Slatterysharma1404

Isoelectronic Zn substitution at the Mg site has been proved to be effective in regulating the carrier concentration of p-type Mg3Sb2 Zintl phase. However, the reported thermoelectric performance is still unsatisfactory compared with that of n-type Mg3Sb2 due to the poor electrical transport properties. Here, we report an enhanced average ZT through improving low-temperature ZTs by introducing Zn vacancy followed suppressing the bipolar effect by doping. First, the Zn vacancy simultaneously increases the power factor and decreases the thermal conductivity, leading to a peak ZT value of ∼0.52 at 773 K in Mg2Zn0.98Sb2. Additionally, doping Li or Ag at the Mg site is identified as a high-efficiency strategy for further increasing the carrier concentration and hence suppressing the bipolar effect. Finally, a peak ZT of ∼0.73 at 773 K and an average ZT of ∼0.46 between 300 and 773 K were obtained in Mg1.98Li0.02Zn0.98Sb2.With the rapid development of nanomanufacturing, scaling up of nanomaterials requires advanced manufacturing technology to composite nanomaterials with disparate materials (ceramics, metals, and polymers) to achieve hybrid properties and coupling performances for practical applications. Attempts to assemble nanomaterials onto macroscopic materials are often accompanied by the loss of exceptional nanoscale properties during the fabrication process, which is mainly due to the poor contacts between carbon nanomaterials and macroscopic bulk materials. In this work, we proposed a novel cross-scale manufacturing concept to process disparate materials in different length scales and successfully demonstrated an electrothermal shock approach to process the nanoscale material (e.g., carbon nanotubes) and macroscale (e.g., glass fiber) with good bonding and excellent mechanical property for emerging applications. The excellent performance and potentially lower cost of the electrothermal shock technology offers a continuous, ultrafast, energy-efficient, and roll-to-roll process as a promising heating solution for cross-scale manufacturing.The high surface-to-volume ratio of nanostructured materials is the key factor for excellent performance when applied to chemical sensors. In order to achieve this by a facile and low-cost fabrication strategy, buffered oxide etchant (BOE) treatment of a silicon (Si)-based sensor was proposed. An n+-n--n+ Si nanofilm structure was treated with a BOE, and palladium nanoparticles (PdNPs) were coated on the n-type Si channel surface via short-time electron beam evaporation to enable a highly sensitive and selective sensing of hydrogen (H2) gas. The BOE treatment effect on lightly doped n-type Si was investigated, and the surface morphology of the etched Si was analyzed. Furthermore, the H2 sensing characterization of PdNP-decorated Si devices with various BOE treatment times was systematically evaluated at room temperature. The results revealed that the surface of n-type Si is roughened by BOE treatment, which can further enhance the H2-sensing performance of Pd-decorated Si. The elaborate study on the BOE-post-treated Si H2 sensor showed that the performance enhancement was stable. The BOE treatment strategy was also applied to the nanopatterned Si sensors, which induced a clear performance enhancement for the H2 sensing.Hollow nanoparticles have received an enormous amount of attention in the field of nanomedicine. Herein, water-soluble hollow bimetallic complex nanoparticles, holmium(III)/iridium(III) bimetallic complex nanoparticles (Ir-Ho HNPs), were fabricated via a coordination assembly. Epigenetic inhibitor Owing to the special metal-to-ligand charge transfer (MLCT) and the heavy-atom effect of Ir(III) in an iridium complex, Ir-Ho HNPs exhibited an intense phosphorescence and the generation of singlet oxygen (1O2). With the long electron relaxation time and high magnetic moment of Ho(III), Ir-Ho HNPs presented a high longitudinal relaxivity (r2) value (160.0 mM-1 s-1at 7.0 T). Their unique hollow structure resulted in their strong and stable ultrasound signal in an aqueous solution. As a proof of concept, Ir-Ho HNPs have been developed for the phosphorescence imaging and photodynamic therapy for living cells, ultrasound imaging, and high-field magnetic resonance imaging in vivo. Our work opened up an avenue for novel application of an iridium complex in cancer theranostics.In Ni-rich cathode materials, dislocation can be generated at the surface of primary grains because of the accumulation of stress fields. The migration of dislocation into grains, accelerating the annihilation of reverse dislocation as well as oxygen loss, is considered as the principal origin of crack nucleation, phase transformation, and consequent fast capacity decay. Thus, reducing the dislocation would be effective for improving cathode stability. Here, we report the inspiring role of oxygen vacancies in blocking and anchoring the dislocation. Specifically, a large number of oxygen vacancies can assemble to form dense dislocation layers at the surface of grains. Thanks to the dislocation interaction mechanism, preformed dense dislocation at the surface can effectively rivet the newly developed dislocation during cycling. Ex situ transmission electron microscopy analysis indicates that the intragranular cracks and phase transformation were hindered by the riveted effect, which in turn improved the structural and cycling stability of the Ni-rich cathode. Overall, this work provides novel crystallographic design and understanding of the enhanced mechanical strength of Ni-rich cathode materials.The selective removal and recovery of silver ions from an aqueous solution is necessary, owing to the toxicity, persistency, and recoverable value. Herein, we first reported that silver ions could be selectively removed from an acidic solution by utilizing redox-active covalent organic framework (COF) materials as an adsorbent, resulting in the loading of Ag nanoparticles (NPs) with a narrow size distribution onto the framework simultaneously. The redox-active COF not only showed promising performance in adsorbing silver ions but also had a high selectivity at a low pH value. Subsequently, it was found that the N sites of amine groups within the framework took responsibility for the Ag NP generation after the systematic investigation on the redox adsorption mechanism. Furthermore, the recycled Ag@COF materials could be further used as new adsorbents to remove Hg(II) ions from water via NPs as a "bridge", exhibiting ultrahigh atomic utilization (>100%). Accordingly, this work not only provides a novel insight for the use of redox-active COF in the removal of metal ions but also opens a new field for designing of functionalized COF for their potential application in diverse areas.