Hybrid Janus Research Articles

Superhydrophobic FeNi3/Al2O3 multifunctional hybrid Janus particles for the catalytic degradation of azo dye, oil/water separation and microplastics removal

Emerging pollutants are causing global health and environmental challenges, necessitating the advancement of methodologies for their efficient removal. In this study, we present the efficacy of superhydrophobic FeNi3/Al2O3 Janus particles in the removal of oils and microplastics from water, combined with the degradation of azo dyes, leveraging their surface properties. Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray Spectroscopy (EDS) revealed the morphology and elemental composition of these particles, which were further complemented by X-ray diffraction (XRD) for phase identification. After surface functionalization of the FeNi3/Al2O3 Janus particles with lauric acid, they exhibited superhydrophobicity (152 ± 1°) and superoleophilicity (0°). High-resolution X-ray photoelectron spectroscopy (HR-XPS) showed that the alumina face was modified with lauric acid, while the intermetallic face remained as FeNi3. Significantly, the alumina face demonstrated 99 % efficiency in separating oils and microplastics, while the FeNi3 face facilitated the complete degradation (100 %) of methyl red within three minutes, as shown by ultraviolet-visible spectrophotometry. These results highlight the multifunctional properties of superhydrophobic FeNi3/Al2O3 Janus particles in removing and degrading various pollutants.

An intriguing way to synthesize a TiO2–ZnO hybrid nanostructure for the pragmatic application as a photocatalyst

In an attempt to counter the problem of treating wastewater more efficiently, we report the study on photocatalytic properties of metal oxide nanostructures under different light sources. A novel sonication-assisted refluxing method was employed to synthesize a binary heterostructure consisting of TiO2 and ZnO. XRD and EDS analysis of synthesized materials confirm the presence of both TiO2 and ZnO. Also, the change in the intensity of XRD peaks and elemental composition are well observed with a change in molar concentration of Ti and Zn. HR-TEM micrographs show nanostructures having hybrid Janus and Core-shell type structures. The XPS spectra were probed to identify the surface chemical species associated with the prepared heterostructures. Raman spectra confirm the smaller ZnO particles attached over agglomerated TiO2 as a shell layer as depicted in TEM results. Optical studies exhibit the modification in the band structure of the materials due to the formation of the heterostructure. The synthesized hybrid catalyst shows impressive results in photocatalytic performance. The catalytic potency of the prepared heterostructures under UV light is reminiscent of Anatase while it gets convalescent with an increment of Zn content under visible light. The photocatalytic performance of synthesized materials under sunlight shows their potential to be utilized as commercial catalysts for direct application in wastewater treatment. The kinetic study of the degradation data reveals interesting facets of the catalysis. It suggests that the photo-corrosion of the catalyst inordinately changes the rate of photocatalytic reaction which ultimately affects the photocatalytic efficiency of the catalyst. The study also discusses the role of kinetic and validation parameters in the selection of the best-fitted kinetic model with realistic arguments.

Effects of structural parameters on radial crashworthiness of 3D braided hybrid tubes with Janus structure

Hybrid fiber reinforced plastic (HFRP) composites have been widely used in various fields, but delamination is a fatal damage mode in laminated hybrid tubes. In the current paper, carbon fibers/Kevlar fibers hybrid tubes with Janus structure were fabricated by three-dimensional (3D) tubular braiding technique. The radial crushing performances of 3D braided Janus hybrid tubes were analyzed while hybrid layer ratio and yarn type were both considered. With the increase of hybrid layer ratio from 1:3 to 2:2 to 3:1, the specific energy absorption (SEA) increased 149 % and 21.39 % for specimens with carbon fibers placed on the skin region, and that decreased 12.46 % and 10.66 % for samples with Kevlar fibers arranged on the skin region. Furthermore, samples with Kevlar fibers arranged on the skin region presented excellent radial crashworthiness. The current work could be helpful for the design, fabrication and application of HFRP tubes.

Thermoresponsive Janus hybrid hydrogel for efficient solar steam generation

Solar-driven interfacial evaporation technology stands out as a promising solution for sustainable freshwater production. To achieve sustained and efficient water evaporation, it is crucial to carefully modulate the distribution of water content within the solar evaporator. In this study, a novel light-temperature responsive composite hydrogel-based solar evaporator was successful constructed. This involved the incorporation of a hydrophilic backbone (polyacrylamide) and a highly efficient solar absorber (multi-walled carbon nanotubes) into a temperature-sensitive hydrogel polymer backbone (poly (N, N-diethylacrylamide)). Due to its low critical solution temperature, the evaporator can undergo a hydrophilic/hydrophobic phase transition alternating day and night conditions. In natural sunlight, the upper hydrogel evaporation region is rendered hydrophobic, minimizing heat loss and preventing salt crystallization. Simultaneously, the bottom water delivery region is hydrophilic to ensure sufficient water supply. At night, the evaporator absorbs water and dissolves, thereby facilitating the rapid return of highly concentrated brine. Leveraging the spontaneously formed Janus structure, the photo-hydrothermal hydrogel achieves an impressive evaporation rate of 2.74 kg m−2 h−1 and exhibits excellent salt resistance. The notable water evaporation performance and robust salt resistance provide exciting possibilities for achieving ultrafast solar water purification.

Enzymatic dual-faced Janus structures based on the hierarchical organic-inorganic hybrid matrix for an effective bioremoval and detoxification of reactive blue-19

A novel, dual-faced, and hierarchical type of Janus hybrid structures (JHSs) was assembled through an in situ growing of lipase@cobalt phosphate sheets on the laccase@copper phosphate sponge-like structures. The chemical and structural information of prepared JHSs was investigated by Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction analysis (XRD). The catalytic activity, storage stability, and reusability of JHSs were then investigated. The SEM-EDX analysis clearly confirmed the asymmetric morphology of the fabricated JHSs with two distinct metal distributions. Under optimized synthesis conditions, the prepared JHSs showed 97.8 % and 100 % of laccase and lipase activity, respectively. Compared to the free biocatalysts, the immobilization resulted in ~ a 2-fold increase in laccase and lipase stability at temperatures of >40 °C. The fabricated JHSs maintained 61 % and 90 % of their original laccase and lipase activity upon 12 successive repetition cycles. Up to 80 % of Reactive Blue-19 (RB-19), an anthraquinone-based vinyl sulphone dye, was removed after 5 h treatment with the prepared JHSs (50 % higher than the free forms of laccase and lipase). The dye removal data fitted very well on the pseudo-second-order kinetic model with a rate constant of 0.8 g mg−1 h−1. Following the bioremoval process, bacterial toxicity also decreased by about 70 %. Therefore, the prepared JHSs provide a facile and sustainable approach for the decolorization, biotransformation, and detoxification of RB-19 by integrating enzymatic oxidation and hydrolysis.

Spin polarization and magnetostriction properties in superperiodic Janus twisted bilayer graphenes

The atomic and electronic structure of superperiodic vertical hybrid Janus heterostructures based on doped twisted bilayer graphenes were theoretically developed and studied using electronic structure calculations. Regularly opposed superperiodic sublattices of fluorine and aluminum adatoms were used to induce structural charge polarization, and uncompensated spin moments up to 1.05 µB per unit cell, caused by local intense transverse electric fields generated by ferromagnetically aligned spin polarization of entire lattices. It was shown that spin polarization of the heterostructures is mostly determined by partial carbon and fluorine electronic states localized in the vicinity of the Fermi level, whereas superlattices of Al adatoms mostly determine the rate of charge polarization, the symmetry, and intensity of the internal transverse electric field up to −0.018 e2/Å. It was shown that proposed heterostructures may display advanced electronic spin, entanglement and magnetostriction properties perspective for various spin- and quantum-related applications.

A Magnetically and Electrically Powered Hybrid Micromotor in Conductive Solutions: Synergistic Propulsion Effects and Label‐Free Cargo Transport and Sensing (Adv. Sci. 8/2023)

Hybrid Micromotor In article number 2204931 by Gilad Yossifon and co-workers, a hybrid Janus particle micromotor for label-free manipulation of biological cargos in conductive near-physiological solutions is investigated. Combining rotating magnetic fields and alternating current electric fields results in synergistic propulsion and steering effects, improved cargo transport, and the sensing of cell's apoptotic state. This hybrid micromotor-based approach opens new opportunities in single cell analysis.

Synthesis of functionalized janus hybrid nanosheets for one-step construction of pickering emulsion and selective photodegradation of water-soluble dyes

Recently, Pickering emulsions stabilized by photocatalytic nanomaterials have become a hotspot in the field of catalysis due to their high interfacial activity. However, since most photocatalytic nanomaterials are extremely hydrophilic, using them as stabilizers is unconvenient for Pickering emulsions construction. Herein, a novel magnetic Janus nanosheets (JMPSN/α-FeOOH) with Janus SiO2 nanosheets as the carrier and iron oxyhydroxide (α-FeOOH) as the catalyst species, respectively, was successfully fabricated through a simple synthetic strategy, which could act as an environmental-friendly Pickering emulsion emulsifier and catalyst simultaneously. We demonstrated that JMPSN/α-FeOOH exhibited good emulsifying properties of various oil phases. Morever, JMPSN/α-FeOOH in the formed Pickering emulsion-based photocatalytic system displayed significantly enhanced photocatalytic efficiency in degradation of dyes as compared to traditional non-emulsified systems while maintaining the stability of Pickering emulsion under constant irradiation. JMPSN/α-FeOOH could also quickly respond to external magnetic fields so as to achieve rapid recovery of catalyst, and catalyst still showed high catalytic activity after many catalytic cycles. Finally, a convenient and promising synthesis strategy for preparing Janus catalyst with low toxicity was proposed, which provided a guidance on how to effectively use the emulsion system stabilized by Janus catalyst to improve the degradation efficiency of various pollutants.

A Janus Au-Polymersome Heterostructure with Near-Field Enhancement Effect for Implant-Associated Infection Phototherapy.

Polymer-inorganic hybrid Janus nanoparticles (PI-JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI-JNPs remains challenging. Herein, the construction of a novel Janus Au-porphyrin polymersome (J-AuPPS) heterostructure by a facile one-step photocatalytic synthesis is reported. The near-field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J-AuPPS is achieved to enhance its near-infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improves the energy transfer and energetic charge-carrier generation. Therefore, J-AuPPS shows a higher NIR-activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non-Janus core-particle Au-PPS nanostructure (28.4%). As a result, J-AuPPS exhibits excellent dual-mode (photothermal/photodynamic) antibacterial and anti-biofilm performance, thereby significantly enhancingthe in vivo therapeutic effect in an implant-associated-infection rat model. This work is believed to motivate the rational design of advanced hybrid JNPs with desirable NFE effect and further extend their biological applications.

Interfacial stabilizing and reinforcing effects of silsesquioxane-based hybrid Janus molecules in extrusion supercritical CO2 foaming of polypropylene

High-melt-strength (HMS) polypropylene (PP) has enabled easy supercritical-CO2 (scCO2) foaming of PP. However, producing microcellular PP foams via simple scCO2 extrusion foaming still remains challenging, whereas macrocellular PP foams with high expansion ratios (ER) generally exhibit poor mechanical strengths. In this study, to simultaneously enhance both ER and compressive strengths of macrocellular PP foams, a type of low-cost Janus molecules, heptaisobutyl open-cage silsesquioxane (HOS), is incorporated into HMS-PP. Since HOS has PP-philic groups and a partially condensed silsesquioxane cage that is relatively CO2-philic, it could diffuse like a surfactant to the PP-CO2 interface during scCO2 extrusion foaming to stabilise the cells in their growth stage and reinforce the cell surface upon solidification. The surfactant effect is validated via X-ray Photoelectron Spectroscopy. Moreover, with 1 wt% HOS, the PP/HOS foam could offer 38 % ER improvement, 23 % density reduction, and 20 % compressive strength increase over the neat PP foam. HOS could also slightly improve the extensional viscosity and melt strength of PP at ≤1 wt% loadings and reduce the shear viscosity of PP by acting as a lubricant. This approach provides a simple and economically viable materials design guideline for alleviating ER-compression strength trade-offs for macrocellular polymer foams.

Anion-Directed Synthesis of Core–Shell and Janus Hybrid Nanostructures

Hybrid nanoparticles show considerable promise with potential applications ranging across catalysis (including photocatalysis), energy conversion, and storage. A generalized synthetic procedure for hybrid nanoparticles is presented. The method offers the flexibility to drive the products toward different hybrid nanostructure morphologies merely via a change in the metal anion, under otherwise identical experimental conditions. Both Ag@CZTS (CZTS = Cu2ZnSnS4) core–shell nanoparticles and Ag2S-CZTS Janus nanoparticles, along with PbS and Au/AuAg hybrid analogues, are synthesized using this methodology, highlighting its versatility and translatability across different materials. The nucleation of the semiconductor is the critical determining step for the synthesis of a given hybrid product. Insight into the mechanism of growth for these two morphologies paves the way for the rational and generalized synthesis of hybrid nanoparticles.

Comfort fitting shape memory elastomer with constructed strong interface based on amphiphilic hybrid Janus particles

Comfort fitting shape memory elastomer exhibits various potential application in flexible wearable and biomedical devices, which can be developed by mixing the comfort fitting elastomer with the materials of reversible transition. However, it's very difficult to obtain the soft touching feeling, high elongation, and excellent shape memory property at the same time, and the key point mainly depends on improving interface stability and adjusting the morphology by the compatibilizer . In the work, silicone elastomer with excellent shape memory property was obtained by developing an amphiphilic PCL-JP-PDMS hybrid Janus particles compatibilizer for methyl vinyl silicone elastomer/polycaprolactone (MVQ/PCL) blend. Only through increasing the PDMS grafting ratio on the PCL-JP-PDMS particles compatibilizer, the morphology of PCL dispersed phase changed from short fibrous to similar spherical, which ensured the comfort feeling (E = 5.9 MPa), high fixity (R f = 95%) and recovery ratio (R r = 99%) of shape memory MVQ/PCL blends. Furthermore, the shape memory silicone elastomer exhibited impressive elasticity in temporary shape at T = 25 °C, which is quite suitable for designing wearable device. Silicone elastomer with excellent shape memory property was obtained by developing an amphiphilic PCL-JP-PDMS hybrid Janus particles compatibilizer for MVQ/PCL blend, the amphiphilic PCL-JP-PDMS Janus particles were anchored at the interface of MVQ/PCL blends by the similar molecular chain entanglement and the stable conformation of asymmetric SiO 2 @PDVB particles. Much more importantly, the PCL-JP-PDMS particles with different PDMS grafting ratio were prepared as the compatibilizer, which made the interface adhesion and the property of MVQ/PCL blend be regulated by PDMS grafting ratio, which ensured the comfort feeling (E = 5.9 MPa), high fixity (R f = 95%) and recovery ratio (R r = 99%) of shape memory MVQ/PCL blends under the content of 3 wt % particles and 30 wt % PCL. Furthermore, the shape memory silicone elastomer exhibited impressive elasticity in temporary shape at T = 25 °C, which is quite suitable for designing wearable device.

Hybrid Janus Nanotubes with Tunable Internal Pore Size Disassembled from Mesoporous Block Copolymer-based Hybrid Scaffolds

Hybrid Janus Nanotubes with Tunable Internal Pore Size Disassembled from Mesoporous Block Copolymer-based Hybrid Scaffolds

Hybrid Janus Membrane with Dual-Asymmetry Integration of Wettability and Conductivity for Ultra-Low-Volume Sweat Sensing.

Highly sensitive and selective analysis of sweat at ultra-low sample volume remains a major challenge in the field of biosensing. Manipulation of small volumes of liquid for efficient sampling is essential to address this challenge. A hybrid Janus membrane with dual-asymmetry integration of wettability and conductivity is developed for regulated micro-volume liquid transport in wearable sweat biosensing. Unlike the uncontrollable liquid diffusion in a conventional porous membrane, the asymmetric wettability of porous Janus membrane leads to unique unidirectional liquid transport with high breakthrough pressure (1737.66 Pa) and fast self-pumping rate (35.94 μL/min) for micro-volume liquid sampling. The asymmetric conductive layer shows excellent flexible conductivity, anti-interference of friction, and efficient electrochemical interface due to the in situ generation of gold nanoparticles on one side of the membrane. The fabricated Pt-enzyme electrodes on the membrane promises effective testing range, great selectivity, and high sensitivity and accuracy (correlation efficiency, glucose: R2 = 0.999, lactate: R2 = 0.997), enabling ultra-low volume (∼0.15 μL) real time measurements on the skin surface. The innovative Janus membrane with unidirectional, self-pumping, and anti-interference performance provides a new strategy for miniaturized wearable microfluidic sweat electrochemical biosensor preparation in athletic performance evaluation, health monitoring, disease diagnosis, intelligent medicine, and so forth.

High Interfacial-Energy and Lithiophilic Janus Interphase Enables Stable Lithium Metal Anodes.

The stability of solid electrolyte interphase (SEI) layers is critical for developing lithium (Li) metal batteries. However, the fabrication of stable SEI layers is plagued by un-controlled structures, properties, and functions. Here a controllable design of an ordered LiF-rich and lithiophilic hybrid Janus interphase (LiF-HJI) is reported using organic fluorination reagent as a functional SEI precursor. The LiF-HJI with a lower crystalline LiF layer and an upper Li organosulfide layer provides high interfacial energy with the Li metal and strong Li-ion affinity, allows homogenous Li-ion distribution, fast and uniform Li-ion transport, and excellent mechanical and passivation properties, enabling stable Li metal anodes under harsh conditions, such as high deposition capacities (6mAhcm-2 ), current densities (10mAcm-2 ), and rates (5 C). Stable LiF-HJI@Li greatly improves cycling stability and capacity retention (80.1% after 300 cycles) of Li||LiNi0.8 Co0.1 Mn0.1 O2 cells at a commercial-level areal capacity (≈4.2mAhcm-2 ). Even under a lean-electrolyte condition of 3gAh-1 , 80% capacity retention can be maintained after 100 cycles, demonstrating excellent cycling performance under such harsh conditions.

Janus hybrid sustainable all-cellulose nanofiber sponge for oil-water separation

Two-faced characteristics and performance of materials driven by asymmetric physical or chemical properties exist in Janus hybrid materials which show synergistic and improved properties for a variety of applications. Here, we report a facile synthesis of Janus hybrid sustainable cellulose nanofibers (CNFs) sponge with asymmetric wettability and strong mechanical property for excellent separation efficiency of oil-water emulsions. Briefly, the CNF Janus hybrid sponge was fabricated by freeze-drying of two separate CNF suspensions into one, each prepared separately by introducing CNFs in methyltrimethoxysilane (MTMS) or 3-glycidoxypropyltrimethoxysilane (GPTMS) for hydrophobic or hydrophilic performance, respectively. The sponge demonstrated satisfactory mechanical stability with an excellent recovery from 80% compressive strain and high pore tortuosity. When employed for oil-water separation, the Janus hybrid sponge could selectively be used to collect water or oil by just switching its side facing the oil-water mixture feed via unidirectional gravity-assisted separation, with recyclability. The fabrication of such Janus hybrid sponge is one of the many approaches for utilizing nanofibers in structurally adaptive, self-supported asymmetric membrane structures in a 3D network.

Fabrication of self-healing nanocomposite hydrogels with the cellulose nanocrystals-based Janus hybrid nanomaterials

Janus nanomaterials possess remarkable prospects in the design of a series of smart materials with unique asymmetric properties. In this work, surface functionalized Janus cellulose nanocrystalline-type (CNCs-type) nanomaterials were manufactured by Pickering emulsion template and the construction of self-healing nanocomposite hydrogels has been realized. During emulsification, the mussel-inspired chemistry was employed to develop Janus nanocomposites. The extension of molecular chain of poly-lysine (PLL) and the polydopamine (PDA) coating were grafted on different sides of CNCs. Afterwards, the prepared nanocomposites were added to poly (acrylic acid) (PAA)-based hydrogels which formed by in-situ polymerization. The collaborative effect of metal-ligand coordination between the molecular chain of PLL, PDA coating, PAA chains and metal ions endowed the nanocomposite hydrogels with excellent mechanical properties (8.8 MPa) and self-healing efficiency (88.9%). Therefore, the synthesized Janus CNCs-PDA/PLL nanocomposites are expected to have diverse application in the development of smart materials with self-healing ability.

Symmetry‐Broken Au–Cu Heterostructures and their Tandem Catalysis Process in Electrochemical CO2 Reduction

AbstractSymmetry‐breaking synthesis of colloidal nanocrystals with desired structures and properties has aroused widespread interest in various fields, but the lack of robust synthetic protocols and the complex growth kinetics limit their practical applications. Herein, a general strategy is developed to synthesize the Au–Cu Janus nanocrystals (JNCs) through the site‐selective growth of Cu nanodomains on Au nanocrystals, which is directed by the substantial lattice mismatch between them, with the assistance of judicious manipulation of the growth kinetics. This strategy can work on Au nanocrystals with different architectures for the achievement of diverse asymmetric Au–Cu hybrid nanostructures. Of particular note, the obtained Au nanobipyramids (Au NBPs)‐based JNCs facilitate the conversion of CO2 to C2 hydrocarbon production during electrocatalysis, with the Faradaic efficiency and maximum partial current density being 4.1‐fold and 6.4‐fold higher than those of their monometallic Cu counterparts, respectively. The excellent electrocatalytic performances benefit from the special design of the Au–Cu Janus architectures and their tandem catalysis mechanism as well as the high‐index facets on Au nanocrystals. This research provides a new approach to synthesize various hybrid Janus nanostructures, facilitating the study of structure‐function relationship in the catalytic process and the rational design of efficient heterogeneous electrocatalysts.

Bioinspired Hydrophilic-Hydrophobic Janus Composites for Highly Efficient Solar Steam Generation.

Solar energy has received extensive attention as a renewable and sufficient energy source. Herein, inspired by the Janus wettability of lotus leaves, we have constructed a bioinspired hydrophilic-hydrophobic Janus hybrid system of carbonized carrot powder (CC powder)-modified cotton cloth with Nafion coating on one side (cotton cloth-NCC) for highly efficient solar steam generation. In cotton cloth-NCC, CC powder functions as a light absorber to achieve high light absorption, whereas the hydrophilic cotton cloth ensures efficient water transport. Meanwhile, the coating of Nafion establishes a hydrophobic-hydrophilic Janus structure, which can not only modulate water supply but also prevent salt deposition even with the high-concentration salt solution. The cotton cloth-NCC has been further shaped into a waved structure (w-cotton cloth-NCC) to increase the water evaporation area and achieve high light absorption (95%). Under 1 sun irradiation, w-cotton cloth-NCC yields a pure water steam generation rate of 1.88 kg m-2 h-1 and a seawater evaporation rate of 1.52 kg m-2 h-1. Furthermore, the w-cotton cloth-NCC also has a good purification effect on sewage: Escherichia coli can be completely removed, and the removal rate of Rhodamine B reaches 98.3%. The simple approach presented here for the construction of a high-efficient, low-cost, environmentally sustainable, long-term stable hydrophobic-hydrophilic Janus solar steam evaporator holds great promise for application in both environmental purification and photothermal conversion.

Multifunctional fabrics finished using electrosprayed hybrid Janus particles containing nanocatalysts

There is great market demand for fabrics equipped with multiple functionalities. However, most methods to impart these properties to a pristine fabric are complicated, time-consuming, and expensive. In this work, Janus particles with one side comprising TiO2 nanoparticles (NPs)-PVDF (poly (vinylidene fluoride)) and the other an epoxy resin (TPE) were deposited on a fabric surface. The aim was to endow the fabric with the superhydrophobic, UV resistance, and antimicrobial properties. The Janus particles were firmly attached to the fabrics through the adhesion effects of the epoxy resin. Characterization by XRD, SEM, EDX, and FTIR verified the successful finishing of the fabric with TPE particles. The ultraviolet protection factor increased from 7.86 for the pristine fabric to 733 after finishing. The finished fabric also exhibited superhydrophobic properties, with a water contact angle of 152°. Further, the coating of the fabric did not hamper its gas permeability. Potent antibacterial properties against E. coli were observed owing to the antibacterial properties of TiO2 under pre-irradiation by UV light. The protocols reported here provide a new platform for the nano-finishing of fabrics, allowing new functions to be imparted without compromising.