Search

Catalytic strategies based on main group metals are significantly less advanced than those of transition metal catalysis, leaving untapped areas of potentially fruitful research. We here demonstrate an effective approach for the modulation of Bi 6p energy levels during the construction of atomically dispersed clusters of amorphous BiOx. Bi oxidation state is proposed to strongly affects the nitrogen fixation activity, with the half‐occupied pz orbitals of the Bi2+ ions being highly efficient toward electron injection into the inert N2 molecule. With sufficient catalytic sites to adsorb and activate N2, the bonding between N2 and catalyst is able to be in situ identified. The catalyst shows an outstanding Faraday efficiency (≈30 %) and high yield (≈113 μg h−1 mg−1cat) in NH3 production, outperforming most of the existing catalysts in aqueous solution. These results lay the basis for developing the potential of p‐block elements for catalysis of multi‐electron reactions. [ABSTRACT FROM AUTHOR]

The lithium dendrite issue is a major bottleneck that limits the utilization of lithium metal anodes in high‐energy rechargeable batteries. From the perspective of the dendrite nucleation mechanism, this work develops a new type of cation‐selective (CS) separator with anion immobilization behavior to boost the lithium metal anode. By taking advantage of the poly(vinylidene fluoride) matrix, a strong binding force with anions contributes to an excellent CS property of the separator, which is further confirmed by molecular dynamics simulations. The CS separator developed in this work presents a high lithium‐ion transference number up to 0.81. Considering such a dramatically reduced transference number of anions, it can prolong the nucleation time of lithium dendrite and thus achieve a high‐stable Li plating/stripping cycling for 1000 h at a high applied current density of 3 mA cm−2. The Li metal stabilization function of the CS separator is further studied in detail through both in‐situ and ex‐situ observations of dendrites growth. When integrating into lithium metal batteries (LMBs), the CS separators also contribute to enhanced electrochemical performances including discharge capacity, rate capability, and cycling durability. This work is anticipated to provide considerable insight for the creative design of CS separators toward dendrite‐free LMBs. [ABSTRACT FROM AUTHOR]

Abstract: Biomimetic solid‐state nanofluidic diodes have attracted extensive research interest due to the possible applications in various fields, such as biosensing, energy conversion, and nanofluidic circuits. However, contributions of exterior surface to the transmembrane ionic transport are often ignored, which can be a crucial factor for ion rectification behavior. Herein, a rational design of robust sandwich‐structured nanofluidic diode is shown by creating opposite charges on the exterior surfaces of a nanoporous membrane using inorganic oxides with distinct isoelectric points. Potential‐induced changes in ion concentration within the nanopores lead to a current rectification; the results are subsequently supported by a theoretical simulation. Except for providing surface charges, functional inorganic oxides used in this work are complementary electrochromic materials. Hence, the sandwich‐structured nanofluidic diode is further developed into an electrochromic membrane exhibiting a visual color change in response to redox potentials. The results show that the surface‐charge‐governed ionic transport and the nanoporous structure facilitate the migration of Li+ ions, which in turn enhance the electrochromic performance. It is envisioned that this work will create new avenues to design and optimize nanofluidic diodes and electrochromic devices. [ABSTRACT FROM AUTHOR]

One‐dimensional (1D) amorphous nanomaterials combine the advantages of high active site concentration of amorphous structure, high specific surface area and efficient charge transfer of 1D materials, so they present promising opportunities for catalysis. However, how to achievie the balance between the high orientation of 1D morphology and the isotropy of amorphous structure is a significant challenge, which severely obstructs the controllable preparation of 1D amorphous materials. Guided by the hard‐soft acids‐bases theory, here we develop a general strategy for preparing 1D amorphous nanomaterials through the precise modulation of bond strength between metal ions and organic ligands for a moderated fastness. The soft base dodecanethiol (DT) is multifunctionally served as both structure‐regulating agent and morphology‐directing agent. Compared with the borderline acids (e.g. Fe2+, Co2+, Ni2+) to construct amorphous structure, soft acid of Cu+ which produced crystalline nanobelts can still be amorphized by reducing the hardness of Cu ions through redox reaction to weak Cu−SR bond. Due to the combined advantages of amorphous structure and one‐dimensional morphology, amorphous CuDT nanobelts exhibited excellent electrocatalytic activity in electrochemical nitrate reduction, outperformed most of the reported Cu‐based catalysts. This work will effectively bridge the gap between traditional 1D crystalline nanomaterials synthesis and their amorphization preparation. [ABSTRACT FROM AUTHOR]