Manipulation of Surface Plasmon Resonance in Sub-Stoichiometry Molybdenum Oxide Nanodots through Charge Carrier Control Technique

Semiconductor nanocrystals are intriguing because they show surface plasmon absorption features like noble metallic nanoparticles. In contrast with metal, manipulation of their unique plasmonic resonance could be easily realized by the free-carrier concentration. Here, it is demonstrated that MoO_3–<i>x</i> nanodots can exhibit striking surface plasmon resonance located at near-infrared region under treatment of two different reducing agents. Furthermore, the tunable resonance mode has been achieved through appropriate redox processes. Refractive index sensing has been demonstrated by monitoring the plasmonic peak. The improved sensing application is ascribed to the enhanced electric field in the plasmonic nanocrystals. These new insights into MoO_3–<i>x</i> nanodots pave a way to develop novel plasmonic applications such as photothermal therapy, light harvesting, and sensing

Integrated Anodes from Heteroatoms (N, S, and F) Co-Doping Antimony/Carbon Composite for Efficient Alkaline Ion (Li⁺/K⁺) Storage

Sb-based materials are widely used in alkali metal-ion batteries due to large specific capacity, low cost, and a suitable operating voltage platform. However, they suffer from tardy dynamic performance and structural instability, along with a vague storage mechanism for alkali metal ion (Li+/K+) confining their further popularization. Herein, a scalable strategy is proposed to make Sb nanoparticles encapsulated in the N, S, and F co-doping carbon skeleton (Sb@NSF-C) with a three-dimensional ordered hierarchical porous structure. The Sb@NSF-C composite shows remarkable electrochemical performances in lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs) due to improved Li+/K+ diffusion kinetics, rapid ion transport path, and stable structure. The Li+/K+ storage mechanism is detailedly investigated for the Sb@NSF-C composite. This work may provide a feasible method to design electrode materials for LIBs and PIBs with excellent performances

Microstructural and Texture Evolution of Strip Cast Nd–Fe–B Flake

In this work, the microstructure and texture evolution of the strip cast Nd–Fe–B flake has been systematically investigated by correlating multiple state-of-the-art characterization techniques. We found that (i) besides the existence of random ultrafine equiaxed grains at the wheel side of the flake, elongated (001) textured grains were formed into a V-shape zone between neighboring nucleation sites, which possibly resulted from the in-plane growth of the low energy preferred growth direction of grains (<i>a</i> axis). Both ultrafine random equiaxed grains and elongated (001) textured grains are detrimental to achieving a high-performance Nd–Fe–B magnet, due to the inhomogeneous grain shape and nonuniform distribution of rare earth-rich phase within these grains or along the grain boundaries, which deteriorate the alignment of the Nd–Fe–B powders in the subsequent hydrogen decrepitation process and jet milling procedure. To overcome the issues mentioned above, two potential approaches are proposed, which are increasing the nucleation rate on the wheel side and homogenization of rare earth-rich phase within grains or along grain boundaries; (ii) columnar grains containing (Nd,Pr)₂Fe₁₄B lamellae with an average spacing of ∼5 μm and discontinuous rare-earth rich phase were formed in the remaining part of the flake. Accordingly, a model in terms of the microstructure and texture evolution was proposed