Photoluminescence Spectrometer Research Articles

A Portable RGB-Type Quantum Dot-Based Water Sensing Device for Heavy Metal Ion Detection

Using fluorescent quantum dots to detect heavy metal ions in water resources has attracted extensive attention. However, bulky photoluminescence spectrometers are generally required to read the signals, which are not suitable for on-site detection.

Solvatochromic Behavior of Solid-State Nitrogen-Doped Carbon Nanoparticles: Initial Study

Carbon nanoparticles (CNPs) have garnered significant attention among researchers due to their cost-effectiveness and tunable properties, rendering them applicable in a wide array of fields, including biomedicine, optoelectronics, catalysis, and sensing. The solvatochromic effect denotes the phenomenon of a compound exhibiting a color change or a shift in its photoluminescence spectrum. In this study, we investigated the solvatochromic behavior of CNPs doped Nitrogen synthesized through the solid-state route using citric acid and urea, dissolved in solvents with varying polarity indices. Significant differences in emission were analyzed using a photoluminescence (PL) spectrometer. The results exhibit the emission shifting towards longer wavelengths (red region) as the solvent’s polarity index increased. This study of solvatochromic behavior in CNPs holds substantial significance for further research into their application as sensors.

Zinc oxide nanoparticles-reduced graphene oxide nanocomposite thin-film for β-D-glucose detection

This work presents a technique to detect β-D-glucose by using zinc oxide nanoparticles-reduced graphene oxide (ZnO NPs-rGO) nanocomposite thin-film. The ZnO NPs were synthesized by the direct precipitation method. The rGO was fabricated via hydrothermal treatment of graphene oxide (GO) powder. The optical properties of the nanocomposite thin-film were characterized via ultraviolet–visible, Raman and photoluminescence (PL) spectrometers. The morphology of the nanocomposite thin-film was obtained from a field emission scanning electron microscope (FESEM). Based on the optical result, the absorption peak was correlated with the excitation wavelength required to induce high PL spectra in the nanocomposite. Furthermore, the FESEM image displayed the spherical and non-uniform sized ZnO NPs on the sheet-like surface of rGO. For the β-D-glucose detection, changes in the wavelength and intensity peak of UV emission in PL spectra were investigated. From the results, a red-shift and reduction of peak intensity of UV emission was observed under 0.25 - 40 mM β-D-glucose concentration. A linear response, with a slope of 0.87 nm/mM and regression coefficient, R2 of 0.99 indicated that the detection range of the nanocomposite thin-film covers from high to low glucose levels. Furthermore, the highest sensitivity of 1.09 %/mM was obtained based on the percentage change of the peak intensity per mM glucose concentration. These observations signify the potential of detecting wide concentrations of β-D-glucose, making the nanocomposite material suitable for practical uses in glucose sensing and monitoring.

Optical Investigation of Reduced Graphene Oxide / Titanium Dioxide Nanocomposite Thin Films Synthesized by Hydrothermal Method

The growing need for unique optical properties in the manufacturing of electronic devices has led the world to the field of hybrid materials and their composites. In this study, a simple physical technique was used to successfully manufacture hybrid nanocomposites containing nanoparticles of titanium dioxide (TiO2) and reduced graphene oxide (rGO) from tetrabutyl titanate (TBT) and graphene oxide (GO) powder using the hydrothermal method. For two hydrothermal treatment times (12h and 24h), various samples were created: TiO2, rGO, and TiO2/rGO nanocomposites thin films. Fourier transformer infrared (FTIR) spectra of the samples gave clear evidence for the reduction of GO and the engagement of Ti with reduced graphene by the formation of a Ti-O-C bond. The measurement of the energy band gap obtained by the photoluminescence spectrometer shows a decrease in the energy band gap for all samples after the hydrothermal reaction time increases, for the composite, the band gap decreases to 2.65 eV and 2.64 eV.

Mg doped ZnO Nanostructures: application as an environmental photo-catalyst

In this era, metal oxide nanoparticles with appliances in solar, catalysis, sensors, actuators, and many other fields, are highly sought-after because of their wide band gap. This study examines the Mg doped ZnO nanoparticles for the structural, electrical transportation and photo-catalytic behaviour. The XRD, FT-IR (Infrared Spectroscopy), PL (Photoluminescence), and Complex Impedance Spectroscopy were used to characterise the prepared sample. The wurtzite hexagonal structure in space group P63mc was shown by the XRD data. The analyzed crystallite sizes, planner distances, and cell volumes of Mg doped ZnO nanoparticles are 35.2 nm, 2.6122 Å, and 60.91 Å3, respectively. The aggregation in sample is visible in the micrographs. The PL spectra was traced at an excitation wavelength of 330 nm (λ) using a PL spectrometer. Using the FTIR approach, IR spectra with acmes about 520–640 cm-1 were traced, leading to Zn–O bond stretching. Using a photocatalytic reactor, the photocatalytic degradation of magnesium-doped ZnO nanoparticles was measured for two hours. For the Mg doped ZnO sample, the degradation efficiencies (ɳ%) is 67 percent.

Effect of high concentration of ZnO on the structural and optical properties of silicate glass system

An investigation was conducted to explore the optimum composition to fabricate a zinc silicate glass substrate for optoelectronic device applications. The composition was determined based on the empirical formula (ZnO)x-(SiO2)1-x, where x = 0.40, 0.50, 0.60 and 0.70 wt%, which was prepared by the conventional melt quenching technique. The focus is on characterizing the physical and structural aspects as well as the optical properties of the glass substrate. The physical properties of zinc silicate samples were assessed using the densitometer and their physical appearance. In addition, the materials' amorphous and glassy characteristics were verified using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques. Finally, ultraviolet–visible (UV–Vis) spectroscopy and photoluminescence spectrometer were used to study the optical properties of samples. The density of the samples was observed to increase from 2805 to 3878 kg/m3 as the percentage of ZnO in the glass composition increased. X-ray diffraction analysis indicated the absence of sharp peaks in the samples containing up to 0.60 wt% of ZnO, suggesting the presence of an amorphous phase. Furthermore, the results of this study indicate that ZnO-SiO2 glass substrate samples favor direct forbidden transitions, with an increase in ZnO leading to higher absorption and consequently a lower band gap. The photoluminescence spectrum showed blue light emissions at 422 nm, associating with the variation of band gaps in the ZnO phase. Overall, from the interesting results achieved, this zinc silicate-based composite material at 0.60 wt% ZnO can be a potent candidate in optoelectronic applications, among other concentrations used in this study.

Investigations on anticancer activity of Eu3+ doped hydroxyapatite nanocomposites against MCF7 and 4T1 breast cancer cell lines: A structural and luminescence Perspective

Breast cancer remains a significant global health concern, necessitating the development of novel therapeutic approaches. In this study, we investigate the role of Eu3+ doped hydroxyapatite nanocomposites (Han: Eu3+) in the treatment of MCF7 and 4T1 breast cancer cell lines. Furthermore, we explored the structural and luminescent properties of these nanocomposites. Han: Eu3+ were synthesized using a modified co-precipitation method, and their morphology and crystal structure were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) in which the average crystalline size of Han: Eu3+ was found to be 25 nm, rendering them suitable for cellular uptake and targeted therapy. To gain insights into the luminescent properties of Han: Eu3+, their excitation and emission spectra were recorded using photoluminescence spectrometer. The characteristic red emission of Eu3+ ions was observed upon excitation, validating the successful doping of Eu3+ into the Han lattice, which was confirmed by the CIE chromaticity coordinate study. These luminescent properties of Han: Eu3+ hold promise for potential applications in bioimaging. To evaluate the efficacy of Han: Eu3+ in breast cancer treatment, MCF7 and 4T1 cell lines were exposed to varying concentrations of the nanocomposites. Cell viability assays revealed a concentration-dependent reduction in cell viability, indicating the potential anticancer activity of Han: Eu3+. The findings of this study contribute to the expanding field of nanomedicine, bringing targeted breast cancer treatments and us closer to more effective.

ZnS and Fe-doped ZnS photocatalysts for improved visible light driven photocatalytic degradation of methylene blue

In the current research un-doped and Fe-doped ZnS nanocrystals (Zn1−xFexS (x = 0.0–0.08) were synthesized by wet chemical method. The synthesized nanocrystals were characterized by X-ray diffraction measurements, scanning electron microscopy, Fourier transformed infrared microscopy, UV–Vis, and Photoluminescence spectrometer. The particle size at different doping concentration was found to be 2.80, 2.77, 2.59 and 1.68 nm and the size of un-doped ZnS is found to be 3.76 nm. Photocatalytic performance of un-doped ZnS and Fe-doped ZnS nanocrystals was evaluated by de-colorization of methyl blue under UV light. It was observed that Fe-doped ZnS decolorized dye solution at fast rate as compared to un-doped ZnS. The maximum degradation (94 %) was observed when Zn0.92Fe0.08S was used as photocatalyst.

Construction of P-C3N4/C3N5 isotypic heterojunction for effective degradation of organic pollutants

BackgroundPhotocatalysis was an effective method for organic pollutant degradation, and graphitic carbon nitride g-C3N4 and g-C3N5 were famous two-dimensional semiconductors. Compared to the allotypic heterojunction, the band alignment and compatibility of isotypic heterojunction were superior. MethodsIn this work, an organic isotypic heterojunction was constructed via coupling phosphorus-doped C3N4 (P-C3N4) and g-C3N5. The characteristics were evaluated using transmission electron microscope, Fourier transform infrared, X-ray diffractometer, X-ray photoelectron spectrum, ultraviolet-visible (UV–vis) diffuse reflection spectrum, electronic spin resonance (ESR) analysis, photoluminescence spectrometer, electrochemical impedance spectroscopy, and photocurrent analysis. SignificantIsotypic heterojunction displayed high UV–vis light harvest, high separation efficiency of photo-induced charge carriers, and low surface resistance. Additionally, an internal-electric-field was established at the interface, which was beneficial for spatial separation of photo-induced charge carriers. As expected, the Rhodamine B (RhB) degradation efficiency was 7.3 and 12.3 times higher than that of the P-C3N4 and g-C3N5. Radical trapping experiment and ESR analysis indicated that •O2−, •OH, hole, 1O2, and electron played joint role in RhB degradation. In this work, a photocatalyst with excellent photocatalytic degradation properties was designed, and it provided a simple and novel strategy for environmental remediation.

Ultrasonic irradiation enhanced the efficacy of antimicrobial photodynamic therapy against methicillin-resistant Staphylococcus aureus biofilm

Antimicrobial photodynamic therapy (aPDT) is a non-pharmacological antimicrobial regimen based on light, photosensitizer and oxygen. It has become a potential method to inactivate multidrug-resistant bacteria. However, limited by the delivery of photosensitizer (PS) in biofilm, eradicating biofilm-associated infections by aPDT remains challenging. This study aimed to explore the feasibility of combining ultrasonic irradiation with aPDT to enhance the efficacy of aPDT against methicillin-resistant staphylococcus aureus (MRSA) biofilm. A cationic benzylidene cyclopentanone photosensitizer with much higher selectivity to bacterial cells than mammalian cells were applied at the concentration of 10 μM. 532 nm laser (40 mW/cm2, 10 min) and 1 MHz ultrasound (500 mW/cm2, 10 min, simultaneously with aPDT) were employed against MRSA biofilms in vitro. In addition to combined with ultrasonic irradiation and aPDT, MRSA biofilms were treated with laser irradiation only, photosensitizer only, ultrasonic irradiation only, ultrasonic irradiation and photosensitizer, and aPDT respectively. The antibacterial efficacy was determined by XTT assay, and the penetration depth of PS in biofilm was observed using a photoluminescence spectrometer and a confocal laser scanning microscopy (CLSM). In addition, the viability of human dermal fibroblasts (WS-1 cells) after the same treatments mentioned above and the uptake of P3 by WS-1 cells after ultrasonic irradiation were detected by CCK-8 and CLSM in vitro. Results showed that the percent decrease in metabolic activity resulting from the US + aPDT group (75.76%) was higher than the sum of the aPDT group (44.14%) and the US group (9.88%), suggesting synergistic effects. Meanwhile, the diffusion of PS in the biofilm of MRSA was significantly increased by 1 MHz ultrasonic irradiation. Ultrasonic irradiation neither induced the PS uptake by WS-1 cells nor reduced the viability of WS-1 cells. These results suggested that 1 MHz ultrasonic irradiation significantly enhanced the efficacy of aPDT against MRSA biofilm by increasing the penetration depth of PS. In addition, the antibacterial efficacy of aPDT can be enhanced by ultrasonic irradiation, the US + aPDT treatment demonstrated encouraging in vivo antibacterial efficacy (1.73 log10 CFU/mL reduction). In conclusion, the combination of aPDT and 1 MHz ultrasound is a potential and promising strategy to eradicate biofilm-associated infections of MRSA.

Synthesis of Ce-doped NiFe2O4 nanoparticles and their structural, optical, and magnetic properties

The impact of Ce3+ doping on the crystallite size, microstructure, optical, and magnetic characteristics of nickel ferrite magnetic nanoparticles prepared by co-precipitation method is discussed in this article. The x-ray diffractometer, ultraviolet–visible spectrometer, photoluminescence spectrometer, electron paramagnetic resonance spectrometer, and vibrating sample magnetometer were used to characterize the prepared samples. The x-ray diffraction technique confirmed the cubic phase of all the samples and it further confirmed that the crystallite size steadily reduces from 55.8 to 33.5 nm as the Ce content rises from 0 to 0.15 then it rises to 41.8 nm with Ce content of 0.20. The lattice parameter ‘a’ was found to increase from 8.3442 to 8.3564 Å with the increase in Ce substitution. As the Ce content increases from 0 to 0.15, the optical band gap increased from 1.50 to 1.95 eV, thereafter, decreasing for Ce content x = 0.20. Fourier transform infrared spectroscopy reveals that the frequency corresponding to the Fe–O vibration of Ce-doped nickel ferrite nanoparticles is pushed towards a shorter wavenumber in contrast to pure nickel ferrite. The spinel structure of the synthesized samples confirmed by the x-ray diffraction pattern was also endorsed by the fourier transform infrared spectra. Photoluminescence spectra confirmed the visible emission from the undoped and Ce-doped nickel ferrite nanoparticles. Transmission electron microscopy analysis confirmed the rectangular shape of the nanoparticles and the reduction in average particle size from 58 to 37.5 nm with an increase in Ce concentration. Energy dispersive x-ray spectroscopy analysis confirmed the presence of Ni, Fe, Ce, and O elements. The explicit magnetic parameters like saturation magnetization, remanence, coercivity, squareness ratio, and magnetic moment were determined from magnetization versus applied field measurements. The result of BET analysis confirmed the porous nature of the Ce-doped NiFe2O4 which may be useful in photocatalytic activity. According to magnetic hysteresis curves, the saturation magnetization of nickel ferrite decreases from 51.9 to 22.6 emu/g after Ce content is 0.15. Vibrating sample magnetometer analysis also confirmed the superparamagnetism in nickel ferrite and cerium-doped nickel ferrite samples. Electron paramagnetic resonance confirmed the decrease in spin numbers and the spin relaxation time, after doping with cerium ions.

Impact of calcination temperature on structural and electrical behaviour of Fe3+/Fe2+ modified Zinc oxide nanostructures

Metal oxide nanomaterials are very popular due to its extensive band gap with significant applications in photovoltaic, catalysis, sensors, actuators and many more. This work on the impact of Fe3+ ion substitution on structural and electronic transportation character of ZnO nano structures prepared through co-precipitation method. The prepared samples were characterized via XRD, Field Emission Scanning Electron Microscope, FT-IR (Infrared Spectroscopy), PL (Photo-luminescence) and Complex Impedance Spectroscopy. From the XRD data, the wurtzite hexagonal structure in space group P63mc was demonstrated. The calculated crystallite sizes, planner distance and cell volume of Fe/ZnO-300 nanoparticles is 28.6 nm, 2.6012 Å and 59.41 Å3. The micrograph of Morphologies reveals the agglomeration in samples. The PL spectrum traced via PL spectrometer with 320 nm excitation wavelength (λ). IR spectrums with acmes close to 529–634 cm−1 were traced via FTIR technique and ensuing to stretching in the Zn-O bond. The impedance spectroscopies of La/ZnO-300 nanoparticles were measured via impedance Analyzer in the frequency assortment 5 MHz to 10 Hz at room temperature (RT). The value of grain margin resistance is 26.10 MΩ (at 300 K or RT) with the dielectric constant value 370 for La/ZnO-300 samples.

Facile Method for the Preperation of a Stable, and High Performance UV-Vis Photodetector with Poly(3-hexylthiophene-2,5-diyl):PCBM Composite Polymer

A high performance and stable UV-Vis hybrid photodetector with P3HT:PCBM composite polymer film encapsulated with a micro thin layer of Polydimethylsiloxane (PDMS) is reported. The hybrid P3HT:PCBM composite junction was chractarized with several tools. XRD revaled the presence of both P3HT and PCBM polymer in the The hybrid P3HT:PCBM composite junction. Furthermore, the ultraviolet-visible (UV-Vis) and photoluminescence (PL) spectrometers reveal that the absorption and emission of the hybrid P3HT:PCBM composite junction have significantly enhanced compared with that of the pure P3HT film, and PCBM. In addition. the hybrid photodetector shows a low-level dark current (0.13 nA), a high-level light current (IL = 0.13 nA), an ON/OFF ratio (2.69×106), a responsivity (R = 7.11 A/W), and a specific detectivity (D* = 3.32×1013 J). The responsivity of the hybrid was improved by 4 times in magnitudes compared with that of the pure PCBM and the P3HT. this result pave the way for utlizing the hybrid P3HT:PCBM composite junction in enhncing performance of optolectronics.

Spectral Characteristics of Unique Species of Burmese Amber

Special species of Burmese amber are highly valued within the gemological market due to their fancy optical characteristics. However, some ordinary amber species are misidentified as precious species, which has disrupted consumers’ purchasing behavior and the market order. In this study, seven Burmese amber species (golden, golden-blue, blood-tea, black-tea, green-tea, brownish-red, and ‘chameleon’ amber) were collected and investigated. By using conventional gemological tests, Fourier transform infrared (FTIR), three-dimensional (3D) fluorescence, and photoluminescence (PL) spectrometers, detailed analyses were performed on unique species. The FTIR spectra identified that there are three groups of peaks that can distinguish Burmese amber from any other origin. Additionally, the ‘Chameleon’ amber exhibited special patterns in the third group, which might be due to its internal aromatic hydrocarbons structures that are different from any other species. The 3D fluorescence spectra displayed that all seven species presented similar fluorescence behavior—the 334 or 347 nm emission wavelength could be optimally excited by 240 or 294 nm excitation wavelength in the ultraviolet region and the 380 ± 10 nm or 400 ± 10 nm excitation wavelength optimally excited the 430 nm emission wavelength in the violet region. In the red region, green-tea amber, black-tea amber, and brownish-red amber presented totally different fluorescence behavior, which could be regarded as a reference feature for differentiation. Obvious pink fluorescence on the surface of the tea amber was efficiently found under PL spectra, and we firstly suggest this test could be used as an effective way to distinguish black-tea amber from green-tea amber and some ordinary species (such as blood-tea amber). Both the PL and 3D fluorescence measurements demonstrated the different luminescence behavior of tea amber in the red region, which might be related to the type and content of red fluorescent substances in the tea amber.

Design and Fabrication of Optical Sensors Based on Neodymium (Nd) Doped Titanium Dioxide (TiO2) Layer Prepared by Sol–Gel Dip-Coating Method

A high performance and stable UV photodetector with a bsorbant layer of Neodymium (Nd) doped Titanium dioxide (TiO2) is reported. The Neodymium (Nd) doped Titanium dioxide (TiO2) layer was chractarized with several tools. XRD and FTIR revaled that the crsytal structure of Neodymium (Nd) doped Titanium dioxide (TiO2) has changed compared with that of the undoped anatase Titanium dioxide (TiO2). Furthermore, the ultraviolet-visibleand photoluminescence spectrometers reveal that the measured absorption and emission of the hybrid Nd doped TiO2 layer have significantly enhanced compared with that of the undoped Titanium dioxide (TiO2). In addition. The photodetector based on Neodymium (Nd) doped Titanium dioxide (TiO2) shows a low-level dark current (Idark = 0.13 nA), a high-level light current (Ilight = 15655.6 nA), an ON/OFF ratio (1.2×105), a responsivity (R = 0.32 A/W), and a specific detectivity (D* = 4.2×1012 J). The photoresponsivity (R) of Nd doped TiO2 layer was improved by nearly 3 times in magnitude in comparison with the photoresponsivity of the undoped TiO2 layer PD without the Nd. This result pave the way for utlizing the hybrid Nd doped TiO2 in enhncing performance of optolectronics.

High-throughput transient photoluminescence spectrometer for deep learning of thermally activated delayed fluorescence materials

The fast acquisition of high dynamic range PL decay profile is realized and new PL decay parameters for deep learning of thermally activated delayed fluorescence materials are presented.

Titanium Nanoparticles Modified NIR Emission of Neodymium Doped Magnesium Zinc-Sulfophosphate Glass: Effect of Heat Treatment on Surface Plasmon Resonance Bands

New type plasmonic sensitizer, titanium nanoparticles (Ti NPs) shown potential in enhancing photoluminescence of rare-earth ions (REIs) as doped into magnesium zinc-sulfophosphate (MZS) glass for optical to optic application. Here, neodymium ions (Nd3+)-doped MZS glass with Ti NPs inclusion gone heat treatment (HT) at 450°C for 6 and 12 hours in order to tune the NPs size and tailor their plasmonic strength. The sample was characterized using X-ray diffractometer (XRD), high-resolution transmission electron microscope (HRTEM), and photoluminescence (PL) spectrometer. Heat treatment (HT) grows Ti NPs with a mean size ≈ 16 nm. The SPR bands are probed around 585and 739 nm. The SPR band intensities change with HT duration. The NIR PL bands were perceived around 878 nm, 1050 nm and 1322 nm corresponding to 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 transitions, accordingly. The PL transition 4F3/2→4I9/2 (878 nm) and 4F3/2→4I13/2 (1322 nm) is enhanced about 1.44 and 1.52 times respectively, after 12 hours HT. The results show that HT enhances PL through SPR amplification. These findings may be useful in developing solid-state lasers and optical materials.

Tunable luminescence and oxygen defects of the spinel MgAl2O4: Eu3+/Eu2+ for photonic application

In this study, we have reported the luminescent property of 0, 0.05, 0.1, and 0.5 mol. % Eu2O3 doped in bulk MgAl2O4 spinel excited at 266 nm. The samples were prepared by slip-cast method and sintered at 1650 °C for 2 h in the air. The sintered samples were subjected to hot isostatic pressing (HIP) in argon atmosphere to achieve theoretical density and transparency. X-ray diffraction patterns for all samples revealed the spinel phase of the face-centered cubic structure. The luminescence of the sintered and HIPed samples was recorded using photoluminescence spectrometers. The sintered samples exhibited characteristic red light emission of Eu3+ at 613 nm. Surprisingly, this Eu3+ emission does not appear for the HIPed samples and shows a characteristic blue emission for the Eu2+ in the 445–480 nm range. Interestingly, further heat treatment of the HIPed samples at 1300 °C for 1 h in air revealed the re-appearance of the characteristic Eu3+ red emission at 613 nm without the Eu2+ blue emission. It is concluded that the Eu3+/Eu2+ emission centers are tunable depending on the processing conditions. Here a characteristic emission center at 482 nm was found for the sintered samples that indicate the presence of oxygen vacancy.

Altering coupled mode of surface plasmon resonance mediated by silver and gold nanoparticles through heat treatment: Judd ofelt, racah and NIR-luminescence of neodymium doped magnesium–zinc-sulfophosphate glass

Manipulating surface plasmon resonance (SPR) of silver (Ag) and gold (Au) nanoparticles (NPs) in amorphous material may open new possibilities in optic and photonic fields. Driven by this fact, heat treatments (HT) were used to tune the excitation mode of SPR. The Nd3+ doped magnesium-zinc-sulfophosphate glasses embedded with Ag and Au NPs were heat-treated at 450 °C for 6 and 12 h and characterized using X-ray diffractometer (XRD), high-resolution transmission electron microscope (HRTEM), UV–Vis–NIR absorption and photoluminescence (PL) spectrometer. The mean size of NPs was slightly reduced (4.68 nm→ 4.35 nm) after 12 h of HT due to the elastic ripening process, causes by internal pressure within NPs. Unusual multiple SPR bands were evidence around 419, 481, 613, 676, 776, 848 and 939 nm after the glass (AgAu6h) is heat-treated for 6 h. Thirteen absorption bands are recorded within 326–875 nm, corresponding to the Nd3+ ion transitions. The NIR PL bands of Nd3+ ion were detected around 878 nm, 1050 nm, and 1322 nm corresponding to 4F3/2 → 4I9/2, 4F3/2 → 4I11/2, and 4F3/2 → 4I13/2 transitions, respectively. Overall, sample coded AgAu12 h disclosed the highest bandwidth gain of 0.09, 1.14, and 3.06 ( × 10−22 cm3) assigned to transition 4F3/2 → 4I9/2, 4F3/2 → 4I11/2, and 4F3/2 → 4I13/2, respectively, with a quantum efficiency of 21.06% (for transition 4F3/2 → 4I11/2). The HT can modify the intensity of PL through different NPs assemblies (single, dimer, trimer) and bonding modes (e.g: longitudinal dipolar or quadrupolar coupling mode). The unique optical feature discovered may be useful in customizing solid-state laser materials.

Novel Approach to Synthesis of AgZnS and TiO2 Decorated on Reduced Graphene Oxide Ternary Nanocomposite for Hydrogen Evolution Effect of Enhanced Synergetic Factors.

In this work, a novel ternary nanocomposites AgZnS-TiO2-reduced graphene oxide (RGO) was successfully synthesized by a facile soft ultrasonic-reduction condition as low as 70 °C. During the ultrasound reaction, the reduction of GO and the growth of AgZnS and TiO2 crystals occurred simultaneously in conjunction with the deposition of AgZnS and TiO2 crystals onto the surface of the graphene. The synthesized nanocatalysts were characterized by XRD, SEM, TEM, EDX, Raman spectroscopy, XPS, UV–Vis DRS, photoluminescence spectrometer, and photocurrent and CV. The AgZnS-G-T was shown as catalytic HER with some synnegetic factors such as pH-universal, temperature, and ultrasonic condition. After 4 h, it was observed that AgZnS-TiO2-RGO has the highest efficiency of photocatalytic activity through hydrogen production by water splitting, which achieved the highest hydrogen evolution rate of 930.45 μmol/g at buffer solution (pH = 5), which was superior to AgZnS-G (790.1 µmole/g) and AgZnS (701.2 µmole/g). Such a significant hydrogen evolution amount far exceeded that of undoped TiO2 and RGO. The H2 evolution amounts increased significantly at ultrasonic irradiation power of 80 MHz. AgZnS-G-T demonstrates the higher H2 evolution amounts of 985 µmole/g at 80 MHz. Its photocatalytic hydrogen-evolution activity remained at a high level over four cycles (16 h) nanoparticle.