Selenide Nanoparticles Research Articles

Engineering of the Photon Local Density of States: Strong Inhibition of Spontaneous Emission near the Resonant and High-Refractive Index Dielectric Nano-objects.

Metallic or dielectric nano-objects change the photon local density of states of closely placed emitters, particularly when plasmon or Mie resonances are present. Depending on the shape and material of these nano-objects, they may induce either a decrease or an increase in decay rates of the excited states of the emitter. In this work, we consider the reduction of the probability of optical transitions in emitters near high-refractive index dielectric (silicon and zinc selenide) nanoparticles. We tune the spectral positions of magnetic and electric modes of nanocylinders to obtain the largest overlap of the valleys in the total decay rate spectra for differently oriented dipoles and, in this way, find the highest inhibition of about 80% for randomly oriented emitters. The spectral positions of these valleys are easy to control since the wavelengths of the modes depend on the height and diameter of nanocylinders. The inhibition value is robust to the distance between the emitter and the nanoparticle in the range of nearly 50 nm, which is crucially important for the applications, such as selective optical transition engineering and photovoltaics.

Mercury speciation in Scottish raptors reveals high proportions of inorganic mercury in Scottish golden eagles (Aquila chrysaetos): Potential occurrence of mercury selenide nanoparticles

Knowledge of the uptake and fate of mercury (Hg) compounds in biota is important in understanding the global cycling of Hg and its transfer pathways through food chains. In this study, we analysed total mercury (T-Hg) and methylmercury (MeHg) concentrations in 117 livers of Scottish birds of prey that were found across Scotland and submitted for post-mortem examination through the Raptor Health Scotland project between 2009 and 2019. Statistical comparisons focussed on six species (barn owl, Tyto alba; Eurasian common buzzard, Buteo buteo; golden eagle, Aquila chrysaetos; hen harrier, Circus cyaneus; Eurasian sparrowhawk, Accipiter nisus; and tawny owl, Strix aluco) and showed that golden eagles had a statistically lower fraction of MeHg compared to other raptor species. Further investigation using stable carbon and stable nitrogen isotope ratio measurements carried out for the golden eagles (n = 15) indicated that the increased presence of inorganic mercury (iHg) correlated with a marine influence on the primarily terrestrial diet. Additional bioimaging (n = 1) with laser ablation – inductively coupled plasma – mass spectrometry indicated the co-location of Hg and selenium (Se) within the liver tissue and transmission electron microscopy showed evidence of nanoparticles within the range of 10–20 nm. Further analysis using single particle – inductively coupled plasma – mass spectrometry (n = 4) confirmed the presence of Hg nanoparticles. Together, the evidence suggests the presence of mercury selenide (HgSe) nanoparticles in the liver of some golden eagles that, to our knowledge, has never been directly observed in terrestrial birds of prey. This study points to two alternative hypotheses: these golden eagles may be efficient at breaking down MeHg and form HgSe nanoparticles as a detoxification mechanism (as previously observed in cetaceans), or some golden eagles with elevated iHg may have accumulated these nanoparticles by foraging on stranded cetaceans or seabirds.

Comment on “New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues”

Some birds and cetaceans can demethylate the toxic methylmercury cysteinate (MeHgCys) complex into inert mercury sulfide (HgSe) through the formation of an intermediate tetrahedral selenolate complex with selenocysteine (Sec) residues (Hg(Sec)4). The nucleation of the HgSe biominerals involves the substitution of the Se ligand for the Sec residues, which is considered to occur in the form of multinuclear Hgx(Se,Sec)y clusters mediated by proteins. Queipo-Abad et al. (2022) isolated HgSe nanoparticles from the biological tissues of giant petrels and measured the mass-dependent fractionation of the 202Hg isotope (δ202Hg). They concluded that the δ202Hg values of the HgSe nanoparticles from each tissue of individual petrels are specific to the HgSe species alone and that the Hg(Sec)4 → HgSe reaction occurs without fractionation of the 202Hg isotope. We show (1) that the HgSe nanoparticles are likely mixtures of MeHgCys, Hg(Sec)4, and HgSe, and therefore that the δ202Hg values are not species-specific, and (2) that the 202Hg isotope is actually fractionated during the Hg(Sec)4 → HgSe reaction, and therefore that this isotope can be used to trace the Hg metabolic pathways between tissues in a single individual and in different animals.

Reply to the comment on “New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues” by A. Manceau, J. Hazard. Mater. 425 (2021) 127922. doi: 10.1016/j.jhazmat.2021.127922

In the comments reported by A. Manceau [1], relating to our recent paper on mercury (Hg) species-specific isotopic characterization in giant petrel tissues [2] two critical questions were raised. Firstly, according to A. Manceau, our method of extraction and isolation of nanoparticles was not able to efficiently isolate mercury selenide nanoparticles (HgSe NPs) and therefore the δ202Hg values measured are not species-specific, but rather δ202Hg of mixtures of complexes such as MeHgCys, Hg(Sec)4, and HgSe. Secondly, he suggests that our main findings showing that no isotopic fractionation is induced during the HgSe NPs biomineralization step from the precursor-demethylated species is erroneous because it contradicts the conclusion of two recent articles by A. Manceau and co-workers [3,4]. In this reply we defend our scientific findings and respectively respond to the questions and comments raised by A. Manceau.

Iron Selenide-Based Heterojunction Construction and Defect Engineering for Fast Potassium/Sodium-Ion Storage.

Suitable anode materials with high capacity and long cycling stability, especially capability at high current densities, are urgently needed to advance the development of potassium ion batteries (PIBs) and sodium ion batteries (SIBs). Herein, a porous Ni-doped FeSe2 /Fe3 Se4 heterojunction encapsulated in Se-doped carbon (NF11 S/C) is designed through selenization of MOFs precursor. The porous composite possesses enriched active sites and facilitates transport for both ion and electron. Ni-doping is adopted to enrich the lattice defects and active sites. The Se-C bond and carbon framework endow integrity of the composite and hamper aggregation of selenide nano-particles during potassiation/de-potassiation. The NF11 S/C exhibits exceptional rate performance and ultra-long cycling stability (177.3mA h g-1 after 3050 cycles at 2 A g-1 for PIBs and 208.8mA h g-1 after 2000 cycles at 8 A g-1 for SIBs). The potassiation/de-potassiation mechanism is investigated via ex-situ X-ray powder diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectrocopy and Raman analysis. PTCDA//NF11 S/C full cell stably cycles for 1200 cycles at 200mA g-1 with a capacity of 103.7mA h g-1 , indicating the high application potential of the electrode for highly stable rechargeable batteries.

Optical, morphological, electrical properties and white light photoresponse of CdSe nanoparticles

ABSTRACT II–VI nanocrystalline semiconductors offer a wide range of applications in electronics, optoelectronics, and photonics. The study of the morphological, electrical, and optical properties of Cadmium selenide (CdSe) nanoparticles prepared with tri ethanolamine (TEA) as a complex agent is reported in the paper. Cadmium acetate as a Cd source and (Na2SeO3) as a Se precursor. Transmission electron microscope (TEM), field emission scanning electron microscope (FESEM), energy dispersive x-ray (EDX), and ultraviolet-visible spectroscopy (UV-VIS) were used to characterise the synthesised nanoparticles for their optical, compositional, morphological, and electrical properties. The film of CdSe was deposited on the glass substrate. The electrical characterisation of CdSe thin films at various temperatures dark electrical conductivity and photoconductivity reveal that the films were semiconducting in nature, indicating the suitability of these films for photo sensor applications.

Ti3C2Tx MXene Nanoflakes Embedded with Copper Indium Selenide Nanoparticles for Desalination and Water Purification through High-Efficiency Solar-Driven Membrane Evaporation.

Solar-driven interface evaporation recently emerges as one of the most promising methods for seawater desalination and wastewater purification, mainly due to its low energy consumption. However, there still exist special issues in the present material system based on conventional noble metals or two-dimensional (2D) nanomaterials etc., such as high costs, low light-to-heat conversion efficiencies, and unideal channels for water transport. Herein, a composite photothermal membrane based on Ti3C2Tx MXene nanoflakes/copper indium selenide (CIS) nanoparticles is reported for highly efficient solar-driven interface evaporation toward water treatment applications. Results indicate that the introduction of CIS improves the spatial accessibility of the membrane by increasing the interlayer spacings and wettability of MXene nanoflakes and enhances light absorption capability as well as reduces reflection for the photothermal membrane. Simultaneously, utilization of the MXene/CIS composite membrane improves the efficiency of light-to-heat conversion probably due to formation of a Schottky junction between MXene and CIS. The highest water evaporation rate of 1.434 kgm-2 h-1 and a maximum water evaporation efficiency of 90.04% as well as a considerable cost-effectiveness of 62.35 g h-1/$ are achieved by using the MXene/CIS composite membrane for solar interface evaporation, which also exhibits excellent durability and light intensity adaptability. In addition, the composite photothermal membrane shows excellent impurity removal ability, e.g., >98% for salt ions, >99.8% for heavy metal ions, and ∼100% for dyes molecules. This work paves a promising avenue for the practical application of MXene in the field of water treatment.

Effect of Sodium Selenosulfate Concentration on Microstructural, Morphological, and Luminescence Characteristics of Cadmium Selenide Nanoparticles

CBD-deposited cadmium selenide nanoparticles in acidic medium production at pH value of bath solution was stayed constant at 6.5 using EDTA as complexing agents; sodium selenosulfite acts as a source of Se2- ion and cadmium acetate as source of Cd2+ ion. The nanoparticles of binary compound CdSe were also grown at different concentrations of sodium selenosulfite, and the influence of this parameter on the behaviours of the nanoparticles was studied. The as-synthesized cadmium selenide nanoparticles are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and PL absorption spectroscopy. Cadmium-selenide nanoparticles were produced using various concentrations as 10, 15, and 20 milliliters on a microscopic glass plate by chemical technique at a growth temperature of 90 degree Celsius. Microstructural constraints realized from the X-ray diffraction pattern decrease in grain size with an increase of concentration (8.25 nm–0.01 nm). It witnessed that the synthesized nanoparticle has a cubic crystal structure with favoured direction towards the (111) Miller indices’ plane. The oriented peak was investigated from the planes (311) and (111). From patterns of PL emissions, it was detected that in increasing concentration of sodium selenosulfate intensity, the nanoparticles with small crystal size could represent maximum luminescence intensity associated with the larger crystal size. This is due to the fact that the amount of ions on the nanoparticle surface rapidly increases as the crystal size of the nanoparticles reduces. Additionally, the transporter recombination ratio was increased as the size of the transporter reduces resulting in an increase in the overlap between the electron and hole wave functions. SEM inspection of produced nanoparticles reveals that the surface is free of cracks and that the grains are spherically formed. The surface is coated with granules of consistent size and shape. There are no fractures or holes visible inside the thin films under examination.

Sequential growth-controlled silver selenide nanoparticles embedded 1D-CdS nanowires: Heterostructure design to enhance power conversion efficiency

Room temperature sequential growth namely, successive ionic layer adsorption and reaction (SILAR) method has been successfully processed towards the controlled growth of silver selenide (Ag2Se) nanoparticles onto one dimensional (1D) CdS nanowires (NWs) array. Well controlled size tuning enables well-aligned heterostructure yielding almost four times enhancement (0.34%) in power conversion efficiency compared to the bare CdS NWs (0.09%) in photoelectrochemical (PEC) solar cell assembly. Results are well equipped through structural, surface morphological, optical and elemental oxidation state in correlation with PEC solar cell, external quantum efficiency (EQE), Mott-Schottky (M − S), and electrochemical impedance spectroscopy (EIS) performances. Interestingly, sequential SILAR method produces extremely conformal coverage of Ag2Se layer with precise thickness control. The optimum mutualistic contribution from Ag2Se and CdS not only broaden the light absorption range but also allows the rapid separation of excited charge carriers at heterostructure interface.

Comparative Study of Bulk and Nanoengineered Doped ZnSe

Chromium- and cobalt-doped zinc selenide nanoparticles were synthesized using a low-temperature reactive solution growth method. The morphological and optical characteristics were compared to those of doped zinc selenide (ZnSe) bulk crystals grown by the physical vapor transport (PVT) method. We observed agglomeration of particles; however, the thioglycerol capping agent has been shown to limit particle grain growth and agglomeration. This process enables doping by addition of chromium and cobalt salts in the solution. A slightly longer refluxing time was required to achieve cobalt doping as compared with chromium doping due to lower refluxing temperature. The nanoparticle growth process showed an average particle size of approximately 300 nm for both Cr- and Co-doped zinc selenide. The optical characterization of Co:ZnSe is ongoing; however, preliminary results showed a very high bandgap compared to that of pure ZnSe bulk crystal. Additionally, Co:ZnSe has an order of magnitude higher fluorescence intensity compared to bulk Cr:ZnSe samples.

A Comparative Study of Structural, Vibrational Mode, Optical and Electrical Properties of Pure Nickel Selenide (Nise) and Ce-Doped Nise Nanoparticles for Electronic Device Applications

A Comparative Study of Structural, Vibrational Mode, Optical and Electrical Properties of Pure Nickel Selenide (Nise) and Ce-Doped Nise Nanoparticles for Electronic Device Applications

CdSe-TiO2 nanocomposites film deposited by electrophoretic co-deposition towards quantum dots sensitized solar cells

In this paper, cadmium selenide (CdSe) nanoparticles were used in quantum dots sensitized solar cells (QDSSCs) as photosensitizer. Electrophoretic co-deposition was employed to deposit cadmium selenide – titanium dioxide (CdSe-TiO2) nanoparticles for the preparation of the QDSSC photoanode. Co-deposition of CdSe-TiO2 were used to prevent the need of thermal treatment to the photoanode which could cause cracks on surface. The formation of CdSe-TiO2 nanocomposites could increase the electron injection speed due to interdigitated between CdSe and TiO2 nanoparticles. CdSe nanoparticles were prepared using hot injection methods at reaction temperature 300 °C for 1 min reaction time. Titanium dioxide (TiO2) nanoparticles solution was prepared using surface modification by propionic acid and n-hexylamine. Cu2S/Brass counter electrode was used with polysulphide electrolyte. Prior to electrophoretic deposition (EPD), the CdSe nanoparticles solution were purified for two times. The efficiency of the QDSSC assembled with photoanode deposited with 250 V and 90 s was the highest amongst of the other EPD parameter studied, were at 2.920 × 10−3 %.

Colloidal synthesis of stable ZnSe nanoparticles

Metal chalcogenides such as ZnX (X = S, Se, Te) nanostructures, belonging to the II-VI group of semiconductor family are known to be potential candidates in diverse applications due to their distinctive characteristics such as size dependent opto-electronic properties and ease in processibility. Herein, the preparation of Zinc selenide (ZnSe) nanoparticles using simple, water soluble precursors under ambient conditions is reported. Thioglycolic acid is used as the capping agent for the controlled nucleation and growth mechanism, resulting in the formation of homogeneous ZnSe nanoparticles. The UV–Vis absorption spectrum clearly showed a remarkable blue shift as compared to its bulk counterpart and the fluorescence spectra exhibited broad- intense emission spectra which may be attributed to defect related emission. The as prepared ZnSe nanoparticles remain stable even after aging. The dearth of the S-H vibration band in the FTIR spectra indicatesthe SH functional group are attached to the Zn2+surfaces of the ZnSe nanoparticles implying that thiol-assisted capping of ZnSe has occurred. The X-ray diffraction pattern reveals the cubic phase crystal structure and the estimated particle size is 3.0 nm. Thus, the present synthetic approach is robust, cost effective, scalable and avoids usage of toxic chemicals, high temperatures and pressures. These ZnSe nanoparticles can be implemented for electrical and optical communication, storage devices and display applications.

Structural and phase features of zinc selenide nanoparticles obtained by laser evaporation

The first production of weakly agglomerated zinc selenide nanopowders by evaporation of a target of the required chemical composition in argon using a fiber ytterbium laser is reported. Nanoparticles have the shape of polyhedrons and, more rarely, spheres with an average size of 18 nm. According to XRD data, the obtained nanopowders contain two phases: a stable cubic phase (sphalerite, 40 wt.%) and a metastable hexagonal phase (wurtzite, 60 wt.%). An analysis of HRTEM showed that most of the nanoparticles have structural defects. Due to superstoichiometry, defects in the crystal structure of the crystallographic shift type are formed in nanoparticles. Magneli phases, Wadsley defects and various kinds of heterogeneity inside the particles were found. Keywords: Laser evaporation, zinc selenide, nanoparticles, high resolution transmission electron microscopy (HRTEM), defects, phase composition, crystallographic shift, Magnelli phase, Wadsley defects.

Solvothermal synthesis and characterization studies of selenium decorated reduced graphene oxide supported CuSe2 nanoparticles as efficient electrochemical catalyst for oxygen reduction reaction

In the energy conversion system, oxygen reduction reaction (ORR) is one of the most significant reactions. Pt-based catalysts are commonly used in fuel cells; the replacement with low-cost materials like transition metal oxides is much needed for the wide application of fuel cells. In this paper, the effective synthesis of copper selenide nanoparticles with selenium-reduced graphene oxide has been described. To establish the existence of selenium, graphene, and copper in manufactured samples, X-Ray diffraction analysis (XRD) has been used. Additionally, fourier transform infrared analysis (FTIR) has been used to examine the functional groups. The structure and morphology have been studied under the scanning electron microscope. UV has been used to assess the synthetic nanoparticles' optical performance. The Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods have been used to analyze their specific surface area and pore size. Cyclic voltammetry has been used to evaluate the produced nanoparticles' electrochemical performance (CV, LSV).

Controllable synthesis of surfactants (PEG and SDS) assisted Copper Selenide Nanoparticles by hydrothermal method for photocatalytic activity

Semiconductor metal chalcogenide nanomaterials are excellent materials which possess interesting properties like existing in different structures under different conditions of synthesis, layered growth nature, low tunable bandgap and can be grown in ambient environmental conditions, etc. Copper Selenide (Cu2Se) is an important p-type semiconducting material, with band gaps 1.2–2.3 eV. Copper Selenide has a wide range of applications in various areas of research such as optical filters, super ionic conductors, window materials, thermal electric conductors and photo electric devices. The experimental synthesis of copper selenide was carried out by the hydrothermal route. The size of nanomaterials can be controlled when it is capped with different types of surfactants (cationic, anionic, nonionic or Zwitter ionic). Two types of surfactants, say sodium dodecyl sulphate (SDS), an anionic surfactant and polyethylene glycol (PEG), a non-ionic surfactant were chosen to study their influence on the particle size. The various characterization techniques namely XRD, UV, SEM, TEM, Dielectric studies and photocatalytic activity were adopted to analysis the samples.

Zinc selenide nanoparticles: Green synthesis and biomedical applications

Zinc selenide nanoparticles: Green synthesis and biomedical applications

Studies on the photocatalytic activity molybdenum doped cadmium selenide nanoparticles towards indigo carmine dye degradation under solar light

In the present study, molybdenum doped cadmium selenide (Mo-CdSe) nanoparticles photocatalyst has been synthesized and utilized for the degradation of indigo carmine dye under solar light irradiation. Mo-CdSe nanoparticles were characterized by X-ray diffraction (XRD), ultraviolet spectroscopy, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDAX), transmission electron microscopy, thermo gravimetric (TGA) and FTIR studies. The XRD and EDAX spectrum confirms the presence of Mo onto CdSe matrix. Thermal proved that the Mo-CdSe nanoparticles possessed greater thermal stability than CdSe nanoparticles. Photodegradation studies under solar light irradiation revealed that the Mo-doped CdSe nanoparticles exhibit higher photocatalytic activity than that of pure CdSe nanoparticles. This significant improvement in the photocatalytic efficiency of Mo-CdSe nanoparticles photocatalyst under solar light irradiation can be attributed to the presence of Mo on the CdSe nanoparticles which greatly enhances absorption in the visible range of solar spectrum enabled by the Mo and better charge separation.

Easy intercalation and size control of zinc selenide by nanospace modification of montmorillonite and saponite with enhanced photoluminescence

The control of size and size distribution of semiconducting materials has easily carried out by intercalating in clay minerals with tailoring optical properties and activities. The solid-liquid reaction was applied to fabricate zinc selenide nanoparticles in montmorillonite and saponite containing the interlayer expanders of cetyltrimethylammonium cation and 18-crown-6. Various experimental results including XRD pattern, TG-DTA curve, TEM image and the spectroscopic observations of the products could confirm the formation of zinc selenide nanoparticles in smectites in the presence of cetyltrimethylammonium and the absence of 18-crown-6. The pre-expansion of the interlayer nanospace of smectites with cetyltrimethylammonium and 18-crown-6 promoted the facile intercalation of zinc selenide with controlling their particle size. The size of zinc selenide nanoparticles in cetyltrimethylammonium modified smectites was slightly larger than that in pristine smectites. The evident reason on the higher photoluminescence intensity of zinc selenide in cetyltrimethylammonium modified smectites rather than those of zinc selenide in smectite and bare zinc selenide was due to the host-guest and guest-guest interactions. This preparation procedure may be a facile pathway for controlling the particle size and tailoring the optical performance of the unstable semiconductors.

New insights into the biomineralization of mercury selenide nanoparticles through stable isotope analysis in giant petrel tissues

Tiemannite (HgSe) is considered the end-product of methylmercury (MeHg) demethylation in vertebrates. The biomineralization of HgSe nanoparticles (NPs) is understood to be an efficient MeHg detoxification mechanism; however, the process has not yet been fully elucidated. In order to contribute to the understanding of complex Hg metabolism and HgSe NPs formation, the Hg isotopic signatures of 40 samples of 11 giant petrels were measured. This seabird species is one of the largest avian scavengers in the Southern Ocean, highly exposed to MeHg through their diet, reaching Hg concentrations in the liver up to more than 900 µg g-1. This work constitutes the first species-specific isotopic measurement (δ202Hg, Δ199Hg) of HgSe NPs in seabirds and the largest characterization of this compound in biota. Similar δ202Hg values specifically associated to HgSe (δ202HgHgSe) and tissues (δ202Hgbulk) dominated by inorganic Hg species were found, suggesting that no isotopic fractionation is induced during the biomineralization step from the precursor (demethylated) species. In contrast, the largest variations between δ202Hgbulk and δ202HgHgSe were observed in muscle and brain tissues. This could be attributed to the higher fraction of Hg present as MeHg in these tissues. Hg-biomolecules screening highlights the importance of the isotopic characterization of these (unknown) complexes.