Anisotropic colloidal particles have attracted great attention over the past few decades because of their significant properties that differ from isotropic particles. Molecular self-assembly provides the possibility to design and construct anisotropic colloidal particles from the single-molecule level, and molecular assemblies can both inherit the properties of molecules in single states and integrate the functions of molecules in collective states, which has attracted great interest to researchers. This review article briefly summarizes the research progress of molecules from small molecules, block copolymers and homopolymers to anisotropic particles, including their self-assembly strategies and applications. Finally, the remaining challenges of this topic and future developments in this field have been discussed. More information can be found in the Review by Bing Liu et al.

Novel water-soluble nanocomposite based on hydrophobic tetraphenylporphyrin molecules and hydrophilic ternary AgInS₂/ZnS quantum dots incorporated into a chitosan matrix was fabricated for applications in antibacterial photodynamic therapy. The enhanced singlet oxygen generation by the formed nanocomposites can be observed due to the efficient resonance energy transfer from ternary quantum dots to tetraphenylporphyrin molecules.

Abstract

Antibacterial photodynamic therapy (a-PDT) has emerged as a promising non-invasive therapeutic modality that utilizes the combination of a photosensitive agent, molecular oxygen, and excitation light to generate reactive oxygen species (ROS), demonstrating remarkable activity against multidrug-resistant bacterial infections. However, the effective use of conventional photosensitizers is significantly limited by a number of their shortcomings, namely, poor water solubility and low selectivity. Herein, we present a novel biocompatible water-soluble nanocomposite based on hydrophobic tetraphenylporphyrin (TPP) molecules and hydrophilic ternary AgInS₂/ZnS quantum dots incorporated into a chitosan matrix as an improved photosensitizer for a-PDT. We demonstrated that TPP molecules could be successfully transferred into chitosan solution while remaining primarily in the form of monomers, which are capable of singlet oxygen generation. We performed a detailed analysis of the Förster resonance energy transfer (FRET) between quantum dots and TPP molecules within the nanocomposite and proposed the mechanism of the singlet oxygen efficiency enhancement via FRET.

Molecular self-assembly becomes an attractive strategy for the preparation of anisotropic colloidal particles that inherit the properties of molecules in single states and the new functions resulting from the coupling between molecules. This article reviews the recent progress towards molecular self-assembly of anisotropic colloids, focusing on molecular self-assembly strategies and their applications.

Abstract

Anisotropic colloidal particles have attracted great attention over the past few decades because of their significant properties that differ from isotropic particles. Molecular self-assembly provides the possibility to design and construct anisotropic colloidal particles from the single-molecule level, and molecular assemblies can both inherit the properties of molecules in single states and integrate the functions of molecules in collective states, which has attracted great interest to researchers. Even in recent years, the self-assembly strategy of anisotropic colloidal particles has been greatly developed. This review article briefly summarizes the research progress of molecules from small molecules, block copolymers and homopolymers to anisotropic particles, including their self-assembly strategies and applications. Finally, we discuss the remaining challenges of this topic and we expect that by manipulating the design of diverse molecules/polymers, anisotropic colloidal particles can evolve into a new era.

A self-assemble N-doped graphene and N-doped carbon nanoparticles integrated composite has been prepared by a multi-step acid etching plus annealing method. The formation of N-doped graphene is likely based on a “decomposition and recrystallization” mechanism without the use of any metallic catalyst. The as-prepared integrated composite exhibits efficient catalytic activity for four-electron oxygen reduction reaction.

Abstract

N-doped carbon-based materials have been regarded as promising alternatives to Pt-based electrocatalysts for the four-electron (4e⁻) oxygen reduction reaction (ORR), which is an important electrochemical reaction for the polymer electrolyte fuel cells. Here, we report a N-doped graphene and N-doped carbon nanoparticles integrated composite electrocatalyst by a multi-step acid etching plus annealing method. Despite the low N-doping level, the material exhibits efficient 4e⁻ ORR activity with an onset potential of 0.932 V, a half-wave potential of 0.814 V, and a limiting current density of 5.3 mA cm⁻² in 0.1 M KOH solution. We demonstrate that the promoted 4e⁻ ORR activity is attributed to the special 2D–0D integrated structure for exposing massive active sites, the favorable porous structure facilitating the H₂O transfer dynamics, and the high content of oxygen-containing C−O−C species and the increased intrinsic carbon defects for additional active sites. A “decomposition and recrystallization” mechanism is proposed for the formation of N-doped graphene.

The reaction between gold(III) chloride and sodium di-isopropyldithiocarbamate produces two compounds. Sub-micron sized gold microcrystals are produced when the complexes are thermally decomposed in the solid-state. The morphology of the resultant gold microcrystals is determined by the choice of complex.

Abstract

Elemental gold was formed by thermolysis of gold(III) dithiocarbamate single-source precursors, which exist as two complexes. The complexes were readily synthesised from the reaction between chloroauric acid and sodium di-isopropyldithiocarbamate and could be isolated from each other. The thermal decomposition processes were evaluated using thermogravimetry and electrical resistance measurements. The structure and purity of the resultant gold was examined using scanning electron microscopy. The resultant gold materials were drastically different and dependent on the thermolysed complex.

A heterogeneous recyclable nanobiohybrid catalyst was developed by combining palladium nanoparticles and α-amylase enzyme. Further, the developed catalyst was employed to catalyze the one-pot chemoenzymatic synthesis of functionalized biphenyls and bis(indolyl)methanes.

Abstract

A chemoenzymatic approach that combines chemical and bio-catalyst has proven very useful in synthetic chemistry, however, mutual deactivation of chemical and bio-catalyst when employed in the same pot is still a challenge. In this context, the development of nanobiohybrid catalysts has played an important role and overcoming the issue of mutual deactivation between catalysts to a certain extent. Herein, we design and synthesize a novel heterogeneous recyclable nanobiohybrid catalyst comprising palladium nanoparticles and α-amylase from Aspergillus oryzae immobilized onto halloysite nanotubes as a solid heterogeneous support. Further, the wider applicability of the developed nanobiohybrid catalyst is revealed in the one-pot chemoenzymatic synthesis of functionalized biphenyls and bis(indolyl)methanes which consists of Pd-catalyzed Suzuki-Miyaura coupling and α-amylase mediated aza-Michael addition or electrophilic substitution reactions respectively. Further, the robustness and generality of the developed one-pot chemoenzymatic synthesis are demonstrated by incorporating different substitutions at the starting materials and obtaining the corresponding products in moderate to good yields.

Monodispersed NiCo₂S₄ nanoparticles are grown in-situ on nickel foam by a one-step colloidal synthetic route, and they deliver a high specific capacitance of 1790.8 F/g at 1 A/g via a three-electrode system and also maintain outstanding energy-storage capacity, high energy density and stability in a two-electrode cell. This study provides a feasible way to design and fabricate electrodes effectively.

Abstract

One-step colloidal synthetic route was adopted to in-situ grow monodispersed NiCo₂S₄ nanoparticles (NPs) on nickel foam (NF) from metallic salts with benzyl disulfide in the media of oleylamine and octadecene. Owing to the favorable dispersion and considerable redox activity of NiCo₂S₄ along with tight and binder-free connection with NF, the obtained battery-type supercapacitor delivered a specific capacitance of 1790.8 F g⁻¹ at 1 A g⁻¹ via a three-electrode system. Simultaneously, it just degraded 40 % at 20 A g⁻¹ and maintained 86.8 % of initial specific capacitance (C₀) after 2000 cyclic trials at 10 A g⁻¹. When the NiCo₂S₄ NPs were assembled with active carbon (AC) forming an asymmetric capacitor device of NiCo₂S₄ NPs//AC, it delivered an energy density (E) of 48.7 W h kg⁻¹ at a power density (P) of 161.1 W kg⁻¹, and kept 21.9 W h kg⁻¹ at a high P of 8.05 kW kg⁻¹. Meanwhile, the capacitor manifested preeminent cycling life (C=94.5 % C₀ after 5000 cyclic trials) at 5 A g⁻¹. The in-situ grown NiCo₂S₄ NPs on NF without any binder exhibited high performance in energy storage, providing a feasible way to improve the electrochemical performance of the electrode materials.

We synthesized a novel p-n heterojunction with rose-like morphology self-assembled from 2D-Co₃O₄ and Bi₂WO₆ nanosheets with highly exposed {010} facets, named Bi₂WO₆/Co₃O₄ composite. It was considered that the composite served as a traditional heterojunction under ultraviolet light, while it played a role as a Z-scheme photocatalyst under visible light, respectively.

Abstract

A composite of two or more materials usually results in enhanced specific properties. In this paper, a kind of composite material composed of Bi₂WO₆ with highly exposed {010} facets and 2D-Co₃O₄ was prepared by a one-pot reaction and then applied to decontaminate hydrocortisone in wastewater. The Bi₂WO₆/Co₃O₄ composite possessed a rose-like surface microtopography self-assembled from Bi₂WO₆ and Co₃O₄ nanosheets. The micro-interface analysis showed that {110} facets of Co₃O₄ and {010} facets of Bi₂WO₆ were glued in situ and formed heterojunction. Additionally, the removal ability of hydrocortisone through Bi₂WO₆/Co₃O₄ varied under different light sources, which was 85.0 % under ultraviolet light and 97.3 % under visible light within 60 min. It was considered that Bi₂WO₆/Co₃O₄ was similar to a traditional heterojunction and the major reactive species was H₂O₂ under ultraviolet light, while it played a role as a Z-scheme photocatalyst and the major reactive species was ⋅OH under visible light. Finally, product analysis of hydrocortisone demonstrated that the dexter chain broke whatever under ultraviolet or visible light, but the breakage of parent nucleus appeared only under visible light. This research revealed the enhanced catalytic properties of p-n heterojunction catalysts and indicated the specifically exposed facets are promising for organic contaminants in water.

The morphology of micelles in surfactant-free emulsion was regulated by adjusting the oil-water ratio and concentration of amphiphilic copolymer. Subsequently, polymer micelles served as templates to direct the assembly of ZIF-8 crystals in the surfactant-free emulsion to fabricate polymer/ZIF-8 composite materials (ZIF-8@CSP) with various structures.

Abstract

An amphiphilic chitosan-g-poly N-(3-dimethylaminopropyl) methacrylamide (CS-g-PDMAPMA, CSP) was proposed and synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT), and further employed as emulsifier to construct a surfactant-free emulsion. The morphology of micelles in surfactant-free emulsion was regulated by adjusting the oil-water ratio and concentration of amphiphilic copolymer. Subsequently, polymer micelles served as templates to direct the assembly of ZIF-8 crystals in the surfactant-free emulsion to fabricate polymer/ZIF-8 composite materials (ZIF-8@CSP) with various structures. Specifically, ZIF-8@CSP with various architectures such as spheres, rods, cubes, leaf-shaped flakes, cross-flowers and wrinkled cubes were obtained by varying the concentration of CSP, the addition sequence of ZIF-8 precursors and the ratio of oil-water.

A promising adsorbent of Quaternary amine based materials is synthesized for CO₂ air capture, and the effect of humidity, temperature and micropore on CO₂ adsorption kinetics is analyzed. The adsorbents with microporous structure showed much higher adsorption kinetics than that with macroporous structure, and the highest kinetics performance of CO₂ adsorption ever reported is obtained.

Abstract

Quaternary amine(QA)-functionalized adsorbents using moisture swing method are demonstrated to have vast application prospect in capturing CO₂ from the ambient air. However, the poor kinetic performance and limited sorbents remain a great challenge. In this work, the porous resins were screened and membrane with controllable porous structure was designed for CO₂ air capture, and the effects of the varieties of QA-based resins and external environmental conditions (humidity and temperature) on CO₂ adsorption performance were quantitatively investigated. The results show that the kinetic performance of porous resins are far superior to the existing QA-based direct air capture(DAC) materials, and the half-time of D290 type membrane is only 102 s, much less than that of gelatinous resin, which is about 2400 s. The effect of microporous structure on CO₂ adsorption rate increases with the increase of humidity, while only slightly effect was found on macroporous adsorbents. The research results can provide basic data for the application of CO₂ capture in different occasions.