Strong Peak Research Articles

Various Applications of Gadolinium Molybdate Down‐Conversion and Up‐Conversion Fluorescent Nanoparticles

AbstractCrystalline α‐Gd2(MoO4)3 is synthesized by sintering at 800 °C using a coprecipitation method to prepare the precursor. The resulting α‐Gd2(MoO4)3 displayed a monocrystalline structure with a strong main peak (‐221) in the X‐ray diffraction signal. To develop a light‐emitting material, rare earth ions are added during synthesis. By doping with Tb3+ and Eu3+, the Gd2(MoO4)3 down‐conversion phosphor shows potential for use in UV–LED chips, counterfeit money prevention, and fingerprint identification. Additionally, co‐doping with [Er3+]/[Yb3+] and [Ho3+]/[Yb3+] ions produce green and red emissions when applied to a 980 nm LED chip, useful for anti‐counterfeit ink. The magnetic properties of gadolinium are leveraged to confirm magnetic resonance imaging luminescence. A flexible composite for heat detection and explored various applications for its use is also developed.

Eco-friendly Strategy for Producing Bio-based Silver Nanoparticles (AgNPs) Employing Sepioteuthis lessoniana ink, in Addition to Biological and Degradation of Dye Applications.

The squid, Sepioteuthis lessoniana, is a remarkable fishery product which is exported by many nations for use in industrial production or human consumption. This study focused on the synthesis of silver nanoparticles (AgNPs) from squid ink (SI) and its wide range of applications. The formation of the nanoparticles was confirmed through UV-Visible spectroscopy, FTIR, XRD, SEM with EDX, DLS, and zeta potential analysis. The results showed a strong absorbance peak at 407nm, the presence of various functional groups, a nanocrystalline structure with a crystalline size of 17.56nm, spherical-shaped particles with an average size of 76nm, and the presence of the highest % mass of Ag and uniformly dispersed particles, respectively. The bioactivity of the synthesized squid ink silver nanoparticles was analyzed through antibacterial, antioxidant, anticancer, and toxicity studies. The dye degradation assay was also analyzed as a means of wastewater treatment for different industrial dyes. The antibacterial activity showed the highest zone of inhibition of 24mm at a concentration of 100μg/ml against Escherichia coli, followed by other tested strains. The nitric oxide radical scavenging assay showed the highest antioxidant activity (92%) at a concentration of 100μg/ml. The cytotoxic ability of SI-AgNPs against the MDA-MB-231 breast cancer cell line revealed an IC50 value of 4.52μg/ml. The toxicity study revealed a dose and time-dependent activity with the LC50 value of 5.090 and 3.303mg/ml for 24 and 48h, respectively. The successful degradation of dyes by SI-AgNPs is attributed to the cooperative action of the electron relay system with Ag as a catalyst and SI as a catalytic support. These findings indicate that SI-AgNPs are a novel potential product that should be further studied to improve its pharmacological, biomedical, and environmental applications.

Investigation of the effect of strontium substitution in bismuth ferrites for enhanced structural and optical properties using experimental and DFT approaches

BiFeO3 doped with Sr, having the composition Bi1-xSrxFeO3 (0.00 ≤ x ≤ 0.20), was synthesized using the auto-combustion method. Various characterization techniques were employed to investigate the structural, morphological, and optical properties. X-ray diffraction (XRD) patterns confirmed that the materials exhibit a distorted rhombohedral structure with the space group R3c. The average crystallite size was determined to be in the range of 18–28 nm. A decrease in the lattice parameters was observed due to the contraction of the unit cell volume (373.83–371.49 Å) caused by Sr doping. Scanning electron microscopy (SEM) images revealed a reduction in grain size, suggesting the suppression of grain growth with Sr doping. Fourier-transform infrared (FTIR) studies identified two strong peaks at 552 cm−1 and 449 cm−1, confirming the perovskite structure of the materials. The optical band gap was found to decrease from 2.14 eV to 2.05 eV with increasing Sr concentration. Theoretical calculations of electronic and optical properties using density functional theory (DFT) were conducted. The calculated direct optical band gaps (2.0 eV, 2.22 eV, 2.1 eV, and 2.09 eV) for Bi1-xSrxFeO3 samples at doping levels x = 0.0, 0.10, 0.15, and 0.20, respectively, were in good agreement with the experimental results. These findings provide valuable insights into the tunability of electronic and optical properties in Sr-doped BiFeO3, making them promising candidates for various technological applications.

Gilded vaterite particles: Synthesis, optical characterization, and label-free imaging

Inorganic nanoparticles are capable of accommodating multiple biomedical modalities, making them prime candidates for realizing light-responsive theranostic carriers. Within this realm, merging the benefits of diverse platforms promises the development of new functionalities, broadening the range of applications. While vaterite, a polymorph of calcium carbonate, is known for its structural versatility and chemical modifiability, gold nanoparticles are recognized for their unique optical properties. Here we explore a new mesoscopic particle, gilded vaterite, which encompasses the advantages of both platforms. A flexible synthesis method is developed and optimized, demonstrating the capability to obtain high-yield fabrication of vaterite particles with controllable form factors alongside tailored surface coverage with gold. Uniform reproducible distributions of gold nanoparticles of up to 80 nm in diameter, with coverage above 40%, were demonstrated. Optical properties of gilded vaterite particles were explored, revealing strong peaks, which built up owing to the resonant hybridization of near-field coupled plasmonic resonances. Confocal microscopy of cells was utilized to explore potential applications of gilded vaterite with tunable optical properties in the realm of label-free imaging. Strong light scattering from vaterite carriers, taken up by cells, alongside the fluorescence from stained cells, was observed via reflectance confocal microscopy. This dual-channel approach allows for simultaneous observation of the particles and their biological environment. Tunable optical and biochemical properties of gilded vaterite promote this perspective platform towards accommodating new modalities and thus becoming an intrinsically optical-responsive multifunctional system.

Low-Temperature Synthesis of Linear Carbon Chain inside Single-Walled Carbon Nanotubes

Linear carbon chain (LCC) has attracted much interest concerning its structure and applications. It has been reported that LCC possesses higher strength, elastic modulus, and stiffness than any known material, which provides a possibility for LCC as a new composite material, yet its chemical stability remains an issue [1]. Therefore, finding a method to efficiently synthesize LCC has become a meaningful research topic in recent years. A landmark study on LCC synthesis was given by using double-walled carbon nanotubes (DWCNTs) as the template combined with a high-temperature annealing treatment at 1460°C to acquire long chains composed of more than 6,000 carbon atoms [2]. Except for DWCNTs, LCC synthesis starting from single-walled carbon nanotubes (SWCNT) as templates was also reported. However, given the instability of SWCNTs at higher temperature [2] the synthesis efficiency is not as good as for DWCNTs. As far as we know, there is still no report on an efficient LCC synthesis inside SWCNTs. Herein, we report the low-temperature (400°C) efficient LCC synthesis starting from a SWCNT template.To this end, a SWCNT dispersion [3] underwent a surfactant exchange process and was fabricated into a SWCNT film by the filtration method. The SWCNT film was annealed under 400°C in an argon atmosphere to synthesize LCC. Raman spectroscopy (laser wavelength 532 nm) was used to characterize the efficiency of the LCC synthesis. A strong peak at 1863 cm-1 appeared after annealing, originating from the well-known C-mode of the linear carbon chain [4] thereby confirming its existence inside SWCNTs. SWCNTs synthesized by a low-pressure alcohol catalytic chemical vapor deposition (ACCVD) method [5] were also adopted for the LCC synthesis template, resulting in a similar LCC Raman peak at 1863 cm-1. We attribute this successful low-temperature LCC synthesis to the appropriate surfactant which could be encapsulated inside CNTs and converted to LCC during the annealing process.Keywords: Linear Carbon Chain, Single-walled Carbon Nanotubes, Surfactants

Green synthesis of copper oxide nanoparticles using Rosmarinus officinalis leaf extract and evaluation of its antimicrobial activity

Due to the development of green technology, researchers are becoming more interested in low-cost, environmental eco-friendly methods for the synthesis of nanoparticles (Nps). In this work, Copper oxide nanoparticles (CuO Nps) were synthesized using a green synthesis technique, with Rosmarinus officinalis leaf extract acting as a capping and reducing agent. The as prepared the samples was characterized using UV-Visible Spectra (UV–VIS), X-ray Diffraction (XRD), Fourier Transform Infrared (FTIR), and Scanning Electron Microscopy (SEM). The UV-Visible spectra result showed that strong absorption was observed for characteristic band of green synthesized CuO Nps and exhibit red shift as the weight fraction of CuO Nps increases. The XRD analysis confirmed the formation of CuO Nps, having a typical monoclinic structure with crystalline size ranging from 18 to 26 nm. From FTIR spectral analysis strong and broad peak observed at 3384 cm−1 can be attributed to (O-H) functional groups of the bioactive compounds which act as reducing and capping agents for the synthesis of CuO Nps in the plant extract. The SEM images of green synthesized CuO NPs was appeared to be aggregated form and almost spherical in shape. The antimicrobial activity of CuO Nps was evaluated against S.aureus and B.cereus (gram-positive), E. coli (gram-negative) bacteria strains and C.albicans fungal Pathogen. The result indicated that at weight fraction of 50 %, CuO Nps exhibit highest antimicrobial activity against E. coli, S. aureus, C.albicans and B.cereus with zone of inhibition of 26.0 ± 0.10, 25.0 ± 0.15, 18.1 ± 0.32 and 17.0 ± 0.0 mm respectively. Furthermore, for the E. coli bacterial strain, the minimum inhibitory concentration (MIC) of CuO Nps was found to be 1.56 mg/mL; whereas, for S. aureus and C. albicans was found to be 3.12 mg/mL. Therefore, the present study shows that Rosmarinus officinalis extract can be easily used as a reducing, stabilizing, and capping agent for the effective green synthesis of CuO Nps for antimicrobial agents. Thus, it is believed that synthesis of nanoparticles using low cost and eco-friendly green approach enhanced the antimicrobial activity and other a potentially applications in fields of biomedical.

To Be or Not To Be: The Role of Rotation in Modeling Galactic Be X-Ray Binaries

Be X-ray binaries (Be-XRBs) are one of the largest subclasses of high-mass X-ray binaries, comprised of a rapidly rotating Be star and neutron star companion in an eccentric orbit, intermittently accreting material from a decretion disk around the donor. Originating from binary stellar evolution, Be-XRBs are of significant interest to binary population synthesis (BPS) studies, encapsulating the physics of supernovae, common envelope, and mass transfer (MT). Using the state-of-the-art BPS code, POSYDON, which relies on precomputed grids of detailed binary stellar evolution models, we investigate the Galactic Be-XRB population. POSYDON incorporates stellar rotation self-consistently during MT phases, enabling detailed examination of the rotational distribution of Be stars in multiple phases of evolution. Our fiducial BPS and Be-XRB model aligns well with the orbital properties of Galactic Be-XRBs, emphasizing the role of rotational constraints. Our modeling reveals a rapidly rotating population (ω/ω crit ≳ 0.3) of Be-XRB-like systems with a strong peak at intermediate rotation rates (ω/ω crit ≃ 0.6) in close alignment with observations. All Be-XRBs undergo an MT phase before the first compact object forms, with over half experiencing a second MT phase from a stripped helium companion (Case BB). Computing rotationally limited MT efficiencies and applying them to our population, we derive a physically motivated MT efficiency distribution, finding that most Be-XRBs have undergone highly nonconservative MT ( β¯rot≃0.15 ). Our study underscores the importance of detailed angular momentum modeling during MT in interpreting Be-XRB populations, emphasizing this population as a key probe for the stability and efficiency of MT in interacting binaries.

A novel material for radiation detection application of zinc bismuth lithium borotellurite glass doped with Dy2O3

Radiation detection glass with the following chemical composition B2O3–TeO2–Li2O3–Bi2O3–ZnO doped with Dy2O3 where x = 0.00, 0.10, 0.50, 1.00, 1.50 and 2.00 mol%, was developed for the characterization of physical properties such as density, molar volume (Vm), and refractive index, optical absorption, luminescence, CIE's diagram, and radiation detection properties. The density and refractive index of glass samples increase with the increase of Dy2O3 composition. The optical property of glass shows eight strongest peaks from 6H15/2 centering at 263 nm (4I13/2 + 4F7/2), 298 nm (4G11/2), 357 nm (4I15/2), 803 nm (6F5/2), 897 nm (6F7/2), 1090 nm (6H7/2 + 6F9/2), 1272 nm (6F11/2 + 6H9/2) and 1671 nm (6H11/2), respectively. The emission peaks are r (4F9/2), 481 nm (6H15/2), 575 nm (6H13/2), 664 nm (6H11/2), and 751 nm (6H9/2) under excited at 453 nm (4F9/2), respectively. The excitation peaks under emission at 575 nm from 6H15/2 centering at 350 nm (6P7/2), 365 nm (4P3/2), 388 nm (4K17/2), 425 nm (4G11/2), 453 nm (4I15/2), and 471 nm (4F9/2) respectively. The study of luminescence characteristics, which includes emission, excitation, and CIE diagrams, reveals white emission bands that coincide with the CIE diagram. Furthermore, measuring the parameters of the thermoluminescence dosimeter (TLD) recorded with a heating rate of 5 °C/s in the temperature up to a maximum of 400 °C yields good results in low dose radiation detection. Based on all the results, it was determined that this glass can be a candidate for radiation detection materials in the future.

A novel fluorescent probe based on coumarin and triazole for monitoring fluoride ions in the substitution reaction

In this paper, a novel coumarin-based fluorescent probe (8-acetyl-3-(2H-benzo[d][1,2,3]triazol-2-yl)-7-((tert-butyldimethylsilyl)oxy)-2H-chromen-2-one, CTA5) was designed and synthesized for monitoring the process of some reaction involving fluoride ions. CTA5 has a strong fluorescent emission peak at 451 nm, and the emission peak is red-shifted to 517 nm after the reaction with fluoride ions and CTA5 has also good selectivity and linear relationship for fluoride ions detection. Furthermore, CTA5 was applied to monitor the change of fluoride ions concentration in some substitution reactions, and the end of the reaction can be judged by the equilibrium of fluoride ion concentration. The experimental results show that it is feasible to use fluorescence signal to monitor the progress of the reaction.

Phase Transformation and Mechanical Behaviour of Different Heat-Treated Nickel-Titanium Rotary Instruments

ObjectivesThis study evaluated the phase composition, phase transformation behaviour, and mechanical properties of five heat-treated NiTi instruments. MethodsProTaper NEXT (M-wire, PTN), ProTaper Gold (Gold-wire, PTG), One Curve (C-wire, OC), EdgeTaper Platinum (Fire-wire, ETP), NeoNiTi (electrical discharge machining-wire, NNA), and ProTaper Universal (conventional wire, PTU, control) with #25-tip size were tested (n = 12/group) for cyclic fatigue resistance (number of cycles to failure; NCF) and torsional resistance (angle of rotation to fracture and maximum torque at fracture [ultimate torsional strength]). The geometry and fracture surfaces of the tested instruments were examined by scanning electron microscopy. The phase transformation temperature and phase composition of the instruments were evaluated using differential scanning calorimetry and X-ray diffraction. Data were statistically analysed using one-way ANOVA and Tukey's post hoc test, with the significance level set at 5%. ResultsPTG showed the highest NCF (P < .05) at 37°C, while ETP exhibited the highest angle of rotation to fracture, ultimate torsional strength, and stiffness (P < .05). Scanning electron microscopy demonstrated typical clusters of fatigue striations and numerous cracks after cyclic fatigue fracture, whereas there was a concentric abrasion pattern with a dimple and microvoids at the centre after torsional fracture. In differential scanning calorimetry curves, austenite-finishing temperatures of heat-treated instruments were higher than 37°C, whereas that of PTU was lower than 37°C. PTU showed strong peaks of austenite at 25 and 37°C, whereas ETP showed a strong peak of R-phase at 25°C, but mostly austenite phase at 37°C in X-ray diffraction. ConclusionsGeometry, alloy type, and phase transformation temperatures of NiTi instruments affected their mechanical behaviour. Clinical relevancePTG showed the highest NCF, suitable for markedly curved canals. ETP had the highest torsional resistance, appropriate for narrow and constricted canals.

The Influence of Different Phases of a Solar Flare on Changes in the Total Electron Content in the Earth’s Ionosphere

Abstract Variations in X-ray and extreme ultraviolet (EUV) irradiance during solar flares lead to a noticeable increase in the electron concentration in the illuminated part of the Earth’s ionosphere. Due to the large amount of experimental data accumulated by global navigation satellite systems, the total electron content (TEC) response to the impulsive phase of a solar flare has been studied quite well. However, recent studies have shown that a large fraction of X-class flares have a second strong peak of warm coronal emission (which is called “EUV late phase”), whose influence on the ionization of ionospheric layers is not yet clear. A combined analysis of successive solar emissions and the caused TEC changes made it possible to numerically estimate the ionospheric response to the impulsive, gradual, and late phases of the X2.9 solar flare that occurred on 2011 November 3 and demonstrate the high geoeffectiveness of the rather weak Fe xv 28.4 nm solar emission during the EUV late phase. It was found that the ionospheric response to the relatively weak emissions of the EUV late phase of the X2.9 solar flare amounted to almost a third of the TEC increase during the impulsive phase.

Structural and Optical Properties of Activated Carbon Derived from Eggshell

This research was done to prepare the eggshell as activated carbon (AC) using the simple chemical activation process. Phosphoric acid (H3PO4) at different molarities of 0.50, 0.75 and 1.00 M is used as an activation agent. All samples were analysed and characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). SEM images show irregular shapes of carbon. XRD patterns of AC were observed at 29.7°, 36.2°, 40.5°, 43.5°, 47.7° and 48.7° which corresponds to Braggs reflection planes of (201), (105), (107), (207), (206) and (304) respectively. The obtained diffraction peaks show the hexagonal crystal structure of carbon and are well matched with standard JCPDS: 721-616. SEM images show that the structure of AC are fake-like structures and exhibit partial geometrical shape when synthesized at 0.50 M. A broad and strong peak is observed at 1400 centimeter and a sharp peak appears at 872 centimeter due to stretching and bending vibration of the carbonate group present in the samples. The band observed at 1071 centimeter corresponds to the vibration of the phosphate group.

Biogenic Fabrication of CuO Nanoparticles by &lt;i&gt;Oxalis corniculata&lt;/i&gt; L. to Evaluate Antibacterial and Hypoglycemic Activity on Diabetic Mice

Plant-based synthesis techniques of nanoparticles are interested because of their cheap production cost, non-toxic nature and eco-friendliness. Metal oxide nanomaterials combined with plant metabolites have synergistic effects on antibacterial and antidiabetic potential. Biogenic fabricated nanoparticles of copper oxide has been accomplished with Oxalis corniculata L. leaf extract. For the characterization of nanomaterial XRD, UV-visible spectroscopy and FTIR Spectroscopy were used. The size and morphology of the NPs were measured using FESEM and HRTEM. The antibacterial potential of synthesized CuO NP has been studied upon Gram (+ve) Staphylococcus aureus and Gram (-ve) Escherichia coli bacteria. Ameliorative action of CuO NPs was tested against streptozotocin-induced diabetes in Swiss albino mice. Synthesized CuO NPs were well crystalline and 20-36 nm sized spherical particles. A strong peak at A298 using UV-Vis was verified the synthesis of CuO NP. Synthesized nanomaterial exhibits satisfactory antibacterial efficacy on both bacterial strains. Data from biochemical, inflammatory and non-inflammatory cytokine profiles of the mice justify its ameliorative action and mode of anti-diabetic activity on Swiss albino mice.

Plant-mediated green route to the synthesis of zinc oxide nanoparticles: in vitro antibacterial potential

AbstractThe plant-mediated, sustainable, facile, eco-friendly, and simple green approaches for the fabrication of metal oxide nanoparticles (NPs) have recently attracted the ever-increasing attention of the scientific community. To date, there has not been any research on green synthesis of ZnO-NPs by Piper guineense (Uziza) seeds widely used as a therapeutic agent is the novelty of the current study. The bioaugmented ZnO-NPs have been manufactured by Uziza seed extract using zinc acetate dihydrate as the precursor and sodium hydroxide with calcination. The hexagonal/spherical crystalline structure at high purely with a mean size of 7.39 nm was confirmed via XRD and SEM analyses of ZnO-NPs. A strong absorption peak at about 350 nm, specific for ZnO-NPs, was observed by a UV-visible spectrometer. The optical bandgap of ZnO-NPs was estimated as about 3.58 eV by the Kubelka-Munk formula. FTIR findings indicated the presence of biofunctional groups responsible for the bioreduction of bulk zinc acetate to ZnO-NPs. The growth rates of E. coli (ATCC 25,922) significantly decreased with ZnO-NPs exhibited compared to the controls. This is making ZnO-NPs promising effective candidates for medical sectors and environmental applications. This current study is hoped to supply a better understanding of the phytosynthesis of ZnO-NPs and promote the advance of green approaches based on plants.

Green Synthesis of Silver Nanoparticle Using Black Mulberry and Characterization, Phytochemical, and Bioactivity.

Synthesis of silver nanoparticles (AgNPs) using plant extracts has been proposed as a more advantageous and environmentally friendly alternative compared to existing physical/chemical methods. In this study, AgNPs were synthesized from silver nitrate using black mulberry (BM) extract. The biosynthesized AgNPs were characterized through an UV-visible spectrometer, X-ray diffraction, and transmission electron microscopy. Additionally, BM-AgNPs were subjected to antioxidant, antibacterial, anti-inflammatory, and anticancer activities. AgNPs biosynthesized from BM extract were dark brown in color and showed a strong peak at 437 nm, confirming that AgNPs were successfully synthesized. The size of AgNPs was 170.17 ± 12.65 nm, the polydispersity index was 0.281 ± 0.07, and the zeta potential value was -56.6 ± 0.56 mV, indicating that the particles were stable. The higher total phenol, flavonoid, and anthocyanin content of BM-AgNPs compared to BM extract indicates that the particles contain multiple active substances due to the formation of AgNPs. The DPPH and ABTS assays showed decreased IC50 values compared to BM extract, demonstrating improved antioxidant activity. AgNPs inhibited the growth of S. aureus and E. coli at 600 μg/mL, with minimum bactericidal concentrations determined to be 1000 and 1200 μg/mL, respectively. The anti-inflammatory activity was 64.28% at a BM-AgNPs concentration of 250 μg/mL. As the concentration increased, the difference from the standard decreased, indicating the inhibitory effect of AgNPs on bovine serum albumin denaturation. The viability of MCF-7 cells treated with BM-AgNPs was found to be significantly lower than that of cells treated with BM extract. The IC50 value of BM-AgNPs was determined to be 96.9 μg/mL. This study showed that BM-AgNPs have the potential to be used in the pharmaceutical industry as antioxidant, antibacterial, anti-inflammatory, and anticancer agents.

An experimental study on jute/banana fiber reinforced poly(vinyl alcohol) composites with nanofiller

AbstractThe incorporation of nanoparticles into natural fiber composites has the potential to alter the characteristics of natural fiber composites. In this study, various properties of jute and banana fiber reinforced poly(vinyl alcohol) (PVA) composites with different nanofillers incorporation were investigated. Samples were prepared using the vacuum bagging technique. Inorganic nanoparticles (Al2O3, ZnO, MgO, CuO, and TiO2) were synthesized using a ball milling machine and in each sample, 3 wt.% of nanofillers were incorporated. The maximum ultimate tensile strength and elongation percentage is found for TiO2, which is 90.433% higher than pure PVA whereas MgO incorporated samples provides maximum flexural strength, which is 162.59% higher than PVA. The sample with Al2O3 provides strongest impact resistance, 17.3 J/cm2. It was found that the decomposition temperatures were slightly higher for MgO and CuO doping than the undoped PVA composite. The FT‐IR spectra exhibited notable hydroxyl groups and minor shifts indicating a reduction in hydrophilicity upon the introduction of nanoparticles. The water absorption exhibited a reduction of up to 36% in conjunction with an increase in density across all samples. The highest crystallinity is found for CuO nanofiller composite, validated by x‐ray diffraction analysis. Additionally, morphological changes in the composites were seen through scanning electron microscopy and EDX shows a strong peak at 2.1 keV indicate some impurities present in the samples.Highlights Jute/banana/PVA composites were prepared with 3 wt% nanoparticles incorporation. Metal oxides such as Al2O3, ZnO, MgO, CuO, and TiO2 were used as nanoparticle. The use of nanoparticle improved the tensile, flexural, and impact properties. Decomposition temperatures were found higher for MgO and CuO incorporated composites. Upon nanoparticle incorporation, water absorption exhibited a reduction of upto 36%.

Growth, thermal, spectroscopy and 2.8 μm laser performance of Er:LuYGG crystal

A novel mid-infrared (Er0.3Lu0.1Y0.6)3Ga5O12 laser crystal is successfully grown by the Czochralski method, the crystal structure, segregation coefficient, thermal performance, spectroscopy and 2.8 μm laser performance are studied systematically. The crystal possesses a pure garnet phase with a thermal conductivity of 4.54 W m−1 K−1. It exhibits a broader absorption band around 966 nm and some strong emission peaks at 2.6–3 μm, corresponding to the absorption cross-section of 1.39 × 10−21 cm2 at 966 nm and emission cross-section of 1.25 × 10−20 cm2 at 2822 nm, respectively. The level lifetimes of 4I11/2 and 4I13/2 are fitted to be 0.885 and 3.203 ms. A LD end-pumped Er:LuYGG laser has been demonstrated, achieving a maximum output power of 339 mW and a slope efficiency of 17.77 %. The primary laser wavelength is centered at 2824.76 nm. All the results indicate that the Er:LuYGG crystal is a novel and promising crystal material to realize the 3 μm laser.

Effects of heating rate and deposition cycle on the structural, optical, and photoelectrocatalytic properties of electrodeposited hematite films

In this research, electrodeposited hematite films were prepared at voltammetry deposition cycles of 60 and calcined at 550 °C in a furnace after ramping the temperature at the rates of 2 °C/min, 10 °C/min, 35 °C/min, and rapid heating of about 100 °C/min. Additional samples were fabricated at deposition cycles of 15, 30, and 80, and also calcined at 550⁰C at a heating rate of 10⁰C/min. The impact of heating rate and deposition cycle number variations on the structural, optical, and photoelectrocatalytic (PEC) properties of the hematite films were assessed. All the films' X-ray diffraction (XRD) measurements showed strong peaks at the lattice planes (104) and (110), verifying hematite's rhombohedral crystal structure. The films prepared at the heating rate of 10⁰C/min boosted the crystallization of the films by 47.2 % relative to the ones prepared at 2⁰C/min. An increase in the deposition cycle number resulted in increasing film thickness and the sample’s crystallization. An indirect bandgap of 1.94–2.1 eV was estimated for the samples, with the least value obtained for the films treated at the heating rate of 10⁰/min and deposition cycles of 60. The same samples also yielded the largest photocurrent density of 26.2 μA/cm2 at 1.23 V vs. reversible hydrogen electrode (RHE), while the photoanodes fabricated at 2 °C/min exhibited the lowest photo-activity. The enhanced photocurrent observed for the films has been associated with high crystallinity, improved photon absorption, reduced flatband potential, and increased charge separation at the film’s surface. This research underscores the importance of optimizing both the heating rate and deposition cycle numbers in the fabrication of electrodeposited photoelectrodes for PEC applications.

Dysprosium doped SrCeO3 nanophosphors for advanced photochemical applications: Synthesis, characterization, photo-assisted dye degradation and latent fingerprint visualization

The present work investigates the novel potential of Sr(1-x)CeO3: xDy3+ (x = 1–9 mol%) nanoparticles, fabricated through Solution Combustion method using citric acid as fuel. The as-fabricated samples were thoroughly characterised using a variety of techniques to obtain structural, morphological, and optical data. Powder X-ray diffraction (PXRD) examination revealed the presence of an orthorhombic crystal structure (Pnma) matching PDF card #01-083-1156. Tauc's plot evaluating band gap energy utilizing absorption spectra reveals a range of 3.4 eV–4.2 eV with refractive index ranging from 0.64 to 1.22. Using Field Emission Scanning Electron Microscopy (FESEM), it was possible to see a coral-like aggregation for the host and initial concentration of Dy3+ ions, and a porous structure for higher concentrations. With an average particle size of 38.20 nm, a comprehensive Transmission Electron Microscopy (TEM) study demonstrates the fused aggregation structure. Moreover, quantifiable evidence of the precursors presence is provided by X-ray Photoelectron Spectroscopy (XPS). For the as-fabricated samples, photoluminescence investigations were carried out. Two strong peaks with a dominating 4F9/2 → 6H13/2 diploe-dipole transition was seen in the observed emission spectra under 366 nm (6H15/2 → 6P7/2) excitation. These peaks are positioned at 573 nm (4F9/2 → 6H13/2) and 478 nm (4F9/2 → 6H15/2). Under UV light, two cationic dyes, Rhodamine-B (Rh–B) and Methylene Blue (MB), were photo-catalytically degraded using the prepared sample (SCD5). According to 0th and 1st order kinetics, the observed data show evidence of effective degradation up to 89.64 % (Rh–B) and 78.86 % (MB) at 80th minute. In addition, the impact of several analytical parameters on the percentage degradation of Rh–B and MB dyes was investigated. These parameters included catalyst changes, dye dosage, and scavenger effect. The produced nanoparticles were used to create latent fingerprints on two non-porous surfaces: glass and aluminium. The results clearly showed that on both surfaces a type-III level of detection was attained. To summarise, the outcomes indicate that Sr(1-x)CeO3: xDy3+ nanoparticles that have been synthesized can be used for advanced forensic applications as well as for the degradation of dye pollutants.

Exploring the synergy of Zn3(OH)2V2O7 2H2O @Betalains as a promising photoluminescent nanocomposite for sustainable optical and electrochemical applications

For the first time, the new approach was utilized to synthesize a novel Zn3(OH)2V2O7 2H2O/Betalains (ZV/Bn) nanocomposite (NCs) through the mediation of natural dye betalains (Bn) extract and a hydrothermal method. With decreased crystallite size (38 nm) and a lower band gap, ZV/Bn NCs are showing a potential candidate with better performances in photoluminescence, nitrite sensing, and corrosion inhibition studies when compared to pure ZV nanoparticles. The optical band gap of ZV/Bn is 2.7 eV, and the Bn is effective in reducing the band gap of ZV by 0.3 eV. ZV/Bn has shown its intense fluorescence properties by emitting a vibrant green emission with a strong emission peak at 535 nm and a subtle peak at 489 nm. The exceptional ability of ZV/Bn fluorescent was significantly employed for the development of latent fingerprint detection, resulting in the high quality of fingerprint images. ZV/Bn-based sensors have proved to be successful due to their low cost, biocompatibility, and high sensitivity towards the detection of the most important bioanalyte, nitrite. The limit of detection (LOD) and the sensitivity of ZV/Bn-based sensor for the detection of nitrite are 17 μM and 7.8E−6 A/M, respectively. Additionally, it shows potential as a corrosion inhibitor. Hence, ZV/Bn NCs emerge as a versatile candidate for optical and electrochemical applications.