Materials Research Bulletin最新文献

In this paper, we investigate the structural, elastic, electronic, and optical properties of the new rare earth-based scintillation materials $R{b}_{2}LuC{l}_5$ and $R{b}_{2}PrC{l}_5$ using DFT calculations. The results show that both compounds are dynamically stable. Analysis of the elastic properties reveals that $R{b}_{2}PrC{l}_5$ is more isotropic in its mechanical behavior, while $R{b}_{2}LuC{l}_5$ exhibits a greater degree of anisotropy. Both $R{b}_{2}LuC{l}_5$ and $R{b}_{2}PrC{l}_5$ have direct band gaps (5.0698 and 4.7022 eV, respectively), according to electronic structure calculations. In terms of optical properties, both compounds exhibit higher transmittance and lower reflectance at lower energies. Calculated light yields show that under ideal conditions, $R{b}_{2}LuC{l}_5$ can achieve a light yield of 78898 photons per $MeV$, while $R{b}_{2}PrC{l}_5$ can reach a light yield of 85066 photons per $MeV$. This study provides valuable insights into the properties of these new rare earth-based scintillation materials, which can contribute to the development and optimization of improved scintillation detectors.

Ultrafine one-dimensional (1D) H₂Ti₃O₇ nanowires were prepared by a hydrothermal reaction with high concentration of KOH as base source. Then 2D/1D rGO/H₂Ti₃O₇ architecture was constructed and investigated as the anode material for lithium-ion batteries. Benefiting from the addition of rGO nanosheets and the retention of ultrafine 1D H₂Ti₃O₇ nanowires, the rGO/H₂Ti₃O₇ electrode presented superior electrochemical performance with excellent rate capability, long cycling stability and high capacity in half cells. It delivered high reversible capacities of 274 mAh g⁻¹ at 0.1 A g⁻¹ and 163 mAh g⁻¹ at 1 A g⁻¹, as well as a long-term cycling performance (259.3 mAh g⁻¹ at 0.2 A g⁻¹ after 1000 cycles). The excellent electrochemical performance of the composite can be attributed to the unique architecture with smaller diameter of 1D H₂Ti₃O₇ nanowires and conductive rGO nanosheets to shorten the transmission distance of electrons and Li⁺ and improve the electrical conductivity in rGO/H₂Ti₃O₇ composite.

Highly blue-luminescent nitrogen & sulfur-doped carbon dots (N, S-CDs) made with homocysteine and ethylene diamine by simple single-step microwave-assisted style. The prepared carbon dots showed a higher photoluminescent quantum yield (PL-QY), which is found to be 45 %. FTIR and XPS analysis reveals that these N, S-CDs contain rich nitrogen, and sulfur as well as C=O and C=C functional groups. N, S-CDs had a mean size around 3-4 nm, very interestingly, obtained carbon dots exhibit excitation-dependent photoluminescent character, are water-soluble, and restore luminescent stability under UV-light exposure and a wide range of pH. The crafted N, S-CDs are hired for precise and discriminating detection of multiple water impurities such as Fe³⁺ ion and Picric acid. The complexation between oxygen species of N, S doped CDs, and Fe³⁺ ion follows the inner-filteration effect (IFE) and with Picric acid follows Forster Resonance Energy Transfer (FRET) for the doped N, S-CDs are found to be the utmost possible mechanism for the observed sensing performance. The lower detection limit (LOD) of Fe³⁺ sensors is about 0.11 µM and for picric acid is 0.07 µM. Moreover, these blue-emissive N, S-CDs as competent fluorescence sensors, have been used as fluorescent inks, as well as in advanced portable devices information security and filter paper-based probes for visual recognition might also hold prominent ability to make wider applications in biological systems.

Recent research has focused on solid polymer electrolytes (SPEs) as the best liquid electrolyte replacements. Poly(ethylene oxide) (PEO) is the most frequent one because of its fast segmental movements in the free volume which controls lithium-ion transport between electrodes. Therefore, PEO-based copolymer electrolytes that can be tailored for mechanical strength and ionic conductivity are often studied. The most popular material is PEO chains containing PMMA because PEO transports ions, and PMMA has good mechanical properties. Further investigations on PEO-based solid polymer electrolytes (SPEs) have shown that chain designs with more nonlinear branches prevent crystallinity and maintain fast segmental dynamics. For this purpose, we worked on PEO-grafted-PMMA copolymers in which the free volume probed by positron annihilation lifetime spectroscopy considerably affects the structure-ionic conductivity relationship. Finally, we investigated the free volume theory of ionic condcutivity using Yahsi-Ulutas-Tav (YUT) theory.

Bi_0.5Na_0.5TiO₃ ceramic is a promising dielectric energy storage material due to its high spontaneous polarization (> 40 μC/cm²). Although many studies have been carried out to enhance the energy storage performance of Bi_0.5Na_0.5TiO₃ ceramic, achieving better energy storage performance is still a considerable challenge. Herein, Bi_0.5Na_0.5TiO₃-BiYbO₃-SrTiO₃ (BNT-BY-STO) relaxor ferroelectric ceramics were constructed, and <111>-oriented (1-x)(0.99BNT-0.01BY)-xSTO ceramics were successfully fabricated by a templated grain growth method. The moderate energy storage performance (the reversible energy storage density of 3.26 J/cm³ and energy storage efficiency of 76.3 % under 290 kV/cm) can be achieved in <111>-oriented 0.8(0.99BNT-0.01BY)-0.2STO ceramics. The enhanced energy storage performance of textured BNT-BY-STO ceramics could be mainly attributed to the grain refinement of STO, and the improved breakdown strength and relaxation behavior caused by orientation engineering. These findings demonstrate that the co-doping of BY and STO and orientation engineering are effective strategies for improving the energy storage performance of BNT ceramic.

Ba(Ti_0.80Zr_0.20)O₃–0.5(Ba_0.7Ca_0.3)TiO₃ (BCTZ) piezoelectric nanofibers (NFs) and nanoparticles (NPs) were fabricated using electrospinning and sol-gel methods, respectively. The impact of BCTZ nanostructure on piezocatalysis was investigated, revealing that both poled NFs and NPs exhibit a piezocatalytic degradation rate of 2.8 × 10^–2 min^-1, which is significantly higher than their unpoled counterparts at 2.3 × 10^–2 min^-1 and 1.9 × 10^–2 min^-1, respectively. The enhanced piezocatalytic degradation rates of the poled BCTZ nanostructures are attributed to their superior piezoelectricity, resulting in larger built-in electric fields under external strain. Moreover, BCTZ NFs provide numerous active piezocatalytic reaction sites confined to the one-dimensional (1D) fibrous boundaries. Simulation results indicate that BCTZ NFs exhibit greater displacement and higher piezoresponse compared to nanoparticles, due to the electromechanical coupling effect facilitated by the 1D nanostructure. This study provides an efficient pathway to understanding the coupling mechanism between the poled built-in electric field and piezotronics.

Solar desalination is a promising solution to address global water scarcity. In this study, a novel superhydrophobic photothermal evaporator based on MoS₂ nanoflowers, known for their excellent photothermal conversion properties, was developed. The evaporator is coated with 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane (PFDTES) to create superhydrophobic structures, which are then loaded onto a macroporous non-woven fabric (NWF) to facilitate efficient steam release. The hydrophobic PFDTES coating effectively prevents salt crystallization, ensuring long-term desalination. The developed device demonstrates an exceptional solar steam generation performance of 1.52 kg m⁻² h⁻¹ with an evaporation efficiency of up to 87.1 %. This evaporator offers a promising solution to water scarcity challenges due to its high evaporation efficiency, impressive durability, and low-cost.

Fromation of CdS/g-C₃N₄/ZnO (CdCN/Z) ternary composites for the water splitting application is reported here. Produced materials were studied for physicochemical, optical, photo-electrochemical (PEC) and photocatalytic pollutant degradation properties. The current density of CdCN/Z exhibited as 7.4 mA/cm² which is 26.4, 21.7, 14.25, and 5.92 folds higher than g-C₃N₄ (CNU), ZnO (Z), CdS, and CNU/Z, respectively. Additionally, the CdCN/Z composite achieved a higher photon-to-hydrogen conversion efficiency of 0.8 %. The finale composite exhibited a effectual degradation of RhB (99 % in 45 min) in water under light and ultrasonication exposure. The coupling of CNU/Z with CdS promoted the optical absorbance in the longer wavelength. This configuration had facilitated the enhanced photogenerated charge carriers separation. The contemporary work validates that the prepared CdCN/Z heterojunction is an auspicious photocatalyst for effectual water splitting as well as photocatalytic elimination of dye pollutants.

Bimetallic nanoparticles are of great significance in numerous areas due to their unique properties and diverse applications. In the present study, silver (Ag) and cobalt (Co) monometallic nanoparticles (MNPs) and AgCo bimetallic nanoparticles (BNPs), are synthesized using a simple wet chemical route. Various analytical techniques are adopted for the confirmation of the BNPs. Powder X-ray diffraction (PXRD) analysis revealed the formation of FCC-structure. Transmission Electron Microscopy (TEM) micrographs confirmed the bimetallic nature and Janus structure. The synthesized nanoparticles exhibit higher catalytic activity for degrading 4-nitrophenol dye. Recognizing the potential of metal nanoparticles to significantly boost the efficiency of triboelectric nanogenerators (TENG), the synthesized AgCo bimetallic nanoparticles are incorporated into polymer matrix to meticulously analyze the impact on the triboelectric performance. Interestingly, TENG with a higher composite quantity of 8 ml BNPs exhibited greater performance, generating an output voltage of about 270.52 V and a current of 5.24 µA. Hence, the procured synergistic BNPs show their promising avenue towards both water treatment and energy harvesting applications.