Rare Metals最新文献

In this work, BiOCl/OVs–BiPO₄ heterojunction photocatalysts were successfully in-situ prepared by treating of BiPO₄ with dilute hydrochloric acid (HCl) under hydrothermal condition. Systematically characterization results confirm that BiOCl/BiPO₄ heterojunctions have been successfully in-situ constructed and oxygen vacancies (OVs) are significantly increased. The OVs on the surface of the BiOCl/OV_S–BiPO₄ heterojunctions photocatalyst and the interface electric field at the interface of the heterojunctions effectively accelerate the separation and migration of photogenerated carriers, and the surface OVs provide more sites for adsorption and reaction. Consequently, BiOCl/OVs–BiPO₄ heterojunction photocatalysts have higher separation rate of photoexcited e⁻/h⁺ pairs and exhibit ascendant photocatalytic degradation activity. Electron paramagnetic resonance (EPR) technology and free radical capture experiments give strong evidence that ·O₂⁻ exists in the reaction system and is the leading species during the degradation process. The experimental results reveal that the degradation efficiency of rhodamine B (RhB) over BiPO₄ treated with 3 ml of 0.1% dilute hydrochloric acid (3HCl-BPO) is 2.42 times of that over the reference BiPO₄. After ultraviolet (UV) light illumination for 20 min, the destruction degree of RhB on the 3HCl-BPO sample reaches 99%. Moreover, the degradation rate of tetracycline (TC) is also obviously improved over 3HCl-BPO compared with that on the reference BiPO₄ after 40 min exposure to ultraviolet light. The excellent stability of the sample was demonstrated by five cycles. A reasonable enhancement mechanism for BiOCl/OVs–BiPO₄ heterojunctions was proposed to elucidate the boosted photocatalytic performance. This work offers a facile and reliable reference to design high performance BiPO₄-based photocatalysts for environment purification.

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In this paper, hierarchical ultra-thin core/shell Ni₃S₂@MoS₂ nano-arrays with Mo atomic site grown on nickel foam (Ni₃S₂@MoS₂-NF) were designed and synthesized through the hydrothermal method. When they are tested as photoelectric catalysis electrodes to anti-bacteria, the Ni₃S₂@MoS₂ within core/shell structure exhibits about several times higher rate capability and outstanding cycling stability than traditional photocatalysts. After reacting with water and oxygen, large numbers of extracellular reactive oxygen species on the surface of Ni₃S₂@MoS₂ are observed. These reactive oxygen species can penetrate bacterial cells, resulting in a rapid rise of intracellular reactive oxygen species in a short time. The integrity of the bacterial cell membrane is also destroyed, which can be observed in both scanning and transmission images. The synthetic primer was used to specifically label the gene fragment with antibiotic resistance, which was oxidized and eliminated after the photoelectron catalysis (PEC) reaction, proving that this material for PEC antibacterial can not only kill bacteria. Successful elimination of antibiotic-resistance gene fragments can also be achieved.

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Implant-related infections and tissue inflammation are the main factors for peri-implantitis. Lack of antibacterial activity and poor soft tissue sealing property increase the occurrence probability of peri-implantitis. To prevent and treat peri-implantitis, cerium-doped defective titanium oxide coatings are prepared on medical titanium surfaces by plasma electrolytic oxidation and thermal reduction treatment. In the darkness, Ce-doped defective titanium oxide coatings with micro-porous structure surface can inhibit the bacteria adhesion to some extent with antibacterial rates of 38.0% against S. aureus and 65.0% against E. coli. Under near infrared (NIR) irradiation, Ce-doped defective titanium oxide coatings show good photothermal antibacterial activity with antibacterial rates of 99.9% against S. aureus and 99.9% against E. coli. Moreover, with the increasing content of Ce-doping, the coatings exhibit higher capacity to scavenge hydrogen peroxide (H₂O₂) and 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS^·+). The coatings with enhanced antioxidant effect can protect human gingival fibroblasts from oxidative stress damage by eliminating reactive oxygen species and promoting initial cell adhesion. Besides, Ce-doped coatings can regulate the immune microenvironment by up-regulating the expression of anti-inflammatory genes and down-regulating the pro-inflammatory genes. In vivo animal experiments further confirm the good antibacterial activity of Ce-doped defective titanium oxide coatings under NIR irradiation and good biosafety. This work provides a novel surface modification strategy for implant abutment, which shows good application prospects for preventing and treating peri-implantitis.

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Recently, high/medium-entropy alloys (HEAs/MEAs) have been considered attractive catalysts due to their unique physicochemical properties. However, the synthesis of nano-sized HEAs/MEAs catalysts with desirable morphology presents significant challenges. Herein, we report the synthesis of NiCoFeCu MEA nanoparticles encapsulated in nitrogen-doped carbon nanotubes (NCTs) via a straightforward one-step pyrolysis method. The unique structure of NiCoFeCu/NCTs and the nano-sized MEA catalysts contributes to the improved hydrogen desorption kinetics of MgH₂. The onset dehydrogenation temperature of the MgH₂-NiCoFeCu/NCTs composite decreased to 173.4 °C, a reduction of 117.4 °C compared to pure MgH₂. The MgH₂-NiCoFeCu/NCTs composite could release 6.50 wt% H₂ within 30 min at 325 °C. Furthermore, an activation energy of 116.3 kJ·mol⁻¹ for the MgH₂-NiCoFeCu/NCTs composite has been obtained, much lower than pure milled MgH₂, demonstrating an enhanced hydrogen desorption kinetics. Moreover, the exceptional dispersion capability of the carbon material contributes to outstanding cyclic stability without any loss of capacity even after 10 cycles of de/hydrogenation at 300 °C.

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Ultrathin Li-rich Li–Cu binary alloy has become a competitive anode material for Li metal batteries of high energy density. However, due to the poor-lithiophilicity of the single skeleton structure of Li–Cu alloy, it has limitations in inducing Li nucleation and improving electrochemical performance. Hence, we introduced Ag species to Li–Cu alloy to form a 30 μm thick Li-rich Li–Cu–Ag ternary alloy (LCA) anode, with Li–Ag infinite solid solution as the active phase, and Cu-based finite solid solutions as three-dimensional (3D) skeleton. Such nano-wire networks with LiCu₄ and Cu_xAg_y finite solid solution phases were prepared through a facile melt coating technique, where Ag element can act as lithiophilic specie to enhance the lithiophilicity of built-in skeleton, and regulate the deposition behavior of Li effectively. Notably, the formation of Cu_xAg_y solid solution can strengthen the structural stability of the skeleton, ensuring the geometrical integrity of Li anode, even at the fully delithiated state. Meanwhile, the Li–Ag infinite solid solution phase can promote the Li plating/stripping reversibility of the LCA anode with an improved coulombic efficiency (CE). The synergistic effect between infinite and finite solid solutions could render an enhanced electrochemical performance of Li metal batteries. The LCA|LCA symmetric cells showed a long lifespan of over 600 h with stable polarization voltage of 40 mV, in 1 mA·cm⁻²/1 mAh·cm⁻². In addition, the full cells matching our ultrathin LCA anode with 17.2 mg·cm⁻² mass loading of LiFePO₄ cathode, can continuously operate beyond 110 cycles at 0.5C, with a high capacity retention of 91.5%.Kindly check and confirm the edit made in the article title.OK

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The development of stable and highly efficient multifunctional electrocatalysts for the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential for the efficient conversion and storage of renewable energy. The significant advantages of single-atom catalysts, such as strong metal slab interactions, unsaturated coordination and efficient atomic utilization, have opened new avenues for designing multifunctional catalysts. Herein, based on density functional theory, a single atom doped PdPX system was designed as a multifunctional electrocatalyst, which demonstrated the synergistic effect between defects and transition metal atoms and led to enhanced catalytic performance. The results showed that PdPS/PdPSe with P/X vacancy, PdPTe with P/Pd vacancy and Co/Rh/Ir@PdPX exhibited promising HER activity. Co@PdPS(Se), with an overpotential of 0.56(0.44) V, was predicted to be a promising OER catalyst. Moreover, Rh(Ir)@PdPS(Se) catalysts exhibited efficient catalytic properties for ORR. Besides, Co@PdPS(Se), Rh(Ir)@PdPS^V(S), Co@PdPSe^V(Se) and Ir@PdPS^V(S)−1 exihibited multifunctional catalytic performance with moderate overpotential. Next, the origin of catalytic activity was revealed by using the crystal orbital Hamilton populations theory. For a strong adsorption system, proper filling of the anti-bonding state can increase the energy of the system, weaken the adsorption strength, and facilitate the desorption of intermediates. Conversely, augmenting bonding states can enhance its adsorption capacity. These findings provide theoretical guidance for the design and fabrication of novel multifunctional electrocatalysts in terms of filling of bonding-state.

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