Janus Nanosheets Research Articles

Low-carbon and high-efficiency nanosheet-enhanced CO2 huff-n-puff (HnP) for heavy oil recovery

CO2 huff-n-puff (CO2-HnP) process is a promising technique for enhanced heavy oil recovery. The huff stage of this process involves the formation of foamy oil flow, characterized by dispersed CO2 bubbles within heavy oil, which plays a pivotal role in both oil recovery and CO2 sequestration. Maintaining the stability of foamy oil is crucial for the efficient implementation of CO2-HnP processes. Herein, ultrathin plate-shaped nanosheets are employed as stabilizers for foamy oil. Carboxyl-alkyl composite Janus nanosheets (SANs) are synthesized using a bottom-up approach. Comprehensive characterizations illustrate that SANs, owing to their amphiphilic and Janus nature, efficiently adsorb at the CO2-oil interface, thereby modifying interfacial properties and enhancing foamy oil stability even at low concentration (0.005 wt%). The incorporation of SANs extends the duration of foamy oil effect, resulting in a substantial enhancement of oil recovery efficiency from 30.7% to 39.4%, and an increase in CO2 storage factor from 6.5% to 7.8%, compared to conventional CO2-HnP processes. Micromodel experiments and molecular dynamics simulations show that SANs strengthen foamy oil stability by increasing interfacial activity and reducing CO2 diffusion rate. Overall, the multifunctional capabilities of SANs in interfacial modification offer promising prospects for enhanced oil recovery and optimizing CCUS efficiency.

Mitochondrial dynamics and energy metabolism interference therapy for promoting photothermal sensitization

Photothermal therapy (PTT) is minimally invasive, precisely controlled, and therapeutically effective treatment method. However, its efficacy is limited by the overexpression of heat shock proteins (HSP), which leads to cellular thermal blockade. Targeting mitochondria with PTT can enhance anticancer efficacy, as mitochondria encode genes related to HSP and provide energy for their production. Nevertheless, mitochondrial dynamics confer resistance to damage from external stimuli. Therefore, disrupting the balance of mitochondrial dynamics is essential to impede HSP production. Herein, we synthesized degradable Cu3BiS3 (CBS) nanosheets (NSs) with one face modified by carboxylated triphenylphosphonium (TPP) to target mitochondria. This modification increases the production of exogenous reactive oxygen species (ROS) and induces the overexpression of dynamin-related protein 1 (Drp1), disrupting mitochondrial dynamic homeostasis. The other face was modified with carboxylated β-cyclodextrin (CD) to load the glycolysis inhibitor (2-deoxyglucose, 2DG), thereby reducing adenosine triphosphate (ATP) production in the extra-mitochondrial space, as glycolysis also occurs in the cytoplasm. The resulting TPP-CBS-2DG Janus NSs (JNSs) not only disrupt mitochondrial energy production, leading to cell starvation, but also inhibit HSP production. Consequently, TPP-CBS-2DG JNSs can enhance tumor thermal sensitivity in PTT, improving its efficacy. This work holds great promise for overcoming tumor heat resistance in PTT and provides a feasible method for fabricating selectively modified multifunctional NSs.

Emulsion properties and plugging performances of active crude oil enhanced by amphiphilic Janus nanosheets

Inadequate strength and stability of active crude oil emulsions stabilized by conventional surfactants always lead to a limited plugging rate of plugging agents. Thus, to address this issue, the synthesis of amphiphilic Janus nanosheets was effectively carried out for enhancing the system performances and subsequently characterized. Based on the outcomes of orthogonal tests, an assessment was conducted on the nanosheet and surfactant formulations to optimize the enhancement of emulsion properties. The experimental demonstration of the complex system has revealed its remarkable emulsifying capability, ability to decrease interfacial tension and improve rheological behavior at high temperature (80 °C) and high salinity (35,000 ppm) conditions. Involving probable mechanism of the system performance enhancement is elucidated by considering the synergistic effect between surfactants and nanosheets. Furthermore, variables including water-to-oil ratio, salinity, temperature and stirring intensity during operation, which affect the properties of prepared emulsions, were investigated in detail. The efficacy and stability of the complex system in obstructing medium and high permeability cores were demonstrated. Notably, the core with a high permeability of 913.58 mD exhibited a plugging rate of 98.55%. This study establishes the foundations of medium and high permeability reservoirs plugging with novel active crude oil plugging agents in severe environments.

Silica Janus nanosheets anchored with Ni nanoparticles for in-situ upgrading and stimulus-responsive demulsification to enhance heavy oil recovery

The enhancement of heavy oil recovery and the promotion of oil-water separation are crucial aspects of fossil fuel resource development. In this study, silica Janus nanosheets were prepared and anchored with Ni nanoparticles for in-situ upgrading and stimulus-responsive demulsification of heavy oil. The results of aquathermolysis reactions revealed that Ni/Ph-SiO2-Ni/P4VP Janus nanosheets exhibited excellent characteristics in reducing heavy oil viscosity by 98.49 %, and 99.52 % with the addition of a hydrogen donor. FT-IR, 1H NMR and GC, etc. analysis of the oil samples indicated that Ni/Ph-SiO2-Ni/P4VP breaks the C-S bond and reduces the content of the resin, asphaltene, polycyclic aromatics, and long chain alkanes in the oil. Moreover, it can stabilize heavy oil emulsions in an acidic medium (pH = 2) and separate oil and water in a neutral medium (pH = 7) due to its stimulus-responsive performance. This work highlights the potential application of Ni/Ph-SiO2-Ni/P4VP Janus nanosheets for the in situ upgrading and stimulus-responsive demulsification of heavy oil.

Janus and Amphiphilic MoS2 2D Sheets for Surface-Directed Orientational Assemblies toward Ex Vivo Dual Substrate Release.

The two-dimensional (2-D) Janus and amphiphilic molybdenum disulfide (MoS2) nanosheet with opposite optical activities on each side (amphichiral) is synthesized by modifying sandwich-like bulk MoS2 with tannic acid and cholesterol through biphasic emulsion method. This new type of amphichiral Janus MoS2 nanosheet consists of a hydrophilic and positive optical activity tannic acid side as well as a hydrophobic and negative optical activity cholesterol side thereby characterized by circular dichroism. Surface-directed orientational differentiation assemblies are performed for the as-synthesized 2D material and are characterized by contact angle, infrared spectroscopy, X-ray photoelectron, and circular dichroism spectroscopies. The amphiphilic nature of the materials is demonstrated by the pre-organization of the nanosheets on either hydrophobic or hydrophilic surfaces, providing unprecedented properties of circular dichroism signal enhancement and wettability. Selective detachment of the surface organic groups (cholesterol and tannic acid fragments) is realized by matrix-assisted laser desorption/ionisation - time-of-flight(MALDI-TOF) mass spectrometry, and the dual substrate release in tissue is detected by ex vivo mass spectrometry imaging.

Free‐Standing Janus Nanosheets: Ultrafast Self‐Assembly and Versatile Biphase‐Application

AbstractThe development of stable Janus architectures suitable for biphasic applications holds significant importance. A novel approach is introduced for interfacial supramolecular self‐assembly, resulting in 2D Janus nanosheets (OA‐TA/Fe) exhibiting an amphiphilic nature. These nanosheets consist of hydrophilic coordination complexes of ferric ions (Fe3+) and tannic acid (TA) on one side of both surfaces and hydrophobic alkyl chains on the other side of both surfaces. The synthesis of these 2D Janus nanosheets involves a simple, ultrafast, and environmentally benign process, eliminating the need for time‐consuming multistep procedures and harsh synthetic conditions typically associated with Janus architecture formation. By exploiting the inherent singular anisotropic wettability inherent in OA‐TA/Fe‐2, the efficacy of these innovative Janus nanosheets in the efficient separation of various organic liquid‐in‐water and water‐in‐organic liquid emulsions is elucidated. Subsequent post‐modification of OA‐TA/Fe has facilitated the highly efficient remediation of contaminated oily wastewater, serving as a model biphasic catalysis reaction, wherein the Janus nanosheets function simultaneously as emulsifiers and catalysts within biphasic mixtures. The methodology establishes a rapid self‐assembly approach for the creation of amphiphilic free‐standing Janus nanosheets, offering compelling prospects for their application in diverse fields, as exemplified by, but not limited to, the case studies presented herein.

Synergistic dispersion and biodegradation of oil in seawater based on Janus nanosheets and oil-degrading bacteria

Janus nanosheets synergistically interact with oil-degrading bacteria for marine oil spill remediation.

Improving the Fracture Toughness and Strength of Epoxy Resin Using NH2‐silica‐C8H17 Janus Nanosheets

AbstractIn this work, a NH2‐silica‐C8H17 Janus nanosheet with short n‐octyl chains on one side and aminopropyl groups on the opposite side was prepared by the sol‐gel method. This nanosheet was used to improve the toughness and strength of epoxy resin. The morphologies and structures of Janus nanosheets and the properties of NH2‐silica‐C8H17/epoxy nanocomposites were characterized. Results show that the addition of Janus nanosheets not only increases the storage modulus and glass transition temperature of nanocomposites, but also improves their mechanical performance and thermal stability. The tensile strength, elongation at break, fracture toughness and impact strength of nanocomposites are increased by ca. 57, 80, 74 and 63 %, respectively, at the 0.5 wt.% loading of Janus nanosheets. These findings suggest that NH2‐silica‐C8H17 Janus nanosheets exert an effective influence on the toughness and strength of ultimate nanocomposites, which is attributed to the fact that NH2‐silica‐C8H17 Janus nanosheet simultaneously contains n‐octyl and aminopropyl groups on both sides, thus improving the nanosheet/matrix interface adhesion.

Preparation of amphiphilic Janus nanosheets based on thermally expandable microspheres and evaluation of their physical and chemical properties

Janus nanosheets can reduce the interfacial tension of oil and water and are of great significance for improving the recovery efficiency of remaining oil. A novel strategy for preparing amphiphilic Janus nanosheets is presented in this paper. Trialkoxysilane is adsorbed on the surface of thermally expandable microspheres (TEMS), and Janus spheres (TEMS@SiO2) are obtained by sol-gel treatment. Dodecyltrimethoxysilane (DTES) is used to modify TEMS@SiO2, which is combined with the thermal expansion of TEMS and the breaking of the outer shell of Janus spheres to prepare amino/alkyl composite silicon-based amphiphilic Janus nanosheets (ASAJN). Characterization of ASAJN is carried out via FTIR, TG, SEM, TEM, and contact angle tester, with the results showing that ASAJN boasts amphiphilicity and two-sidedness, and a sheet structure with a thickness of 210 nm. The stability, wettability evaluation, emulsification properties, and interface properties of ASAJN nanofluids have been evaluated, with the results showing that ASAJN nanofluids boast good stability without delamination after 30 days. ASAJN nanofluid can convert oil-wet core slices into water-wettable ones. ASAJN nanofluid manifests excellent emulsification, with the 240-hour emulsification index of ASAJN nanofluid and silica fluid respectively at0.40 and 0.021 under ultra-low concentration (1000 mg/L). ASAJN is obviously able to reduce oil–water interfacial tension. At 1000 mg/L (60 ℃) concentration, the oil-water interfacial tension is reduced to 2.6 mN/m, while that of nano-silica at the same concentration is 15.1 mN/m. ASAJN flooding can significantly improve the recovery efficiency of low-permeability reservoirs, increasing the recovery efficiency by 32.8 % at a permeability of 7.5 × 10-3 μm2.

Thermo-Switchable Pickering Emulsion Stabilized by Smart Janus Nanosheets for Controllable Interfacial Catalysis

Thermo-Switchable Pickering Emulsion Stabilized by Smart Janus Nanosheets for Controllable Interfacial Catalysis

Anisotropic dispersion promoting and passivation protecting of CA@JNs@Zn2+ Janus nanosheets on epoxy anticorrosive coatings

Defects in the curing process of epoxy coatings tend to deteriorate the anticorrosion performance of the coatings. An important way to enhance the anticorrosion performance of epoxy coatings is to add flaky fillers. In this paper, anisotropic Janus nanosheets (JNs) were prepared and modified by cardanol (CA) and Zn2+. Then, the obtained CA@JNs@Zn2+ Janus composite nanosheets were introduced into epoxy coatings. When the content of CA@JNs@Zn2+ is 0.2 %, the mechanical properties and corrosion resistance of the coating were effectively improved. The tensile strength of 0.2 %-CA@JNs@Zn2+/EP coating is 79 % higher than that of pure epoxy coating. The EIS analysis showed that the low-frequency impedance of the coating remained as high as 16.45 Gohm·cm2 after 35 days of immersion, and remained above 10 Gohm·cm2 during the whole immersion period, which demonstrating the optimal corrosion resistance. This paper provides a theoretical basis for the preliminary application of Janus material in the field of anticorrosion, and the prepared composite coatings are expected to be used for anticorrosion in harsh environment.

Effect of Janus Nanosheets in Polypropylene on Rheological Properties and Autoclave Foam Performance.

Our experiment revealed that the addition of Janus nanosheets to polypropylene (PP) has a significant impact on the viscoelasticity of the composite system. Specifically, when 0.10 wt% of Janus nanosheets were added, the complex viscosity of the composite system increased. However, when we added less than 0.05 wt% of Janus nanosheets, there was a reduction in complex viscosity, which is known as the non-Einstein phenomenon. The Cole-Cole plot showed that the nanosheet network structure did not have a significant effect on the viscosity of the composite system. Additionally, we used carbon dioxide as a foaming agent to autoclave foaming using modified PP from Janus nanosheets, and the results demonstrated that increasing the number of Janus nanosheets decreased the apparent density and strengthened the cell structure of foaming beads, resulting in improved closed porosity.

Barrier and passivation effects of 2D PANI@JNSs Janus nanosheets in epoxy anticorrosion coating

AbstractThe filled sheet‐like inorganic materials can usually improve the anticorrosion performance of the coating. Herein, the Janus nanosheets (JNSs) with two‐dimensional structure were prepared by phase separation method, modified by polyaniline (PANI) on the amino side of JNSs and composited with epoxy resin (EP). Scanning electron microscope (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FT‐IR), thermogravimetry (TG) were used to characterize the morphology and chemical structure of JNSs and PANI@JNSs. The anti‐corrosion performance of coatings was measured by electrochemical impedance spectroscopy (EIS) and salt spray experiment. Compared with pure EP, the |Z|0.01Hz of 0.5%‐JNSs/EP coating and that of 0.5%‐PANI@JNSs/EP coating reached 5.6 × 108 and 5.4× 1010 Ω·cm2 after immersed for 35 days, nearly 2 and 4 orders of magnitude higher than pure EP respectively. The excellent anti‐corrosion performance of 0.5%‐PANI@JNSs/EP coating is due to the synergistic effect of physical barrier effect of PANI@JNSs, interfacial interaction between PANI@JNSs and epoxy resin and passivation effect of PANI. Moreover, PANI@JNSs possess both strengthening and toughening effects on composite coating. Janus nanosheets provide a new idea and method for preparing high‐performance anticorrosive materials.

Enhanced catalytic degradation performance of azo dyes based on Janus emulsification

Amphiphilic Janus nanosheets with an asymmetric structure of non-polar phenyl side and polar ionic liquid side (1-Butyl-3-methylimidazolium chloride, [BMIM]Cl), denoted as Janus-[BMIM]Cl, were prepared and used as a carrier to achieve the integration of catalyst and emulsifier. Catalytic heteropolyanions (e.g., [PW12O40]3-, [PMo12O40]3- or [SiW12O40]4-) were selectively decorated on the polar side induced by anion-exchange of [BMIM]Cl moieties, Janus catalysts (Janus-[BMIM][heteropolyanions]) were assembled and utilized as an open degradation platform for azo dyes such as methyl orange (MO). Morphology, structure, and properties were characterized by SEM, FT-IR, XPS, UV–Vis, Zeta potential, etc. The inbuilt amphipathy of Janus nanosheets endowed the decolorization process of dyes to perform in the emulsified system. The extremely increased interface coupled with the effective dispersion of catalysts at the interface synergistically improved the catalytic degradation performance. Compared with the decolorization catalyzed in a conventional immiscible system, the removal efficiency of MO achieved in the Janus emulsion greatly improved from 78.6 to 98.2% within 3 h. Besides, the Janus emulsion could be demulsified easily by centrifugation, and the degradation efficiency was still maintained at 93.7% after five cycles. These results provide valuable information for exploring and enriching the applications of Janus functional materials.

Nanofluids of Amphiphilic Kaolinite-Based Janus Nanosheets for Enhanced Oil Recovery: The Importance of Stable Emulsion.

To meet the increasing global demand for energy, better recovery of crude oil from reservoirs must be achieved using methods that are economical and environmentally benign. Here, we have developed a nanofluid of amphiphilic clay-based Janus nanosheets via a facile and scalable method that provides potential to enhance oil recovery. With the aid of dimethyl sulfoxide (DMSO) intercalation and ultrasonication, kaolinite was exfoliated into nanosheets (KaolNS) before being grafted with 3-methacryloxypropyl-triemethoxysilane (KH570) on the Alumina Octahedral Sheet at 40 and 70 °C to form amphiphilic Janus nanosheets (i.e., KaolKH@40 and KaolKH@70). The amphiphilicity and Janus nature of the KaolKH nanosheets have been well demonstrated, with distinct wettability obtained on two sides of the nanosheets, and the KaolKH@70 was more amphiphilic than the KaolKH@40. Upon preparing Pickering emulsion in a hydrophilic glass tube, the KaolKH@40 preferentially stabilized emulsions, while the KaolNS and KaolKH@70 tended to form an observable and high-strength elastic planar interfacial film at the oil-water interface as well as films climbing along the tube's surface, which were supposed to be the result of emulsion instability and the strong adherence of Janus nanosheets towards tube's surface. Subsequently, the KaolKH was grafted with poly(N-Isopropylacrylamide) (PNIPAAm), and the prepared thermo-responsive Janus nanosheets demonstrated a reversible transformation between stable emulsion and the observable interfacial films. Finally, when the samples were subjected to core flooding tests, the nanofluid containing 0.01 wt% KaolKH@40 that formed stable emulsions showed an enhanced oil recovery (EOR) rate of 22.37%, outperforming the other nanofluids that formed observable films (an EOR rate ~13%), showcasing the superiority of Pickering emulsions from interfacial films. This work demonstrates that KH-570-modified amphiphilic clay-based Janus nanosheets have the potential to be used to improve oil recovery, especially when it is able to form stable Pickering emulsions.

Versatile Pickering Emulsions Stabilized by Polyphenolic 2D Janus Nanosheets Enhance Foliar Deposition of Agrochemicals

Pesticide emulsion, as an important agrochemical formulation, usually suffers from poor stability, weak foliar deposition, and pollution caused by too much dosage of conventional surfactants. Herein, we propose an effective strategy to solve these issues via designing a green and functional surfactant, 2D Janus nanosheets (JNSs), based on adhesive catecholamine compounds to stabilize a pesticide-loaded Pickering emulsion. First, amphipathic 2D octadecylamine–polypyrogallol JNSs (ODA–PPG JNSs) are prepared by a facile and one-step route and are applied to construct a versatile Pickering emulsion. The JNSs-stabilized Pickering emulsions present a remarkable tolerance stability toward ultra-pH (pH = 3, 11) and can achieve an unusual phase inversion accompanying the variation of emulsion viscoelasticity. Owing to the outstanding adhesivity and surfactivity endowed by ODA–PPG JNSs, the pesticide emulsion loaded with a model pesticide avermectin (Av-Emul) performs significantly enhanced foliar deposition than the commercial Av-Tech. Combined with the theoretical calculation, the adhesion mechanism involved in the synergistic action of π–π stacking and H-bonds is unraveled in a molecular scale. The “JNSs-stabilized pesticide emulsions” not only present excellent adhesion on both the hydrophilic and hydrophobic surfaces but also outperform the other conventional pesticide emulsions stabilized by small-molecule surfactants in wettability and spreadability to reduce droplets bouncing on the foliage. This work provides an insight into the structure–adhesivity relationship derived from the non-covalent interaction of polyphenolic JNSs. The proposed innovative strategy for facilitating pesticide utilization demonstrates great promise in formulating agrochemicals.

Regulation of dewetting and morphology evolution in spin-coated PS/PMMA blend films via graphene-based Janus nanosheets

Spin-coated blend films with complex phase-separated morphology find broad applications while precise tailoring of the morphology is still challenging. In this study, graphene oxide (GO)-based Janus nanosheets were synthesized by interfacial polymerization in a GO nanosheet stabilized Pickering emulsion with polystyrene (PS) and poly(hydroxyethyl methacrylate) synchronously being grafted to the GO nanosheet from the oil and water sides. The Janus nanosheets make the morphology of spin-coated PS/poly(methyl methacrylate)(PMMA) blend films tunable over the full height of the film until the substrate as their preferential assembly at the PS/PMMA interface and attachment on the glass substrate drive the top PS phase to migrate towards the substrate and the bottom PMMA phase to dewet from the substrate towards the air. By varying blend composition and Janus nanosheet loading, morphologies are readily transformed from a PS network on top of PMMA to PS droplets in the PMMA matrix and from PS encapsulated by PMMA to PMMA cavities in the PS network, etc.. This enables generating thin films with various morphologies ranging from a flat surface to cavity-network structures, droplet-matrix structures or bi-continuous structures, etc. at will. Moreover, the morphologies trapped by jammed nanosheets at the interface are super stable against further evolution upon annealing.

Preparation and Application of Laponite®-Based Amphiphilic Janus Nanosheets for Enhanced Oil Recovery

AbstractIn this study, the interfacial reaction method was used to modify the laponite particles using 3-glycidoxypropyltrimethoxysilane and octadecylamine, and the structure, morphology, and displacement performance tests of the modified particles were carried out. Elemental analysis, Fourier-transform infrared spectrometer, thermogravimetric analysis, and transmission electron microscopy are used to characterize the structure and morphology of the modified particles, and the results showed that laponite particles had been successfully modified. Results of the study indicated that Laponite®-based amphiphilic janus nanosheets (LAS) can accumulate at the interface, reduce the interfacial tension from 14.9 to 9.6 mN/m, and have a good emulsification effect for a long time. Second, the wettability alteration exhibited by LAS can change the wettability of the rock from oil-wet to water-wet. In addition, oil displacement experiments showed that LAS nanofluids can extract 11.6% at low concentration, which has a certain application potential.

Effect of modification degrees on the interfacial properties and EOR efficiency of amphiphilic Janus graphene oxide

Asymmetrically modified Janus graphene oxide (JGO) has attracted great attention due to its unique physical chemistry properties and wide applications. The modification degree of Janus nanosheets inevitably affects their interfacial activity, which is essential for their performances in enhanced oil recovery (EOR). In this study, the interfacial properties of Janus graphene oxide (JGO) with various modification degrees at liquid-liquid and liquid-solid interfaces were systematically evaluated via the measurements of interfacial tension (IFT), dilatational modulus, contact angle, and EOR efficiency was further assessed by core flooding tests. It is found that JGO-5 with higher modification degree exhibits the greater ability to reduce IFT (15.16 mN/m) and dilatational modulus (26 mN/m). Furthermore, JGO can construct interfacial and climbing film with the assistance of hydrodynamic power to effectively detach the oil from the rock surface and greatly enhance oil recovery. Moderately modified JGO-2 can highly improve recovery of residual crude oil (11.53%), which is regarded as the promising EOR agent in practical application. The present study firstly focuses on the effects of modification degrees on the JGO interfacial properties and proposes diverse EOR mechanisms for JGO with different modification degrees.

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.