Rare Metals最新文献

Recently, stimuli-responsive nanocarriers capable of precision drug release have garnered significant attention in the field of drug delivery. Here, an in-situ dynamic covalent self-assembled (DCS) strategy was utilized to develop a co-delivery system. This assembly was based on a thiol-disulfide-exchange reaction, producing disulfide macrocycles in an oxidizing aerial environment. These macrocycles encapsulated the anti-cancer drug (paclitaxel, PTX) on the surface of gold nanoparticles, which served as photothermal therapy agents during the self-assembly. In the DCS process, the kinetic control over the concentration of each building unit within the reaction system led to the formation of a stable co-delivery nanosystem with optimal drug-loading efficiency. Notably, the high glutathione (GSH) concentrations in tumor cells caused the disulfide macrocycles in nanostructures to break, resulting in drug release. The stimuli-responsive performances of the prepared nanosystems were determined by observing the molecular structures and drug release. The results revealed that the self-assembled nanosystem exhibited GSH-triggered drug release and good photothermal conversion capability under near-infrared light. Moreover, the in vitro and in vivo results revealed that conjugating the targeting molecule of cRGD with co-delivery nanosystem enhanced its biocompatibility, chemo-photothermal anti-cancer effect. Overall, our findings indicated that in-situ DCS strategy enhanced the control over drug loading during the construction of the co-delivery system, paving a way for the development of more functional carriers in nanomedicine.

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Advanced electrode materials for electrocatalysis of electrolytic decomposition are crucial materials in the field of hydrogen production from renewable energy. In this work, a new type of integrated hydrogen evolution electrode material was synthesized by selective acidification etching and in situ growth technology. A novel-integrated Ni-Mo sulfide electrode material with a three-dimensional network structure was successfully prepared using a two-step method (convenient surface modification and in situ growth techniques), which involved surface modification at 30% HNO₃ for 10 min and followed by annealing treatment at 600 °C for 1 h with 10 °C·min⁻¹ heating rate. The structure displayed an electrochemical active surface area (ECSA) of 30.125 mF·cm⁻², calculated on 0.10–0.30 V (vs. RHE) CV curves with a 5–50 mV·s⁻¹ sweep rate range. The ECSA of other samples was also tested by aforementioned methods, which had great distinction on ECSA with different samples. The novel-integrated Ni-Mo sulfide electrode material appeared to have extremity electrochemical performance in a three-electrode configuration employing 1 M KOH solution as an electrolyte, including an excellent hydrogen evolution overpotential of 346 mV at the current density of 500 mA·cm⁻², superior Tafel slope with 103 mV·dec⁻¹. Such outstanding electrochemical performances of the novel-integrated Ni-Mo sulfide electrode materials were directly related to the distinctive integrated structure. Therefore, it was facility to find that the successful preparation of novel-integrated Ni-Mo sulfide electrode material provided more selection opportunities for alkaline electrolysis of water and offered an innovative mentality for the preparation of other types of electrode materials.

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Lutetium aluminum garnet doped with cerium (LuAG:Ce) thin films have been identified as a promising material for high-power laser-driven lighting applications. In this study, spray pyrolysis we employed to fabricate LuAG:Ce films on sapphire substrates and the impact of film thickness on thermal management and light emission efficiency was investigated. Our results show that, regardless of thickness, LuAG:Ce films exhibit impressive internal quantum efficiencies (IQE) exceeding 83.2% and external quantum efficiencies (EQE) surpassing 56.4%, with minimal alteration of luminescent color. Notably, thinner films facilitate more efficient heat dissipation to the underlying sapphire substrate, resulting in superior thermal management and outstanding luminous performance under high-power laser excitation. Specifically, the thinnest LuAG:Ce film (15.79 μm) exhibited rapid thermal stabilization (~ 130 °C within 30 s) and maintained stability during continuous irradiation lasting 30 min, with a corresponding decrease in luminous flux to 87.9% of its initial value within the first 60 s. This film also demonstrated relatively high and stable conversion efficiency and luminous efficiency, achieving higher saturation thresholds (15 W·mm⁻²) and luminous flux (1070 lm). In contrast, thicker films exhibited a shift in the saturation point toward lower power densities. These findings provide valuable insights for the practical implementation of LuAG:Ce films in advanced lighting technologies.

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In this work, a novel microwave absorbing material (MAM) made of a pseudo-binary of Sr₂TiMoO₆–Al₂O₃ (STM) is proposed first. The MAMs labeled as STM X (X = 60, 70, 80 and 100, respectively), in which X is the initial weight percent of Sr₂TiMoO₆, were synthesized using the solid-state reaction method. Compared with STM100, some equilibrium phases, including SrTiO₃, Mo, Sr₈(Al₁₂O₂₄)(MoO₄)₂ and a few undefined ones, are presented in the composites as evidenced by X-ray diffraction results and scanning electron microscopy due to the chemical reaction between Sr₂TiMoO₆ and Al₂O₃ component. Besides conductance loss, heterogeneous interfaces between various equilibrium phases introduce interfacial polarization, which causes an enhancement of dissipation for the incident electromagnetic wave. Among the synthesized samples, STM80 presents the best microwave absorbing properties. It has a minimum reflection loss (RL_min) of − 26 dB and an effective absorbing bandwidth up to 2.7 GHz when the thickness is only 1 mm. This indicates that STM80 is a new type of microwave absorbing material with strong absorption and ultrathin thickness.

Metal clusters or even single-atoms dispersed and anchored on the photocatalysts’ surface can enhance photocatalytic performances on organic pollutant oxidation. Here, a simple photoreduction method was used to create atomically dispersed metal single-atoms/clusters (MSCs, M = Cu, Pd, Au and Ag) on P-modulated tubular carbon nitride (TCN). The obtained MSCs@TCN demonstrated excellent photocatalytic performances for the degradation of sulfamethazine (SMZ). In particular, the photocatalyst with 2 wt% Cu loading showed ultrahigh SMZ oxidation efficiency (k = 0.06110 min⁻¹), almost three times that of TCN (k = 0.02066 min⁻¹). It also shows excellent stability in the 5th-cycle measurements. The improved photocatalytic activity of the CuSCs@TCN is ascribed to the synergistic promotion of photogenerated charge separation by Cu single-atoms/clusters as active sites, accelerated charge transfer from bulk TCN to Cu sites through Cu–N_x interaction. Meanwhile, the active sites of Cu single-atoms/clusters could promote the production of ·O₂⁻, which participates in organic oxidation with strong oxidizing holes (h⁺). This strategy paves a new avenue for designing high-performance photocatalysts decorated with metal single-atoms and clusters.

Crystallization, while a common process in nature, remains one of the most mysterious phenomena. Understanding its physical mechanisms is essential for obtaining high-quality crystals. Typically, crystals grown by thermal evaporation or sublimation nucleate the substrate facing the evaporation source. Here, a novel vapor micro-turbulence mass transport mechanism in the growth process of ultrathin BiOCl single crystals has been revealed. In this mechanism, the precursor vapor bypasses the solid substrate, forming micro-turbulent vaporizing flows to nucleate on the surface of the substrate facing away from the evaporation source. Considering nucleation kinetics, fast shear flows are known to cause secondary nucleation, increasing nucleation quantity while decreasing the final size of the crystals. Thus, the nucleation and growth process of BiOCl crystals are controlled by adjusting the micro-turbulence intensity to reduce shear flow energy and dilate phase distribution, resulting in BiOCl crystals with uniform distribution and regular shape. Subsequent structural and morphological characterization confirms the high crystallization quality of the obtained crystals, and the performance of the constructed solar-blind photodetectors is comparable to that of similar devices. These findings contribute to a deeper understanding of vapor mass transport and crystal growth techniques and may be useful for applications related to metal oxide crystals.

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