Controlled Growth and Applications of Complex Metal Oxide ZnSn(OH)6 Polyhedra

One-Step Phase Separation for Core-Shell Carbon@Indium Oxide@Bismuth Microspheres with Enhanced Activity for CO2 Electroreduction to Formate

It is a substantial challenge to construct electrocatalysts with high activity, good selectivity, and long-term stability for electrocatalytic reduction of carbon dioxide to formic acid. Herein, bismuth and indium species are innovatively integrated into a uniform heterogeneous spherical structure by a neoteric quasi-microemulsion method, and a novel C@In₂ O₃ @Bi₅₀ core-shell structure is constructed through a subsequent one-step phase separation strategy due to melting point difference and Kirkendall effect with the nano-limiting effect of the carbon structure. This core-shell C@In₂ O₃ @Bi₅₀ catalyst can selectively reduce CO₂ to formate with high selectivity (≈90% faradaic efficiency), large partial current density (24.53 mA cm^-2 at -1.36 V), and long-term stability (up to 14.5 h), superior to most of the Bi-based catalysts. The hybrid Bi/In₂ O₃ interfaces of core-shell C@In₂ O₃ @Bi will stabilize the key intermediate HCOO* and suppress CO poisoning, benefiting the CO₂ RR selectivity and stability, while the internal cavity of core-shell structure will improve the reaction kinetics because of the large specific surface area and the enhancement of ion shuttle and electron transfer. Furthermore, the nano-limited domain effect of outmost carbon prevent active components from oxidation and agglomeration, helpful for stabilizing the catalyst. This work offers valuable insights into core-shell structure engineering to promote practical CO₂ conversion technology.

Room-temperature triethylamine sensing of a chemiresistive sensor based on Sm-doped SnS2/ZnS hierarchical microspheres

An Sm-doped SnS2/ZnS sensor shows excellent gas-sensing performance towards triethylamine at room temperature.

Antimicrobial Metal Nanomaterials: From Passive to Stimuli-Activated Applications

The development of antimicrobial drug resistance among pathogenic bacteria and fungi is one of the most significant health issues of the 21st century. Recently, advances in nanotechnology have led to the development of nanomaterials, particularly metals that exhibit antimicrobial properties. These metal nanomaterials have emerged as promising alternatives to traditional antimicrobial therapies. In this review, a broad overview of metal nanomaterials, their synthesis, properties, and interactions with pathogenic micro-organisms is first provided. Secondly, the range of nanomaterials that demonstrate passive antimicrobial properties are outlined and in-depth analysis and comparison of stimuli-responsive antimicrobial nanomaterials are provided, which represent the next generation of microbiocidal nanomaterials. The stimulus applied to activate such nanomaterials includes light (including photocatalytic and photothermal) and magnetic fields, which can induce magnetic hyperthermia and kinetically driven magnetic activation. Broadly, this review aims to summarize the currently available research and provide future scope for the development of metal nanomaterial-based antimicrobial technologies, particularly those that can be activated through externally applied stimuli.

Localized inside-out Ostwald ripening of hybrid double-shelled cages into SnO2 triple-shelled hollow cubes for improved toluene detection

Unique SnO2 triple-shelled hollow cages with a well-defined cubic shape have been successfully prepared via additional deposition of polycrystalline SnO2 on hybrid Zn2SnO4/SnO2 double-shelled nanotemplates followed by removal of Zn2SnO4. Structural characterization demonstrates that SnO2 triple-shelled hollow cubes (THCs) are hierarchically composed of numerous primary nanoparticles with a size of about several nanometers. The synthetic step-dependent multilayered evolution mechanism can be addressed in terms of different hollowing strategies. Based on the unique less-agglomerated multilayered and porous configuration, the gas sensing performances of SnO2 THCs exhibit an obvious improvement of response and shortened response-recovery characteristics at their optimal working temperature, compared with those of referenced single- and double-shelled SnO2 nanostructures.

A family of microscale 2 × 2 × 2 Pocket Cubes

A family of Pocket Cubes with different chemical compositions but with the same overall mesoscale microstructures was prepared for potential applications in energy storage and water treatment.

Synthesis of double-shelled SnO2 nano-polyhedra and their improved gas sensing properties

A new type of non-spherical SnO2 hollow structure with double-shelled and mesoporous shells was prepared via a sacrifice template strategy in the case of SnO2, which shows high response and good selectivity to toluene.

Light-responsive three-dimensional microstructures composed of azobenzene-based palladium complexes

We describe not only fleeting assembly of photoisomerizable azobenzene-based palladium complexes into microstructured crystalline architectures but also their light-responsive functions. A transformation in the crystalline morphology from two-dimensional (2D) parallelogram-like sheets to three-dimensional (3D) cuboid- or rhombus-like structures was achieved by changing the solvent from tetrahydrofuran (THF) to acetone and N,N-dimethylformamide (DMF). The sizes of the structures, ranging from a few hundred nanometers to several hundred micrometers, were also modified by varying the complex concentration. In stark contrast to the very stable 2D sheets in the THF-H2O suspensions, exposure of 3D structures in polar DMF-H2O suspensions to ultraviolet (UV) light led to fast disassembly of the structures into isolated metal complexes and further dissociation of free azobenzene ligands from the complexes. In acetone-H2O suspensions, interestingly, disassembly of 3D cuboid-like structures into isolated complex components occurred upon exposure to UV light without further dissociation of azobenzene ligands from the palladium complexes. Considering the photoisomerization ability of the azobenzene-based palladium complex in common organic solvents, the π-stacking interactions that support 3D structures are likely to be sufficiently weak that they might be broken by the UV-induced trans-to-cis isomerization in more polar solvent mixtures. As a consequence, disassembly proceeded under UV light irradiation. Moreover, the effect of solvent polarity on the UV-assisted dissociation (in DMF-H2O) may be associated with the coordination ability of solvent molecules with the metal center.