Stable 1T-MoS2 by Facile Phase Transition Synthesis for Efficient Electrocatalytic Oxygen Evolution Reaction

The 1T phase of MoS2 exhibits much higher electrocatalytic activity and better stability than the 2H phase. However, the harsh conditions of 1T phase synthesis remain a significant challenge for various extensions and applications of MoS2 . In this work, a simple hydrothermal-based synthesis method for the phase transition of MoS2 is being developed. For this, the NH2 -MIL-125(Ti) (Ti MOF) is successfully utilized to induce the phase transition of MoS2 from 2H to 1T, achieving a high conversion ratio of ≈78.3%. The optimum phase-induced MoS2 /Ti MOF heterostructure demonstrates enhanced oxygen evolution reaction (OER) performance, showing an overpotential of 290 mV at a current density of 10 mA cm-2 . The density functional theory (DFT) calculations are demonstrating the benefits of this phase transition, determining the electronic properties and OER performance of MoS2 .

Bioactivation of an orthodontic wire using multifunctional nanomaterials to prevent plaque accumulation

Controlling the growth of biofilm on orthodontic material has become a difficult challenge in modern dentistry. The antibacterial efficacy of currently used orthodontic material becomes limited due to the higher affinity of oral microbial flora for plaque formation on the material surface. Thus it is crutial to device an efficient strategy to prevent plaque buildup caused by pathogenic microbiota. In this work, we have fabricated a bioactive orthodontic wire using titanium nanoparticles (TiO₂NPs) and silver nanoparticles (AgNPs). AgNPs were synthesized from the extracts of Ocimum sanctum, Ocimum tenuiflorum, Solanum surattense, and Syzygium aromaticum, while the TiO₂NPs were synthesized by the Sol-Gel method. The nanoparticles were characterized by various biophysical techniques. The surface of the dental wire was molded by functionalizing these AgNPs followed by an additional coating of TiO₂NPs. Functionalized dental wires were found to counteract the formation of tenacious intraoral biofilm, and showed an enhanced anti-bacterial effect against Multi-Drug Resistant (MDR) bacteria isolated from patients with various dental ailments. Data revealed that such surface coating counteracts the bacterial pathogens by inducing the leakage of Ag ions which eventually disrupts the cell membrane as confirmed from TEM micrographs. The results offer a significant opportunity for innovations in developing nanoparticle-based formulations to modify or fabricate an effective orthodontic material.

Efficient sonocatalytic degradation of heavy metal and organic pollutants using CuS/MoS2 nanocomposites

Eco-friendly and highly effective catalysts are receiving considerable attention for the removal of heavy-metal ions and organic pollutants. In this study, we developed CuS/MoS₂ nanocomposite sonocatalysts to enhance the degradation rate of environmental contaminants by harnessing ultrasonic irradiation. The successful synthesis of nanocomposite sonocatalysts was confirmed by X-ray diffraction (XRD) analysis, and energy-dispersive X-ray spectroscopy. The incorporation of CuS into MoS₂ resulted in a flower-like structure with an increased surface area. Importantly, the sonocatalytic efficiency was enhanced by increasing CuS concentration in the nanocomposites, achieving maximum removal efficiencies of 99% and 88.52% for rhodamine B (RhB) and Cr(VI), respectively. In addition, they showed excellent stability and recyclability over five consecutive cycles, without noticeable changes in the nanocomposite structure. Reactive oxygen species (ROS) used for the degradation were identified using ROS scavengers. We believe that this strategy of exploiting nanocomposite sonocatalysts has a great potential in the field of environmental catalysis.

Mimosine functionalized gold nanoparticles (Mimo-AuNPs) suppress β-amyloid aggregation and neuronal toxicity

Evidence suggests that increased level/aggregation of beta-amyloid (Aβ) peptides initiate neurodegeneration and subsequent development of Alzheimer's disease (AD). At present, there is no effective treatment for AD. In this study, we reported the effects of gold nanoparticles surface-functionalized with a plant-based amino acid mimosine (Mimo-AuNPs), which is found to cross the blood-brain barrier, on the Aβ fibrillization process and toxicity. Thioflavin T kinetic assays, fluorescence imaging and electron microscopy data showed that Mimo-AuNPs were able to suppress the spontaneous and seed-induced Aβ_1-42 aggregation. Spectroscopic studies, molecular docking and biochemical analyses further revealed that Mimo-AuNPs stabilize Aβ_1-42 to remain in its monomeric state by interacting with the hydrophobic domain of Aβ_1-42 (i.e., Lys₁₆ to Ala₂₁) there by preventing a conformational shift towards the β-sheet structure. Additionally, Mimo-AuNPs were found to trigger the disassembly of matured Aβ_1-42 fibers and increased neuronal viability by reducing phosphorylation of tau protein and the production of oxyradicals. Collectively, these results reveal that the surface-functionalization of gold nanoparticles with mimosine can attenuate Aβ fibrillization and neuronal toxicity. Thus, we propose Mimo-AuNPs may be used as a potential treatment strategy towards AD-related pathologies.

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Mimosine functionalized with gold nanoparticles (Mimo-AuNPs) can cross blood-brain barrier.

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Mimo-AuNPs inhibit aggregation of Aβ peptides by interacting with its hydrophobic domain.

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Mimo-AuNPs can trigger disassembly of pre-aggregated Aβ fibers.

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Mimo-AuNPs can protect neurons against Aβ toxicity by attenuating intracellular signaling.

High-performance dye-sensitized solar cell using dimensionally controlled titania synthesized at sub-zero temperatures

The subject of the current study is a concoct of anatase and rutile mixed phase titania synthesized at −40 °C and −10 °C.

HfO2 nanodots incorporated in TiO2 and its hydrogenation for high performance dye sensitized solar cells

HfO₂ nanodots are incorporated in TiO₂ and hydrogenated together resulting in a photoelectrode material with a bandgap of 2.4 eV. The material exhibits interesting optical properties that are best suited for solar applications.