Gd Concentration Research Articles

Effect of Gd content on microstructure and mechanical properties of Mg-xGd-Zr alloys via semicontinuous casting

Mg-Gd based alloys are an important class of high-performance Mg alloys. In this study, three Mg-Gd alloys with different gadolinium (Gd) contents: Mg-9.54Gd-0.40Zr (wt.%, G10 K), Mg-15.11Gd-0.35Zr (wt.%, G15 K) and Mg-19.67Gd-0.33Zr (wt.%, G20 K) were prepared by semicontinuous casting and subsequent solution and aging heat treatments. The role of Gd content on microstructures and mechanical properties of the Mg-Gd-Zr alloy is studied. All three as-cast alloys exhibit eutectic phases of Mg5Gd, with the amount increasing as the Gd content rises. Mg5Gd disappears after the solution heat treatment (the G10 K alloy solution-treated at 480 °C for 4 h, the G15 K alloy at 500 °C for 12 h and the G20 K alloy at 520 °C for 24 h, respectively). Aging heat treatment at 200 °C for 64 h after solution introduces numerous prismatic β′ precipitates, with a significant increase in their area number density corresponding to increased Gd content. Additionally, the morphology of the β′ precipitates exhibits distinct variations: the G10 K alloy is characterized by an enhanced aspect ratio. Consequently, the peak-aged G10 K alloy demonstrates superior strength-ductility synergy, with a yield strength (YS) of 216 ± 1 MPa, an ultimate tensile strength (UTS) of 363 ± 1 MPa, and an elongation (EL) of 8.7 ± 0.6 %. This study suggests that plasticity diminishes and precipitation strengthening is limited when the gadolinium content exceeds 15 wt.%.

Advancing biodegradable Mg-Gd-Y alloy for cardiovascular stent applications

The implants of percutaneous coronary intervention are making progress to periodic degradation and the reduction of complications. Thus, magnesium alloys have emerged as excellent candidate materials for preparing cardiovascular stents due to their excellent biodegradability and biocompatibility. This study investigates the effect of Gd content on the mechanical properties and corrosion behavior of Mg-xGd-5Y alloys. The results indicate that Gd dissolved in the Mg matrix, enhancing ultimate tensile strength (UTS of 344MPa) through a solid solution-strengthening effect and activating Prismatic <a> slip systems to enhance elongation (EL of 15.7%). The Pilling-Bedworth ratio (PBR) of Mg-xGd-5Y alloys was analyzed after being immersed in Hank's Balanced Salt Solution for 24h, with Mg-10Gd-5Y exhibiting a PBR value of 1.1. Furthermore, the product film of Mg-xGd-5Y alloys, mainly oxides and carbonates, effectively improved corrosion resistance. Mg-xGd-Y alloys with low Gd content (Gd≤10wt.%) demonstrated good cell compatibility with L929 cells (relative growth rate≥75%). These results suggest that Mg-xGd-5Y alloys (Gd≤10wt.%) have significant potential for cardiovascular stent application.

Influence of Gd content on the structural, morphological, and optical properties of electrodeposited Mn–Fe–Gd/Cu thin Films

Influence of Gd content on the structural, morphological, and optical properties of electrodeposited Mn–Fe–Gd/Cu thin Films

Effect of Gd doping on the microstructure and electrical characteristics of Maghemite (γ-Fe₂O₃) ceramics

AbstractThis paper presents a novel study on the microstructure and electrical properties of gadolinium (Gd) doped maghemite (γ-Fe₂O₃) nanoparticles, emphasizing their significance for advanced applications in efficient materials. X-ray diffraction analysis confirmed that both pure and doped samples crystallized in a cubic structure (P4332 space group) with high purity. Gd doping significantly increased crystallite size and altered particle morphology, as shown by transmission electron microscopy (TEM), which revealed larger nanoparticles with cubic shapes. Thermal analysis (TGA and DTG) indicated that higher Gd concentrations enhanced thermal instability, affecting structural integrity. FTIR spectra showed shifts in Fe-O bond vibrations, suggesting lattice distortions and increased disorder. BET measurements indicated that higher Gd doping led to greater mesoporosity and surface area, countering expectations of densification. Electrical conductivity and impedance studies revealed two distinct regions: a constant conductivity at low frequencies and an exponential increase at high frequencies, attributed to small polaron hopping. Activation energy values below 200 meV support this mechanism. Gd doping decreased overall conductivity due to disrupted atomic arrangements, increased electron scattering, and modifications in the electronic band structure. Complex impedance spectroscopy illustrated higher real impedance values for doped samples, with increased Gd concentration leading to enhanced impedance. These findings elucidate the impact of Gd on the electrical properties of maghemite nanoparticles and highlight their importance in meeting the growing demands for highly efficient technologies in energy storage and electronic devices. Graphical Abstract

Promoting transparency: Defect-driven sintering of Gd2Zr2O7 ceramics for advanced radiation applications

Transparent Gd2Zr2O7 (GZO) ceramics show significant potential for radiation detection and nuclear energy applications. However, scalable production through cost-effective solid-state vacuum sintering is challenging due to the material's high melting point and low thermal conductivity. This study introduces a novel approach by incorporating excess Gd to increase lattice defects, such as cation disorder and oxygen vacancies, which have low formation energy. This strategy lowers the energy barrier for ion diffusion, enhances material migration during sintering, and promotes the elimination of residual pores, leading to high densification. We examined the densification behavior of GZO compositions with varying Gd content (Gd1.8Zr2O6.7 to Gd2.5Zr2O7.75) during vacuum sintering at 1450°C to 1900°C, focusing on phase transformation, grain growth, and pore elimination. Notably, the optimal sample achieved 78.3 % transmittance, approaching the theoretical maximum. These findings offer a promising route for the large-scale production and commercialization of transparent GZO ceramics for advanced radiation applications.

Optimization of structural, optical, dielectric and magnetic properties of Gd3+ substituted Mg-Mn mixed spinel ferrite ceramics

Manganese magnesium ferrite (Mg0.5Mn0.5Fe2O4) and Gd doped Mg0.5Mn0.5Fe2O4 (Mg0.5Mn0.5Fe2-xGdxO4 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) were synthesized using the solid-state method. The structural study was performed using the powder X-ray diffraction (XRD) technique. The XRD plot confirms the presence of a spinel cubic structure for pure MgMn ferrite and the existence of a secondary GdFeO3 phase in addition to the cubic spinel phase for Gd-doped MgMn ferrite. The average crystallite size estimated from the Williamson-Hall plot decreases from 42.75 nm to 18.97 nm with the increase in Gd content. The microstructural study confirms the clear grains with well-defined grain boundaries. The Fourier Transform Infrared (FTIR) spectra of the samples show the vibrational bands at 3440 cm−1, 1636 cm−1, 1385 cm−1, 1100 cm−1, and 560 cm−1 assigned to tetrahedral and octahedral sites. The improvement in dielectric property has been observed for Gd-doped samples. The saturation magnetization and remnant magnetization decrease from 0.7 to 0.3 emu and 0.035 to 0.0273 emu respectively. The coercivity increases from 31 to 75 Oe with the increase in Gd content. The fabricated spinel ferrites have significant electrical and magnetic properties which may be promising candidates for microwave devices.

The elemental variance between the "rice" and "non-rice" portions of Maifanitum and its health risk assessment

BackgroundMaifanitum, a mineral used in Chinese medicine, was first documented during the Song Dynasty (960-1279). Historical records suggest its multifaceted therapeutic properties, including detoxification and stasis resolution, necrosis removal and tissue regeneration, diuretic and calculi dissolution and prolonging life. The concentration of elements in Maifanitum may vary depending on its origin, different parts, which can affect its effectiveness in different fields of applications. Therefore, the analysis of elements in Maifanitum and the subsequent health risk assessment have been conducted. This provides an important basis for the quality control and application safety of Maifanitum. MethodThe analytical techniques employed in this study are inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), utilized for the quantitative assessment of 60 elements (Refer to Appendix 1) within Maifanitum samples. Based on the test results, chemometric methods are employed to evaluate the characteristics and differences in elemental concentration from different sources and locations. Additionally, a preliminary health risk assessment is conducted for Maifanitum from different origins and various parts. ResultsWe have established a fingerprint of the elements within Maifanitum, demonstrating a commendable level of similarity. The findings from hierarchical cluster analysis（HCA） corroborated with those from principal component analysis (PCA), collectively unveiling a systematic profile of elemental disparities between Maifanitum samples of diverse origins and applications. It also revealed that there are differences in the concentration of Al, Ga, Be, Hf, Na, Sn, Ti, Zr, Gd, Tb, Sr, Pb, Ce, Ba and other elements in different parts of Maifanitum. While Cd, As, and Cu levels in all samples were within the permissible limits as defined by the Chinese Pharmacopeia, Pb concentrations in the majority of samples were found to surpass these standards, albeit slightly in the ''non-rice'' fraction. The assessment of both beneficial and deleterious elements indicates that the ''non-rice'' fraction of Maifanitum possesses superior quality attributes. Moreover, the overall concentration of rare earth elements in Maifanitum is substantially below the established lower threshold for daily human consumption, with no immediate evidence suggesting any adverse health risks. ConclusionThis study provides a basis for the quality control and safety evaluation of Maifanitum in clinical use.

Fabrication and characterization of novel high-efficiency and high-durability neutron-absorbing Ni-based alloys

New neutron-absorbing Ni-based functional alloys that depend on the gadolinium and dysprosium neutron absorption units were fabricated using vacuum induction melting. The effects of Gd and Dy contents on the microstructure characteristics and properties of Ni-based alloys were investigated. Adding Gd, Dy, and Gd + Dy into Ni-based alloys formed Ni5Gd, Ni5Dy and Ni5(Gd,Dy), respectively, and their volume fraction increased with increasing of Gd/Dy content. Different type of elements, Gd or Dy, had no obvious influence on mechanical properties and corrosion resistance, while the amount of Gd and Dy elements played an important role. The shielding properties were calculated by the Monte Carlo method, and the alloys possessed high efficiency and high durability performance due to the high contents of Gd and Dy elements. The developed alloys are expected to be good functional materials for use in the field of nuclear shielding.

Gd3+ doped Na2O-CaO-P2O5-B2O3-ZrO2 glass ceramics for γ-ray radiation dose detection

In this study, Gd3+-doped NCPBZ glass-ceramics were prepared using melt-quenching technique, and their radiation dose performance was investigated. By varying the concentration of Gd3+ ions, we found that the sample with 0.5 mol% concentration exhibited the strongest luminescence and the best optically stimulated luminescence (OSL) intensity. Therefore, further OSL related tests were conducted on samples with this concentration under different doses. The results showed that the continuous wave OSL dose response fitting value of the sample in the range of 0.1–1000 Gy was m = 0.928, which is close to 1, while R2 was 0.9992 in the range of 50–1000 Gy, indicating better linearity. Meanwhile, the relative standard deviation of the OSL intensity for the sample's ten-cycle tests was 1.5%. The Gd3+-doped NaCaPO4 microcrystalline glass studied here is expected to have broad application prospects in wide-range linear radiation dose monitoring.

Deformation behavior and microstructure evolution of one novel superalloy with high rare earth gadolinium content: Multi-scale modeling and experimental study

It has been proved that rare earth elements have a positive effect on the performance of superalloys and steels at only trace levels, but rare earth phases are always tricky in the manufacturing process. In this work, one Ni–Mo–Cr-Gd alloy with ultrahigh rare earth Gd content (1.75 wt %) was designed to reveal the influence of hard and brittle Ni5Gd particles on hot deformation behavior and microstructure evolution. The Ni–Mo–Cr-Gd alloy exhibits higher deformation activation energy and smaller processable regions in the processing maps as compared with the Ni–Mo–Cr alloy. Combining electron back scatter diffraction and crystal plastic finite element method, it was found that strain concentrates around Ni5Gd particles, especially at grain boundaries, and rapidly reaches the critical value for recrystallization, which verifies particle stimulated nucleation. The recrystallization fraction decreases with strain rates from 0.01 to 1 s−1 but increases from 1 to 10 s−1, which is because meta-dynamic recrystallization occurs faster when the strain rate is greater than 1 s−1 and Ni5Gd particles promote the process indirectly by introducing more severely deformed matrix. Furthermore, the finite element modeling shows that plastic strain and temperature rise at the central region of samples increase with strain rate increasing, which can explain the unusual fragmentation of Ni5Gd at 1200 °C with the highest strain rate. Our results firstly reveal the evolution mechanism of Gd-containing superalloy during hot deformation, which can help to solve the manufacturing problems of similar alloys.

Effect of Gadolinium Doping on the Structure of Ce1-xGdxO2-x/2 Solid Solutions Prepared by Ionic Gelation Approach

The current research aims to present the structural characterization of Gd-doped ceria powders and ceramics, investigating the structural evolution resulting from cerium substitution with Gd across the entire composition range from 0 to 100 mol.% Gd2O3. Ce1-xGdxO2-x/2 powders with varying Gd contents (0 ≤ x ≤ 1) were synthesized using the ionic gelation method followed by thermal annealing. The resulting powders were subjected to high-temperature treatment to obtain ceramics. Characterization methods included X-ray diffraction (XRD) to identify phase composition and confirm the formation of Ce1-xGdxO2-x/2 solid solutions, infrared spectroscopy (IR) and scanning electron microscopy (SEM) for structural and morphological studies, and X-ray photoelectron spectroscopy (XPS) to evaluate the electronic structure. Comparative analysis of Gd-doped calcined powders and sintered pellets revealed the impact of thermal treatment on the structural features of the resulting solid solutions, elucidating the influence of gadolinium substitution. The novelty of this research lies in demonstrating the successful preparation of Ce1-xGdxO2-x/2solid solutions via an alginate-mediated ion-exchange process and providing a detailed structural investigation over the entire range of dopant concentrations. This assessment highlights the feasibility for further research of these materials as suitable candidates for intermediate-temperature solid oxide fuel cells (IT-SOFCs) or catalyst applications. Doi: 10.28991/ESJ-2024-08-05-01 Full Text: PDF

Influence of gadolinium doping on structural, optical, and magnetic properties of CuS nanostructures

To examine the effect of rare earth ions on CuS nanostructures, a series of Gadolinium-doped copper sulphide (Cu1-xGdxS) nanostructures were synthesized through the hydrothermal method. These nanostructures were prepared at x = 0, 1, 3, 5, and 7 at. % concentrations. The prepared samples’ structural, optical, and magnetic characteristics were investigated. Powder X-ray diffraction and Raman analysis were performed to examine the structural analysis of the samples and confirm the existence of a covellite phase hexagonal structure. XPS analysis was conducted to study the valence states. Observations of the surface morphology study from FESEM reveal the formation of flower-shaped structures resembling nanospheres, while at lower magnification nanoflakes were observed. Optical reflectance spectra were recorded using UV–Vis spectroscopy, which showed the increase in bandgap as the concentration of Gd rises. The fluorescence spectrophotometer was utilized for the analysis of room-temperature photoluminescence. The prepared samples showed significant emission peaks at 435 nm. Fluorescence lifetime studies were carried out to confirm the fluorescence decay of CuS nanostructures doped with Gd. Magnetic measurements revealed that prepared samples exhibit an unexpected superparamagnetic nature at room temperature.

Simultaneously enhanced photoluminescence and persistent luminescence in SrLaAlO4: Tb type layered perovskite via Gd3+ codoping

Gd3+ co-doping is effective to enhance the photoluminescence of rare earth activators in various host due to energy transfer, however, it is rarely reported via such strategy to regulate persistent luminescence properties. In this work, Gd3+ was co-doped into the SrLaAlO4: Tb persistent luminescence phosphors, and it is found that the photoluminescence and persistent luminescence of the products can be simultaneously improved. The results indicate that as the doping concentration of Gd3+ increases, the particle diameters increase which contributes the increased luminescence. Additionally, an energy transfer process from Gd3+ to Tb3+ ions was observed, which enhances the emission of Tb3+ ions. Furthermore, the persistent luminescence properties of the synthesized phosphors were improved. When the UV light source is turned off, the persistent luminescence of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) can last for more than 2 h, which is 100 % enhanced compared to SrLaAlO4: 0.03Tb3+. The trap distribution of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) phosphors was analyzed by thermoluminescence. It is found that after the substitution of La3+ with Gd3+, the trap position shifted towards higher temperatures and the trap concentration increased. The initial intensity of the persistent luminescence was also enhanced after Gd3+ co-doping. Based on the experimental findings, the luminescence and persistent luminescence mechanism of SrLaAlO4: 0.03Tb3+, xGd3+ (x = 0.00–0.97) phosphors were described and discussed.

Effects of Gd on the microstructure and mechanical properties of GdxCoCrFeNiV0.4 high-entropy alloys

This study investigated the microstructure and mechanical properties of GdxCoCrFeNiV0.4 alloys. Various techniques such as XRD, SEM, EBSD, and TEM were utilized, alongside hardness and compression tests at room temperature. The findings revealed that the high-entropy alloy without Gd element exhibited a single face-centered cubic (FCC) phase. Upon the introduction of Gd element, the phase composition shifted to FCC + hexagonal structure (HS) phases, and further addition of Gd resulted in the presence of FCC + HS + body-centered cubic (BCC) phases. Additionally, the inclusion of Gd element led to the precipitation of Gd-rich particles within the alloy. The Vickers hardness test results revealed a significant increase in alloy hardness as the Gd content rose, from 177.5 HV for Gd0 to 848.4 HV for Gd0.4. This suggests that the presence of the HS phase and BCC phase notably influences alloy hardness. Furthermore, compressive test outcomes demonstrated that the alloy's yield strength rose from 173.74 MPa for Gd0 to 1356.17 MPa for Gd0.3 with increasing Gd content. However, the excessive addition of Gd elements results in significant precipitation of V and Cr elements, leading to grain coarsening, adversely affecting its mechanical properties. The high strength of Gd-containing high-entropy alloys can be attributed to various strengthening mechanisms, such as solid solution strengthening, the presence of the HS phase, the precipitation of a small number of Gd-rich particles, and the grain refinement caused by the addition of Gd.

Effect of Granite Fly Ash on Mechanical Properties of Basalt and Glass Fiber Reinforced Polymer Composite

The granite processing industry generates a substantial volume of residual granite waste daily. This residue is collected through a filtration process during the drying and heating stages of concrete mixture production. Utilizing this residue, known as granite fly ash (GD), offers a promising avenue for mitigating adverse effects due to this waste material. The present study undertakes an experimental investigation into the potential utilization of granite fly ash as a filler to enhance the mechanical properties of basalt/glass composites (BFRC/GFRC). The research focuses on assessing the density and tensile characteristics of the developed fibre-reinforced polymer (FRP) composites. Composite samples were fabricated by incorporating GD at varying loadings, i.e., 1 wt.%, 3 wt.%, and 5 wt.%. The FRP laminates were produced using hand lay-up and vacuum silicon mold curing techniques. The outcomes show a slight increase in density, in which a maximum of 7% increment at 5 wt% of GD in BFRC. Meanwhile, tensile properties displayedsignificant enhancements, especially FRP with 3 wt.% GD content, for both BFRC and GFRC. Notably, the addition of 1 wt.% GD resulted in a 9% increase in tensile strength and a substantial 27% increase in modulus for the BFRC composite. In summary, the study underscores the advantageous influence of GD incorporation, particularly within the 1 wt.%, 3 wt.%, and 5 wt.%, on the mechanical properties of both BFRC and GFRC composites.

Study on the room temperature compression deformation mechanism and microstructural evolution of Mg-Gd-Y-Zr alloy

This study explores the dynamic impact deformation mechanisms of Mg-Gd-Y-Zr alloys, specifically focusing on the influence of varying Gd content. Using metallographic observation, SEM, EDS, XRD, EBSD, and TEM, along with hardness and room-temperature compression tests, the research investigates the effects of Gd content on the microstructure, mechanical properties, and deformation behaviors of as-cast Mg-(x)Gd-3Y-0.5Zr (x = 6.5/7.5/8.5) alloys.The results show that increasing Gd content reduces grain size and increases the volume fraction of the non-equilibrium eutectic phase Mg24(Gd,Y)5, though with smaller phase dimensions. These alloys exhibit excellent compressive properties at room temperature, with the highest compression deformation rate of 27.8 % observed at 6.5 % Gd and the maximum compressive strength of 401 MPa recorded at 8.5 % Gd, surpassing some high-Gd-content cast and extruded alloys.At lower Gd content, basal slip and tensile twinning are the primary deformation mechanisms. As Gd content increases, these mechanisms evolve to include prismatic slip and compressive twinning. The fracture mode transitions from predominantly ductile to a combination of ductile and brittle features, with an increase in brittle cleavage at higher Gd levels.

Influence of gadolinium substitution on the crystal structure of NiO and its maximized photocatalytic degradation activity on tetracycline and direct yellow pollutants

Gadolinium-substituted NiO crystal structures with excellent stability were utilized for the first time to degrade antibiotic and organic dye pollutants. A simple hydrothermal technique was used to synthesize different concentrations of Gd3+ substituted NiO, and the catalysts were thoroughly characterized using sophisticated techniques to explore the influence of Gd3+ on the crystal structure and optical characteristics of NiO. The 1.5% Gd3+ substituted NiO showed outstanding photocatalytic activity on tetracycline and direct yellow degradation, with percentages of 90.72 and 95.5%, respectively. The improvement of photocatalytic degradation efficiency is primarily due to the suppression of photoinduced electron and hole recombination via the creation of Gd3+ as the inner energy band state below the conduction band. The recycling experiments revealed that the catalyst is more stable, with no indication of loss after ten cycles. Scavenging investigations also demonstrated that superoxide and holes were responsible for the efficient degradation of pollutants.

Detangling past and modern zinc anthropogenic source contributions in an urbanized coastal river by combining elemental, isotope and speciation approaches

The accumulation of trace metals in the environmental compartments of coastal rivers is a global and complex environmental issue, requiring multiple tools to constrain the various anthropogenic sources and biogeochemical processes affecting the water quality of these environments. The Valao fluvio-estuarine system (Rio de Janeiro, Brazil) presents a challenging case of a coastal river contaminated by both modern and historical anthropogenic metal sources, located in the land and in the intra-estuary, continuously mixed by tidal cycles. This study employed a combination of spatial distribution analysis of trace metals including gadolinium (Gd), zinc (Zn) isotopic analyses, and X-ray absorption spectroscopy (XAS) to distinguish between these sources. The concentrations of metals in both dissolved (water samples) and surficial sediment compartments (Suspended Particulate Matter and sediment samples) display an overall enrichment trend from upstream to downstream. Multivariate statistical analysis allows to discriminate geogenic elements derived from watershed geology (Ti, K, and Mg) vs anthropogenic contaminants from urban runoff and domestic sewage discharges (Cu, Cr, Pb, Zn, and Gd); and legacy metal contaminants (Zn and Cd) remobilized from ancient metallurgical wastes and transported upstream in the estuary during tidal cycles. The anthropogenic Gd concentration in the dissolved compartment increases along the watercourse, highlighting continuous ongoing sewage discharge. Zinc solid speciation also indicates that Zn contribution from legacy metallurgy waste is primarily associated with sulfide-Zn and Zn-phyllosilicate in the outlet estuary, while in upstream sediments of fluvio-estuarine system, Zn is found bound to organic matter. Zinc isotope systematically reveals a progressive downstream shift to heavier isotope compositions. Upstream, the relatively pristine site and the urbanized section of the river exhibit a relatively uniform δ66/64Zn value (+0.20 ± 0.07 ‰) in suspended particulate matter (SPM) and surficial sediments. These results indicate that domestic sewage discharges contribute to Zn enrichment in sediments of the Valao fluvio-estuarine system but without modifying its isotope signature in sediments. The sediment of the downstream estuarine section shows a heavier δ66/64Zn value (+0.48 ± 0.08 ‰), indicating the strong influence of the intra-estuarine source identified as the historical metallurgic contamination. An integrated view of the geochemical tracers allows thus inferring that the untreated sewage and legacy metallurgical contamination are the primary sources of anthropogenic Zn contamination. It highlights the progressive mixing along the estuarine gradient under tidal dynamics. The influence of the former source continuously expands from the headland towards the estuary.

Solar light driven enhanced in photocatalytic activity of novel Gd incorporated ZnO/SnO2 heterogeneous nanocomposites

The Gd-doped ZnO/SnO2 nanocomposites with various atomic percentages (0, 0.5, 0.8, and 1.2 at%) of gadolinium (coded as GdZS0, GdZS1, GdZS2, and GdZS3) was synthesis via the sol–gel method and explored for photodegradation against dye solutions exposing solar light irradiation. The synthesized nanocomposites were characterized employing the XRD, FTIR, FE-SEM, Raman spectroscopy, BET analysis and UV–Vis spectrophotometer. The FE-SEM results indicated that the formation of nanoparticles to nanoflowers covered with Gd ions was observed with an increased doping concentration of Gd. The optical bandgap was evaluated and found in the range of 3.21–3.27 eV for GdZS nanocomposites. The GdZS nano-photocatalysts were investigated against the degradation of different organic dyes and GdZS3 shows the highest degradation efficiencies of 99.3%, 98.3% and 99.4% towards MO, MB and RhB dyes, respectively at neutral pH in aqueous media. Before and after photodegradation. Biological oxygen demand and chemical oxygen demand tests to make estimations of mineralization. The investigations are very promising for the degradation process in rare earth doped metal oxide nanocomposites. A plausible photodegradation mechanism of synthesized nanocomposites under investigation has also been proposed.

Synthesis, characterization and effective UV photo-sensing properties of Ga3+ doped NiO nanoparticles

In this work, resistive type photodetectors were fabricated using Gd3+ ions doped NiO nanoparticles to improve the detection of ultraviolet (UV) light. The occurrence of the simple cubic phase in NiO systems has been shown by X-ray diffraction patterns. The crystalline size of the NiO nanoparticles doped with different concentrations of Gd3+ at levels of pure, 1 %, 2 %, and 3 % were 6 nm, 8 nm, 9 nm, and 12 nm, respectively. The presence of dopants in the material was established by the Raman spectrum analysis. Transmission electron microscopy (TEM) pictures were used to validate the morphological properties of Gd3+ doped NiO nanoparticles nanoparticles at different degrees of dopant concentration (0 %, 1 %, 2 % and 3 %). The introduction and concentration of dopants alter the shape of NiO material. Based on the findings of UV–visible absorption spectroscopic studies, it can be concluded that the addition of Gd3+ ions to the system improved the absorption characteristics. The measured bandgap values for various degrees of Gd3+ doping, namely 0 %, 1 %, 2 %, and 3 %, are 3.51 eV, 3.45 eV, 3.36 eV, and 3.23 eV, respectively. According to the measured photoluminescence spectrum, Gd3+ ions may efficiently trap and maintain excited electrons within an energy level between the ground and excited states. This process greatly extends the lifespan of excitons from immediate recombination. The use of Gd3+-doped NiO sensors in UV photodetection resulted in a significant increase in conductivity and photocurrent. The photodetector fabricated using a 3 % concentration of Gd3+ doped NiO, has a responsivity of 24 × 10−2 AW−1, a detectivity of 14 × 109 Jones, and an external quantum efficiency (EQE) of 62 %.