BO3 Groups Research Articles

Sonification of Deproteinized Bovine Bone Functionalized with Genistein Enhances Bone Repair in Peri-Implant Bone Defects in Ovariectomized Rats

Estrogen deficiency is one of several contributing factors to catabolic changes in bone surrounding dental implants, impairing bone repair in defects requiring bone regeneration. Functionalizing bone substitutes is an alternative approach among various strategies to address this challenge. In this study, the aim was to evaluate the effect of functionalizing deproteinized bovine bone (Bio-Oss®, BO) with genistein via sonication on peri-implant bone defects in ovariectomized rats. The animals were randomly distributed according to the treatment into the following four groups (n = 10): BO sonicated with genistein (BOS + GEN), BO sonicated alone (BOS), untreated BO (BO), and blood clot only (CLOT). After twenty-eight days, implant removal torque was determined, and the peri-implant bone parameters were calculated based on computed microtomography. Additionally, the gene expression of bone turnover markers was evaluated. As a main result, the functionalization with genistein increased implant removal torque and the peri-implant bone volume in the BOS + GEN group compared to both BOS and BO groups (both p < 0.05). These findings suggest that the sonification of deproteinized bovine bone functionalized with genistein improves bone repair in peri-implant bone defects in ovariectomized rats.

Key non-volatile taste components and characteristics in abdominal muscle of Eriocheir sinensis under various thermal processing methods

This study identified the key non-volatile taste components and characteristics in the abdominal muscle (AM) of Eriocheir sinensis under various thermal processing methods: boiling at rising temperature (BO-R), boiling at constant temperature (BO-C), steaming with water vapor (ST) and salt-baked (BK). The results showed that arginine (Arg), alanine (Ala), glycine (Gly), glutamate (Glu), 5’-AMP, histidine (His), lysine (Lys), proline (Pro), K+, PO43−, betaine, succinic acid, and lactic acid were the key taste contributors, exhibiting taste activity values (TAV) higher than 1.0. Compared to BO groups, ST and BK group showed higher expression in SFAAs. BK exhibited the highest Arg, 5’-AMP contents, EUC (4.49 g MSG/100 g), and reduced BFAAs. The cluster and correlation analysis demonstrated that Arg, Ala, and His were identified as the primary differential components under various thermal degradation. These findings could deepen the understanding of taste for subsequent studies.

Synergistic Surface Engineering of BiVO4 Photoanodes for Improved Photoelectrochemical Water Oxidation.

Surface engineering of BiVO4 photoanodes is effective and feasible for photoelectrochemical (PEC) water splitting. To achieve superior PEC performance, however, more than one surface engineering method is usually indispensable, for which a positive synergistic effect is vital and thus highly desired. Herein, it is reported that the incorporation of borate moieties into ultrathin p-type NiOx catalysts can induce the reconfiguration of surface catalytic sites to form new highly active species, in addition to enhanced fast charge separation and transfer. The photocurrent density of BiVO4 photoanodes is enhanced from 1.49 to 5.76 mA cm-2 at 1.23 V versus reversible hydrogen electrode (RHE) under AM 1.5G illumination, which is achieved by successive modifications of NiOx and borate moieties. It is found that BO3 groups anchored to Ni atoms by replacing the surface hydroxyl sites of NiOx catalysts not only increase the relative ratio of Ni3+ species to facilitate charge transfer but also provide efficient active sites for H2O molecule adsorption and oxidation reactions. This work demonstrates the positive synergistic effect of these two surface engineering methods and provides an effective pathway to construct highly efficient and stable photoanodes for PEC water splitting.

Structural, elastic and gamma-ray attenuation properties of potassium borate glasses doped with BaO, Bi2O3, or Pb3O4: A comparative assessment

This study investigates the effect of substituting boron oxide (B2O3) with heavy metal oxides (HEMOs) on the structural, mechanical, and gamma-ray shielding properties of potassium borate (KB) glass systems. The glass compositions analyzed include 80B2O3–20K2O and 65B2O3–20K2O-15HEMO (where, HEMO = BaO, Bi2O3, or Pb3O4). All samples were prepared using the melt-quenching method, and their amorphous nature was confirmed through X-ray diffraction (XRD). Fourier-transform infrared spectroscopy (FTIR) had revealed BO3, BO4, and BiO6 groups beside the B–O–B linkages. The density increased with the addition of HEMOs, following the order: Pb3O4 (KB4) > Bi2O3 (KB3) > BaO (KB2) > and pure KB (KB1). This trend was also observed in the molar volume (Vₘ) and oxygen molar volume (Vₒ), while the oxygen packing density (Pρ) decreased. Mechanical properties assessed using the Makishima-Mackenzie model indicated that KB3 exhibited the highest elastic modulus (Yₘ) and Poisson's ratio (μ). The microhardness (Hₘ) followed the sequence KB2 > KB3 > KB4 > KB1, attributed to the higher bonding energy in KB2. Gamma-ray shielding parameters, including mass attenuation coefficients (MAC), were calculated using Phy-X and XCOM software for photon energies between 0.2835 MeV and 1.333 MeV. KB4 (Pb3O4) showed superior shielding performance with the highest linear attenuation coefficient (LAC) and the lowest half-value layer (HVL) and mean free path (MFP). Despite KB4's high density, KB3 (Bi2O3) is suggested as a more suitable candidate for radiation shielding applications due to its balanced combination of mechanical strength and γ-ray attenuation efficiency.

Synthesis of Polyether Block Copolymers from 1,2-Epoxybutane and AEOn and Comparative Study of Physicochemical and Application Properties before and after the Synthesis.

In this study, the AEOnBO2 series of block polyoxybutenol ethers was synthesized by combining the AEO series of polyoxyethylene and preparing 1,2-epoxybutane (BO) block polyether using a semicontinuous method. The synthesis was performed by HPLC, MALDI-TOF-MS, FT-IR, and 1H NMR for structural analysis. The interaction parameters and surface tension of the systems before and after synthesis were studied using surface tension meter. The diffusion process of the systems before and after synthesis was studied using a KRÜSS bubble pressure tensiometer. The surfactant properties of AEOn and AEOnBO2 were evaluated by static and dynamic surface tension measurements. Each system formed a saturated adsorption layer in a water solution. The critical micelle concentration decreased dramatically after the introduction of BO groups, and the diffusion-adsorption process was consistent with the kinetic mechanism of hybrid diffusion. The microscopic self-assembled aggregate micellar behavior of all the systems was investigated using DLS, TEM, and SEM. The micellization process in all systems was spontaneous and enthalpy-driven, forming spherical aggregates, with the BO block reducing the aggregate diameter of the feedstock from 220.06 nm to about one-third of 80.02 nm. In addition, the dynamic contact angle, application, and physicochemical properties such as foaming and foam stabilization of each system were investigated. The contact angle was reduced from 70 to 50° at 120 s of stabilization, with a foam volume of 80 mL in all systems at 200 s. However, the AEOnBO2 showed accelerated foam decay at 500 s, with an increase in the contact angle from 70 to 50° at 200 s, but the AEOnBO2 showed accelerated foam decay at 500 s, with a decrease in the contact angle from 70 to 50° at 120 s stabilization. At 200 s, the foam volume of all systems was 80 mL, but AEOnBO2 showed an accelerated foam decay process, which shows that the BO group can accelerate the foam decay, and the comparative results show that the BO group can also optimize other application properties and physicochemical properties.

Using widely targeted metabolomics profiling to explore differences in constituents of three Bletilla species

Bletilla striata has been used in traditional Chinese medicine for thousands of years to treat a variety of health diseases. Currently, metabolic causes of differences in medicinal values are unknown, due to the lack of a large-scale and comprehensive investigation of metabolites in Bletilla species. In order to gain a better understanding of the major chemical constituents responsible for the medicinal value, this study aimed to explore the metabolomic differences among three Bletilla species (Bletilla striata: Bs, Bletilla ochracea: Bo and Bletilla formosana: Bf). There were 258 different metabolites between ‘Bo’ and ‘Bf’, the contents of 109 metabolites had higher abundance, while 149 metabolites showed less accumulation. There were 165 different metabolites between the ‘Bs’ and ‘Bf’, content of 72 metabolites was increased and content of 93 metabolites was decreased. There were 239 different metabolites between the ‘Bs’ and ‘Bo’, content of 145 metabolites was increased and content of 94 metabolites was decreased. In the Bo_vs_Bf, Bs_vs_Bf and Bs_vs_Bo groups, the major differential categories were flavonoids, phenolic acids, organic acids and alkaloids. Moreover, the differential metabolites were clustered into clear and distinct profiles via K-means analysis. In addition, the major differential categories were flavonoids, phenolic acids, organic acids and alkaloids. The ‘Flavonoid biosynthesis’ (ko00941) and ‘Phenylalanine metabolism’ (ko00360) pathways were significantly enriched in Bo_vs_Bf, Bs_vs_Bf and Bs_vs_Bo comparisons. These results clarify the metabolomics in different Bletilla species, as well as providing basis for the phamaceutical value of novel species of Bletilla.

Elastic and radiation shielding properties of zinc borotellurite glass systems: The impact of gadolinium oxide

Using the formula [(TeO2)70(B2O3)30], this study examines the impact of Gd2O3 on the elasticity and radiation shielding characteristics of zinc borotellurite glass. Glass samples containing 1–5% mol% Gd2O3 were created by employing the melt quench technique. XRD verified that they are amorphous in nature, and the existence of TeO3, TeO4, BO3, and BO4 vibrational groups was revealed by infrared spectra. The structural alterations were shown by the range of longitudinal and shear ultrasonic velocities, which were 3908–4076 m/s and 2222–2277 m/s, respectively. The glass's rigidity was improved by the large rise in elastic moduli, such as bulk (45 GPa), longitudinal (80 GPa), shear (25 GPa), and Young's moduli (60 GPa), with a higher Gd2O3 content. Higher concentrations of Gd2O3 resulted in a rise in the mass attenuation coefficient (μρ), as measured by WinXcom, which enhanced gamma-ray shielding. The half-value layer (HVL) and mean free path (MFP) at 0.662 MeV decreased with increasing Gd2O3 in a consistent manner. The maximum density and optimum gamma-ray shielding performance were found in the glass containing 5 mol% Gd2O3. These results show Gd2O3 for applications needing greater rigidity and better radiation protection by demonstrating how it affects the elastic and radiation-shielding efficiency of the glass network.

Physical, Structural and Elastic Properties of New Oxyfluoride Borate Glasses

New mixed alkali/alkaline oxyfluoride borate glasses with composition xCaF2–(50-x)LiF–50B2O3 (x = 0, 5, 10, 15 and 20 mol%) were prepared by the conventional melt-quenching technique. X-ray diffraction (XRD) patterns confirmed the amorphous nature of the prepared samples, while energy dispersive X-ray (EDX) analysis confirmed the presence of the constituent elements B, O, F, and Ca. Fourier transform infrared (FTIR) spectra revealed the formation of BO3, BO2F, BO4 and BOF3 structural groups, as well as non-bridging oxygen/fluorine atoms in the glass network. The concentrations of these structural groups were found to vary with CaF2 concentration. The measured density and the calculated molar volume were found to increase over the entire range of composition. The increase in ultrasonic velocity, elastic moduli, micro-hardness and Debye temperature with the addition of CaF2 was discussed in terms of competition between the above-mentioned borate groups. Fraction of four-coordinated boron atoms, average boron–boron separation, fluorine molar volume, total packing density, dissociation energy per unit volume and average cross-link density were estimated. A close correlation is achieved between these quantities and elastic properties. Excellent agreement is found between the experimentally determined values and the theoretically calculated values of elastic properties from Makishima–Mackenzie's theory.

The electronic structure and optical properties of BaBiBO4, a promising compound with high birefringence

Birefringence is a crucial parameter for various advanced optical devices like birefringent crystals, and nonlinear optical materials. In this paper, the electronic structures and optical properties of centrosymmetric BaBiBO4 are investigated using the first-principles method. The results show that BaBiBO4 could be a good birefringent compound whose birefringence is 0.195 @ 1064 nm and 0.266 @ 532 nm. The spin–orbit-coupling effect plays an important role in electronic structures, leading to downshift and band splitting of the conduction band, resulting in a reduced bandgap of 3.32 eV and enhanced birefringence. The projected density of states and real-space atom-cutting results reveal that BiO5 groups with asymmetric distribution of stereochemical active lone pairs and the staggered parallel arrangement of the BO3 groups give the main contribution to birefringence.

Structures and chemical bonding of B6O50/-/2-: The first boron oxide clusters with five-membered ring and their structural diversity.

Based upon global-minimum searches and first-principles electronic structural calculations, we present the perfectly planar B6O50/-/2- (1-3) systems. Notably, the C2v B6O50/- (1-2) clusters mark a groundbreaking advancement as the first boron oxide clusters to feature a five-membered ring. Both structures exhibit remarkable similarity, each characterized by a central B3O2 ring surrounded by three terminal BO groups. However, a notable difference lies in the bond lengths within the B3O2 core, which are uniform in the former but uneven in the latter. Detailed canonical molecular orbital and AdNDP analyses reveal the delocalized π bonds over the B3O2 ring, affirming the π aromaticity of B6O5-. The Cs B6O52- (3) cluster showcases a chain-like arrangement with three terminal BO groups and a typical OBO group linked to a B2 core, emphasizing the crucial role of electrons in shaping the structure. Detailed chemical bonding analyses reveal the presence of dual three-center four-electron (3c-4e) π hyperbonds in 3, shedding further light on its unique bonding characteristics. Moreover, this study comprehensively extends the B(BO)n0/- (n = 1-5) series and provides valuable perspectives on their structural evolution.

Structural investigation and physical properties of RO-ZnO-Li2B4O7-K2B4O7 (RO= SrO and BaO) glasses

Glass samples 10RO-30ZnO-xLi2B4O7-(60-x) K2B4O7 (RO=SrO and BaO) with alkali tetra borates varying from 0 to 60 mol% were produced by traditional quenching procedure. Peak free broad X-ray diffraction patterns established the amorphous feature of glass samples. FTIR and Raman spectroscopic analysis had shown existence of BO3 and BO4 structural groups along with other borate units. The BO3 ⇔ BO4 conversion rate was not much affected with variation in one of the alkali-tetraborates. EPR spectra of copper doped glasses confirmed the ground state of Cu2+ ions as 2B1g. Physical and optical properties namely density, molar volume, refractive index, molar refractivity, optical band gap and Urbach energy values were found to be composition dependent. The inflections observed in density, and other optical properties around equal mol% of alkali oxides in the glass system were attributed to structural modifications and mixed alkali effect. These results exposed the structural variations caused due to competitiveness between the two different alkali and alkaline oxides in occupying the geometrical positions of the borate glass network.

Metabolic effects of testosterone added to intensive lifestyle intervention in older men with obesity and hypogonadism.

Whether testosterone replacement therapy (TRT) conveys additional cardiometabolic benefit to an intensive lifestyle therapy (LT) in older men with obesity and hypogonadism remains unclear. To determine whether TRT augments the effect of LT on metabolic outcomes in older men with obesity and hypogonadism. Secondary analysis of a randomized, double-blind, placebo-controlled trial. Veterans Affairs Medical Center. 83 older (age ≥ 65 years) men with obesity (BMI ≥ 30 kg/m2) and persistently low AM testosterone (< 10.4 nmol/L) associated with frailty. LT (weight management and exercise training) plus either testosterone (LT+TRT) or placebo (LT+Pbo) for six months. Primary outcome was change in glycated hemoglobin (HbA1c). Secondary outcomes included changes in other glucometabolic and lipid profile components, liver enzymes, inflammatory markers, adipokines; subcutaneous, visceral, intramuscular, and hepatic fat; blood pressure, and metabolic syndrome score. HbA1c decreased similarly in LT+TRT and LT+Pbo groups (-0.5% vs. -0.6%, respectively; p= 0.35). While TRT showed no synergistic effect with LT on ameliorating secondary outcomes, it eliminated the augmentative effect of LT on high-density lipoprotein cholesterol concentration (5.4 ± 1.0 mg/dL in LT+Pbo group vs. 0.2 ± 1.1 mg/dL in LT+TRT group, p= 0.01) and adiponectin levels (-408 ± 489 ng/mL in TRT+LT group vs 1832 ± 468 ng/mL in LT+Pbo group, p= 0.02). In older men with obesity and hypogonadism, adding TRT for six months to LT does not result in further improved cardiometabolic profiles, and could potentially blunt some of the metabolic benefits induced by LT.

Isochemical crystallization in condensed borate LaMgB5O10 glass-ceramics doped with optical probe Eu3.

The isochemical glass-ceramics doped with Eu3+ were prepared by the heat treatment of lanthanum magnesium borate glass. The crystalline phase was chemically identical to a glass matrix and consisted of condensed borate LaMgB5O10. The isochemical crystallization process begins with the formation of rings by BO4 groups. The emergence of ordered crystalline phase gives rise to intense charge transfer absorption of Eu3+, allowing the efficient luminescence under UV. The analysis of Judd-Ofelt parameters and comparison to purely crystalline samples obtained by solid-state synthesis reveal a switch of parameter relations from Ω2 > Ω4 for glass to Ω2 < Ω4 for crystals but also a maximum value of Ω6 for glass-ceramic sample, which indicates enhanced structural rigidity and results in superior luminescence output. The quantum yield measurements confirmed higher luminescence efficiency for glass-ceramics compared to both pure glass and pure crystalline samples.

Improvement in Muscle Fatty Acid Bioavailability and Volatile Flavor in Tilapia by Dietary α-Linolenic Acid Nutrition Strategy.

To investigate the modification of muscle quality of farmed tilapia through dietary fatty acid strategies, two diets were formulated. Diet SO, using soybean oil as the lipid source, and diet BO, using blended soybean and linseed oils, each including 0.58% and 1.35% α-linolenic acid (ALA), respectively, were formulated to feed juvenile tilapia for 10 weeks. The muscular nutrition composition, positional distribution of fatty acid in triglycerides (TAGs) and phospholipids (PLs), volatile flavor, lipid mobilization and oxidation were then analyzed. The results showed that there was no distinct difference between the SO and BO groups in terms of the nutrition composition, including crude protein, crude lipid, TAGs, PLs, and amino acid. Although the fatty acid distribution characteristics in ATGs and PLs showed a similar trend in the two groups, a higher level of n-3 PUFA (polyunsaturated fatty acid) and n-3 LC-PUFA (long-chain polyunsaturated fatty acid) bound to the glycerol backbone of TAGs and PLs was detected in the BO group than the SO group, whereas the opposite was true for n-6 PUFA. Additionally, the muscular volatile aldehyde and alcohol levels were higher in the BO group. Moreover, the expression of enzymatic genes and protein activities related to lipid mobilization (LPL, LPCAT, DGAT) and oxidation (LOX and GPX) was higher in the BO group. The results demonstrate that high-ALA diets may improve the fatty acid bioavailability and volatile flavor of tilapia by improving the lipid mobilization and oxidation, which provides new ideas for the improvement of muscle quality in farmed fish.

Antibiofilm Efficiency of CaF&lt;sub&gt;2&lt;/sub&gt;/TiO&lt;sub&gt;2&lt;/sub&gt; Strontium Borate Bioactive Glass Composites against &lt;i&gt;Pseudomonas aeruginosa&lt;/i&gt; and Gamma Radiation Effect

Microbial drug resistance has emerged as one of the most fundamental health threats. The current work aims to assess the antibacterial and antibiofilm potential of strontium borate bio-glasses (BBGs). Three CaF2/TiO2 strontium borate compositions have been prepared through melting annealing methods. The XRD pattern displays the amorphous nature of the glassy samples. The primary structural components of the borate, the trigonal BO3 and tetrahedral BO4 group, can be observed in FTIR spectra. Sharpness and shifting peaks to longer wavenumbers were evident after 40 kGy of gamma radiation. In contrast, density and molar volume (Vm) reveal an obvious change after irradiation. The agar diffusion technique was conducted as a preliminary screening of the antibacterial activity against Pseudomonas aeruginosa. The studied samples possessed no antimicrobial activity toward this strain; however, samples with 2% CaF2 strontium borate (T1) and 5% TiO2 strontium borate (T3) had higher biofilm inhibition potential (inhibition percentages of 75.17 and 65.77%, respectively). The gamma irradiation procedure had an unexpected detrimental effect on the bio-glass antibiofilm activity, making it unsuitable for use in sterilization procedures. Collectively, BBGs could be further investigated as possible antibacterial agents against biofilm-producing resistant strains.

Borate speciation and structural studies of vanadium ion doping in borate bioglass

Different glasses in the system, xV2O5-(45–x)B2O3–24.5Na2O–24.5CaO–6P2O5, (x = 0, 3, 6, 9, 12, 15, 18, 20 and 25 Wt%) were prepared through melt quenching method. X-ray diffraction (XRD) patterns have revealed that the amorphous structure is the dominant type. There is no tendency for crystallization even with higher vanadium content. Crystallization occurred utilizing treating the glasses thermally. FTIR spectral absorption data showed the presence of both BO3 and BO4 structural groups in combination with the presence of VO4 and VO5 structural building units. The deconvolution analysis technique (DAT) was adopted to retrace the conversion progressions of the coordinated boron. At low V2O5 content (up to 10 wt%), it entered as a glass modifier as well as both Na2O and CaO. The high content of the glass modifier (Na2O + CaO + V2O5) could destroy some of the well-formed BO4 units which are transformed into asymmetric BO3. The back conversion of BO4 to asymmetric or loose BO3 can simply reduce the fraction of tetrahedral units (N4). When V2O5 entered as a glass former (> 10 wt%), the N4 fraction increased. The change in the measured densities and estimated molar volumes may assigned to the formation of BO4 units resulting from increasing vanadium oxide content.

Structural investigation and effect of gamma-ray irradiation on barium borate glasses containing vanadium oxide

This work investigates the structural changes induced in barium borate glasses by gamma irradiation doses and vanadium doping using FTIR spectroscopic technique. Binary Barium borate parent glass and samples of the same composition containing different concentrations of vanadium oxide with formula xV2O5-(65-x)B2O3-35BaO (x = 0, 2, 4, 6, 8, and 10) were synthesized by melt quenching technique. FTIR spectroscopy approves the formation of both BO3 trigonal and BO4 tetrahedral structural units within the network backbone. V2O5 additions lead to borate network depolymerization by breaking B-O-B bonds and increasing V2O5 content causes systematic reductions in boroxol rings and B-O-B linkages, indicating disruption of the borate network. Gamma irradiation also damages the borate structure by cleaving B-O-B bonds in boroxol rings and BO3 units. This progressively converts BO3 to BO4 groups. Infrared spectroscopy reveals decreases in BO3 vibrations at higher doses as the network degrades. The radiation-induced network damage leads to changes in glass properties including thermal stability and hardness. A clearer understanding of borate structural modifications helps target these glasses for optical devices with controlled properties.

Evaluation of Two Anorganic Bovine Xenogenous Grafts in Bone Healing of Critical Defect in Rats Calvaria.

The purpose of this study was to provide an evaluation of two different xenogeneic bone substitutes in bone healing of critical-sized bone defects (Ø =5mm) created in rats calvaria. Thirty animals were randomized into 3 groups with one of the following treatments. In the control group (n=10), the defects were filled with blood clots; BO group (n=10), the defects were filled with bovine medullary bone substitute (Bio-Oss®); BF group (n=10), the defects were filled with bovine cortical bone substitute (Bonefill®). All defects were covered with an absorbable membrane. Five animals from each group were euthanized at 30 and 45 days, subsequently histomorphometrical and immunohistochemical analyses were performed. The histomorphometry was used to measure the percentage of new bone formation in the total area of the defect while the immunohistochemistry evaluated the expression of bone immunomarkers for bone morphogenetic protein 2/4 (BMP2/4), osteocalcin (OCN) and tartrate-resistant acid phosphatase (TRAP). Data was statistically analyzed with a 5% significance level. The results demonstrated that the BO group showed greater bone formation compared to the BF group at 30 days (P<0.05). However, there was no statistically significant difference between the control and BO groups at 30 days (P>0.05). The expression of BMP2/4 and OCN were higher in the BO group at 45 days compared to the BF at 30 and 45 days respectively (P<0.05). In conclusion, even with the higher expression of proteins related to bone formation, there was no difference in new bone formation at 45 days when both anorganic bovine xenogenous grafts were evaluated.

Two new rare-earth oxyborates Ba4BiTbO(BO3)4 and Ba1.54Sr2.46BiTbO(BO3)4 and luminescence properties of the Ba4BiTb1-xEuxO(BO3)4 phosphors.

Single crystals of two new terbium oxyborates Ba4BiTbO(BO3)4 and Ba1.54Sr2.46BiTbO(BO3)4 were obtained by the high-temperature solution method. They crystallize in the hexagonal P63/mmc group (Z = 2) with lattice parameters of a = 5.41865(9) Å, c = 26.3535(5) Å, V = 670.12(3) Å3 and a = 5.36534(19) Å, c = 26.0661(10) Å, V = 649.83(5) Å3, respectively. Their crystal structures feature two kinds of layers: [Tb(BO3)2]n3n- formed by corner-sharing TbO6 octahedra and BO3 triangles, as well as [Bi(BO3)2O]n5n- consisting of Bi2O13 dimers and BO3 groups, with alkali-earth cations sitting inside and between the layers. In addition, solid solutions of Ba4BiTb1-xEuxO(BO3)4 (0 ≤ x ≤ 0.2) were prepared via the solid-state reaction method. The obtained products were characterized by powder XRD, SEM, IR/Raman, XPS, DRS, and luminescence spectroscopy. It was found that as the Eu3+ doped content varies from x = 0 to 0.2, the emission color of the Ba4BiTb1-xEuxO(BO3)4 phosphors can be adjusted from cyan to near-white and then to orange-red or from green to orange and then to red under the excitation of 349 and 377 nm, respectively. Furthermore, the emission intensities and chromaticity coordinates were found to be sensitive to the temperature for the phosphor Ba4BiTb0.999Eu0.001O(BO3)4 upon 377 nm excitation. The above results demonstrate that Ba4BiTb1-xEuxO(BO3)4 phosphors have potential as multifunctional materials for solid-state lighting and temperature sensing applications.

Prediction of ultraviolet optical materials in the K2O-B2O3 system.

Ultraviolet (UV) birefringent crystals play a crucial role in various fields, such as laser technologies, optical telecommunications, and advanced scientific instrumentation. Alkali metal borates, with their diverse structures and remarkable ultraviolet optical properties, have garnered significant attention in recent years. In this study, employing the evolutionary crystal structure prediction algorithm USPEX, in conjunction with ionic substitutions and first-principles calculations, we systematically explored the pseudo-binary K2O-B2O3 system and predicted two stable structures (oP56-K3BO3 and mC44-K4B2O5) previously unreported, and twelve metastable structures in the K2O-B2O3 system. A comprehensive analysis of their structural, electronic and optical properties is conducted. The coplanar arrangement of BO3 and B3O6 groups is found to enhance optical anisotropy, thereby increasing the birefringence. In the K2O-B2O3 system, six structures with wide band gaps and high birefringence (mP28-1-K3BO3, tR72-KBO2, oP112-1-KB5O8, oP112-2-KB5O8, mC220-K5B19O31, and hR21-K3BO3) are found to be possible candidates for UV optical materials. Importantly, hR21-K3BO3, the only non-centrosymmetric structure in this system, exhibits a significant frequency doubling coefficient (about 4.6 KDP) and a moderate birefringence index (0.056@1064 nm), marking it a promising UV nonlinear optical material.