Versatile synthesis of uniform mesoporous superparticles from stable monomicelle units.

Superstructures with architectural complexity and unique functionalities are promising for a variety of practical applications in many fields, including mechanics, sensing, photonics, catalysis, drug delivery and energy storage/conversion. In the past five years, a number of attempts have been made to build superparticles based on amphiphilic polymeric micelle units, but most have failed owing to their inherent poor stability. Determining how to stabilize micelles and control their superassembly is critical to obtaining the desired mesoporous superparticles.

Micelle-directed self-assembly of single-crystal-like mesoporous stoichiometric oxides for high-performance lithium storage.

Due to their uncontrollable assembly and crystallization process, the synthesis of mesoporous metal oxide single crystals remains a formidable challenge. Herein, we report the synthesis of single-crystal-like mesoporous LiTiSiO by using soft micelles as templates. The key lies in the atomic-scale self-assembly and step-crystallization processes, which ensure the formation of single-crystal-like mesoporous LiTiSiO microparticles via an oriented attachment growth mechanism under the confinement of an formed carbon matrix.

Surface Stretching Enables Highly Disordered Graphitic Domains for Ultrahigh Rate Sodium Storage.

Hard carbons (HCs) with high sloping capacity are considered as the leading candidate anode for sodium-ion batteries (SIBs); nevertheless, achieving basically complete slope-dominated behavior with high rate capability is still a big challenge. Herein, the synthesis of mesoporous carbon nanospheres with highly disordered graphitic domains and MoC nanodots modification via a surface stretching strategy is reported. The MoO surface coordination layer inhibits the graphitization process at high temperature, thus creating short and wide graphite domains.

Chiral Skeletons of Mesoporous Silica Nanospheres to Mitigate Alzheimer's β-Amyloid Aggregation.

Chiral mesoporous silica (mSiO) nanomaterials have gained significant attention during the past two decades. Most of them show a topologically characteristic helix; however, little attention has been paid to the molecular-scale chirality of mSiO frameworks. Herein, we report a chiral amide-gel-directed synthesis strategy for the fabrication of chiral mSiO nanospheres with molecular-scale-like chirality in the silicate skeletons.

Modular super-assembly of hierarchical superstructures from monomicelle building blocks.

Manipulating the super-assembly of polymeric building blocks still remains a great challenge due to their thermodynamic instability. Here, we report on a type of three-dimensional hierarchical core-satellite SiO@monomicelle spherical superstructures via a previously unexplored monomicelle interfacial super-assembly route. Notably, in this superstructure, an ultrathin single layer of monomicelle subunits (~18 nm) appears in a typically hexagon-like regular discontinuous distribution (adjacent micelle distance of ~30 nm) on solid spherical interfaces (SiO), which is difficult to achieve by conventional super-assembled methods.

Unusual Mesoporous Titanium Niobium Oxides Realizing Sodium-Ion Batteries Operated at -40 °C.

Sodium-ion batteries (SIBs) are a promising candidate for grid-scale energy storage, however, the sluggish ion-diffusion kinetics brought by the large radius of Na seriously limits the performance of SIBs, let alone at low temperatures. Herein, a confined acid-base pair self-assembly strategy to synthesize unusual Ti Nb O @C for high-performance SIBs operating at room and low temperatures is proposed. The confinement self-assembly of the acid-base pair around the micelles and confined crystallization by the carbon layer realize the formation of ordered and stoichiometric mesoporous frameworks with opened ion channels.

Inorganic-organic competitive coating strategy derived uniform hollow gradient-structured ferroferric oxide-carbon nanospheres for ultra-fast and long-term lithium-ion battery.

The gradient-structure is ideal nanostructure for conversion-type anodes with drastic volume change. Here, we demonstrate an inorganic-organic competitive coating strategy for constructing gradient-structured ferroferric oxide-carbon nanospheres, in which the deposition of ferroferric oxide nanoparticles and polymerization of carbonaceous species are competitive and well controlled by the reaction thermodynamics. The synthesized gradient-structure with a uniform size of ~420 nm consists of the ferroferric oxide nanoparticles (4-8 nm) in carbon matrix, which are aggregated into the inner layer (~15 nm) with high-to-low component distribution from inside to out, and an amorphous carbon layer (~20 nm).

General Synthesis of Ultrafine Monodispersed Hybrid Nanoparticles from Highly Stable Monomicelles.

Ultrafine nanoparticles with organic-inorganic hybridization have essential roles in myriad applications. Over the past three decades, although various efforts on the formation of organic or inorganic ultrasmall nanoparticles have been made, ultrafine organic-inorganic hybrid nanoparticles have scarcely been achieved. Herein, a family of ultrasmall hybrid nanoparticles with a monodisperse, uniform size is synthesized by a facile thermo-kinetics-mediated copolymer monomicelle approach.

Precisely Controlled Vertical Alignment in Mesostructured Carbon Thin Films for Efficient Electrochemical Sensing.

Two-dimensional carbon materials, incorporating a large mesoporosity, are attracting considerable research interest in various fields such as catalysis, electrochemistry, and energy-related technologies owing to their integrated functionalities. However, their potential applications, which require favorable mass transport within mesopore channels, are constrained by the undesirable and finite mesostructural configurations due to the immense synthetic difficulties. Herein, we demonstrate an oriented monomicelle assembly strategy, for the facile fabrication of highly ordered mesoporous carbon thin films with vertically aligned and permeable mesopore channels.

Surface-Confined Winding Assembly of Mesoporous Nanorods.

Bending and folding are important stereoscopic geometry parameters of one-dimensional (1D) nanomaterials, yet the precise control of them has remained a great challenge. Herein, a surface-confined winding assembly strategy is demonstrated to regulate the stereoscopic architecture of uniform 1D mesoporous SiO (mSiO) nanorods. Based on this brand-new strategy, the 1D mSiO nanorods can wind on the surface of 3D premade nanoparticles (sphere, cube, hexagon disk, spindle, rod, etc.

Sequential Chemistry Toward Core-Shell Structured Metal Sulfides as Stable and Highly Efficient Visible-Light Photocatalysts.

A universal sequential synthesis strategy in aqueous solution is presented for highly uniform core-shell structured photocatalysts, which consist of a metal sulfide light absorber core and a metal sulfide co-catalyst shell. We show that the sequential chemistry can drive the formation of unique core-shell structures controlled by the constant of solubility product of metal sulfides. A variety of metal sulfide core-shell structures have been demonstrated, including CdS@CoS , CdS@MnS , CdS@NiS , CdS@ZnS , CuS@CdS, and more complexed CdS@ZnS @CoS .

Versatile Nanoemulsion Assembly Approach to Synthesize Functional Mesoporous Carbon Nanospheres with Tunable Pore Sizes and Architectures.

Functional mesoporous carbons have attracted significant scientific and technological interest owning to their fascinating and excellent properties. However, controlled synthesis of functional mesoporous carbons with large tunable pore sizes, small particle size, well-designed functionalities, and uniform morphology is still a great challenge. Herein, we report a versatile nanoemulsion assembly approach to prepare N-doped mesoporous carbon nanospheres with high uniformity and large tunable pore sizes (5-37 nm).

A facile self-template strategy for synthesizing 1D porous Ni@C nanorods towards efficient microwave absorption.

Ni@C composites, which simultaneously possess porous, core-shell and 1D nanostructures have been synthesized with a facile self-template strategy. The precursors were obtained by a hydrothermal process using NiCl · 6HO and nitrilotriacetic acid as the starting material and then annealed at 400 °C, 500 °C, and 600 °C. The Ni@C composites annealed at 500 °C display a nanorod feature with a length of ∼3 μm and diameter of 230-500 nm.

Thermal conversion of an Fe₃O₄@metal-organic framework: a new method for an efficient Fe-Co/nanoporous carbon microwave absorbing material.

A novel FeCo nanoparticle embedded nanoporous carbon composite (Fe-Co/NPC) was synthesized via in situ carbonization of dehydro-ascorbic acid (DHAA) coated Fe3O4 nanoparticles encapsulated in a metal-organic framework (zeolitic imidazolate framework-67, ZIF-67). The molar ratio of Fe/Co significantly depends on the encapsulated content of Fe3O4 in ZIF-67. The composites filled with 50 wt% of the Fe-Co/NPC-2.

Enhancement photocatalytic activity of the graphite-like C₃N₄ coated hollow pencil-like ZnO.

The pencil-like ZnO hollow tubes with 9-12 μm in length, 350-700 nm in width, 200 nm in wall thickness coating with g-C3N4 have been prepared via a chemical deposition process. As compared with uncoated ZnO or g-C3N4, these g-C3N4/ZnO composites showed the enhanced photocatalytic activity which can be attributed to the heterojunction structure. Furthermore, it is worth pointing out that the weight ratios of g-C3N4 to ZnO (g-C3N4/ZnO) played a significantly influence on the photodegradable properties.

The role of Sn in enhancing the visible-light photocatalytic activity of hollow hierarchical microspheres of the Bi/BiOBr heterojunction.

Hollow hierarchical microspheres of Bi/BiOBr (SBB) with oxygen vacancies were prepared using a one step solvothermal method. It was found that the stannous chloride dihydrate played key roles in the formation of Bi, defects and the stacking mode of hierarchical construction units. Positron annihilation lifetime spectroscopy (PALS) was used to demonstrate the oxygen vacancies in Bi/BiOBr samples.