparticles in terms of size and phase through the use of a statistical response surface methodology. Colloidal nickel phosphide nanoparticles were synthesized by replacing octadecene (ODE), a commonly used organic solvent, by a more sustainable phosphonium-based ionic liquid (IL). The replacement of ODE with the phosphonium-based IL resulted in faster crystallization at lower temperatures to yield phase-pure, monodisperse Ni2P nanoparticles. Using a first-order design, the PPh3/Ni precursor ratio was identified as the most critical factor influencing the resulting size and phase of the nanoparticles. Optimization using a Doehlert matrix for second-order design yielded a second-degree polynomial equation used to predict the mean diameter of the nanoparticles (over...

Alternating amphiphilic copolymers are macromolecular systems with a polarity duality in their structure, since they are generally formed by alternating segments corresponding to a potential electrolyte group and an alkyl (aliphatic or aromatic) group. These systems, depending on the ionization degree, as well as the time, may form different types of intra and interpolymeric aggregates in aqueous media. Therefore, this study, which in fact is the continuation of a previously reported work, is focused on establishing how the ionization degree of the sodium and potassium salts of the poly(maleic acid-alt-octadecene) affect zeta potential, pH, electrical conductivity, particle size, polydispersity index, and surface tension over time. The results showed that polymeric salts with a high ionization degree in aqueous media formed homogeneous systems with bimodal sizes and high zeta potential values, which tended to quickly become less negative, lowering the pH and slightly increasing the electrical conductivity, while systems with low ionization degree lead to the opposite, forming heterodispersed systems with several populations of particle sizes, high polydispersity, low zeta potential values, neutral and invariable pH values, and high electrical conductivity values. Consequently, these results suggest that the values of particle size, polydispersity index, zeta potential, pH, and electrical conductivity change regarding the polymeric ionization degree, as well as the time. Therefore, such variables should be considered and controlled when working with this kind of polymeric materials.

We developed a biomineral-inspired hybrid material composed of CaCO3 and an organic polymer as a column packing material for HPLC. This material combines a hierarchical mesoporous structure and the functionality of the polymer. The surface of monodispersed mesoporous CaCO3 microspheres was modified with poly(maleic acid-alt-1-octadecene) (PMAcO) comprising hydrophobic alkyl chains and anionic carboxylate groups. PMAcO adsorbed onto the surface of CaCO3 through electrostatic interaction between Ca2+ sites and carboxylate groups, resulting in an octadecene coated microsphere interface. These microspheres were applied as a HPLC column and exhibited reversed-phase retention behavior in the separation of alkylbenzenes. This column showed high alkaline mobile phase resistance compared with the conventionally applied ODS column packing material. Quantitative analysis of the basic antidepressants clomipramine and imipramine spiked into whole blood was achieved with an alkaline mobile phase, demonstrating the potential of the biomineral-inspired material as a HPLC stationary phase for practical applications in routine analyses of basic drugs requiring alkaline mobile phases.

Transformation of the photoluminescence (PL) spectra of hybrid Si/SiOx nanoparticles of the crystalline core–oxide shell type has been investigated in the temperature range of 10–320 K upon 325-nm laser excitation. Si/SiOx nanoparticles are synthesized from silicon monoxide and functionalized in dimethyl sulfoxide (DMSO) or octadecene (OD). The PL spectra of the nanoparticles are considered as superpositions of short-wavelength (400–550 nm) and long-wavelength (600–900 nm) bands, which have significantly different ratios of the total intensities of these components in Si/SiOx/OD and Si/SiOx/DMSO samples. For Si/SiOx/DMSO samples, the intensity of the short-wavelength band monotonically decreases with an increase in temperature from 10 K, whereas the intensity of the long-wavelength band first increases; however, then (at approximately 70 K) its slope begins to decrease and levels off. The specific features of the temperature dependence of the long-wavelength PL band intensity can be explained in this case by efficient energy transfer from defect oxygen-containing centers at the core boundary to exciton centers that arise under laser irradiation. In the case of Si/SiOx/OD particles, for which the short-wavelength band intensity is initially low, this effect is not observed. For these particles, the influence of 405-nm cw laser radiation on the kinetics of changes in the intensity of the long-wavelength PL band has been studied beginning with a temperature of 10 K. It has been found that the PL intensity increases at temperatures near 10 K with an increase in the exposure time, which is explained by additional heating of nanoparticles in a vacuum.

Silver-nickel core-shell nanoparticles (NP) were prepared by solvothermal hot injection synthesis by simultaneous thermolysis/reduction of AgNO3 and Ni(acac)(2) precursors in the hot mixture of octadecene and oleylamine. Oleylamine decreases decomposition temperature of AgNO3 to that of Ni(acac)(2) thus ensuring favorable reaction conditions. The prepared AgNi NPs with different Ag/Ni ratios were completely characterized. Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) were used for particle size characterization of as-prepared AgNi colloids. There is no dependence of the particle size (13-21 nm by SAXS) on the Ag/Ni stoichiometric ratio, but the ultraviolet-visible spectroscopy (UV-vis) reveals that the intensity of the surface plasmon (SPR) decreases with increasing Ni content. Transmission electron microscopy (TEM) verified the results of DLS and SAXS and showed spherical nanoparticle shape. Distribution of individual elements in the nanoparticles was mapped by high resolution scanning transmission electron microscopy and energy dispersive X-ray spectroscopy (STEM-EDS) and revealed their core-shell structure where an Ag nucleus is covered by a thin amorphous Ni layer. Upon heating to 400 degrees C, Ni crystallization is substantiated by appearance of diffractions in the high-temperature X-ray powder diffractograms (HT-XRD) and of a magnetic moment. Ultimate phase separation was proven by scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDS) in samples heated to 1000 degrees C. The reaction course and nanoparticle formation studied by DLS, UV-vis, and Ag and Ni elemental analyses reveal an initial Ag seed formation with subsequent Ni overlayer deposition after 180 s. (C) 2018 Elsevier B.V. All rights reserved.

The core-shell-structured NaYF4:Er3+,Yb3+@NaYF4:Eu3+ (NYFEY@NYFE) nanocrystals with dual-mode emission have been satisfactorily prepared through a solvothermal method utilizing oleic acid and octadecene. From the emission spectra of dual-mode luminescent nanocrystals, it could be seen that nanocrystals consisted of two disparate units, one supplying up-converting luminescence excited with the 980 nm laser and the other providing down-converting luminescence by means of ultraviolet excitation, which are assigned to 4S(3/2) → 4I(15/2) transitions of Er3+ and 5D0 → 7F2 transitions of Eu3+, separately. And then, a novel photoelectrode structure via introducing dual-mode luminescent materials was proposed. The photoelectric conversion efficiency of DSSCs with NYFEY@NYFE photoelectrode attains 7.37%, raised by a factor of 1.37 in comparison to that of the DSSCs without Eu3+ and Er3+ doping. The preparation of dual-mode NYFEY@NYFE not only has great significance to the study of material itself but its application in DSSCs, and can be also applied to other types of solar cells.

I-III-VI group “green” quantum dots (QDs) are receiving increasing attention in photoelectronic conversion applications. In this work, a facile one-pot route directly dissolving copper iodide, gallium acetylacetonate and selenium powder as precursors into a mixed solution of dodecanethiol, oleylamine (OLA) and octadecene was developed to synthesize Cu-Ga-Se/ZnSe (CGSe/ZnSe) core/shell QDs. The resulting CGSe/ZnSe QDs with a relatively high photoluminescence quantum yield (PL QY) of 77.73% can be obtained and the particle size control from 4.20 to 5.73 nm can be realized via the variation of OLA dosage. The tunable emission from 485 to 630 nm can be acquired by introducing sulfur ion into CGSe host materials (anionic alloying) and varying the Cu/Ga precursor molar ratio. Furthermore, the PL recombination process in CGSe/ZnSe QDs is discussed using the PL decay curve. The proposed one-pot synthesis route for highly efficient color-tunable CGSe/ZnSe QDs is facile, rapid and environmentally-friendly. The as-prepared QDs are promising candidates for the exploration of novel and efficient light-emitting diodes.

Nitrogen-doped bamboo-shaped carbon nanotubes (N-BCNTs) were produced by catalytic chemical vapor deposition using butylamine as carbon sources. The morphology of the nanotubes and the type of nitrogen incorporation was studied. The surface polarity of the synthetized nanotubes was tuned by using three different oxidizing agents, H2SO4/HNO3 mixture, cc. HNO3, and H2O2. It has been shown that due to the oxidation, the presence of oxygen containing functional groups (–COOH, –OH), and therefore, the hydrophilic character of the N-BCNTs considerably increased. The functionalized N-BCNTs and non-treated CNTs were used as support materials to prepare 5 wt% Pd catalysts. The synthesized Pd nanocomposites were successfully tested in liquid phase heterogeneous hydrogenation (octadecene to octadecane). Although, the catalytic activity decreased by the increasing surface polarity of the nanotubes, which can be attributed to the non-polar reactants, this effect could be beneficial in case of hydrophilic systems.

Three reversed-phase liquid chromatography (RPLC) stationary phases were obtained to by using long-chain 1-octadecene (OD) co-grafted with three short-chain monomers, including N-vinylpyrrolidone (NVP), 1-vinylimidazole (VIm) and 4-vinylpyridine (VPy), respectively (noted as Sil@ODNVP, Sil@ODVIm and Sil@ODVPy). Peak broadening phenomenon in RPLC mode which resulted by short-chain was examined carefully. Compared with Sil@ODNVP, both Sil@ODVIm and Sil@ODVPy had smaller peak width and higher column efficiency in the separation of 10 polycyclic aromatic hydrocarbons (PAHs), 7 alkyl benzenes, 7 aromatic acids, 7 aromatic esters and 9 phenols. In addition, VPy has the strongest ion exchange capacity than other two short-chains. In this case, we can see that VPy and VIm maybe more suitable to be used as functional monomeric modifiers of new chromatographic stationary phases.

Classical molecular dynamics has been used to study the stabilization of colloidal quantum dots of CdSe with n-octadecylphosphonic acid molecules in combination with different auxiliary ligands, such as trioctylphosphine, trioctylphosphine oxide, and hexadecylamine. The effects of different ligands that may be formed due to interactions of n-octadecylphosphonic acid with CdO and Se in an initial mixture have been considered. It has been shown that, among these ligands, the stabilizing effect increases with a rise in the charge of a ligand per n-octadecyl chain. The role of the auxiliary ligands, e.g. octadecene that devoid of functional groups, has been studied.

Monodispersed CoFe2O4 nanoparticles were synthesized by the thermal decomposition of Co and Fe acetylacetonate in octadecene, which contained oleic acid (OA) and oleylamine (OLA). The hydrophobicity of the CoFe2O4 nanoparticles was alleviated such that they were water dispersible by encapsulating them with poly(maleic anhydride-alt-1-octadecene) (PMAO). The heating ability of these magnetic fluids was assessed by calorimetry measurement of specific absorption rate under an alternating magnetic field of 300 Oe within the frequency interval of 290–450 kHz. The highest value of the specific absorption rate was 297.4 W g−1 for a sample concentration of 1 mg mL−1 under an applied field of 300 Oe and frequency of 450 kHz. Linear response theory was used to explain the results. The high specific absorption rate of the nanofluid based on PMAO-encapsulated CoFe2O4@OA/OLA showed that it may meet the requirements for practical applications in tumor-targeted hyperthermia treatment. In vitro cytotoxicity analysis was also performed on Sarcoma 180 cancer cells, and the results showed that these nanoparticles were nontoxic to cells.

Quantum dots (QDs) with composition/size dependent optoelectronic properties have been regarded as emerging materials to be potentially applied in photoelectric fields. For QDs based light emitting diodes (QDLEDs), the efficient devices are still focused on toxic binary QDs containing heavy metals. Herein, a series of less-toxic and emission color tunable Ag, Mn codoped Zn-In-Se optimized dQDs are synthesized and detailed studied via the facile low-cost one-pot hot-injection synthetic method using Se in octadecene as ‘green’ Se source. After coating a thick ZnSe shell (~7.9 monolayers) on the core dQDs, higher photoluminescence (PL) quantum yield (QY) up to 68% was achieved and higher emission efficiency was retained even when the initially oil-soluble QDs are transferred into aqueous media by ligand replacement. Furthermore, both photostability and thermal stability of the core/shell dQDs were significantly enhanced as compared with those of core dQDs due to the suppressed surface defects resulting from the passivation of the dense ZnSe layers. The dQDs are further applied in QDLEDs as singly emitter and exhibited good performance with color rendering index (CRI) of 79, CIE coordinates of (0.368, 0.327), CCT of 4105 K and maximum luminance of 180 cd m−2, indicating that the studied core/shell dQDs could be a potential candidate in QD-based lighting or solid-state lighting as a single color-converting materials.

Here, we present a controlled synthesis of Mn-doped ZnO nanoparticles (NPs) with predominantly nail-like shapes, whose formation occurs via tip-to-base-oriented attachment of initially formed nanopyramids, followed by leveling of sharp edges that lead to smooth single-crystalline “nails”. This shape is prevalent in noncoordinating solvents such as octadecene and octadecane. Yet, the double bond in the former promotes oriented attachment. By contrast, Mn-doped ZnO NP synthesis in a weakly coordinating solvent, benzyl ether, results in dendritic structures because of random attachment of initial NPs. Mn-doped ZnO NPs possess a hexagonal wurtzite structure, and in the majority of cases, the NP surface is enriched with Mn, indicating a migration of Mn2+ ions to the NP surface during the NP formation. When the NP formation is carried out without the addition of octadecyl alcohol, which serves as a surfactant and a reaction initiator, large, concave pyramid dimers are formed whose attachment takes place via bas...

We report a method to synthesize both organicinorganic CH3NH3PbBr3 and all-inorganic CsPbBr3 perovskite nanocrystals in nonpolar solvent at high temperature. The cesium oleate and CH3NH3Br (MABr) are prepared and then injected into the nonpolar solvent of octadecene including oleic acid, oleylamine, and lead halide. In the synthesis of organic-inorganic perovskites of CH3NH3PbBr3, the frequently-used polar solvent of dimethylformamide or other polar solvents are not used. The prepared CsPbBr3 nanocrystals are spherical nanoparticles with the diameter of 250 nm. The CH3NH3PbBr3 perovskites are micro- scale hexagonal nanoplatelets. The colloidal perovskites exhibit high-efficient fluorescence and excellent stability.

Size and morphology controlled silver sulfide (Ag 2 S) nanoparticles were synthesized using single (oleylamine) and mixed (octadecene and dodecanethiol) solvents by thermal decomposition method. Structural and morphological properties of Ag 2 S nanostructures were analyzed by X-ray diffraction method and transmission electron microscope. Comparatively higher crystalline Ag 2 S nanoparticles were synthesized in single solvent than mixed solvent, however, larger size of the particles (>10 nm) synthesized in single solvent became fluorescence inactive. The controlled size of 3–5 nm in diameter was achieved irrespective of increasing temperature till 225 °C by mixed solvent synthesis and the photoluminescence showed the emission in the second near infrared region (NIR II).

Self-doped copper-based selenides, typically for Cu2−xSe, are attracting great interest for many researchers due to their unique local surface plasmonic resonance (LSPR). To obtain highly-quality Cu2−xSe nanocrystals (NCs), a phosphine-free selenium precursor such as octadecene (ODE)-Se, oleylamine (OLA)-Se or oleic acid (OA)-Se are normally used. However, in order to effectively dissolve selenium powder in these phosphine-free reaction systems mentioned above, high dissolving or reacting temperatures are generally inevitable. In this work, we utilized a phosphine-free selenium precursor, which was prepared by dissolving selenium powder in a mixture solvent of oleylamine and 1-dodenethiol at room temperature, to successfully synthesize the pure-phase and monodispersed berzelianite Cu2−xSe nanoplates (NPs) with an obvious LSPR character at a relatively low temperature of 180 °C. In addition, just by changing the Cu/Se molar ratios of the precursor, klockmannite Cu0.87Se and CuSe NPs with different sizes we...

1-Octadecene is a widely used solvent for high temperature nanocrystal synthesis (120-320 degrees C). Here, we show that 1-octadecene spontaneously polymerizes under these conditions, and the resulting poly(1-octadecene) has a comparable solubility and size to nanocrystals stabilized by hydrophobic ligands. Typical purification procedures (precipitation/redispersion cycles or size exclusion chromatography) fail to separate the poly(1-octadecene) impurity from the nanocrystal product. To avoid formation of poly(1-octadecene), we replace 1-octadecene with saturated, aliphatic solvents. Alternatively, the nanocrystals' native ligands are exchanged for polar ligands, leading to significant solubility differences between nanocrystals and poly(1-octadecene), therefore allowing isolation of pure nanocrystals, free from polymer impurities. These results will help design superior syntheses and improve nanocrystal purity, an important factor in many applications.

Luminescent inorganic phosphors are widely used as wavelength-converting materials in many emerging applications including displays, solar cells, and bioimaging. This study demonstrates the synthesis of highly luminescent colloidal AlOH nanoparticles and the preparation of transparent luminescent AlOH/polymer composites. Colloidal AlOH nanoparticles are synthesized by the thermal decomposition of aluminum acetate hydroxide precursors in octadecene solution. The addition of oleic acid in the reaction mixture enables the control of the size and dispersity of the nanoparticles. As-synthesized nanoparticles are colloidally stable in non-polar solvents and exhibit excellent photoluminescence properties. Highly dispersible colloidal AlOH nanocrystals form stable mixtures with ethylene vinyl acetate (EVA) copolymers. Transmittance and photoluminescence measurements of the AlOH/EVA composite films when varying AlOH loading demonstrate that the transparent and luminescent AlOH/EVA composite films are promising candidates for applications in spectral converters. Keywords: Aluminum oxide, Aluminum hydroxide, Nanophosphor, Spectral converter

Fine-tuning of multi-color emission characteristics of upconversion lanthanide-ion-doped nanocrystals is of high importance for 3-D color displays, multi-color bio-imaging, and multiplexed cellular labeling. Here, we report a strategy enabling crystal phase transition and morphology transformation between GdF3:Yb3+,Tm3+ and GdOF:Yb3+,Tm3+ nanocrystals for fine-tuning of upconversion multi-color emissions. By controlling the ratio between oleylamine (OM)/octadecene (ODE), the orthorhombic phase of rhombic nanoplates (GdF3:Yb3+,Tm3+) was transformed to the cubic phase of nanospheres (GdOF:Yb3+,Tm3+), along with their upconversion color change from blue to red. Broadband upconversion emission was observed from GdOF:Yb3+,Tm3+ nanocrystals at a high excitation power, which is expected to originate from oxygen defects. Multi-color upconversion nanocrystals providing broadband emission are expected to find their applications in broad band multi-color biomolecular imaging requiring a high imaging resolution.

With the aim of controlling the first steps in HgI 2 film growth onto amorphous substrates, we employed HgI 2 nanoparticles for nucleation. Hg(NO 3 ) 2 and NaI were used for obtaining HgI 2 in water with and without citric or oxalic acid as capping agents. These samples were then subjected to a hydrothermal treatment at a constant temperature of 120 oC during 2 h. All samples were washed, centrifuged and dried. This method presents a facile route for obtaining HgI 2 nanoparticles and is easily scalable. HgI 2 tetragonal phase was confirmed by powder X-ray diffraction. Nanoparticles were characterized in their size and morphology by transmission electron microscopy and the capping agent presence was studied by infrared spectroscopy. HgI 2 nanoparticles synthesized in octadecene, previously reported, as well as nanoparticles obtained in the present work, were used for nucleation onto amorphous substrates. They were deposited onto floating silica glass by spin coating and the morphology of the layer was studied by atomic force microscopy. The results we obtained are the first involving HgI 2 nucleation by spin coating, and are very promising for improving the film growth orientation and therefore the current applications of this material, as well as for opening new ones.

Catalytic hydrogenation is an important process used for the production of everything from foods to fuels. Current heterogeneous implementations of this process utilize metals as the active species. Until recently, catalytic heterogeneous hydrogenation over a metal-free solid was unknown; implementation of such a system would eliminate the health, environmental, and economic concerns associated with metal-based catalysts. Here, we report good hydrogenation rates and yields for a metal-free heterogeneous hydrogenation catalyst as well as its unique hydrogenation mechanism. Catalytic hydrogenation of olefins was achieved over defect-laden h-BN (dh-BN) in a reactor designed to maximize the defects in h-BN sheets. Good yields (>90%) and turnover frequencies (6 × 10–5–4 × 10–3) were obtained for the hydrogenation of propene, cyclohexene, 1,1-diphenylethene, (E)- and (Z)-1,2-diphenylethene, octadecene, and benzylideneacetophenone. Temperature-programmed desorption of ethene over processed h-BN indicates the formation of a highly defective structure. Solid-state NMR (SSNMR) measurements of dh-BN with high and low propene surface coverages show four different binding modes. The introduction of defects into h-BN creates regions of electronic deficiency and excess. Density functional theory calculations show that both the alkene and hydrogen-bond order are reduced over four specific defects: boron substitution for nitrogen (BN), vacancies (VB and VN), and Stone–Wales defects. SSNMR and binding-energy calculations show that VN are most likely the catalytically active sites. This work shows that catalytic sites can be introduced into a material previously thought to be catalytically inactive through the production of defects.

Low toxic, non-stoichiometric colloidal copper–indium–sulphur [Cu–In–S (CIS)] ternary quantum dots with different Cu:In molar ratios by a hot-injection method in octadecene was synthesised. The Cu:In precursor molar ratios were 1/10, 1/20 and 1/40. Varying the fraction of cationic and capping agents, the compositions of CIS nanocrystals were precisely controlled. The photoluminescence (PL) results reveal that, reducing the Cu:In ratio in the CIS is the feasible strategy for bandgap engineering. Tunable PL emissions have been observed. X-ray powder diffraction and high-resolution transmission electron microscopy results indicate that as-prepared CIS nanocrystals are compositional homogeneity. The single-crystal nature of CIS nanocrystals improves the relative PL quantum yield up to 12%, which exhibits substantial enhancement comparing with the stoichiometric CuInS2 and CIS-based semiconductor core QDs. The PL decay curve of CIS has a triexponential feature. The value of τ1, τ2 and τ3 of CIS sample agree well with CuInS2 core QDs. The average PL lifetime of CIS is reduced to 146.9 ns, which can be attributed to the reduction of surface-related trap states.

Cubic and tetragonal structured Cu2SnS3 (CTS) nanoparticles are rapidly synthesized within a short reaction time of 5 min using low cost amine free octadecene (ODE) solvent by hot injection technique. The effects of precursor concentration, sulfur source and reaction time on the CTS nanoparticle synthesis are studied. The crystal structure, size, phase purity, atomic composition, oxidation state and optical properties of these nanoparticles are studied in detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) and UV–visible spectroscopy techniques. Spherical shaped particles in the size range of 25–30 nm are obtained with atomic composition in close agreement with the stoichiometry of Cu2SnS3. The reaction mechanism of CTS nanoparticle formation is proposed. The synthesized cubic and tetragonal structured CTS nanoparticles exhibit optimal band gaps of 1.23 eV and 1.45 eV, respectively, suitable for use in photovoltaic applications.

We herein report the synthesis of orange emitting CdSe-polycaprolactone nanofiber via a simple and total phosphine free method. The hexadecylamine (HDA)-capped CdSe NPs was synthesized by dispersing the as-synthesized CdSe cluster in octadecene followed by thermolysis in hexadecylamine in the absence of an inert gas. The as-synthesized CdSe NPs are of good quality with high orange luminescent intensity, narrow emission width and high photostability. The transmission electron microscopy (TEM) micrograph revealed that the particles are small, monodispersed and highly crystalline with an average particle size of 2.67±43 nm. The dispersion of the as-synthesized CdSe NPs in biopolymer polycaprolactone (PCL) produced reddish orange emitting electrospun polymer nanocomposite nanofibers.

Background: To improve quality of surgery in oncology, it is necessary to completely remove the tumor, including its metastases, to minimize injury to normal tissues and to reduce duration of an intervention. Modern methods of detection based on radiological computerized tomography and magnetic resonance imaging can identify a tumor after its volume has become big enough, i.e. it contains more than 10 billion cells. Therefore, an improvement of sensitivity and resolution ability of diagnostic tools to identify early stages of malignant neoplasms seems of utmost importance. Aim: To demonstrate the potential of a new class of anti-Stokes luminescence nanoparticles for deep optical imaging with high contrast of malignant tumors. Materials and methods: Upconversion nanoparticles with narrow dispersion and a size of 70 to 80 nm, with a core/shell structure of NaYF4:Yb3+:Tm3+/NaYF4 were used in the study. The nanoparticles have an intensive band of anti-Stokes photoluminescence at a wavelength of 800 nm under irradiation with a wavelength of 975 nm (both wavelengths are within the transparency window for biological tissues). The conversion coefficient of the excitation radiation into the anti-Stokes luminescence was 9%. To increase the time during which nanoparticles can circulate in blood flow of small animals, the nanoparticles were covered by a biocompatible amphiphilic polymer shell. As a tumor model we used Lewis epidermoid carcinoma transfected to mice. Results: We were able to obtain stable water colloids of nanoparticles covered with amphiphilic polymer that could preserve their initial size at least for one month. The use of upconversion nanoparticles with a hydrophilic shell made of intermittent maleic anhydride and octadecene co-polymer with subsequent coating with diglycidyl polyethylene glycol ether allowed for reduction of non-specific reaction of nanoparticles with plasma proteins. In its turn, it resulted in an increased time of their circulation in blood flow of small animals for up to 1 hour. With the Lewis lung carcinoma transfected to mice model we demonstrated аn in-life transportation of upconversion nanoparticles into the tumor with a high degree of localization due to a passive EPR effect. The contrast of luminescent signal in the tumor compared to adjacent tissues was at least 70%. The possibility of visualization of upconverted nanoparticles up to 15 mm of biological tissue was shown. Conclusion: The optical imaging techniques with anti-Stokes photoluminescent markers ensure a high contract real-time detection of tumor tissues that allows for their use for intra-operative diagnostics.

We report a facile strategy to tune the growth behavior and surface structures of Pt nanocrystallites by varying the concentration of oleylamine (OAm) in mixed solutions of OAm and octadecene (ODE); the resulting Pt nanorods (NRs) and nanodendrites (NDs) show superior electrocatalytic performance for the oxygen reduction reaction (ORR). Long wormlike NRs with uniformly small diameters and NDs branched with NRs were obtained at low and medium concentrations of OAm, respectively. Time-dependent morphology measurements showed that small Pt nanoparticles (NPs) were initially formed, which evolved into NRs or NDs depending on the reaction kinetics for Pt atom formation. Benefiting from the selective exposure of the ORR-active (111) facet, the wormlike Pt NRs exhibited significantly higher ORR activity and electrochemical stability than state-of-the-art Pt NP catalysts, which are enclosed with both the (111) and (100) facets. The ORR activity and stability of these catalysts were further enhanced by forming Pt NDs, probably as a result of the fact that the NR-interconnected architectures produce more-active high-index facets in the junction areas.

In this work, ternary CuInSe 2 (CISe) chalcopyrite nanocrystallites efficiently passivated by a novel combination of capping agents viz: aniline and 1-octadecene during chemical route synthesis were dispersed in conducting polymer matrix poly(3-hexylthiophene) (P3HT). By varying the composition and concentration of the ligands, the properties of the resulting CISe nanocrystallites and its corresponding polymer nanocomposites thus could be tailored. The structural, morphological and optical studies accomplished by various complimentary techniques viz. Transmission Electron Microscopy (TEM), Contact angle, Photoluminescence (PL) and Raman have enabled us to compare the different hybrid organic (polymer)-inorganic nanocomposites. On the basis of aniline–octadecene equilibrium phase diagram, the polydispersity of the CISe nanocrystals could be tuned by using controlled variations in the reaction conditions of nucleation and growth such as composition of the solvent and temperature. To the best of author’s knowledge, the beneficial effects of both the capping agents; aniline and octadecene contributing well in tandem in the development of large-sized (100–125 nm) high quality, sterically- and photo-oxidative stable polycrystalline CISe and its corresponding polymer (P3HT):CISe composites with enhanced charge transfer efficiency has been reported for the first time. The low-cost synthesis and ease of preparation renders this method of great potential for its possible application in low-cost hybrid organic–inorganic photovoltaics.

Metal-halide perovskites are novel optoelectronic materials that are considered good candidates for solar harvesting and light emitting applications. In this study, we develop a reproducible and low-cost approach for synthesizing highquality cesium lead halide perovskite (CsPbX3, X = Cl, Br, and I or Cl/Br and I/Br) nanocrystals (NCs) by direct heating of precursors in octadecene in air. Experimental results show that the particle size and composition of as-prepared CsPbX3 nanocrystals can be successfully tuned by a simple variation of reaction temperature. The emission peak positions of the as-prepared nanocrystals can be conveniently tuned from the UV to the NIR (360–700 nm) region, and the quantum yield of the as-obtained samples (green and red emissions) can reach up to 87%. The structures and chemical compositions of the as-obtained NCs were characterized by transmission electron microscopy, X-ray diffraction, and elemental analysis. This proposed synthetic route can yield large amounts of high-quality NCs with a one-batch reaction, usually on the gram scale, and could pave the way for further applications of perovskite-based light-emitting and photovoltaic solar cells.

We report the formation of an indium phosphide quantum dot/1-octadecene polymer composites by in situ polymerization and their improved properties in white LED (WLED) applications. The in situ polymerization process is very simple and efficient because the monomer is octadecene solvent, and hence, the composite was easily obtained. The quantum dots inside the composite are effectively passivated, and their stability is significantly improved. The WLED device with OE-6630 as an encapsulant shows an external quantum efficiency (EQE) of 160 lm W −1 and a color rendering index (CRI) of 90. Additionally, neutral (∼6000 K) and warm white light (∼3400 K) can be obtained by controlling the ratio of red-to-green quantum dots. Compared to a quantum dots-only system, the quantum dots/polymer composite shows significantly improved color rendering index (CRI) and external quantum efficiency (EQE) in the similar correlated color temperature (CCT) and color coordination. We expect that this new approach, based on our research, can be extended to many other applications.

Inorganic cesium lead halide perovskites CsPbX3 nanocrystals (NCs) have been widely used in optoelectronic applications due to their excellent optical properties. Furthermore, the final morphology and size of as-grown CsPbX3 NCs play crucial roles in determining their stability and luminescent properties. Here, CsPbBr3 NCs with various morphologies such as nanocubes, nanospheres, nanorods (NRs) and nanowires (NWs) have been fabricated by controlling the amount of solvent octadecene (ODE), the concentrations of trioctylphosphine oxide (TOPO)/tetradecylphosphonic acid (TDPA), the reaction temperatures and the final cooling rate. Finally, high-quality CsPbBr3 NWs exhibiting cubic phase have been successfully obtained by optimizing the reaction parameters. These well-controlled CsPbBr3 NWs with aspect ratio ~19 show great potential in helping nanodevice development. In summary, this study provides important insights for producing inorganic perovskite materials with tunable morphologies and properties for multi-applications.

Formation of gold nanoparticles (NPs) from the mixture containing NaAuCl4 as a precursor, octadecene as a solvent and oleylamine as a reducing agent was studied in situ by means of optical and X-ray spectroscopies. Dynamic light scattering (DLS) revealed the presence of initial aggregates of 500 nm average size which split into nanoparticles of about 8 nm width shortly after the reduction from Au3+ to Au+ has been completed. Based on Density Functional Theory (DFT) simulations and analysis of X-ray absorption spectra (XAS) we identified the structure of Au3+ and Au+ gold complexes. Quantitative analysis shows that Au NPs formation proceeds in following steps: substitution of chlorine ligands in Au3+ complex by four oleylamines; reduction of Au3+ to Au+ coordinated by two oleylamines. Latter process occurs in oleylamine micelles in octadecene. The third step is a fragmentation of large micelles into smaller ones shortly after reduction Au3+ to Au+, and subsequent slow growth of Au NPs via reduction of Au+ to Au0.

In recent years, lead halide perovskite nanocrystals (NCs) have attracted significant attention in both fundamental research and commercial applications because of their excellent optical and optoelectrical properties. However, the protective ligands on the surface of the perovskite NCs could be easily removed after the tedious process of centrifugation, separation, and dispersion, which greatly hampers their stability against light, heat, moisture, and oxygen and limits their practical applications. Here, we report a new post-processing free strategy (i.e., without centrifugation, separation, and dispersion process) of using an ultraviolet (UV)-polymerizable acrylic monomer of lauryl methacrylate as the solvent to synthesize CsPbBr3 NCs, and then adding polyester polyurethane acrylate oligomer, monomer (IBOA), and initiator for direct UV polymerization to fabricate NC-polymer composite films. These films exhibited an improved photoluminescence quantum yield (85-90%) than classic NC films (40-50%), which were processed using octadecene (ODE) as the solvent for NC synthesis and postprocessed for UV polymerization. Significantly, the as-fabricated films by post-processing free strategy exhibited excellent photostability against strong Xe lamp illumination; while the other films using classic methods were quickly photodegraded. Meanwhile, these NC-polymer composite films showed good stability against moisture and heating when aging in water at 50 °C for over 200 h. These films, along with K2SiF6:Mn4+ (KSF) phosphor emitters, were used as downconverters for blue light-emitting diodes in liquid-crystal displays with a wide color gamut of 115% in the International Commission on Illumination (CIE) 1931 color space. This work provides a facile and effective strategy for the preparation of ultrastable and bright color-conversion NC films for the development of the next-generation wide color gamut displays.

We report a solution-phase approach to the synthesis of crystalline copper nanowires (Cu NWs) with an aspect ratio >1000 via a new catalytic mechanism comprising copper ions. The synthesis involves the reaction between copper(II) chloride and copper(II) acetylacetonate in a mixture of oleylamine and octadecene. Reaction parameters such as the molar ratio of precursors as well as the volume ratio of solvents offer the possibility to tune the morphology of the final product. A simple low-cost spray deposition method was used to fabricate Cu NW films on a glass substrate. Post-treatment under reducing gas (5% H2 + 95% N2) atmosphere resulted in Cu NW films with a low sheet resistance of 24.5 Ω/sq, a transmittance of T = 71% at 550 nm (including the glass substrate), and a high oxidation resistance. Moreover, the conducting Cu NW networks on a glass substrate can easily be transferred onto a polycarbonate substrate using a simple hot-press transfer method without compromising on the electrical performance. Th...

In situ growth of ZnO layer on the surface of carbon dots was realized via a two-step method, which resulted in an enhancement of the broad visible emission with a high quantum yield. Influence of the refluxing time, the temperature and the oleylamine/octadecene ratio was investigated to address the key factors on the preparation of the carbon dots. Under the optimal conditions, the carbon dots with an average diameter of 3.4 ± 0.4 nm and a photoluminescence quantum yield of 29.3% were achieved. Remarkable improvements of photoluminescence were achieved by the hybridization of the ZnO layer, which can eliminate the surface-trap from the C cores and form the new centers of emission. The synergistic effect arising from the C/ZnO hybridized structure obviously broadened the visible emission and enhanced their photoluminescence quantum yield from 29.3% to 47.3%. The as-prepared highly emissive quantum dots exhibited a broad and stable emission with the Commission Internationaled ‘E’ clairage chromaticity coordinate of (0.23, 0.34), which could offer a promising solution for the future-generation white light emitting diodes.