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Doping and compositional tuning of Cs(2)AInCl(6) (A = Ag, Na) double perovskite nanocrystals (PNCs) is considered a promising strategy toward the development of light-emitting sources for applications in solution-processed optoelectronic devices. Oleic acid and oleylamine are by far the most often used surface capping ligands for PNCs. However, the undesirable desorption of these ligands due to proton-exchange reaction during isolation and purification processing results in colloidal and structural instabilities. Thus, the improvement of colloidal and optical stability of PNCs represents one of the greatest challenges in the field. Here, we report a trioctylphosphine-mediated synthesis and purification method toward Sb-alloyed Cs2NaInCl6 PNCs with excellent stability and optical features. Nuclear magnetic resonance spectroscopy enabled one to explain the role of trioctylphosphine and to reveal the reaction mechanism during crystal nucleation and growth. Under the optimized reaction conditions, in situ-generated trioctylphosphonium chloride and benzoyl trioctylphosphonium chloride serve as highly reactive halide sources, while benzoyl trioctylphosphonium and oleylammonium cations together with the oleate anion serve as surface capping ligands, which are bound strongly to the PNC surface. The tightly bound ionic pair of oleylammonium oleate and benzoyl trioctylphosphonium chloride/oleate ligands allows one to obtain monodispersed bright-blue-emitting PNCs with high photoluminescence quantum yields exceeding 50% at an optimum Sb content (0.5%), which also exhibit long-term colloidal stability. The approach based on dual cationic ligand passivation of double PNCs opens the doors for applications in other systems with a potential to achieve higher stability along with superior optical properties. Web of Science 13 40 47859 47845

Lead halide perovskite quantum dots (PQDs) are reported as a promising branch of perovskites, which have recently emerged as a field in luminescent materials research. However, before the practical applications of PQDs can be realized, the problem of poor stability has not yet been solved. Herein, we propose a trioctylphosphine (TOP)-assisted pre-protection low-temperature solvothermal synthesis of highly stable CsPbBr3/TiO2 nanocomposites. Due to the protection of branched ligands and the lower temperature of shell formation, these TOP-modified CsPbBr3 PQDs are successfully incorporated into a TiO2 monolith without a loss of fluorescence intensity. Because the excellent nature of both parent materials is preserved in CsPbBr3/TiO2 nanocomposites, it is found that the as-prepared CsPbBr3/TiO2 nanocomposites not only display excellent photocatalytic activity but also yield improved PL stability, enabling us to build highly stable white light-emitting diodes and to photodegrade rhodamine B.

Zinc tin phosphide (ZTP) has attracted recent research interest as a low-cost light sensing material, alternative to III–V and II–III-based compounds, for photo-detector and solar cell applications. In this study, a versatile chemical route for the synthesis of ZTP nanoparticles starting from commercially available alkyl-zinc and tin, alkyl-phosphoramides and trioctylphosphine at a relatively low temperature of 160 °C is reported, which can straightforwardly be extended to other analogous II–IV-P2 group ternary compounds. The particles displayed high stability and can be deposited as layers with few monolayers of thickness. The structural and chemical analysis revealed that the particles are of sub-10 nm size with chalcopyrite structure and ZnSn-phosphide composition. The particles exhibited optical band-gap in the range of 1.65–1.75 eV and a broadband photo-response in the visible wavelengths (400–700 nm) with excellent response to red light.

Zinc-alloyed cadmium selenide (Cd/ZnSe) quantum dots (QDs) were synthesised in a wet chemical method using thioglycolic acid as a stabilising agent. This facile synthesis method does not require high-temperature or inert gas (argon or nitrogen) atmosphere as required in prevailing methods. Also, this method does not require pyrophoric compounds such as trioctylphosphine (TOP) and trioctylphosphine oxide (TOPO). The synthesised QDs were characterised using a spectrofluorometer, Fourier transform infrared (FT-IR) spectrometer, zeta potential, fluorescence lifetime spectrometer, ICP-OES, and selected area electron diffraction (SAED). The synthesised QDs were spherical with an average diameter of 5.08 nm and has a carboxyl group on their surface making them readily soluble in water and are biologically compatible. The QDs were evaluated for visible light–induced photocatalysis of Rhodamine 6G, and around 68% of the dye was degraded with 60 min of visible light irradiation. The synthesised QDs were tested for its toxicity in Danio rerio embryos including survival percentage, percentage of hatching, heartbeat counts and body length. Based on the toxicity evaluation, along with the presence of the carboxyl group on their surface, these QDs can harbour targeting molecules which will serve as a less toxic molecular imaging probe.

Separation of carboxylic acids from their aqueous solutions by reactive extraction using a newly developed deep eutectic solvent (DES) was investigated. DESs were prepared using trioctylphosphine o...

Chemical conversion provides a versatile platform for the synthesis of advanced nanomaterials with targeted phase, composition, and architecture. Here, we report a trioctylphosphine (TOP)-driven chemical conversion route to transform lamellar Fe1-xCoxS1.2-DETA (x = 0.1, 0.3, 0.5, 0.7, DETA = diethylenetriamine) inorganic-organic hybrid solid solutions into two-dimensional (2D) single-crystal Fe1-xCox alloy with controllable composition and dimensionality. Synergetic transformation coupled with DETA removal and sulfur extraction of lamellar Fe0.9Co0.1S1.2-DETA hybrids was examined in detail. The highest magnetization of 175 emu g-1 was recorded for the prepared Fe0.7Co0.3. Our results not only provide a new lamellar inorganic-organic hybrid solid solution but also extend the chemical conversion strategy to the synthesis of previously unavailable magnetic alloy nanosheets.

Recently, lead halide perovskite nanocrystals (PNCs) have attracted intense interest as promising active materials for optoelectronic devices. However, their extensive applications are still hampered by poor stability under ambient conditions. Oleic acid and oleylamine are the most commonly used ligands in colloidal CsPbX3 (X = Cl, Br, and I) synthesis. Oleylamine plays a dual role as it stabilizes the surface but in the long run or post-synthesis, it may disturb the colloidal stability due to facile proton exchange leading to the formation of labile oleylammonium halide, which detaches the halide ions from the NC surface. To address these issues, herein, we report an open-atmospheric, facile, efficient, and completely amine-free synthesis of cesium lead bromide perovskite nanocrystals using a novel bromine precursor, bromopropane, which is inexpensive and available at hand. The reaction mechanism follows a trioctylphosphine/oleic acid-mediated surface passivation route that provides an amine-free reaction environment to stabilize ligand capping on the NC surface. Uniform, highly monodisperse NCs of size ∼29 nm were obtained. The as-synthesized NCs have a high photoluminescence quantum yield (PLQY) of around 80%, and especially, exhibited strong stability under ambient conditions and continuous UV irradiation. The PLQY can maintain 83% of the initial one even after 120 days. Furthermore, after 96 h of continuous irradiation under UV light at 365 nm (8 W cm−2) under open ambient conditions, the photoluminescence (PL) intensity showed retention of 68% of its original value with no significant changes in the full width at half-maximum, whereas the amine-based sample retains only 5% of its original PL intensity. Furthermore, we have utilized these NCs to fabricate stable down-converted LED devices. The present work demonstrated the synthesis of ultra-stable CsPbBr3 NCs that can be an ideal candidate for display applications.

In recent years inorganic lead halide perovskite nanocrystals (PNCs) have been used in photocatalytic reactions. The surface chemistry of the PNCs can play an important role in the excited state interactions and efficient charge transfer with redox molecules. In this work, we explore the impact of CsPbBr3 nanocrystal surface modification on the excited state interactions with the electron acceptor benzoquinone (BQ) for three different ligand environments: as oleic acid/oleylamine (OA/OAm), oleic acid (OA)/trioctylphosphine (TOP), and oleic acid (OA)/oleylamine (OAm)/trioctylphosphine (TOP) ligands. Our finding concludes that amine-free PNCs (OA/TOP capped) exhibit the best excited state interactions with benzoquinone compared to the conventional oleylamine ligand environment. The photoinduced electron transfer (PET) rate constants were measured from PL-lifetime decay measurement. The amine-free PNCs show the highest PET which is 9 times higher than that of conventional ligand capped PNCs. These results highlight the impact of surface chemistry on the excited-state interactions of CsPbBr3 NCs and in photocatalytic applications. More importantly, this work concludes that amine-free PNCs maintain a redox-active surface with a high photoinduced electron transfer rate which makes them an ideal candidate for photocatalytic applications.

The chemical transformation from zinc oxide (ZnO) to zinc sulphide (ZnS), using di-tert-butyl disulphide (TBDS) as a highly reactive sulphur precursor, is demonstrated herein. Through anion exchange, we investigate the phase and morphological changes associated with the nanoparticle (NP) transformation of ZnO to ZnS using TBDS. The Zn–O–S alloy was not formed through the anion exchange reaction, only the ZnO and ZnS phases were detected. The NPs were transformed from a solid sphere to a hollow structure, induced by the nanoscale Kirkendall effect. Even with the dramatic shape and phase changes occurring in the NPs, the Zn oxidation state remained as 2+ throughout the 2 h anion exchange reaction. In addition, trioctylphosphine (TOP), a soft base ligand, increased the anion exchange reaction rate, facilitating the reaction with TBDS. Furthermore, anion exchange with elemental sulphur required a longer reaction time (3 h) than that with TBDS (2 h). Consequently, this study offers not only insights into phase and morphological transformations by anion exchange, but also the advantages of utilizing TBDS as a sulphur precursor.

Inorganic CsPbI3 perovskite quantum dots (PQDs) show high potential for photovoltaic applications. However, the surface matrix of the PQDs significantly suffers from deterioration during the purification process with antisolvent, significantly affecting their optoelectronic properties and stability. Herein, a “surface matrix curing” (SMC) strategy is introduced to restore the surface matrix of CsPbI3 PQDs. The PQD surface matrix with iodide vacancies was substantially restored using the nucleophilic substitution reaction of tert-butyl iodide (TBI) and nucleophile trioctylphosphine (TOP), which could produce sufficient iodide ions to fill in the iodide vacancies of the PQD surface matrix. With this strategy, the optoelectronic properties and stability of the PQDs were significantly improved. As a result, the PQD solar cell (PQDSC) yielded an improved power conversion efficiency of 16.21% (stabilized power output efficiency of 15.45%), which is the highest value among inorganic CsPbI3 PQDSCs. The improved photovoltaic performance in PQDSCs was attributed to significantly suppressed charge carrier recombination induced by the surface defects of the PQDs. This work provides important insights into the surface chemistry of PQDs and offers a new avenue to realize high-performing PQD optoelectronic devices.

Identification of novel materials with enhanced thermoelectric (TE) performance is critical for advancing TE research. In this direction, this is the first report on TE properties of low-cost, nontoxic, and abundant core-shell Cu@Cu2O nanocomposites synthesized using a facile and cheap solution-phase method. They show ultralow thermal conductivity of nearly 10-3 of the copper bulk value, large thermopower of ∼373 μVK-1, and, consequently, a TE figure of merit of 0.16 at 320 K which is larger than those of many of the potential TE materials such as PbTe, SnSe, and SiGe, showing its potential for TE applications. The ultralow thermal conductivity is mainly attributed to the multiscale phonon scattering from intrinsic defects in Cu2O, grain boundaries, lattice-mismatched interface, as well as dissimilar vibrational properties. The large thermopower is associated with a sharp modulation in carrier density of states due to charge transfer between Cu and Cu2O nanoparticles and carrier energy filtering. They are tuned by varying the trioctylphosphine concentration.

Iron phosphide (FeP) is in the spotlight as a hydrogen evolution reaction (HER) catalyst due to its cost efficiency, good catalytic activity, and stability within a wide pH range. However, there is still a need to synthesize FeP nanoparticles (NPs) with systematic analysis to improve their catalytic activity. Herein, we report FeP NPs synthesized with various phosphorus sources (TOP, trioctylphosphine; TPP, triphenylphosphite; TEAP, tris(diethylamino)phosphine; and TBP, tri-n-butylphosphine) via phosphorization reaction. We clearly demonstrate that the HER activity of the catalyst based on the FeP phase is dependent on the choice of phosphorus source used in the colloidal NP synthesis. Among the samples, FeP NPs synthesized with TPP achieved the highest HER activity with an overpotential of 76 mV at 10 mA cm−2 in 0.5 M H2SO4. Our results reveal a critical aspect of colloidal synthesis to achieve enhanced catalytic activity in the synthesis of transition metal phosphide NPs.

Cation exchange reactions of colloidal copper sulfide nanoparticles are widely used to produce derivative nanoparticles having unique compositions, metastable crystal structures, and complex heterostructures. The copper sulfide crystal structure plays a key role in the mechanism by which cation exchange occurs and the product that forms. Here, we show that digenite copper sulfide nanoparticles undergo a spontaneous phase transition to tetragonal chalcocite in situ, prior to the onset of cation exchange. Room-temperature sonication of digenite (Cu1.8S) in trioctylphosphine, a Lewis base that drives cation exchange, extracts sulfur to produce tetragonal chalcocite (Cu2S). The subtle structural differences between digenite and tetragonal chalcocite are believed to influence the accessibility of cation diffusion channels and concomitantly the mechanism of cation exchange. Structural relationships in nanocrystal cation exchange are therefore dynamic, and intermediates generated in situ must be considered.

Background For multicenter clinical studies, PET/CT and SPECT/CT scanners need to be validated to ensure comparability between various scanner types and brands. This validation is usually performed using hollow phantoms filled with radioactive liquids. In recent years, 3D printing technology has gained increasing popularity for manufacturing of phantoms, as it is cost-efficient and allows preparation of phantoms of almost any shape. So far, however, direct 3D printing with radioactive building materials has not yet been reported. The aim of this work was to develop a procedure for preparation of 99mTc-containing building materials and demonstrate successful application of this material for 3D printing of several test objects. Method The desired activity of a [99mTc]pertechnetate solution eluted from a 99Mo/99mTc-generator was added to the liquid 3D building material, followed by a minute amount of trioctylphosphine. The resulting two-phase mixture was thoroughly mixed. Following separation of the phases and chemical removal of traces of water, the radioactive building material was diluted with the required volume of non-radioactive building material and directly used for 3D printing. Results Using our optimized extraction protocol with trioctylphosphine as complex-forming phase transfer agent, technetium-99m was efficiently transferred from the aqueous 99Mo/99mTc-generator eluate into the organic liquid resin monomer. The observed radioactivity concentration ratio between the organic phase and the water phase was > 2000:1. The radioactivity was homogeneously distributed in the liquid resin monomer. We did not note differences in the 3D printing behavior of the radiolabeled and the unlabeled organic liquid resin monomers. Radio-TLC and SPECT studies showed homogenous 2D and 3D distribution of radioactivity throughout the printed phantoms. The radioactivity was stably bound in the resin, apart from a small amount of surface-extractable radioactivity under harsh conditions (ethanol at 50 °C). Conclusions 3D printing of radioactive phantoms using 99mTc-containing building materials is feasible. Compared to the classical fillable phantoms, 3D printing with radioactive building materials allows manufacturing of phantoms without cold walls and in almost any shape. Related procedures with longer-lived radionuclides will enable production of phantoms for scanner validation and quality control.

α-CsPbI3 perovskite quantum dots (PQDs) have great potentials in red-emitting LED and solar cell applications. However, their instability with quick photoluminescence loss with time greatly limits their development. In this study, we found that the nonluminous aged α-CsPbI3 PQDs instantly regained fluorescence emission after a surface treatment with trioctylphosphine. Meanwhile, this surface treatment also worked on fresh α-CsPbI3 PQDs to enhance photoluminescence emission. The structures and compositions of fresh and aged PQDs before and after surface treatment were analyzed in detail. We demonstrated that a surface chemical equilibrium shift mechanism involving oleylammonium led to the PL loss and recovery of α-CsPbI3 PQDs. This chemical equilibrium shift also played an important role in other PQD stabilities against long-term storage, temperature, UV irradiation and ethanol, which were all significantly improved after treatment. The treated α-CsPbI3 PQDs were phase stable for more than 6 months. Oleic acid and oleylamine are common ligands used in PQD syntheses; this study shall promote the understanding of PQD surface chemistry and the preparation of stable α-CsPbI3 PQDs.

The design of active and stable electrocatalysts for the methanol oxidation reaction (MOR) plays a vital role in the large-scale commercialization of direct methanol fuel cells. Herein, one-dimensional P-doped PtTe nanotubes with uniform mesoporous shells (P-PtTe MNTs) have been synthesized using F127 and Te nanowires as the dual template and trioctylphosphine as the phosphorus dopant. The resultant P-PtTe MNTs with sufficient exposed surface atoms can improve the atom utilization of Pt. Moreover, the incorporation of P atoms into Pt lattices can tailor the electronic structure of Pt and induce a strong synergic effect, thus leading to highly active and durable performance for the MOR. This phosphorus doping is very valuable for controllable synthesis of various metal–nonmetal catalysts with desired morphologies.

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).

CuInSe2 I–III–VI2 ternary semiconductor considered as one of the most promising semiconductor material which considers a very efficient solar energy conversion material. An organometallic pyrolysis method is used to prepare monodisperse CuInSe2 nanoparticles using a mixture of oleylamine, and trioctylphosphine (TOP) as capping materials. Controlling the particle shape dot, rods or flowers occurs via varying the reaction temperatures (160, 200, 220°C) respectively. The obtained particles have been characterized to determine the shape and size of CuInSe2 nanoparticles using HR-TEM and XRD. The optical and the electronic properties of these particles have been investigated and discussed in details. Then the different shapes of CIS nanoparticles (nanodots, nanorods, and nanoflowers) were introduced to the DSSC to study their effect on the optical switching properties. It was found that the nanoflowers provide better photovoltaic performance than the other shapes; since it reduces the settling time to 50 milliseconds after it was more than 17 second before adding CIS nanoparticles to the cells.

Different organic ligands capped CdSe quantum dots (QDs) are synthesized. Our results show that CdSe QDs exhibit high photoluminescent intensity when the surface dangling bonds are passivated by trioctylphosphine and oleylamine together. FT-IR vibrational spectra reveal that the oleylamine mainly bond to the metal sites. In the process of synthesis, oleylamine can make CdSe more uniform by controlling the rate of nucleation and growth. Because of size-dependent band gap, core/shell QDs emitting desired color can be obtained by coating different sized cores. The photoluminescence peaks of core/shell QDs cover a wide range from 580 to 615 nm. The core/shell QDs are successfully transferred into aqueous solution through ligand exchanging with reduced glutathione and used to label HeLa cells.

Formation of InP quantum dots (QDs) in a non-coordinating solvent is divided into four stages for studying the chemical reactions. By introducing tertiary phosphines, such as trioctylphosphine (TOP...

Perovskite solar cells have achieved comparable power conversion efficiencies as commercial silicon cells, making the issue of long-term operation stability as the most critical scientific factor toward industrial realization. In this work, we introduce SnS quantum dots (QDs) as a new inorganic hole transporting material (HTM) to perovskite solar cells. The SnS QDs decorated with the oleylamine (OAm), oleic acid (OA), and trioctylphosphine (TOP) ligands are prepared through the traditional nonaqueous solvothermal method. Therefore, the as-synthesized SnS QDs can be orthogonally processed onto the top of a triple cation perovskite film, exhibiting a good surface coverage and an excellent hole extraction ability. With careful device engineering towards film thickness, annealing procedure, and ligand exchange on the SnS layer, we have obtained a power conversion efficiency (PCE) of 13.7%. Compared with the 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD)-based control device, the SnS-based perovskite solar cell presents a better air stability, showing unaltered device performance after 1000 h storage under ambient conditions.

Perovskite nanocrystals (PNCs) have demonstrated their potential use in many applications such as optical encryption because of their excellent optical properties. However, the optical encryption using PNCs is mainly based on the formation of static patterns with luminescence on/off switching. In this work, we demonstrated that the capping ligands play an important role in tuning the luminescence intensity of the PNCs during ion exchange. The surfactant, oleylamine (OAm), is essential in shifting the luminescence color of the PNCs from green to yellow during the ion exchange. In the absence of OAm, the luminescence in the green and yellow regions is quenched during the ion exchange and the luminescence is recovered in the red region by adding trioctylphosphine (TOP) into the ion-exchange solution. On the basis of these findings, we proposed a dynamic optical encryption strategy using PNCs with different capping ligands by tuning the luminescence intensity. The encoded message is hidden in the green pattern at the beginning, shown during the ion exchange, and erased when the pattern is completely converted from a green color to a red color after the ion exchange ends. This dynamic encryption strategy enhances the security level and is compatible with human eye-perceivable patterns and binary coding algorithms.

There is a large and growing demand for the vigorous development of new high performance liquid chromatography stationary phases in order to solve complex phospholipids separation. Herein, phosphonium-based ionic liquid trioctyl(allyl)phosphonium bromide ([P888Allyl]Br) was first synthesized with trioctylphosphine and allyl bromide. With [P888Allyl]Br as the polymerizable monomer, polymerized phosphonium ionic liquid functionalized silica microsphere (PIL@SiO2) was further synthetized via click chemistry reaction. Significantly, based on the inherent amphiphilic nature of the introduced [P888Allyl]Br, the packed PIL@SiO2 column displayed hydrophilic/hydrophobic mixed-mode retention mechanisms. The PIL@SiO2 column can achieve separation of nucleic acid bases and nucleosides, sulfonamides, amides and anilines with excellent selectivity in a shorter separation time. The column efficiency reached 109,700 N/m for 2-iodoacetamide. One of the important characteristics of the PIL@SiO2 column is that both phospholipid classes and species can be efficiently separated via the same column, outperforming that of the commercial amino column. Furthermore, the application potential of the PIL@SiO2 column was further verified via separation of phospholipids extracted from soy lecithin. The proposed PIL@SiO2 column provides a promising candidate for separation of complex phospholipid samples.

Highly active metal-free mesoporous phosphated silica was synthesized by a two-step process and used as a SO2 hydrogenation catalyst. With the assistance of a microwave, MCM-41 was obtained within a 10 min heating process at 180 °C, then a low ratio of P precursor was incorporated into the mesoporous silica matrix by a phosphorization step, which was accomplished in oleylamine with trioctylphosphine at 350 °C for 2 h. For benchmarking, the SiO2 sample without P precursor insertion and the sample with P precursor insertion into the calcined SiO2 were also prepared. From the microstructural analysis, it was found that the presence of CTAB surfactant was important for the incorporation of active P species, thus forming a highly dispersed, ultrafine (uf) phosphate silica, (Si-P) catalyst. The above approach led to the promising catalytic performance of uf-P@meso-SiO2 in the selective hydrogenation of SO2 to H2S, the latter reaction is very important in sulfur-containing gas purification. In particular, uf-P@meso-SiO2 exhibited activity at the temperature range between 150 and 280 °C, especially SO2 conversion of 94% and H2S selectivity of 52% at 220 °C. The importance of the CTAB surfactant can be found in stabilizing the high dispersion of ultrafine P-related species (phosphates). Intrinsic characteristics of the materials were studied using XRD, FTIR, EDX, N2 adsorption/desorption, TEM, and XPS to reveal the structure of the above catalysts.

Significant advance was realized on the economic synthesis of InP quantum dots (QDs) by using aminophosphines as phosphorus precursor. However, the low reaction activity and thermal degradation of aminophosphines bring severe difficulty for growth control of InP QDs. Here, we employed trioctylphosphine (TOP) as a surfactant to accelerate the growth of the InP QDs. The reaction mechanism study reveals that the TOP could form a reactive complex with indium halides that effectively accelerates the formation of InP monomer and reduces the demand for reaction temperature. On this basis, the effect of reaction temperature, precursors, and zinc halide additives on the growth of the TOP-InP QDs was explored. This strategy alleviates the difficulty in growth control of InP QDs and also benefits to the synthesis of luminescent InP/ZnS core–shell QDs within visible regime. A white-light emitting diode device was fabricated with the InP/ZnS QDs that demonstrates their application potential in light-emitting devices.

Solution-processed CdTe semiconductor nanocrystals (NCs) have exhibited astonishing potential in fabricating low-cost, low materials consumption and highly efficient photovoltaic devices. However, most of the conventional CdTe NCs reported are synthesized through high temperature microemulsion method with high toxic trioctylphosphine tellurite (TOP-Te) or tributylphosphine tellurite (TBP-Te) as tellurium precursor. These hazardous substances used in the fabrication process of CdTe NCs are drawing them back from further application. Herein, we report a phosphine-free method for synthesizing group II-VI semiconductor NCs with alkyl amine and alkyl acid as ligands. Based on various characterizations like UV-vis absorption (UV), transmission electron microscope (TEM), and X-ray diffraction (XRD), among others, the properties of the as-synthesized CdS, CdSe, and CdTe NCs are determined. High-quality semiconductor NCs with easily controlled size and morphology could be fabricated through this phosphine-free method. To further investigate its potential to industrial application, NCs solar cells with device configuration of ITO/ZnO/CdSe/CdTe/Au and ITO/ZnO/CdS/CdTe/Au are fabricated based on NCs synthesized by this method. By optimizing the device fabrication conditions, the champion device exhibited power conversion efficiency (PCE) of 2.28%. This research paves the way for industrial production of low-cost and environmentally friendly NCs photovoltaic devices.

The size-dependent optoelectronic properties of semiconductor nanocrystals quantum dots (QDs) are hugely beneficial for color tunability but induce an inherent relative PL brightness mismatch in QDs emitting different colors, as larger emitters absorb more incident photons than smaller particles. Here, we examine the effect of core composition, shell composition, and shell thickness on optical properties including high energy absorption, quantum yield (QY), and the relative brightness of InP/ZnS and InP/ZnSe core/shell and InP/ZnSe/ZnS core/shell/shell QDs at different excitation wavelengths. Our analysis reveals that the presence of an intermediate ZnSe shell changes the wavelength of enhanced absorption onset and leads to highly excitation wavelength dependent QYs. Switching from commercial CdSe/ZnS to InP/ZnS reduces the brightness-mismatch between green and red emitters from 33- to 5-fold. Incorporating a 4-monolayer thick optically absorbing ZnSe shell into the QD heterostructure and heating the QDs in a solution of zinc oleate and trioctylphosphine produces InP/ZnSe/ZnS QDs that are ~10-fold brighter than their InP/ZnS counterparts. In contrast to CdSe/CdS/ZnS core/shell/shell QDs, which only photoluminesce at red wavelengths with thicker CdS shells due to their Quasi-Type II bandstructure, Type I InP/ZnSe/ZnS QDs are uniquely suited to creating a rainbow of visible-emitting, brightness matched emitters. By tailoring the thickness of the intermediate ZnSe shell, heavy metal-free, brightness-matched green and red emitters are produced. This study highlights the ability to overcome the inherent brightness mismatch seen in QDs through concerted materials design of heterostructured core/shell InP-based QDs.

Solution-processed iron selenide nanocrystals (NCs) have recently attracted considerable attention in electrocatalysis water splitting. Nevertheless, a primary challenge in current iron-based NCs chemical synthesis is controlling phase purities between each chalcogen (monochalcogenide, dichalcogenides, and oxides), which requires a comprehensive understanding of the reaction mechanisms at the early stages of nucleation. Herein, we investigate the fundamental steps in transforming molecular organoiron and organoselenium precursors to iron selenides NCs with the view of developing universal synthesis protocols for phase pure metal selenium and metal oxides NCs. The main intermediate species and volatile by-products are identified by high-resolution electron microscopy and Nuclear Magnetic Resonance (NMR) spectroscopy (1H, 13C, and 31P). Experimental evidence suggests that the phase determining factor is the coordinating reactivity difference between olefins (1-octadecene, oleylamine), tributylphosphine and trioctylphosphine associated with their corresponding Se bond cleavage. This work proposes organoselenium interconversion reaction mechanisms during iron selenides synthesis, offering a universal synthetic strategy for other electrocatalytically or photocatalytically active layered metal selenides materials.

Fe–Ni nanoparticles are attractive candidates for magnetic cores of transformers and inductors that are operated at high frequencies. When applying Fe–Ni nanoparticles in magnetic cores, particle size must be controlled to enhance magnetic properties. A two-step synthetic method can be useful for fabricating size-controlled Fe–Ni nanoparticles. In the first step, Ni nanoparticles are synthesized by reducing Ni (II) acetylacetonate in oleylamine (OA) with trioctylphosphine (TOP). Thereafter, Fe (III) acetylacetonate is reduced and Fe atoms diffuse into the preformed Ni nanoparticles in OA. The size of the Fe–Ni nanoparticles depends on that of the Ni nanoparticles. However, no studies have conducted extensive investigations of their synthesis and magnetic properties with various particle sizes. Here, we attempted particle-size-controlled synthesis of Fe–Ni nanoparticles and investigated their magnetic properties. The particle size of the Fe–Ni nanoparticles was varied between 13.1. and 20.5 nm by varying the size of Ni nanoparticles. The saturation magnetization (Ms) gradually reduced with the decrease in particle size because of the increased amount of oxidized surface atoms and phosphides. Coercive forces (Hc) also decreased as the particle size decreased to 15 nm because of the increased effect of superparamagnetism, while the Hc greatly increased with the particle size reduction below 14 nm because of the ferromagnetism exhibited by the Fe layer owing to undiffused Fe atoms. Thus, using this synthetic method, Fe–Ni nanoparticles with a size of approximately 15 nm can be produced, which have a minimum Hc and are the most appropriate for magnetic cores.

Highly luminescent europium complexes modified mesoporous silica particles (MSP) were synthesized as an imaging probes for both in-vitro diagnostic and in-vivo cellular tracking agents. Europium &beta, diketone chelates (4,4,4-trifluoro-l-(2-thienyl)-l,3-butanedione) trioctylphosphine europium (III) (Eu(TTA)3(P(Oct)3)3) were incorporated inside the nanocavities that existed in hierarchical MSP (Eu@MSP). The MSP and Eu@MSP on mouse bone marrow-derived macrophages (BMDMs) did not show any toxic effect. The MSP and Eu@MSP in the BMDMs were found at cytoplasm without any degradation and immunogenicity. However, both pro- and anti-inflammatory cytokines of macrophages were significantly increased when lipopolysaccharide and a high concentration (100 &mu, g/mL) of MSP and Eu@MSP were treated simultaneously.

Study of the liquid-liquid extraction of Ag(I) ions with a series of phosphine oxides (trioctylphosphine, tributylphosphine, triphenylphosphine, and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide) and phosphorus-containing calix[4]arene by the well-known method of slope analysis and determination of the process parameters are presented employing CHCl3 and an ionic liquid, 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C1C4im+][Tf2N−]) as diluents. The ligand effect on the complexation properties of Ag(I) is quantitatively assessed. The silver-containing extracts are examined by 1H, 31P NMR as well as by SEM and TEM approaches in order to viewing the cation coordination and ligands’ binding mode inside, in the organic phase solution at micro-scale level. A conclusion can be made about aggregation in micelle formation of the calix[4]arene under study upon extraction of Ag(I) ion. A method employing thermogravimetric analysis (TGA) is also exploited for the determination of the solubility of CMPO ligand diluted in [C1C4im+][Tf2N−]. Final conclusions are given highlighting the role of the diluent, molecular or ionic, in complexation processes and selectivity involving ligands with P=O donor group and various metal s-, p-, d- and f-cations. The Ag(I) ions have shown the best extraction behavior compared to the other ions in the +1 oxidation state. Indeed, the calix[4]arene derivative bearing four P=O functions at the lower rim, shows strongly enhanced extraction as well as pronounced separation abilities towards lanthanoids in an ionic liquid environment.

Understanding how to control the nucleation and growth rates is crucial for designing nanoparticles with specific sizes and shapes. In this study, we show that the nucleation and growth rates are correlated with the thermodynamics of metal–ligand/solvent binding for the pre-reduction complex and the surface of the nanoparticle, respectively. To obtain these correlations, we measured the nucleation and growth rates by in situ small angle X-ray scattering during the synthesis of colloidal Pd nanoparticles in the presence of trioctylphosphine in solvents of varying coordinating ability. The results show that the nucleation rate decreased, while the growth rate increased in the following order, toluene, piperidine, 3,4-lutidine and pyridine, leading to a large increase in the final nanoparticle size (from 1.4 nm in toluene to 5.0 nm in pyridine). Using density functional theory (DFT), complemented by 31P nuclear magnetic resonance and X-ray absorption spectroscopy, we calculated the reduction Gibbs free energies of the solvent-dependent dominant pre-reduction complex and the solvent-nanoparticle binding energy. The results indicate that lower nucleation rates originate from solvent coordination which stabilizes the pre-reduction complex and increases its reduction free energy. At the same time, DFT calculations suggest that the solvent coordination affects the effective capping of the surface where stronger binding solvents slow the nanoparticle growth by lowering the number of active sites (not already bound by trioctylphosphine). The findings represent a promising advancement towards understanding the microscopic connection between the metal–ligand thermodynamic interactions and the kinetics of nucleation and growth to control the size of colloidal metal nanoparticles.

The effect of the functional groups of capping agents was investigated in the synthesis of copper selenide, copper sulphide and copper oxide nanoparticles using oleylamine (OLA) and trioctylphosphine (TOP). These capping molecules have demonstrated their ability to act as reducing agents, surfactants, solvents and enhancement of colloidal stabilization. They also offer electron donating abilities from the two group 5A elements, P and N. Nitrogen atom in an amine group possess stronger surface interactions and higher basicity than P atom in the phosphines. Copper chalcogenide nanoparticles were prepared using Hot-injection method and characterized using UV/Vis spectroscopy, TEM and XRD. The optical and structural properties of the yielded nanoparticles showed dependence on the type of capping interactions from the two agents. Nanoparticles synthesized using TOP produced two phases whereas a single phase was observed from OLA as confirmed by XRD. Although TOP and OLA exhibit similar features, but their affinity to metals differs resulting to significant different morphology and crystallinity of the produced nanoparticles. Amine group has higher affinity for protons than phosphine due to the lone pair of electrons it possesses which it easily donates to H+ compared to phosphine. The high proton affinity of oleylamine makes it interact faster than trioctylphosphine. OLA in overall produced larger particle sizes compared to TOP but generated a wider variety of shapes., Inorganic chemistry; Materials chemistry; Nanotechonology, Oleylamine; Trioctylphosphine; Copper oxide nanocrystals; Copper sulphide nanocrystals; Copper selenide nanocrystals; Capping molecule; Shape and size.

Highly fluorescent magnetic nanoparticles (Eu(TTA)3(P(Oct)3)3@mSiO2@SPION) [europium (III) chloride hexahydrate = Eu, 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione = TTA, trioctylphosphine = (P(Oct)3), mesoporous silica = mSiO2, superparamagnetic iron oxide nanoparticle = SPION] were developed as a dual-functional imaging agent. The hierarchical structure was composed of a magnetic core and mesoporous silica shell was constructed using a cationic surfactant template after coating with phosphatidylcholine of oleic acid coated SPION. Afterward, the surface and cavities of mSiO2@SPION were modified with 3-(trimethoxysilyl) propyl methacrylate (TMSPMA) as a silane coupling agent to introduce methacrylate groups. Eu(TTA)3(P(Oct)3)3 molecules are penetrated, located and bonded covalently inside of the cavities/mesopores of mSiO2, it shows extremely stable anti-photobleaching properties. The emission spectra of Eu(TTA)3(P(Oct)3)3@mSiO2@SPION indicated typical hypersensitivity transition 5D0&rarr, 7F2 at 621 nm. The concentration of Eu(TTA)3(P(Oct)3)3@mSiO2@SPION was varied between 10 and 500 &mu, L/mL to evaluate the cytotoxicity with NCI-H460 (H460) cells using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. In addition, the presence of a strong red-emitting Eu(TTA)3(P(Oct)3)3@mSiO2@SPION in the cytoplasm was observed by fluorescence microscopy. Those results that it can be a potential candidate for dual-functional contrast agent and PL nanomaterials for fabricating the diagnostic kits to amplify the low signal.

Lithium extraction from ammoniacal solution with thenoyltrifluoroacetone (HTTA) and neutral ligand was studied in various organic solvents. The remarkable enhancement of lithium extraction was observed by the addition of neutral organophosphorus compounds and the experiments showed that trioctylphosphine oxide(TOPO) was preferable for lithium extraction. The synergistic effect of thenoyltrifluoroacetone and trioctylphosphine was studied in detail and the results indicated that the strongest enhancement coefficient was 1205 when molar ratio of two extractants was 1:1. The extracted lithium complex was found to be Li•TTA•2TOPO by slope method and the results of thermodynamic study indicated that the extraction process was spontaneous exothermic process and the degree of disorder increased after extraction. In addition, stripping and regeneration condition of organic phase were investigated in detail. It was demonstrated that the synergistic extraction system containing HTTA and TOPO could effectively separate lithium and other alkali metal ions and was feasible for lithium extraction from ammoniacal solution.

For the first time, a one pot thermolysis of [Pd(PPh3)2Cl2] prepared by reacting Ph3P with PdCl2 in a 2 : 1 molar ratio in MeOH at 280 °C in a trioctylphosphine (TOP) and oleylamine(OA)-octadecane(ODE) mixture (1 : 1) was used to prepare quantum dots (QDs; size ∼2–3 nm) and nanoparticles (NPs; size ∼13–14 nm), respectively, of composition Pd3P0.95. TEM, SEM-EDX, powder-XRD and XPS (for QDs only) were used to authenticate the two nanophases. 31P{1H}NMR experiments performed to monitor the progress of thermolysis reactions revealed that the phosphorus present in the Pd3P0.95 QDs had come from TOP, whereas in Pd3P0.95 NPs, its source is triphenylphosphine. The nature of the solvent did not affect the chemical composition of the nano-phase but controlled its size. Probably, solvent dependent, unique, single source precursors (SSPs) of palladium were generated in situ, and controlled the size. The catalytic activity of both Pd3P0.95 QDs and NPs was explored. The QDs were found to be efficient as a catalyst for the amide–nitrile interconversion at room temperature (yield up to 92% in 4 h), hydration of nitriles and transfer hydrogenation (TH) of carbonyl compounds with yields up to 96% in 3–4 h. The yields and reaction rates of amide–nitrile inter-conversion and TH when catalyzed by Pd3P0.95 QDs were found to be higher compared to the ones observed with the Pd/C catalyst. The binding energy of Pd(3d) in the X-ray photoelectron spectrum (XPS) of Pd3P0.95 indicated an electron transfer from the metal to phosphorus, resulting in electron deficient palladium, which facilitates the coordination of a substrate to Pd and drives the reaction. The reusability of Pd3P0.95 QDs for the interconversion was found to be up to 4-times, while for the transfer hydrogenation of carbonyl compounds it was up to 6-times, but with a diminished yield. Pd3P0.95 NPs were found to be less active (yield up to 36% in optimized reaction conditions) in comparison to Pd3P0.95 QDs. The mercury poisoning test suggested that the catalysis predominantly proceeded heterogeneously on the surface of the QDs. The PXRD and XPS results did not suggest a significant variation in the phase of QDs after the third catalytic cycle. The bleeding of Pd during catalysis (determined by flame AAS) and the agglomeration of QDs as supported by the SEM-EDX and TEM results are probably responsible for the reduction in the catalytic activity of QDs after reusing three times.

The use of hybrid associates in biological, optoelectronics and energy fields are increasing day by day. In this context, in this study, CdSeTe Quantum dots (QD): Bromophenol Blue (BPB) hybrid associates were studied for the first time in the literature and their spectroscopic characterizations were examined. In the study, CdSeTe QDs were synthesized with trioctylphosphine (TOP) ligands by hot injection method, and it was planned that the BPB would passivate the surface of the QD by interacting with the TOP ligand of the CdSeTe QDs. CdSeTe QD: BPB hybrid associates were prepared in different concentrations, and the effects of QD: BPB ratios on absorbance and emission characterizations were examined. Structures have been characterized using Uv-vis, PL, ICP-OES and FTIR. With the results found, the predictive mechanism has been put forward.

Palladium acetate trimer, Pd3(OAc)6, is a common precursor for Pd nanoparticle synthesis and an important precatalyst for homogeneous catalysis reactions. Added ligands (L, e.g., phosphines) are well-known to dissociate the Pd3(OAc)6 trimer into Pd(OAc)2 monomers and form Pd(OAc)2(L)2 complexes. Despite the importance of the trimer dissociation and ligand–monomer binding thermodynamics on the properties of the resulting Pd complex, little is known about either reaction. Using a combination of isothermal titration calorimetry (ITC), X-ray absorption fine structure (XAFS), and 31P nuclear magnetic resonance (31P NMR) on trimer samples containing monomer impurities, we developed a methodology and a trimer–monomer ITC model to obtain the Gibbs free energy, enthalpy, and entropy for both reactions in toluene and quantify the monomer content. The results provide the following, previously inaccessible, quantitative insights on the reactions. Trioctylphosphine (TOP)-monomer binding reaction is enthalpically drive...

Copper indium diselenide (CuInSe2) nanocrystals are a prototypical I–III–VI semiconductor quantum dot material, typically synthesized in oleylamine (OLAm) as a solvent and capping ligand, often with the addition of diphenylphosphine (DPP) to improve the reaction yield. Using 1H nuclear magnetic resonance spectroscopy, we study the association of OLAm and DPP on CuInSe2 nanocrystals and find that they both behave as tightly bonded L-type ligands. There is no observable desorption of OLAm or DPP when a toluene-d8 dispersion is heated to 100 °C, and no ligand exchange occurs when the nanocrystals are exposed to other L-type species like trioctylphosphine (TOP) or octadecanethiol (ODT), which can bind as either X-type or L-type. Molecular iodine (I2), however, is found to readily displace both OLAm and DPP from the nanocrystal surface and facilitate efficient and complete ligand exchange with either TOP or ODT and appears to behave as a Lewis acid Z-type ligand. We also find that the X-type ligand, stearic ac...

In anion exchange membrane fuel cells, Pd nanoparticles are extensively studied as promising non-Pt catalysts due to their electronic structure similar to Pt. In this study, to fabricate Pd nanoparticles well dispersed on carbon support materials, we propose a synthetic strategy using mixed organic ligands with different chemical structures and functions. Simultaneously to control the Pd particle size and dispersion, a ligand mixture composed of oleylamine(OA) and trioctylphosphine(TOP) is utilized during thermal decomposition of Pd precursors. In the ligand mixture, OA serves mainly as a reducing agent rather than a stabilizer since TOP, which has a bulky structure, more strongly interacts with the Pd metal surface as a stabilizer compared to OA. The specific roles of OA and TOP in the Pd nanoparticle synthesis are studied according to the mixture composition, and the oxygen reduction reaction(ORR) activity and durability of highly-dispersed Pd nanocatalysts with different particles sizes are investigated. The results of this study confirm that the Pd nanocatalyst with large particles has high durability compared to the nanocatalyst with small Pd nanoparticles during the accelerated degradation tests although they initially indicated similar ORR performance.

Rare earth elements (REEs) are the core of many future-sustainable technologies. One example is magnetocaloric refrigeration, an emerging field essential for the efficient use of energy. Future adoption of this technology will require adequate processing of end-of-life units and production residues. Currently, REEs have very high supply risk, and their recovery rates are below 1%. So far, their recovery from magnetocaloric materials has not been addressed. This work reports on a leaching and solvent extraction process to recover REEs from genuine magnetocaloric materials comprising cerium, iron, lanthanum, manganese and silicon. Leaching was studied using nitric, hydrochloric and sulfuric acid solutions, with optimizations in terms of temperature, acid concentration and solid-to-liquid ratio. Recovery of REEs from nitric, hydrochloric, and sulfuric acid leachates was investigated with three types of solvating extractants: tributyl phosphate (TBP), trioctylphosphine oxides (Cyanex 923) and tetraoctyl digylcol amide (TODGA). Extraction was most effective from nitric acid media. Very good extraction selectivity between REEs and non-REEs was achieved with TODGA. Cyanex 923 showed better extraction efficiency than TBP, and performed best in aliphatic diluents. A separation factor of 3.3 between cerium and lanthanum was achieved with 1 mol/L Cyanex 923 in Isopar L.

A classical all-atom molecular dynamics simulation has been used to study the adsorption of mesotetra( 3-pyridyl)porphyrin dye on colloidal quantum dots of cadmium selenide. The competition between dye molecules and ligands covering the quantum dots has been investigated by the examples of trioctylphosphine, trioctylphosphine oxide, octadecylphosphonic acid, and hexadecylamine. It has been shown that the dye is strongly retained by the surface and is not washed out with a solvent either from a free surface or in the presence of trioctylphosphine in the shell. The strength of the adsorption of the dye is equal to that of trioctylphosphine. At the same time, it gives up its place on the surface to stronger ligands, octadecylphosphonic acid and hexadecylamine.

Solution-processed optoelectronic devices are attractive because of the potential low-cost fabrication and the compatibility with flexible substrate. However, the utilization of toxic elements such as lead and cadmium in current optoelectronic devices on the basis of colloidal quantum dots raises environmental concerns. Here we demonstrate that white-light-emitting diodes can be achieved by utilizing non-toxic and environment-friendly gold nanoclusters. Yellow-light-emitting gold nanoclusters were synthesized and capped with trioctylphosphine. These gold nanoclusters were then blended with the blue-light-emitting organic host materials to form the emissive layer. A current efficiency of 0.13 cd/A was achieved. The Commission Internationale de l’Eclairage chromaticity coordinates of (0.27, 0.33) were obtained from our experimental analysis, which is quite close to the ideal pure white emission coordinates (0.33, 0.33). Potential applications include innovative lighting devices and monitor backlight.

Quantum dots (QDs) are useful for demonstrating the particle-in-a-box (PIB) model utilized in quantum chemistry, and can readily be applied to a discussion of both thermodynamics and kinetics in an undergraduate laboratory setting. Modifications of existing synthetic procedures were used to create QDs of different sizes and compositions (CdS passivated with polymer, and CdSe passivated with oleic acid/trioctylphosphine). These were investigated by spectroscopy, to which standard 3D PIB mathematical models were applied to determine their effective size. The data were compared to those from other methods for students to see the validity of the PIB model. For CdSe QDs, an empirical formula was applied to the spectroscopic data. In the case of CdS, the synthesized QDs were studied with X-ray diffraction, from which one can also estimate the size of the QDs. Finally, the QDs were utilized as the light-harvesting layer in photovoltaic cells by attachment to a layer of surface-modified titania (TiO2) nanoparticl...