Recent advances in 2D transition metal dichalcogenide-based photodetectors: a review.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) have emerged as a highly promising platform for the development of photodetectors (PDs) owing to their remarkable electronic and optoelectronic properties. Highly effective PDs can be obtained by making use of the exceptional properties of 2D materials, such as their high transparency, large charge carrier mobility, and tunable electronic structure. The photodetection mechanism in 2D TMD-based PDs is thoroughly discussed in this article, with special attention paid to the key characteristics that set them apart from PDs based on other integrated materials. This review examines how single TMDs, TMD-TMD heterostructures, TMD-graphene (Gr) hybrids, TMD-MXene composites, TMD-perovskite heterostructures, and TMD-quantum dot (QD) configurations show advanced photodetection. Additionally, a thorough analysis of the recent developments in 2D TMD-based PDs, highlighting their exceptional performance capabilities, including ultrafast photo response, ultrabroad detectivity, and ultrahigh photoresponsivity, attained through cutting-edge methods is provided. The article conclusion highlights the potential for ground-breaking discoveries in this fast developing field of research by outlining the challenges faced in the field of PDs today and providing an outlook on the prospects of 2D TMD-based PDs in the future.

Exploring the mechanical, vibrational optoelectronic, and thermoelectric properties of novel half-Heusler FeTaX (X = P, As): a first-principles study.

In this study, the density functional theory (DFT) was employed to study the structural, electronic, optical, and thermoelectric characteristics of half-Heusler (HH) FeTaX (X = P or As). Optimization of the structures was achieved using Perdew-Burke-Ernzerhof (PBE) parametrized generalized gradient approximation (GGA). These HH FeTaX (X = P, As) showed indirect bandgaps of 0.882 eV and 0.748 eV, respectively. The predicted density of states (DOS) spectra suggest that Fe-d and Ta-d states contribute predominantly to both valence and conduction bands, whereas P/As-p states contribute less. Optical properties were investigated to assess their potential in optoelectronic applications. The estimated values of various optical parameters and low loss suggest that the studied HH FeTaX (X = P, As) are suitable for optoelectronic device applications. The thermoelectric responses of the studied HH FeTaX (X = P, As) were computed, and their highest power factors at high temperature reflects their usage in thermoelectric devices.

Outstanding Performance of Mg/g-C3N4-Doped Al2O3 Serving as a Nanocatalyst and Its Bactericidal Behavior: An In Silico Molecular Docking Study.

A coprecipitation approach was employed to synthesize aluminum oxide (Al2O3) with a fixed quantity of graphitic carbon nitride (g-C3N4) and various concentrations of Mg (2 and 4 wt. %). The main objective of this research is to explore and enhance the dye degradation potential and antimicrobial efficacy of synthesized pristine and doped Al2O3 with molecular docking analysis. Al2O3 has potent mechanical, thermal, antimicrobial, phosphoric, optical, and electrical properties, but it leaches into water and has a high band gap and low refractive index. g-C3N4 was incorporated into Al2O3 to increase the degradation potency. The incorporation of Mg enhances the metal oxide characteristics and performance in catalysis. XRD patterns revealed the orthorhombic phase of Al2O3. The SAED pattern of Al2O3 and (2 and 4 wt %) Mg/g-C3N4-Al2O3 nanostructures (NSs) showed bright polycrystalline rings. UV-visible spectra showed the absorption of Al2O3 at 289 nm, and upon doping, a blue shift was accompanied. The EDS spectra indicated the existence of Al, O, Na, and Mg, thereby verifying the elemental composition of the pristine and doped samples. TEM images revealed the nanowires (NWs) of Al2O3. The NSs demonstrated outstanding catalytic performance for the remediation of RhB dye in a basic medium of around 97.36%. Mg/g-C3N4-Al2O3 (4 wt %) exhibited a notable augmentation in the inhibition zone, measuring 5.25 mm, when exposed to high-level doses against Staphylococcus aureus. In silico predictions have recently shed light on the underlying mystery of the bactericidal actions of these doped NSs against specific enzyme targets such as DNA gyraseS. aureus.

Comprehensive analysis of novel cubic HgCrO3 perovskite: a first principles, structural, thermodynamic, and magnetic properties study for spintronic applications.

The main goal of modern manufacturing is to create products that are affordable, eco-friendly, and energy-efficient. With a focus on HgCrO3, this study sought to discover molecules that meet these requirements. The structural, electrical, thermodynamic, and transport properties of the material were investigated using Wien2K, a full-potential, linearized augmented plane wave program (FP LAPW). Utilizing the generalised gradient approximation (GGA) and lattice constants that have previously produced excellent theoretical and practical findings, structural optimization was carried out. Calculated HgCrO3 magnetic characteristics show that the Cr and Hg atoms are the main contributors to magnetism. Over a temperature range of 0-1200 K and a pressure range of 0-196 GPa, thermodynamic characteristics were evaluated. The thermoelectric properties of HgCrO3 were evaluated using the Boltzmann transport method provided by the BoltzTrap program. This analysis revealed that at room temperature, the figures of merit (ZT) values for HgCrO3 were nearly equal to one. A ZT value close to one indicates that a material has excellent thermoelectric properties and can efficiently convert heat into electricity or vice versa. This investigation highlights the promising thermoelectric capabilities of HgCrO3, which could contribute to more sustainable and energy-efficient technologies in the future.

Developing a Simple, Effective, and Quick Process to Make Silver Nanowires with a High Aspect Ratio.

A growing number of people are interested in using silver nanowires (AgNWs) as potential transparent and conductive materials. The production of high-performance and high-throughput AgNWs was successfully optimized in this work using a one-step, straightforward, and reproducible modified polyol approach. The factors influencing the morphology of the silver nanowires have undergone extensive research in order to determine the best-optimized approach for producing AgNWs. The best AgNW morphology, with a length of more than 50 m and a diameter of less than 35 nm (aspect ratio is higher than 1700), was discovered to be produced by a mixture of 44 mM AgNO3, 134 mM polyvinylpyrrolidone (PVP) (Mo.Wt 40,000), and 2.4 mM KCl at 160 °C with a stirring rate of 100 rpm. With our improved approach, the overall reaction time was cut from almost an hour with the conventional polyol method to a few minutes. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and ultraviolet (UV) spectroscopy were used to characterize AgNWs. The resultant AgNWs' dispersion was cleaned using a centrifuge multiple times before being deposited on glass and PET substrates at room temperature. In comparison to commercial, delicate, and pricey indium-doped tin oxide (ITO) substrates, the coated samples displayed exceptionally good sheet resistance of 17.05/sq and optical haze lower than 2.5%. Conclusions: Using a simple one-step modified polyol approach, we were able to produce reproducible thin sheets of AgNWs that made excellent, flexible transparent electrodes.

Mechanochemical Synthesis of Bi2VO5.5 for Improved Photocatalytic Dye Degradation.

A single-phase Bi2VO5.5 powder is formed effectively through a mechanochemical ball milling approach at 650 °C in 5 h and its photocatalytic performance on methylene blue dye is explored. X-ray diffraction and Raman spectroscopy analytical instruments are utilized to confirm the phase formation. The evident presence of irregular-shaped grains is affirmed using a scanning electron microscope. To ascertain the chemical condition of the components present, the Bi2VO5.5 powdered sample undergo an X-Ray photoelectron spectroscopy investigation. The sample is analyzed using a time-dependent photocurrent to discern its charge carrier transportation behavior. A photocatalytic study using Bi2VO5.5 powder produced through the mechanochemical ball milling method has not been explored till now. The efficacy of the ball-milled Bi2VO5.5 powder to attain enhanced photocatalytic efficiency which hasn't been investigated till now, is explored. The ball-milled Bi2VO5.5 sample achieved 70% degradation efficiency when performing the photocatalysis investigation. The photocatalytic dye degradation discerns pseudo-first-order kinetics and achieves a notable k value of 0.00636 min-1. The scavenger test indicates that h+ radicals are the prominent active species during the photocatalysis experiment. The germination index is determined by conducting a phytotoxicity test with the use of Vigna radiata seeds. Here ball-milled Bi2VO5.5 powder attains enhanced dye degradation efficiency.

Enhanced Emission of Tellurite Glass Doped with Pr3+/Ho3+ and Their Applications.

The shielding and spectroscopic properties of Pr+3 and Pr3+/Ho3+-codoped tellurite glass were investigated. The intensity parameters (Ω2 = 3.24-, Ω4 = 1.64-, Ω6 = 1.10 × 10-20 cm2) as well as the radiative lifetimes of 3F4 + 5S2 and 5I6 excited states of Ho3+ ions were equal to 301 µs and 3.0 µs, respectively. The former value appears to be much higher than that obtained from the lifetime measurement, indicating the presence of various energy transfer processes. The NIR spectrum of Pr3+/Ho3+-co-doped tellurite glass is dominated by strong Ho3+: 5I6 emission at around 1200 nm, being the result of the energy transfer from Pr3+ to Ho3+ ions. The shielding effectiveness of the prepared glasses showed good performance against high-energy photons. These findings suggest that the prepared glasses could be used in laser technology such as photodynamic therapy (PDT) treatment procedures and as shielding for radiation protection.

Influence of Mn Ions' Insertion in Pseudo-Tetragonal Phased CaBi4Ti4O15-Based Ceramics for Highly Efficient Energy Storage Devices and High-Temperature Piezoelectric Applications.

In the present era of advanced technology, the surge for suitable multifunctional materials capable of operating above 300 °C has increased for the utilization of high-temperature piezoelectric devices. For this purpose, a pseudo-tetragonal phased CaBi4Ti3.98 (Nb0.5Fe0.5)0.02O15:xwt%MnO2 (CBTNF:xMn), with x = 0-0.20, ceramic system has been engineered for the investigation of structural, ferroelectric, dielectric and high-temperature-dependent piezoelectric properties. XRD analysis confirms that low-content Mn-ion insertion at the lattice sites of CBTNF does not distort the pseudo-tetragonal phase lattice of CBTNF:xMn ceramics, but enhances the functional behavior of the ceramic system, specifically at x = 0.15 wt%Mn. Compared to pure CBT and CBTNF ceramics, CBTNF:0.15Mn has demonstrated a highly dense relative density (~96%), a saturated polarization (PS) of 15.89 µC/cm2, a storage energy density (WST) of ~1.82 J/cm3, an energy-conversion efficiency (ƞ) of ~51% and an upgraded piezoelectric behavior (d33) of 27.1 pC/N at room temperature. Sharp temperature-dependent dielectric constant (εr) peaks display the solid ferroelectric behavior of the CBTNF:0.15Mn sample with a Curie temperature (TC) of 766 °C. The thermally stable piezoelectric performance of the CBTNF:0.15Mn ceramic was observed at 600 °C, with just a 0.8% d33 loss (25 pC/N). The achieved results signify that multi-valence Mn ions have effectively intercalated at the lattice sites of the pseudo-tetragonal phased CBTNF counterpart and enhanced the multifunctional properties of the ceramic system, proving it to be a durable contender for utilization in energy-storage applications and stable high-temperature piezoelectric applications.

Fabrication of a Ternary Nanocomposite g-C3N4/Cu@CdS with Superior Charge Separation for Removal of Organic Pollutants and Bacterial Disinfection from Wastewater under Sunlight Illumination.

The synthesis of a photo-catalyst with a narrow bandgap and efficient capability to degrade contaminants in the presence of sunlight is currently challenging but exciting. In this work, an efficient photocatalytic ternary nanocomposite g-C3N4/Cu@CdS has been synthesized successfully by using the co-precipitation method. The synthesized composite was then characterized by SEM, XRD studies, EDX analysis, and ultra-violet-visible (UV-VIS) spectroscopy. The catalytic efficiency for the methylene blue (MB) dye and drug degradation (ciprofloxacin) was assessed by UV-visible absorption spectra. Gram-positive and Gram-negative bacteria were used to test the fabrication composite's antibacterial properties. Various compositions (1%, 3%, 5%, 7%, and 9%) of/Cu@CdS nanocomposite (NCs) and 20%, 30%, 40%, 50%, and 60% of g-C3N4 NCs were prepared. Results reveal that 5%Cu@CdS and 40%g-C3N45%Cu@CdS showed maximum antibacterial activity and photocatalytic degradation of dye and drug. The X-ray pattern showed no remarkable change in doped and pristine CdS nanoparticles (NPs). The efficient photocatalytic degradation activity of the fabricated ternary nanocomposite against MB dye and ciprofloxacin an antibiotic drug makes it a viable contender for solving environmental problems.

Enhancement of Optical Telecommunication Bands: Pr3+-Doped Halide Phosphate Glasses Display Broadband NIR Photoluminescence Emission.

In the optical energy gap, visible and near-IR emission of halide phosphate glasses with a composition of 40P2O5-30ZnO-20LiCl-10BaF2 in mol% doped with 3.5 × 104 ppm Pr2O3, referred to as PZLBPr, were synthesized. The UV-VIS-NIR and spectroscopic properties of these glasses were also predicted. The current glasses had broadband emission photoluminescence covering a wavelength range of 1250 to 1700 nm when excited at 455 nm. These bands for near-infrared emission luminescence relate to the transitions 1G4 → 3H5, 1D2 → 1G4, and 3H4 → 3F3, 3F4 in the optical telecommunication window. The significant PL emission wideband was caused by the radiative transition from Pr3+: 1D2 to 1G4. At 445 nm excitation, these glasses exhibited emission bands that corresponded to blue/reddish orange spectral ranges in visible ranges. The prepared glass has a high lasing quality factor (Ω4/Ω6 = 0.9), high optical energy (4.72 eV), and quantum efficiency = 87.3% with FWHM = 156 nm of transition emission from the 1D2 → 1G4 level. As a result, broadband near infrared optical amplifiers can be fabricated from the prepared glasses.

Investigation of Structural, Physical, and Attenuation Parameters of Glass: TeO2-Bi2O3-B2O3-TiO2-RE2O3 (RE: La, Ce, Sm, Er, and Yb), and Applications Thereof.

A novel series of glass, consisting of B2O3, Bi2O3, TeO2, and TiO2 (BBTT) containing rare earth oxide RE2O3, where RE is La, Ce, Sm, Er, and Yb, was prepared. We investigated the structural, optical, and gamma attenuation properties of the resultant glass. The optical energy bands, the linear refractive indices, the molar refractions, the metallization criteria, and the optical basicity were all determined for the prepared glass. Furthermore, physical parameters such as the density, the molar volume, the oxygen molar volume, and the oxygen packing density of the prepared glass, were computed. Both the values of density and optical energy of the prepared glass increased in the order of La2O3, Ce2O3, Sm2O3, Er2O3, and then Yb2O3. In addition, the glass doped with Yb2O3 had the lowest refractive index, electronic polarizability, and optical basicity values compared with the other prepared glass. The structures of the prepared glass were investigated by the deconvolution of infrared spectroscopy, which determined that TeO4, TeO3, BO4, BO3, BiO6, and TiO4 units had formed. Furthermore, the structural changes in glass are related to the ratio of the intensity of TeO4/TeO3, depending on the type of rare earth. It is also clarified that the resultant glass samples are good attenuators against low-energy radiation, especially those that modified by Yb2O3, which exhibited superior shielding efficiency at energies of 622, 1170, and 1330 keV. The optical and gamma ray spectroscopy results of the prepared glass show that it is a good candidate for nonlinear optical fibers, laser solid material, and optical shielding protection.

Remarkable non-linear optical properties of gold cluster doped graphyne (GY): A DFT study.

The nonlinear optical (NLO) properties of gold (Au) doped graphyne (GY) complexes are the subject of this quantum mechanical investigation. Detailed profiling of GY@Aucenter, GY@Auside, GY@2Auabove,GY@2Auperpendicular, and GY@3Aucenter is accomplished at CAM-B3LYP/LANL2DZ. The differential influence of various GY based complexes on molecular geometry, vertical ionization energy (VIE), interaction energy (Eint), frontier molecular orbitals (FMOs), density of states (DOS), absorption maximum (λmax), molecular electrostatic potential (MEP), electron density distribution map (EDDM), transition density matrix (TDM), dipole moment (µ) and non-linear optical (NLO) properties have been investigated. Non-covalent interaction (NCI) analysis has been done to explore the sort of interactions in designed complexes. The vibrational frequencies are probed via infrared (IR) analysis. Doping tactics in all complexes dramatically changed charge carrier properties, such as shrinking band gap (Eg) and increasing λmax in the range of 3.97-5.58 eV and 288-562 nm respectively, compared to pure GY with 5.78 eV Eg and 265 nm λmax. When compared to GY (αO = 281.54 andßO = 0.21 au), GY@3Aucenter exhibited a significant increase in static mean polarizability (αO = 415 au) and the mean first hyperpolarizability (ßo = 3652 au) attributable to its lowest excitation energy (ΔE). GY doping has been discovered to be advantageous for designing potential nanoscale devices by focusing on the symphony between small Au clusters and GY and their impacts on NLO aspects.

Evaluation of the Radiation Shielding Properties of a Tellurite Glass System Modified with Sodium Oxide.

In this study, the X-ray and gamma attenuation characteristics and optical properties of a synthesized tellurite-phosphate-sodium oxide glass system with a composition of (85 - x)TeO2-10P2O5-xNa2O mol% (where x = 15, 20, and 25) were evaluated. The glass systems we re fabricated by our research group using quenching melt fabrication. The shielding parameters of as-synthesized systems, such as the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), effective atomic number (Zeff), half-value layer (HVL), tenth value layer (TVL), mean free path (MFP), and effective electron density (Neff) in a wide energy range between 15 keV and 15 MeV, were estimated using well-known PHY-X/PSD software and recently developed MIKE software. Herein, the optical parameters of prepared glasses, such as molar volume (VM), oxygen molar volume (VO), oxygen packing density (OPD), molar polarizability (αm), molar refractivity (Rm), reflection loss (RL), and metallization (M), were estimated using MIKE software. Furthermore, the shielding performance of the prepared glasses was compared with that of commonly used standard glass shielding materials. The results show that the incorporation of sodium oxide into the matrix TeO2/P2O5 with an optimum concentration can yield a glass system with good shielding performance as well as good optical and physical properties, especially at low photon energy.

Thermal Stability, Optical Properties, and Gamma Shielding Properties of Tellurite Glass Modified with Potassium Chloride.

The synthesized glass system with a composition of (80-x) TeO2-10P2O5-10Nb2O5-xKCl mol% (where x = 5, 10, 15, 20, and 25) was successfully fabricated. The density (ρ) and molar volume (Vm) have been calculated. The investigated glasses were characterized using different analysis methods (differential thermal analysis (DTA) and UV-VIS-NIR spectroscopy). The radiation shielding effectiveness of the synthesized glass system was evaluated using different shielding parameters, such as mass and linear attenuation coefficients (MAC, LAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and effective electron number (Neff). The results showed that with the increasing potassium chloride (KCl) concentration and decreasing tellurium oxide (TeO2) concentration, the density, refractive index, Urbach energy (Eu), and glass transition temperature (Tg) decreased, while the optical energy gap (Eopt) and thermal stability increased. As the KCl concentration increases, the values of MAC, LAC, and Zeff increase in the following order: TPNK5 % > TPNK10 % > TPNK15 % > TPNK20 % > TPNK25 %. Additionally, the shielding effectiveness of TPNK glass system showed good performance compared with some standard materials. The synthesized glass with a minimum KCl content has both good shielding effectiveness and good optical properties, in addition to reasonable thermal stability, which makes it suitable for shielding and optical applications.

The Effect of ZnO, MgO, TiO2, and Na2O Modifiers on the Physical, Optical, and Radiation Shielding Properties of a TeTaNb Glass System.

Novel glass samples with the composition 75TeO2-5Ta2O5-15Nb2O5-5x (where x = ZnO, MgO, TiO2, or Na2O) in mole percent were prepared. The physical, optical, and gamma radiation shielding properties of the glass samples were studied over a wide energy spectrum ranging between 0.015 and 20 MeV. The glasses' UV-vis spectra were utilized to evaluate the optical energy gap and refractive index. Glass samples had a refractive index ranging from 2.2005 to 2.0967. The results showed that the sample doped with zinc oxide (ZnO) recorded the highest density (ρglass), molar polarizability (αm), molar refraction (Rm), refractive index (n), and third-order nonlinear optical susceptibility (χ3) and the lowest optical energy gap (Eopt) among the samples under investigation. When comparing the current glass system with various standard glass shielding materials, the prepared glass system showed superior shielding performance at energies ranging between 40 and 85 keV. These findings indicate that the prepared glass systems can be used in diagnostic X-rays, especially in dental applications.

Optical and radiation shielding characteristics of tellurite glass doped with different rare-earth oxides.

Shielding glass materials doped with heavy metal oxides show an improvement in the effectiveness of the materials used in radiation shielding. In this work, the photon shielding parameters of six tellurite glass systems doped with several metal oxides namely, 70TeO2-10P2O5- 10ZnO- 5.0PbF2- 0.0024Er2O3- 5.0X (where X represents different doped metail oxides namely, Nb2O5, TiO2, WO3, PbO, Bi2O3, and CdO) in a broad energy spectrum, ranging from 0.015 MeV to 15 MeV, were evaluated. The shielding parameters were calculated using the online software Phy-X/PSD. The highest linear and mass attenuation coefficients recorded were obtaibed from the samples containing bismuth oxide (Bi2O3), and the lowest half-value layer and mean free path were recorded among the other samples. Furthermore, the shielding effectiveness of tellurite glass systems was compared with commercial shielding materials (RS-369, RS-253 G18, chromite, ferrite, magnetite, and barite). The optical parameters viz, dispersion energy, single-oscillator energy, molar refraction, electronic polarizability, non-linear refractive indices, n2, and third-order susceptibility were measured and reported at a different wavelength. Bi2O3 has a strong effect on enhancing the optical and shielding properties. The outcome of this study suggests the potential of using the proposed glass samples as radiation-shielding materials for a broad range of imaging and therapeutic applications.

Optically transparent glass modified with metal oxides for X-rays and gamma rays shielding material.

BACKGROUND: Metal oxide glass composites have attracted huge interest as promising shielding materials to replace toxic, heavy, and costly conventional shielding materials. OBJECTIVE: In this work, we evaluate shielding effectiveness of four novel tellurite-based glasses samples doped with oxide metals (namely, A, B, C, and D, which are 75TeO2- 10P2O5- 10ZnO- 5PbF2- 0.24Er2O3 ; 70TeO2- 10P2O5- 10ZnO- 5PbF2 -5MgO- 0.24Er2O3; 70TeO2- 10P2O5- 10ZnO- 5PbF2- 5BaO- 0.24Er2O3 ; and 70TeO2- 10P2O5-10ZnO- 5PbF2- 5SrO; respectively) by assessing them through a wide range of ionizing radiation energies (0.015-15 MeV). METHODS: The radiation-shielding parameters including mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), mean free path, (MFP), effective atomic number (Zeff), effective electron number (Neff), and the transmission factor are computed in the selected range of ionizing radiation energies. Furthermore, the proposed samples were compared with the most common shielding glass materials. The optical parameters viz oscillator, dispersion energy, nonlinear refractive indices, molar, and electronic polarizability of these transparent glasses are reported at different wavelengths. RESULTS: The results show that the proposed samples have considerable effectiveness as transparent shielding glass materials at various ionizing radiation energies. They can be employed for effective radiation-protection outcomes. Sample C demonstrated slightly better shielding properties than the other samples with differences of 1.33%, 4.6%, and 4.2% for samples A, B, and D, respectively. A similar trend is observed regarding the mass attenuation coefficients. Nevertheless, sample B shows better optical properties than the other prepared glass samples. CONCLUSIONS: Our findings indicate that the proposed novel glass samples have good shielding properties and optical characteristics, which can pave the way for their utilization as transparent radiation-shielding materials in medical and industrial applications.

Visible and mid-infrared spectral emissions and radiative rates calculations of Tm3+ doped BBLC glass.

Quaternary glasses with the composition 75Li2B2O7-(15-x)BaO-10CdO-xTm2O3 (BBLC) (0 ≤ x ≤ 2 mol %) have been prepared by melt-quenching method. The structure changes, the absorption coefficient of OH- and the maximum phonon energy of these glasses are studied by FT-IR spectra. Optical and emission properties of Tm3+ doped BBLC glasses have been investigated at room temperature. The optical band gap (Eopt), dispersion parameters and Urbach's energy (Eu) of the prepared samples have been estimated. Judd-Ofelt theory has been applied to obtain the radiative rates and optical intensity parameters. Oscillator strengths, radiative lifetimes, and branching ratio of different transitions have been calculated. Derived emission cross sections of the emission transitions in the visible range are determined. A strong emission is observed at 455 nm, this line is attributed to 1D2→3F4. Spectral line in the blue region has been observed at wavelength of 515 nm, as well. Two central wavelengths of 1.2 µm and 1.8 µm, which are located in the short- and mid- wave IR spectral regions, are analyzed. These emissions are attributed to the transitions 3H5→3H6 and 3F4→3H6, respectively.

Visible-Light Driven Effective Photocatalytic Degradation of Methylene Blue Dye Using Perforated Curly Zn0.1Ni0.9O Nanosheets.

Herein, we report the facile synthesis, characterization and visible-light-driven photocatalytic degradation of perforated curly Zn0.1Ni0.9O nanosheets synthesized by hydrothermal process. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies confirmed the cubic phase crystalline structure and growth of high density perforated curly Zn0.1Ni0.9O nanosheets, respectively. As a photocatalyst, using methylene blue (MB) as model pollutant, the synthesized nanosheets demonstrated a high degradation efficiency of ~76% in 60 min under visible light irradiation. The observed results suggest that the synthesized Zn0.1Ni0.9O nanosheets are attractive photocatalysts for the degradation of toxic organic waste in the water under visible light.

Mechanical and tribological properties of the tricalcium phosphate - magnesium oxide composites.

The mechanical of the tricalcium phosphate matrix sintered with different amounts of the magnesium oxide have been investigated. The tricalcium phosphate - magnesium oxide composites were characterized by using the mechanical properties such as rupture strength, Vickers hardness and elastic modulus. The effects of the sintering process on the structural changes of the composites were investigated. At 1300 °C, the highest performance was obtained for the tricalcium phosphate containing 5 wt% MgO. The maximum mechanical strength and Young's modulus of the composites reached 9 MPa and 38 GPa, respectively. The result can be explained by the formation of both, liquid phase, which helps to fill the pores in the microstructure, and a new phase relative to the calcium magnesium phosphate. At 1400 °C and beyond 5 wt% MgO, the performances of the composites are hindered by the intragranular porosity formation and by the exaggerated grain growth. The addition of the magnesium oxide to the tricalcium phosphate matrix promotes the reduction of the wear rate and the friction coefficient. The composites performances are close to the enamel.