Self-assembly Strategy Research Articles

A chitosan-based near-infrared ratiometric fluorescent nanoprobe created by molecular assembly with applications in hypochlorous acid detection in live mouse

Hypochlorous acid (HClO/ClO−) is a key reactive oxidative species (ROS) in the body. The HClO/ClO− concentrations are imbalanced during cancer formation due to the ROS stress response. This paper introduces a novel chitosan-based self-calibration fluorescent nanoprobe (ChCyNil) constructed by molecular assembly for the ratiometric detection of HClO/ClO−. Two chromophores with different fluorescence characteristics and HClO/ClO− sensitivity were labeled on chitosan, and nanoparticles were prepared by a self-assembly strategy for HClO/ClO− detection. ChCyNil exhibits several advantages, such as dual near-infrared emissions at 670 nm and 845 nm, tunable fluorescence intensity, self-calibration fluorescence, and good biocompatibility, improving its accuracy in HClO/ClO− detection. Our study confirmed that ChCyNil exhibits a well-assembled spheroidal nanostructure and good photophysical properties in solution. The fluorescence imaging properties were further proved by detecting endogenous HClO/ClO− produced by LPS/PMA stimuli in cells and zebrafish. In addition, ChCyNil was used to detect the fluorescence behavior of HClO/ClO− in tumors of live mice. The successful design and fabrication of ChCyNil have presented a new strategy for constructing detection tools with improved fluorescence properties for HClO/ClO− in live animals.

Supramolecular-driven construction of multilayered structure by modified hummers method for robust silicon anode

Rational design of nano-structured silicon (Si)-based composites to enhance the structural stability and electrical conductivity is key to developing high-performance lithium-ion batteries. Here, a supramolecular self-assembly strategy is first adopted to prepare Si@rGO composites with multilayered structure through the modified Hummers method. Experimental results demonstrate that Si@SiOx NPs are uniformly distributed in rGO interlayers by supramolecular interaction. In situ Raman results suggest that the multilayer embedded structure can effectively confine the Si NPs and preserve the integrity of the electrode. Theoretical calculations indicate that the imbalanced charge distribution in inner interface shows enhanced dual-interfacial bonding and charge interactions in the Si@SiOx⊂rGO composite, resulting in an interfacial electric-field between Si NPs and rGO for fast ionic and charge migration. The fabricated MSi@SiOx⊂rGO anode with high Si contents (> 60 wt.% Si) exhibits superior Li-ion reaction kinetics (882.4 mAh g−1 at 8 A g−1), durable structural stability (0.031% per cycle capacity attenuation with an average Coulombic efficiency > 99.7%), and low expansion rate. High-mass-loading electrodes show great potential for commercial applications. Full cells assembled with LiCoO2 cathodes also demonstrate outstanding Li-ion storage properties. This work provides insights into the interfacial design of Si@C anodes for advanced Li-ion battery.

Multifunctional 3D pristine graphene with tunable electromagnetic properties via self-assembly strategy

Nowadays, there is an urgent demand for multifunctional materials with tunable properties to meet the requirements of intricate environments with alternating temperatures and electromagnetic conditions. Pristine graphene is a highly promising electromagnetic material owing to its intrinsic advantages. However, issues related to aggregation and weak gelation capability would hinder the fabrication and advancement of multifunctional pristine graphene. Herein, multifunction properties are first integrated into one 3D structured pristine graphene via a self-assembly method. By regulating the microstructures, 3D structured pristine graphene can exhibit a range of electromagnetic properties, including wave transmission (wave transmittance of 88 %-93 %), electromagnetic wave (EMW) absorption (reflection loss of −50.70 dB), and electromagnetic interference (EMI) shielding (shielding effectiveness (SE) of ∼37.90 dB), which are not available in existing graphene materials. Furthermore, the 3D structured pristine graphene exhibits mechanical stability and thermal performances to guarantee a stable and durable electromagnetic response for complex environmental applications. The outstanding multifunction can be attributed to the low defects and controllable microstructures of pristine graphene. This work supplies an inspiration for the development of multifunctional graphene materials as well as the microstructure design of 3D pristine graphene.

Programmable Reconfiguration of Supramolecular Bottlebrush Block Copolymers: From Solution Self-Assembly to Co-Crystallization-Assistant Self-Assembly.

Achieving structural reconfiguration of supramolecular bottlebrush block copolymers toward topological engineering is of particular interest but challenging. Here, we address the creation of supramolecular architectures to discover how assembled topology influences the structured aggregates, combining hydrogen-bonded (H-bonded) bottlebrush block copolymers and electrostatic interaction induced polymer/inorganic eutectics. We first design H-bonding linear-brush block copolymer P(NBDAP-co-NBC)-b-P(NBPEO), bearing linear block P(NBDAP-co-NBC) (poly(norbornene-terminated diaminopyridine-co-norbornene-terminated hexane)) with pendant H-bonding DAP (diaminopyridine) motifs, and PEO (poly(ethylene oxide)) densely grafted P(NBPEO) brush block. Thanks to H-bonding association between DAP and thymine (Thy), incorporation of Thy-functionalized polystyrene (Thy-PS65) enables solution self-assembly and formation of H-bonded bottlebrush block copolymers, generating augmented nanospheres with increasing Thy-PS65 amount. Noteworthy that integration of inorganic cluster silicotungstic acid (STA) to P(NBC-co-NBDAP)-b-P(NBPEO), endows the formation of PEO/STA eutectic core. Therefore, co-crystallization-assistant self-assembly at the interfaces of polymeric, inorganic and supramolecular chemistry is realized, reflecting multi-stage morphology transformation from hexagonal platelets, needle-like, curved rod-like micelles, finally to end-to-end closed rings, by gradually increasing Thy-PS65 while fixing STA content. Interestingly, such solution self-assembly to co-crystallization-assistant self-assembly strategy not only endows unique nanostructure transition, also induce in-to-out reconfiguration of PS domains. These findings clearly provide unique methodology towards programmable fabrication of geometrical objects promising in smart materials.

Biphase TiO2\\Zn-tetracarboxy-phthalocyanine twin S-scheme heterojunction nanowires with efficient charge transfer and CO2 photocatalytic conversion

Constructing heterojunction photocatalysts with proper charge transfer channels has been confirmed to be a promising strategy for CO2 photoreduction into chemical fuels. However, promoting photoinduced charge separation in traditional heterojunction catalysts still remains a big obstacle for practical applications. In this work, the TiO2(B)-Anatase\\ZnTcPc twin S-scheme heterojunctions are designed and constructed by loading Zn (II) tetracarboxy phthalocyanine (ZnTcPc) on the prepared TiO2(B)-Anatase biphase TiO2 nanowires by self-assemble strategy. The TiO2(B)-Anatase\\ZnTcPc twin S-scheme heterojunctions effectively promote charge transport across the multi-heterointerfaces and enhance visible light absorption and CO2 adsorption. Thus the optimized hybrid photocatalyst exhibits a remarkable photocatalytic CO2 reduction performance, and the CO yield reaches 237.8μmol g−1h−1. The CO2 photoreduction mechanism and charge transfer properties in the twin S-scheme heterojunction are also investigated and characterized. This research offers a viable approach to enhancing the heterojunction system for excellent photocatalytic performance.

Room-Temperature Liquid Crystalline Tetraphenylethylene-Surfactant Complex with Chiral Supramolecular Structure and Tunable Circularly Polarized Luminescence.

A novel room-temperature liquid crystal of tetraphenylethylene derivative (TPE-DHAB) was synthesized using an ionic self-assembly strategy. The TPE-DHAB complex exhibits typical aggregation-induced emission properties and a unique helical supramolecular structure. Moreover, the generation and handedness inversion of circularly polarized luminescence (CPL) can be achieved through further chiral solvation, providing a facile approach to fabricate room-temperature liquid crystalline materials with controllable supramolecular structures and tunable CPL properties through a synergistic strategy of ionic self-assembly and chiral solvation process.

Photosynthetic biohybrid systems for solar fuels catalysis.

Photosynthetic reaction center (RC) proteins are finely tuned molecular systems optimized for solar energy conversion. RCs effectively capture and convert sunlight with near unity quantum efficiency utilizing light-induced directional electron transfer through a series of molecular cofactors embedded within the protein core to generate a long-lived charge separated state with a useable electrochemical potential. Of current interest are new strategies that couple RC chemistry to the direct synthesis of energy-rich compounds. This Feature Article highlights recent work from our lab on RC and RC-inspired hybrid systems that capture the Sun's energy and convert it to chemical energy in the form of H2, a carbon-neutral energy source derived from water. Biohybrids made from the Photosystem I (PSI) RC are among the best photocatalytic H2-producing protein hybrids to date. Targeted self-assembly strategies that couple abiotic catalysts to PSI translate to catalyst incorporation at intrinsic PSI sites within thylakoid membranes to achieve complete solar water-splitting systems. RC-inspired biohybrids interface synthetic photosensitizers and molecular catalysts with small proteins to create photocatalytic systems and enable the spectroscopic discernment of the structural features and electron transfer processes that underpin solar-driven proton reduction. In total, these studies showcase the incredible scientific opportunities photosynthetic biohybrid research provides for harnessing the optimal qualities of both artificial and natural photosynthetic systems and developing materials that capture, convert, and store solar energy as a fuel.

3D organic-inorganic hybrid based on Strandberg-type cluster of [(PIIIO3)2Mo5O15]6−: Synthesis, crystal structure and electrochemical properties

The rational design of crystalline materials coupled with polyoxometalate as electrocatalyst is an effective strategy for the sensitive electrochemical detection of H2O2. Here, a new organic-inorganic hybrid, H2(NH4)3[Him][(PIIIO3)2Mo5O15]·4H2O (1) (im=imidazole), was isolated by a one-pot self-assembly strategy. Structural analysis indicates that compound 1 adopts a three-dimensional (3D) supramolecular structure based on the Strandberg-type [(PIIIO3)2Mo5O15]6− clusters linked with protonated [Him]+ cations via hydrogen bond interactions. Electrochemical studies reveal that compound 1 exhibits the multi-electron redox processes ascribed to MoVI centers, and has good electrocatalytic activity in the reduction of H2O2. By utilizing compound 1 as electrode material, the designed electrode showed excellent electrochemical performance towards H2O2 detection, including a wide linear range (50–450 μM), high sensitivity of 0.085 μA·μM−1 and a low detection limit of 3.52 μM, as well as good selectivity and stability.

Hydrogen bond-induced supramolecular self-assembly strategy to fabricate ultra-dispersed Cu-loaded porous tubular graphitic carbon nitride with rich nitrogen vacancies and CuNx sites for efficient photo-Fenton catalysis

The low utilization of visible light and easy recombination of charge carriers of graphitic carbon nitride (CN) restrain its application as photo-electron donor and metal site support in photo-Fenton system. Herein, a hydrogen bond-induced supramolecular self-assembly strategy was created to fabricate an ultra-dispersed Cu-loaded porous tubular CN composite (CA-Cu/TCN) by the hydrothermal–pyrolysis method with citric acid (CA) as initiator and chelating agent. CA-Cu/TCN with rich nitrogen vacancies (NVs) and abundant ultra-dispersed CuNx sites exhibited narrow bandgap, favorable visible light absorption capability, and high separation and transfer efficiency of charge carriers. CA-Cu/TCN effectively catalyzed the activation of H2O2 for generating abundant reactive oxygen species under visible light irradiation, contributing to efficient degradation of ciprofloxacin (CIP) with removal rate of 95.9 % and kinetic rate constant of 0.0948 min−1. The superior catalytic activity of CA-Cu/TCN can be ascribed to the effective transport of photogenerated electrons, high specific surface area, atomically dispersed Cu species, and enriched surface NVs. The mechanism of photo-Fenton catalytic degradation of CIP and possible degradation pathways were proposed as the dominant role of 1O2. Toxicity evaluation of CIP and intermediates indicated that the degradation of CIP was a gradual detoxification process. This work offers a novel self-assembly strategy to design and synthesize highly active and sustainable visible light-driven photo-Fenton catalysts for effectively degrading organic pollutants.

Investigation of the regulatory mechanism of monolayer colloidal crystals prepared by gas-liquid-solid three-phase interfacial self-assembly method

In recent years, the gas-liquid interface self-assembly method has emerged as a recognized and efficient technique for preparing two-dimensional monolayer colloidal crystals. However, challenges such as limited preparation area, dependence on complex equipment, and high costs persist in the conventional preparation process. This paper proposes a straightforward, rapid, and cost-effective method to implement a gas-liquid-solid three-phase interfacial self-assembly strategy. This approach enhances the gas-liquid interfacial self-assembly method, allowing for the preparation of large-area, high-quality single-layer colloidal crystals (>10 cm2) without using any surfactant. The gas-liquid-solid three-phase interfacial self-assembly process was analyzed in detail, and it was found that the main factors affecting the quality of the monolayer colloidal crystals were the volume ratio of PS colloidal solution to ethanol and the self-assembly temperature. It was shown that the optimal self-assembly conditions were achieved after dispersion by ultrasonic dispersion in a water bath at 32 °C–30 °C at a volume ratio of 1:2.5 of PS colloidal solution to ethanol. In addition, particles of various sizes can be prepared by this method to produce tightly arranged monolayer films that can be transferred to a variety of different substrates with great versatility. The demonstrated efficiency of this self-assembly method underscores its significant potential for application in large-scale manufacturing and practical industrialization.

MXene@PBA heterostructures via end-group-directed self-assembly strategy for effective inhibition of shuttle effect in lithium–sulfur batteries

The commercialization of lithium-sulfur batteries (LSBs) has been hindered by the shuttle effect and slow sluggish conversion kinetics. This study developed MXene and Prussian blue analogue (PBA) heterostructures using an end-group-directed self-assembly strategy. MXene@PBA heterostructures were synthesized through layer-by-layer stacking and in situ growth of Mn-PBA, driven by the electrostatic interactions between Mn2+ and the polar terminal groups of MXene. The dual-metal synergistic adsorption of Mn2+ and Fe3+ within PBA framework significantly enhances both the adsorption capacity and cycling stability of the composite. Furthermore, the in-situ growth of PBA not only reinforces the structural integrity but also increases the number of active sites, mitigates the collapse of the accordion-like layered structure, alleviates volume expansion, and accelerates rapid ion diffusion. Theoretical calculations confirm the composite's superior adsorption capacity for Li polysulfides (LiPSs). As a S host, MXene@PBA facilitates the solid-liquid phase transformation of polysulfides, improving reaction kinetics and delivering exceptional electrochemical performance. MXene@PBA composite exhibited an initial discharge capacity of 1220 mAh g−1 at 0.1 C. Its cycle stability is equally remarkable, with a minimal decay rate of 0.062 % per cycle after 500 cycles at 0.5 C. The construction of these layered heterostructures as S hosts presents an effective strategy to mitigate the shuttle effect and enhance the reaction kinetics of LSBs.

Graphene-Wrapped Magnetic Multichamber Ti3C2Tx Spheres for Stable Broadband Microwave Absorption.

Two-dimensional transition metal carbides/nitrides (MXenes) have aroused widespread interest in the field of microwave absorption because of their unique layered structures. However, the inherent aggregation, poor impedance matching, and low chemical stability of MXenes inevitably obstruct their practical applications. Herein, a multichamber Fe3O4/Ti3C2Tx@reduced graphene oxide (FT@RGO) hierarchical structure was constructed through self-assembly and sacrificial template strategies where the Ti3C2Tx nanosheets were assembled into hollow microspheres that were decorated with Fe3O4 nanospheres and wrapped by RGO nanosheets. The massive heterointerfaces and interior cavities favor enhanced microwave absorption performance via interfacial polarization, multiple scattering/reflections, and dielectric-magnetic synergistic effects. Consequently, the synthesized ultralight FT@RGO foam (0.009 g/cm3) presents superior microwave absorption ability with the minimum reflection loss of -50.5 dB at the matching thickness of 2.5 mm and effective absorption bandwidth of 8.0 GHz covering the frequency range of 10.0-18.0 GHz at the thickness of 2 mm. Furthermore, the encapsulation of hollow Ti3C2Tx spheres by RGO nanosheets avoids direct contact with external air, which considerably improves the stability of Ti3C2Tx and ensures the long-term application of FT@RGO foam in a conventional environment. This work provides a reference for the structural design of MXene-based materials as broadband and durable microwave absorbers.

Stereospecific supramolecular polymerization of nanoclusters into ultra-long helical chains and enantiomer separation

During the construction of supramolecular polymers of smaller nanoparticles/nanoclusters bearing hierarchy and homochirality, the mechanism understanding via intuitive visualization and precise cross-scale chirality modulation is still challenging. For this goal, a cooperative self-assembly strategy is here proposed by using ionic complexes with uniform chemical composition comprising polyanionic nanocluster cores and surrounded chiral cationic organic components as monomers for supramolecular polymerization. The single helical polymer chains bearing a core-shell structure at utmost length over 20 μm are demonstrated showing comparable flexibility resembling covalent polymers. A nucleation-elongation growth mechanism that is not dealt with in nanoparticle systems is confirmed to be accompanied by strict chiral self-sorting. A permeable membrane prepared by simple suction of such supramolecular polymers displays high enantioselectivity (e.e. 98% after four runs) for separating histidine derivatives, which discloses a benefiting helical chain structure-induced functionalization for macroscopic supramolecular materials in highly efficient racemate separation.

Confined interfacial self-assembly of graphene-like carbon/MXene composite electrodes for capacitive deionization

Electrodes that have high desalting capacity, fast desalting rates and stable desalination performance are needed in capacitive deionization (CDI) technologies for water security. Herein, confined interfacial self-assembly of lignin-based graphene-like carbon (GC) precursors in Ti3C2-MXene interlayers was developed for forming GC/MXene composites. The formation of GC was generated in-situ by KHCO3-assisted pyrolytic carbonization which leads to exfoliation of multilayered MXene thereby forming GC/MXene heterostructures having strong interfacial interactions. GC/MXene exhibited tremella-like nanosheets morphology, accompanied by the formation of a TiO2 phase at the interface of GC and MXene hybridization, which confirmed formation of a heterostructure. Crystallographic phase identification of GC/MXene showed the exfoliation of MXene. GC/MXene had an ultra-negative surface charge of −39.3 mV, making it favorable for application as a cathode for Na+ removal. The GC/MXene heterostructure had high desalting capacity (54.2 mg g−1), high desalting rate (2.7 mg g−1 min−1), and stable cycling performance (90 % SAC retention after 30 cycles). The interfacial self-assembly strategy developed in this work is expected to enable green synthesis routes for graphene/MXene-based composite materials that allow construction of 2D/2D heterostructures for multilayer MXene and their analogues.

One-Step Self-Assembled WO3/rGO Microspheres Photoanode Assembled Efficient Photocatalytic Fuel Cells for Simultaneous Organic Pollutant Degradation and Electricity Generation.

Photocatalytic fuel cells (PFCs) present a promising and environmentally friendly approach to simultaneously treat organic pollutants in wastewater and electricity generation. The development of photoanodes with high light absorption and carrier mobility is essential for enhancing the performance of PFCs but remains challenging. Herein, a one-step self-assembly strategy was adopted to develop flower-like WO3/rGO microspheres for PFC devices. Attributed to the abundant surface-active sites, enhanced light harvesting, and efficient separation of photogenerated charge carriers, the WO3/rGO photoanode demonstrated superior rhodamine B (RhB) degradation rate (90% in 2 h), maximum power density (4.74 μW/cm2), and maximum photocurrent density (0.096 mA/cm2), 1.4, 2.4, and 4.0 times higher than the corresponding pure WO3 photoanode, respectively. Density functional theory (DFT) calculations reveal that the built-in electric field formed between the interface of WO3 and rGO promotes the transfer of photogenerated electrons from WO3 to rGO, thus exerting a significant impact on improving the migration and separation of photoinduced charge carriers. Moreover, by combining experimental and theoretical results, a complete PFC operation mechanism for the PFC system was proposed. This study focuses on the strategy of constructing rGO-doped photocatalysts to enhance the interfacial charge transfer mechanism, providing a promising approach for the development of high-performance photoanodes in PFC systems.

Functionalization and morphology control of graphene oxide for intelligent barrier coatings against corrosion

Designing intelligent fillers for high-performance corrosion protection coatings, especially for the strong corrosion harsh environment of desulfurized flue gas, remains a huge challenge. In this paper, a novel graphene-based intelligent nanofiller with tunable morphology was successfully synthesized via a self-assembly strategy. Using polydopamine (PDA) as gatekeeper, the mesoporous silica nanocontainer (MSNs) was loaded with the corrosion inhibitor benzotriazole (BTA), preparing the pH response MSNs-BTA/PDA (PBM) nanocontainers. Graphene oxide (GO) was modified by PBM through non-covalent interactions including hydrogen bond and π-π stacking. A self-unfolding GO/PBM (GO@PBM-5) was obtained through adjusting the ratio of GO to PBM. The active/passive corrosion protection properties of the novolac epoxy coating (EPN) are endowed by the GO@PBM-5 intelligent nanofiller with a self-unfolding structure, which can be ascribed to the corrosion inhibition and labyrinth effect. As a result, the value of |Z|0.01Hz of coating reinforced with GO@PBM-5(GO@PBM-5/EPN) remained above 1010 Ω cm2 after immersion in 10 wt% H2SO4 solution at 55 °C for 60 days. The thermal conductivity of GO@PBM-5/EPN is 0.312 W m−1 K−1. In addition, no cracking occurred after 400 cycles of −60–140 °C cold-thermal shock. Moreover, the GO@PBM-5/EPN is intact and no rust spots, bubbles, or peeling occur after the salt spray test for 14 days. Showing extremely strong barrier performance as well as thermal conductivity, cold-thermal shock resistance and high self-healing properties. This study opens a new avenue for improving the service life of organic coating in the strong corrosion environment of desulfurized flue gas.

Modular Customized Biomimetic Nanofluidic Diode for Tunable Asymmetric Ion Transport.

Artificial ion diodes, inspired by biological ion channels, have made significant contributions to the fields of physics, chemistry, and biology. However, constructing asymmetric sub-nanofluidic membranes that simultaneously meet the requirements of easy fabrication, high ion transport efficiency, and tunable ion transport remains a challenge. Here, a direct and flexible in situ staged host-guest self-assembly strategy is employed to fabricate ion diode membranes capable of achieving zonal regulation. Coupling the interfacial polymerization process with a host-guest assembly strategy, it is possible to easily manipulate the type, order, thickness, and charge density of each module by introducing two oppositely charged modules in stages. This method enables the tuning of ion transport behavior over a wide range salinity, as well as responsive to varying pH levels. To verify the potential of controllable diode membranes for application, two ion diode membranes with different ion selectivity and high charge density are coupled in a reverse electrodialysis device. This resulted in an output power density of 63.7W m-2 at 50-fold NaCl concentration gradient, which is 12 times higher than commercial standards. This approach shows potential for expanding the variety of materials that are appropriate for microelectronic power generation devices, desalination, and biosensing.

Synergistic Coordination in Cu Single-Atom Catalysts Enhances High-Valent Copper-Oxo Species for Efficient PMS Activation.

In the domain of heterogeneous catalytic activation of peroxymonosulfate (PMS), high-valent metal-oxo (HVMO) species are widely recognized as potent oxidants for the abatement of organic pollutants. However, the generation selectivity and efficiency of HVMO are often constrained by stringent requirements for catalyst adsorption sites and electron transfer efficiency. In this study, a single-atom catalyst, CuSA/CNP&S, is synthesized featuring multiple types (planar/axial) of heteroatom coordination via an H-bond-assisted self-assembly strategy. It isconfirmed that CuN3 active centers with axial S coordination are uniformly distributed in a carbon matrix modified by planar P atoms. CuSA/CNP&S activated PMS to selectively generate Cu(III)═OH species as the primary reactive oxygen species (ROS). The pseudo-first-order kinetic rate for bisphenol A degradation reached 1.51min-1, a 17.57-fold increase compared to the unmodified CuSA/CN catalyst. Additionally, the CuSA/CNP&S catalyst demonstrates high efficiency and durability in removing contaminants from various aqueous matrices. Theoretical calculations and experimental results indicate that the intrinsic electric field generated by distal planar P atoms enhances electron transfer efficiency within the carbon matrix. Meanwhile, axial S coordination elevates the d-band center and tunes the eg * band broadening of Cu, thereby enhancing the adsorption selectivity for the terminal oxygen of PMS. This multitype coordination synergistically mitigates the issues of low selectivity and yield of HVMO species.

A polyelectrolyte-induced highly processable pigment-like photonic crystal ink

Developing a straightforward strategy for constructing highly processable photonic crystals (PCs) is crucial for various applications, yet remains a challenge. Here, we present a simple polyelectrolyte-induced self-assembly strategy for producing novel photonic crystal (PC) inks with outstanding processing flexibility by adding the polyelectrolytes into the ultralow concentration of colloidal nanoparticle solution. The polyelectrolyte can cover the nanoparticles through the hydrogen bond interaction to induce the aggregation and mutual repulsion of them simultaneously, enabling the self-assembly of ultralow concentration (0.01–1.0 v/v%) of nanoparticles into short-range ordered arrays with angle-independent structural colors. The resulting PC inks present unprecedented pigment-like color modulation capacity, as well as ultrahigh freedom in processing methods due to the fact that the rheological behaviors of PC inks can be widely adjusted by varying the properties of polyelectrolytes. Consequently, the PC inks can be easily shaped into complex and exquisite multicolor patterns/3D structures using various techniques, including injection molding, writing, drawing, and 3D printing. This general approach paves the way for quick and scalable production of advanced PC materials deeply required in practical applications.

Construction of Molecularly Dispersed Polyoxometalate-Alumina Hybrid Hollow Nanoflowers via Water-Induced Kirkendall Effect.

Hybrid nanomaterials with controllable structures and diverting components have attracted significant interest in the functional materials field. Here, we develop a solvent evaporation-induced self-assembly (EISA) strategy to synthesize nanosheet-assembled phosphomolybdic acid (H3PMo)-alumina hybrid hollow spheres. The resulting nanoflowers display a high surface area (up to 697 m2 g-1), adjustable diameter, high chemical/thermal stability, and especially molecularly dispersed H3PMo species. By employing various microscopic and spectroscopic techniques, the formation mechanism is elucidated, revealing the simultaneous control of the morphology by heteropoly acids and water through the water-induced Kirkendall effect. The versatility of the synthesis method is demonstrated by varying surfactants, heteropoly acids, and metal oxide precursors for the facile synthesis of hybrid metal oxides. Spherical hybrid alumina serves as an attractive support material for constructing metal-acid bifunctional catalysts owing to its advantageous surface area, acidity, and mesoporous microenvironment. Pt-loaded hollow flowers exhibit excellent catalytic performance and exceptional stability in the hydrodeoxygenation of vanillin with recyclability for up to 10 cycles. This research presents an innovative strategy for the controllable synthesis of hybrid metal oxide nanospheres and hollow nanoflowers, providing a multifunctional platform for diverse applications.