Rare Earth Terbium Research Articles

Synergetic Modulation of Electronic Properties of Cobalt Oxide via "Tb" Single Atom for Uphill Urea and Water Electrolysis.

Exploring single-atom (SA) catalysts in hybrid urea-assisted water electrolysis offers a viable alternative to both Hydrogen (H2) generation and polluted water treatment. However, the unfavorable electronic stabilization, low SA content, intrinsically slow kinetics, and imbalanced adsorption-desorption steps are the bottleneck for its scale-up implementation. Herein, a rare-earth Terbium single atom (TbSA) is topologically stabilized on defect-rich Co3O4 (TbSA@d-Co3O4) by Tb─O co-ordination for urea oxidation reaction (UOR) and H2 evolution reaction (HER). Benefitting from the strong TbSA interaction with the d-Co3O4, the TbSA@d-Co3O4 achieves a 10mAcm-2 current density at 1.27V and -35mV for UOR and HER, respectively. Remarkably, when TbSA@d-Co3O4 is applied as a bi-functional catalyst in a two-electrode system, it merely requires 1.22V to acquire 10mAcm-2 with excellent operational stability for 100 h. The hybrid electrolyzer can be successfully empowered by the triboelectric nanogenerator, AA battery, and solar panel with a nominal potential of 1.5V. The mechanistic investigation predicts "TbSA" insertion in d-Co3O4 lowered the potential determining step, attributed to balanced reaction energetics for adsorption-desorption of intermediates and favorable charge transfer characteristics for UOR. This work offers a new paradigm to explore the catalytic properties of rare-earth "f-block" elements to create advanced electrocatalysts via structural modulation.

Dual Optical Response Strategy for the Detection of Cytochrome c Using Highly Luminescent Lanthanide-Based Nanotubular Sensor Arrays.

Here, we demonstrate a label-free dual optical response strategy for the detection of cytochrome c (Cyt c) with ultrahigh sensitivity using highly luminescent lanthanides containing inorganic-organic hybrid nanotubular sensor arrays. These sensor arrays are formed by the sequential incorporation of the photosensitizers 2,3-dihydroxynaphthalene (DHN) or 1,10-phenanthroline (Phen), and trivalent lanthanide terbium ions (Tb3+) into sodium lithocholate (NaLC) nanotube templates. Our sensing platform relies on the detection and quantification of Cyt c in solution by providing dual photoluminescence quenching responses from the nanotubular hybrid arrays in the presence of Cyt c. The large quenching of the sensitized Tb3+ emission within the DHN/Phen-Tb3+-NaLC nanotubular sensor arrays caused by the strong binding of the photosensitizers to Cyt c provides an important signal response for the selective detection of Cyt c. This long-lived lanthanide emission response-based sensing strategy can be highly advantageous for the detection of Cyt c in a cellular environment eliminating background fluorescence and scattering signals through time-gated measurements. The DHN containing nanotubular sensor arrays (DHN-NaLC and DHN-Tb3+-NaLC) provide an additional quenching response characterized by a unique spectral valley splitting with quantized quenching dip on the DHN fluorescence emission. This spectral quenching dip resulting from efficient FRET between the protein bound DHN photosensitizer and the heme group of Cyt c serves as an important means for specific detection and quantification of Cyt c in the concentration range of 0-30 μM with a low detection limit of around 20 nM.

Terbium based (poly)ionic liquids for anti-counterfeiting and droplet manipulation

A magnetic ionic liquid and magnetic poly(ionic liquid) with Tb(NO3)4− as counteranions are prepared. The resulting M(P)ILs show magnetic and luminescent properties, which are used in droplet manipulation and anti-counterfeiting application.

Magnetic ordering in terbium at high pressures and low temperatures

We have investigated magnetic ordering in the heavy lanthanide terbium (Tb) for pressures up to 70 GPa and temperatures down to 20 K by synchrotron x-ray diffraction at the Advanced Photon Source, Argonne National Laboratory. The x-ray diffraction studies were complemented by neutron diffraction studies at the Spallation Neutron Source, Oak Ridge National Laboratory. We focused on the higher-pressure phases of Tb, such as the double hexagonal close-packed (dhcp, above 16 GPa), distorted face-centered cubic (hR24, above 30 GPa), and orthorhombic (oF16, above 51 GPa) phases. We observed the phenomenon of spontaneous magnetostriction in the dhcp and hR24 phases, where magnetic ordering at low temperatures gives rise to subtle splitting in x-ray diffraction peaks. The neutron diffraction study of the dhcp phase at 20 GPa revealed magnetic peaks that can be assigned a propagation vector k=(12,0,12), and a magnetic ordering temperature that is consistent with the magnetostriction effect observed with x-ray diffraction. The high-pressure and low-temperature x-ray diffraction study at 70 GPa in the collapsed oF16 phase did not show any evidence of magnetostriction, indicating a significant decrease in the magnetic moment of the 4f-shell due to band broadening at ultra-high compression.

A Novel Ultra-Low Work Function TbFx for High Efficiency Dopant-Free Silicon Solar Cells.

The ability of carrier selective contact is mainly determined by the surface passivation and work function for dopant-free materials applied in crystalline silicon (c-Si) solar cells, which have received considerable attention in recent years. In this contribution, a novel electron-selective material, lanthanide terbium trifluoride (TbFx ), with an ultra-low work function of 2.4eV characteristic, is presented, allowing a low contact resistivity (ρc ) of ≈3mΩcm2 . Additionally, the insertion of ultrathin passivated SiOx layer deposited by PECVD between TbFx and n-Si resulted in ρc only increase slightly. SiOx /TbFx stack eliminated fermi pinning between aluminum and n-type c-Si (n-Si), which further enhanced the electron selectivity of TbFx on full-area contacts to n-Si. Last, SiOx /TbFx /Al electron-selective contacts significantly improves the open circuit voltage (Voc ) for silicon solar cells, but rarely impacts the short circuit current (Jsc ) and fill factor (FF), thus champion efficiency cell achieved approaching 22% power conversion efficiency (PCE). This study indicates a great potential for using lanthanide fluorides as electron-selective material in photovoltaic devices.

Exploration for oxygen diffusion during deoxidation process of terbium with 18O as isotope tracer

Oxygen (O) is the most difficult kind of impurity to be removed from rare earth terbium (Tb), which seriously restricts the promotion of high purity rare earth metal quality. Study the law of oxygen removal during the purification process and clarify the influence and synergism of active substance are of great significance. Herein, isotopic tracer technique (using 18O) has been used to explore the oxygen diffusion process. Secondary ion probe mass spectrometer (SIMS) and Scanning Electron Microscope (SEM) investigated the occurrence state, migration trajectory and relative concentration gradient of oxygen in Tb. The diffusion coefficient as a function of depth and temperature can be simulated based on the experimental data, which is of great significance for the purification and corrosion prevention of Tb. X-ray photoelectron spectroscopy (XPS) clarified the variation of metal valence, indicating the bonding characteristics between O and Tb.

Tb3+-xylenol orange complex-based colorimetric and luminometric dual-readout sensing platform for dipicolinic acid and metal ions

A dual-readout sensing platform based on two signal transduction channels can integrate the unique advantages of each sensing pattern, compensate for the deficiency in the adaptive capacity, and enable a more convincing performance in analytical applications. Here, we introduce a responsive molecule dye, xylenol orange (XO), to combine with lanthanide terbium ions (Tb3+). The resultant Tb3+-XO complex exhibited tunable optical properties and was used as a novel colorimetric and luminometric dual-readout sensing platform for assaying the anthrax biomarker, dipicolinic acid (DPA). In the presence of Tb3+, the XO solution underwent a color change from yellow to magenta; however, upon adding DPA, the color changed back to yellow immediately, accompanied by the characteristic luminescence emission of Tb3+. Considering the strong affinity between DPA/XO and metal ions, the proposed sensing platform was further employed for the determination and differentiation of certain metal ions using linear discriminant analysis. This convenient dual-readout sensing platform offers several notable features and significantly promotes the application and development of lanthanide-based materials.

Isotypic lanthanide-organic frameworks and scintillating films with colour-tunable X-ray radioluminescence for imaging applications.

Lanthanide-organic frameworks (LnOFs) have been brought into focus due to their unique structure-function relevance, and have shown good application prospects in many fields. According to the characteristics of scintillating materials, we synthesized two isomorphic LnOFs with the lanthanides terbium and europium as emission centers: Tb(bmb)3·H2O (LnOF-1) and Eu(bmb)3·H2O (LnOF-2). Tb3+ and Eu3+ were used as X-ray absorption centers, and large conjugated organic ligands were used as energy transfer bridges, which can effectively convert X-rays into visible light. LnOF-1 and LnOF-2 show good X-ray scintillation performance and anti-radiation stability. At the same time, we prepared a LnOF-1 mixed matrix scintillating film by the physical deposition method for X-ray imaging experiments, and its spatial resolution can reach 9.5 lp mm-1@MTF20%. The excellent imaging application effect prospect makes the lanthanide-organic frameworks show development potential in the field of scintillating materials.

Total antioxidant capacity investigation of electrochemically deposited atractylodes macrocephala traditional medicine

Electrochemically deposited sensors and DNA biosensors have been widely used in the food industry, and various other fields due to their high sensitivity, fast response, easy operation, no pollution, and low price. A rare earth electrochemically deposited gadolinium ferricyanide thin film modified glassy carbon electrode, and the investigation of electrocatalytic oxidation of guanine by GaHCF/GCE is reported. We deposited electrochemically a rare earth terbium ferricyanide thin film modified glassy carbon electrode. OH was investigated through various characteristics such as capacitance–voltage, Differential Pulse Voltammetric and many more by the comparison of catalytic oxidation signal of guanine with ·OH in Fenton reaction.

Effect of terbium doping on the optical, electrical and magnetic properties of nanocrystalline nickel ferrite

The present study focuses on the preparation and the characterization of a series of rare-earth terbium (Tb3+) ion-doped nickel ferrite (NFO) nanoparticles [(NiTbxFe2−xO4, x = 0.10, 0.15, 0.20)]. These samples were synthesized using sol–gel method. Rare-earth Tb was doped to tune the structural, optical, dielectric and magnetic features of the spinel nickel ferrite nanoparticles. Therefore, the systematic impact of Tb3+ on the structural, optical, electrical and magnetic studies were carried out. X-ray diffraction (XRD) profile reveals the presence of a single spinel ferrite phase for small doping while in moderately doped NFO NPs, an additional orthorhombic phase along with the spinel phase exists. The strain is increased in Tb-doped NFO lattice. X-ray photoelectron spectroscopy (XPS) study also confirms the presence of Tb ions at the tetrahedral site of Tb-NFO nanoparticles. In absorption spectroscopy, the shift of absorption towards the visible region is significantly increased with the increase in doping amount of trivalent Tb ion. The empirical variable range hopping (VRH) model is introduced to evaluate the density of states and the hopping range, respectively. The electrical properties of Tb-doped NFO compounds exhibit high values of dielectric constant at room temperature with Tb doping. Electric modulus study confirms the presence of non-Debye type of relaxation behaviour in the samples. Two relaxation peaks are observed at higher doping concentration. Room temperature magnetization study confers hysteresis behaviour in Tb-doped nickel ferrite nanoparticle at high frequencies. Different magnetic parameters are evaluated from the magnetic hysteresis loops. There is a significant decrease in magnetization with Tb doping due to the lower magnetic ordering of rare-earth ions.

Effect of spin–orbit coupling on opto-electronic and magnetic properties of rare-earth terbium dioxide (TbO2): first principle calculations

A density functional theory calculation via first principle approach of electronic and magnetic properties of f-electron systems is a matter of pronounced challenge in the materials research due to the struggle in simultaneous stability to delight both the localized and itinerant states. In f-electron systems, f-states show a significant part in defining their chemical and physical properties. In the present investigations, spin-polarized electronic and magnetic calculations have been done for TbO2. We have employed the PBE-GGA and Tb-mBJ exchange correlation functional for the calculation along with the spin–orbit coupling effect. The band gap of TbO2 ~ 5.8 eV for spin up states with a magnetic moment of ~ 7.0 μB per unit cell was estimated using the PBE-GGA exchange correlation which is in well agreement with previous theoretical studies. The maximum absorption and optical conductivity lies within the visible and UV region with refractive index ~ 3.5 at zero photon energy. These properties of TbO2 show the ferromagnetic semiconductor character. We have also observed the effect of spin–orbit coupling (SOC) on opto-electronic properties of the compound. Density of states and band structure shows the splitting of the f-states of Tb atoms on inclusion of SOC. The overall electronic, magnetic and optical properties of TbO2 are suitable for its use in solid state and opto-electronic devices.

Response Surface Methodology for Spectrophotometric Determination of Two β-Adrenergic Agonists-Terbium Chemosensors in Urine and Pharmaceutical Dosage Forms.

According to literature reports, none of the previous methods of analysis had touched the multivariate approach for the quantification of significant factors affecting the interaction of dobutamine or hexoprenaline with Terbium. Two novel β-adrenergic agonists-lanthanide chemosensors were prepared for the determination of dobutamine and hexoprenaline in their pure and pharmaceutical dosage forms and in urine samples. Fabrication of the two chemosensors was based on their ligand-metal interaction with the lanthanide Terbium. A Plackett-Burman Design (PBD) was selected for the screening of four main variables (reaction time, metal volume, pH, and temperature). Applying Response Surface Methodology (RSM), a Central Composite Design (CCD) was executed for the optimization of the significant factors with narrower upper and lower limits. Spectrophotometric technique was exploited for the analysis of the two chemosensors. Maximum absorption was obtained at 299 and 298 nm for dobutamine-terbium and hexoprenaline-terbium complexes, respectively. Only factors that were found to bear significant effects on the formed complexes were promoted to the optimization level. Model verification was carried out, where target results coincided with those at the predicted levels, indicating the efficiency of the two proposed models. Validation of the proposed was implemented and linear ranges were found to be 3.30-13.50 and 1.90-10.00 µg/mL, for dobutamine and hexoprenaline, respectively. Recovery and relative standard deviation values by application in pure powder, pharmaceutical dosage forms and spiked urine samples indicated high accuracy and reproducibility. Wide-ranging linear values and comparatively low detection limits inferred the effectiveness of the proposed method. RSM for optimization of spectrophotometric determination of dobutamine and hexoprenaline β-adrenergic agonists-lanthanide chemosensors; PBD was used for screening and CCD for optimization of variables affecting the spectrophotometric method; Determination of dobutamine and hexoprenaline in pure powder, pharmaceutical dosage form, and spiked urine samples was accomplished after method validation.

Effect of Terbium Ion Substitution in Inverse Spinel Nickel Ferrite: Structural and Magnetic Study

Doping rare-earth ions into spinel ferrites can alter their electrical and magnetic properties. The present study delineates the structure–property relationship of the effect of rare-earth terbium doping in NiFe2O4 ferrite. X-ray diffraction analysis (XRD) showed unit cell lattice expansion with increased Tb3+ content. The Fourier transform infrared spectroscopy (FTIR) results indicate preferential occupancy of Tb3+ at the octahedral B site. The magnetic parameters derived from room temperature hysteresis loops where both the saturation magnetization, Ms, and coercivity, Hc, value decreased with the Tb3+ substitution and reached a minimum value of Ms ~30.6 emu/g at x = 0.1 and Hc ~102 Oe at x = 0.075. The temperature-dependent magnetocrystalline anisotropy derived from the magnetic isotherm was observed to be the highest for x = 0.1 at 5 K with the value K1 ~1.09 × 106 J/m3. The Tb3+ doping also resulted in the Curie temperature reduction from 938 K at x = 0.0 to 899 K at x = 0.1.

Modulation of spin effect in electronic and vibrational properties of terbium dihydride (TbH2): An ab-initio study

The interaction of hydrogen with terbium was correlated and the structural and electronic structure properties for the cubic rare earth terbium dihydride (TbH2) using density functional theory (DFT) have been studied. The electronic band structure and density of states (DOS) for spin-up, spin-down and non-spin cases were studied and furthermore influence of higher pressure was also investigated. The charge contribution shows that TbH2 has metallic characteristic with a mixed covalent and ionic bonding. The Fermi surfaces show hole type structure and provide a space where hydrogen can be absorbed and filled easily. The Löwdin population analysis show that the decrease in charge density of Tb atom which explain absorption of H atom by Tb. The charge density of TbH2 also show decrease in differential charge density which verify the Löwdin population analysis. Furthermore, we have also analysed phonon dispersion curve at ambient and higher pressure and changes were studied. The TbH2 can be a good alternative to develop a hydrogen storage device as mass ratio percentage is around 1.27%.

In Vivo Shaping of Inorganic Functional Devices using Microalgae.

The usage of biomineralization processes performed by living microalgae to create 3D nanostructured materials are advantageous compared to conventional synthesis routes. Exploitation of in vivo shaping using living cells leads to inorganic intricate biominerals, produced with low environmental impact. Since biomineralization processes are genetically controlled, the formation of nanostructured materials is highly reproducible. The shells of microalgae, like coccoliths, are particularly of great interest. This study shows the generation of mesoporous highly structured functional materials with induced optoelectronical properties using in vivo processes of the microalga species Emiliania huxleyi. It demonstrates the metabolically driven incorporation of the lanthanide terbium into the coccoliths of E. huxleyi as a route for the synthesis of finely patterned photoluminescent particles by feeding the microalgae with this luminescent element. The resulting green luminescent particles have hierarchical ordered pores on the nano- and microscale and may act as powerful tools for many applications; they may serve as imaging probes for biomedical applications, or in microoptics. The luminescent coccoliths combine a unique hierarchical structure with a characteristic luminescence pattern, which make them superior to conventional produced Tb doted material. With this study, the possibility of the further exploitation of coccoliths as advanced functional materials for nanotechnological applications is given.

Tb–Al–Si systems

There are presently limited information regarding the liquid–solid equilibria at the (Al)-rich region of the different R–Al–Si systems (R = rare earth elements). These data, along with the ternary systems isothermal section, are needed to outline the design, plan and develop new Al–Si-based alloys. The effect of the lanthanide terbium addition to the Al–Si system, in the Al-rich corner, has been experimentally studied. The constitution of the alloys and the liquidus surface projection have been determined by means of differential thermal analysis, scanning electron microscopy, electron microprobe analysis and X-ray powder diffraction. In the system investigated have been identified five regions of primary crystallization: TbAl(3 − x)Six, Tb2Al3Si2, TbAlxSi2 − x, (Al) and (Si).

Lanthanide terbium complex: synthesis, electrochemiluminescence (ECL) performance, and sensing application.

In this study, a new lanthanide terbium complex, Tb(pzda)3(NO3)3·nH2O, was synthesized by a hydrothermal method and characterized by Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDS). It was found that the as-synthesized Tb-complex exhibited good electrochemiluminescence (ECL) behavior in the presence of triethanolamine (TEOA) in a HAc-NaAc buffer solution on a glassy carbon electrode. The possible reaction mechanism has been discussed based on the fluorescence spectra and ECL spectra. For sensing applications, it was found that protocatechuic acid (PCA) had an obvious quenching effect on the ECL signal of the Tb-complex, and this resulted in a decreased ECL signal associated with the concentration of PCA. Therefore, a highly sensitive method for the detection of PCA was established with a linear range of 1.283 × 10-10 M to 3.845 × 10-4 M and a detection limit of 0.085 nM at an S/N ratio of 3. This novel ECL assay strategy with an outstanding ECL efficiency offers great potential for pharmaceutical analyses.

Study on the Tb–Dy–Fe–Co magnetic nanowires prepared by AAO template

The Tb–Dy–Fe–Co nanowires have been fabricated into anodic aluminum oxide (AAO) templates by direct-current (DC) electrodeposition. The results show that there are amorphous structures in the as-deposited Tb–Dy–Fe–Co nanowires. Due to the induced co-deposition of Fe–Co phase, the rare earth elements terbium and dysprosium can be deposited in AAO templates, and the stepped phase distribution can be observed in the annealed Tb–Dy–Fe–Co nanowires. It can be seen from the hysteresis loops that the coercivity of annealed nanowires is significantly improved, showing remarkable hard magnetic properties. When the concentration of Tb3+ is 0.04 mol/L and Dy3+ is 0.002 mol/L, the magnetic properties of the Tb–Dy–Fe–Co nanowires are improved significantly.

Synthesis and Characterization of PVP/Tb4/3L•7H2O Luminescent Complex

Rare earth terbium [Tb (III)]-pyromellitic acid [H4L] luminescent complex has been synthesized in polyvinylpyrrolidone (PVP) matrix by precipitation method. The chemical constitution of the complex has been demonstrated as PVP/Tb4/3L•7H2O by a combination of elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and Fourier-transform infrared spectroscopy (FT-IR). X-ray diffraction analysis (XRD) has shown that the complex is a new kind of crystal whose structure is totally different from the ligand. The morphology of the complex has been investigated by scanning electron microscopy (SEM). The results have shown that the well dispersed complex has a bulk crystal structure and the diameter of the crystal is about 1-2 μm. Thermogravimetric analysis (TG) has indicated that the luminescent complex is thermally stable below 467 °C. Photoluminescence spectra (PL) have revealed that the complex can emit Tb3+ characteristic green fluorescence under ultraviolet excitation.

Synthesis and Fluorescence Properties of a Terbium Complex with Ferrocenylazobenzoic Acid in Nanoparticles

Tb (AUFA)32H2O, a rare earth terbium complex,was synthesized by introducing 4-(11-azobenzene-undecyloxy) ferrocene acid (AUFA) as the ligand. This complex was characterized by elemental analysis, MS, IR, Raman, UV spectroscopy and fluorescence spectrophotometry. The complex exhibited ligand-sensitized green emission, and Tb (AUFA)32H2O had a higher sensitized luminescence efficiency and a longer lifetime than the other terbium complexes (DPC: 2, 6-Pyridinedicarboxylic acid, Aspirin: 2-ethanoylhydroxybenzoic acid). The organic-inorganic thin film of complexe Tb (AUFA)32H2O in nanoTiO2 was fabricated, and the nanoTiO2 has been used in the luminescence layer to change the luminescence property of complexes Tb (AUFA)32H2O. It was found that there was an efficient energy transfer process between the ligands and metal ions. Moreover, In an ITO/PVK/Tb (AUFA)32H2O/Al device, Tb3+ may be excited by intramolecular energy transfer from the ligand, as observed by electroluminescence. The main emitting peak at 545 nm can be attributed to the 5D4→7F5 transition of the Tb3+ ion, and this process results in the enhancement of the green emission from the electroluminescence device.