Interface Of Nanoparticles Research Articles

How Interplay between UV and Visible Activation Dictates Charge Transfer in Nanoengineered Gold Nanoparticle Interfaces at Rutile TiO2 Polymorphism: Photocatalysis with Contrasting Results

How Interplay between UV and Visible Activation Dictates Charge Transfer in Nanoengineered Gold Nanoparticle Interfaces at Rutile TiO₂ Polymorphism: Photocatalysis with Contrasting Results

Synthesis and Specific Properties of the Ceria and Ceria-Zirconia Nanocrystals and Their Aggregates Showing Outstanding Catalytic Activity in Redox Reactions—A Review

Non-stoichiometric CeO2−y, especially in the form of nanocrystal aggregates, exhibits exceptional catalytic activity in redox reactions. It significantly improves the activity of transition metals and their oxides dispersed on/or in it, also acting as an oxygen buffer. Particularly, active oxygen species (O2n−, O−) are generated at the M/CeO2−y nanoparticle interface, as well as in the surface layer of their solid-state solutions MxCe1−xO2−y. The crystal structure of CeO2, ZrO2 and (Ce, Zr)O2 and its defects are discussed in connection with the resulting specific catalytic activity. All the methods (simple precipitation and co-precipitation from mother liquors, sol–gel methods, precipitation from nanoemulsions, hydrothermal and solvothermal techniques, combustion and flame spray pyrolysis, precipitation using molecular and solid-state matrices, 3D printing and mechanochemical methods) used for the synthesis of these nanomaterials are comprehensively reviewed, describing the rules of individual procedures and preparation details. Methods of deposition of metal catalysts and their oxides on CeO2 nanoparticles, such as impregnation, washcoating and precipitation deposition, were also discussed. This review contains more than 160 references to representative papers wherein the reader can find further details on individual syntheses of effective ceria-based catalysts for redox reactions.

Combining surface-accessible Ag and Au colloidal nanomaterials with SERS for in situ analysis of molecule-metal interactions in complex solution environments.

The interactions between molecules and noble metal nanosurfaces play a central role in many areas of nanotechnology. The surface chemistry of noble metal surfaces under ideal, clean conditions has been extensively studied; however, clean conditions are seldom met in real-world applications. We developed a sensitive and robust characterization technique for probing the surface chemistry of nanomaterials in the complex environments that are directly relevant to their applications. Surface-enhanced Raman spectroscopy (SERS) can be used to probe the interaction of plasmonic nanoparticles with light to enhance the Raman signals of molecules near the surface of nanoparticles. Here, we explain how to couple SERS with surface-accessible plasmonic-enhancing substrates, which are capped with weakly adsorbing capping ligands such as citrate and chloride ions, to allow molecule-metal interactions to be probed in situ and in real time, thus providing information on the surface orientation and the formation and breaking of chemical bonds. The procedure covers the synthesis and characterization of surface-accessible colloids, the preliminary SERS screening with agglomerated colloids, the synthesis and characterization of interfacial nanoparticle assemblies, termed metal liquid-like films, and the in situ biphasic SERS analysis with metal liquid-like films. The applications of the approach are illustrated using two examples: the probing of π-metal interactions and that of target/ligand-particle interactions on hollow bimetallic nanostars. This protocol, from the initial synthesis of the surface-accessible plasmonic nanoparticles to the final in situ biphasic SERS analysis, requires ~14 h and is ideally suited to users with basic knowledge in performing Raman spectroscopy and wet synthesis of metal nanoparticles.

Performance enhancement of HfO2-based resistive random-access memory devices using ZnO nanoparticles

In this study, resistive random-access memory (ReRAM) devices with ZnO nanoparticles (NPs) are suggested to enhance performance and reduce variation in device switching parameters. The ZnO NPs are formed by annealing ZnO prepared via atomic layer deposition on HfO2, which is verified using transmission electron microscopy, x-ray diffraction pattern, and atomic force microscopy. The depth profile analysis of x-ray photoelectron spectroscopy shows that oxygen diffuses from HfO2 to ZnO NPs during annealing. This can be explained by the calculation results using density functional theory (DFT) where the formation energy of oxygen vacancies is reduced at the interface of ZnO NPs and HfO2 compared to single HfO2. The fabricated ZnO NPs ReRAM demonstrates reduced forming voltage, stable resistive switching behavior, and improved cycle-to-cycle uniformity in a high-resistance state.

Advanced heterostructure of Pd nanosheets@Pt nanoparticles boosts methanol electrooxidation

Heterostructures have emerged as elaborate structures to improve catalytic activity owing to their combined surface and distinct inverse interface. However, fabricating advanced nanocatalysts with facet-dependent interface remains an unexploited and promising area. Herein, we render the controlled growth of Pt nanoparticles (NPs) on Pd nanosheets (NSs) by regulating the reduction kinetics of Pt2+ with solvents. Specifically, the fast reduction kinetic makes the Pt NPs uniformly deposited on the Pd NSs (U-Pd@Pt HS), while the slow reduction kinetic leads to the preferential growth of Pt NPs on the edge of the Pd NSs (E-Pd@Pt HS). Density functional theory calculations demonstrate that Pd (111)-Pt interface in U-Pd@Pt HS induces the electron-deficient status of Pd substrates, triggering the d-band center downshift and amplifying the Pd-Pt intermetallic interaction. The synergy between the electronic effect and interfacial effect facilitates the removal of poisonous intermediates on U-Pd@Pt HS. By virtue of the Pd NSs@Pt NPs interface, the heterostructure achieves exceptional methanol oxidation reaction activity as well as improved durability. This study innovatively proposes heterostructure engineering with facet-dependent interfacial modulation, offering instructive guidelines for the rational design of versatile heterocatalysts.

Tunable Subnanometer Gaps in Self-Assembled Monolayer Gold Nanoparticle Superlattices Enabling Strong Plasmonic Field Confinement.

Nanoparticle superlattices produced with controllable interparticle gap distances down to the subnanometer range are of superior significance for applications in electronic and plasmonic devices as well as in optical metasurfaces. In this work, a method to fabricate large-area (∼1 cm2) gold nanoparticle (GNP) superlattices with a typical size of single domains at several micrometers and high-density nanogaps of tunable distances (from 2.3 to 0.1 nm) as well as variable constituents (from organothiols to inorganic S2-) is demonstrated. Our approach is based on the combination of interfacial nanoparticle self-assembly, subphase exchange, and free-floating ligand exchange. Electrical transport measurements on our GNP superlattices reveal variations in the nanogap conductance of more than 6 orders of magnitude. Meanwhile, nanoscopic modifications in the surface potential landscape of active GNP devices have been observed following engineered nanogaps. In situ optical reflectance measurements during free-floating ligand exchange show a gradual enhancement of plasmonic capacitive coupling with a diminishing average interparticle gap distance down to 0.1 nm, as continuously red-shifted localized surface plasmon resonances with increasing intensity have been observed. Optical metasurfaces consisting of such GNP superlattices exhibit tunable effective refractive index over a broad wavelength range. Maximal real part of the effective refractive index, nmax, reaching 5.4 is obtained as a result of the extreme field confinement in the high-density subnanometer plasmonic gaps.

The Metal-Oxide Nanoparticle-Aqueous Solution Interface Studied by Liquid-Microjet Photoemission.

ConspectusThe liquid-microjet technique combined with soft X-ray photoelectron spectroscopy (PES) has become an exceptionally powerful experimental tool to investigate the electronic structure of liquid water and nonaqueous solvents and solutes, including nanoparticle (NP) suspensions, since its first implementation at the BESSY II synchrotron radiation facility 20 years ago. This Account focuses on NPs dispersed in water, offering a unique opportunity to access the solid-electrolyte interface for identifying interfacial species by their characteristic photoelectron spectral fingerprints. Generally, the applicability of PES to a solid-water interface is hampered due to the small mean free path of the photoelectrons in solution. Several approaches have been developed for the electrode-water system and will be reviewed briefly. The situation is different for the NP-water system. Our experiments imply that the transition-metal oxide (TMO) NPs used in our studies reside close enough to the solution-vacuum interface that electrons emitted from the NP-solution interface (and from the NP interior) can be detected.We were specifically exploring aqueous-phase TMO NPs that have a high potential for (photo)electrocatalytic applications, e.g., for solar fuel generation. The central question we address here is how H2O molecules interact with the respective TMO NP surface. Liquid-microjet PES experiments, performed from hematite (α-Fe2O3, iron(III) oxide) and anatase (TiO2, titanium(IV) oxide) NPs dispersed in aqueous solutions, exhibit sufficient sensitity to distinguish between free bulk-solution water molecules and those adsorbed at the NP surface. Moreover, hydroxyl species resulting from dissociative water adsorption can be identified in the photoemission spectra. An important aspect is that in the NP(aq) system the TMO surface is in contact with a true extended bulk electrolyte solution rather than with a few monolayers of water, as is the case in experiments using single-crystal samples. This has a decisive effect on the interfacial processes that can occur since NP-water interactions can be uniquely investigated as a function of pH and provides an environment allowing for unhindered proton migration. Our studies confirm that water is dissociatively adsorbed at the hematite surface and molecularly adsorbed at the TiO2 NP surface at low pH. In contrast, at near-basic pH the water interaction is dissociative at the TiO2 NP surface.The liquid-microjet measurements presented here also highlight the multiple aspects of photoemission necessary for a full characterization of TMO nanoparticle surfaces in aqueous environments. For instance, we exploit the ability to increase species-specific electron signals via resonant photoemission, so-called partial electron yield X-ray absorption (PEY-XA) spectra, and from valence photoelectron and resonant Auger-electron spectra. We also address the potential of these resonance processes and the associated ultrafast electronic relaxations for determining charge transfer or electron delocalization times, e.g., from Fe3+ located at the hematite nanoparticle interface into the aqueous-solution environment.

Toughening and strengthening of Silicon carbide/Aluminium composites by the optimization of Fe3O4 distribution at hot rolling

To produce SiC /Aluminum composites with a 35 % SiC content, hot pressing and hot rolling were the successful methods. In-depth investigations of the mechanical characteristics, anisotropy and interface circumstances of SiC/Aluminum mixtures are carried out after hot rolling of the material. The distribution of interfacial Fe3O4 nanoparticles was enhanced by hot rolling, resulting in an increase in both strength and ductility. Because of Fe3O4 nanoparticles aggregating at the SiC/Aluminum matrix interface after the composites were sintered, the binding strength between the two materials was decreased. After rolling, aluminium nanoparticles diffused into the Al grain interior, creating a strong bond among SiC particles and Aluminium composites. The Fe3O4 nanoparticles detached within the Aluminum grain internal also contributed to the material's ductility and strength by increasing the material's Orowan strength. In-depth discussion is provided on the composites' mechanisms for strengthening and toughening.

Study of CdS/CdS Nanoparticles Thin Films Deposited by Soft Chemistry for Optoelectronic Applications.

Chalcogenides semiconductors are currently being studied as active layers in the development of electronic devices in the field of applied technology. In the present paper, cadmium sulfide (CdS) thin films containing nanoparticles of the same material as the active layer were produced and analyzed for their application in fabricating optoelectronic devices. CdS thin films and CdS nanoparticles were obtained via soft chemistry at low temperatures. The CdS thin film was deposited via chemical bath deposition (CBD); the CdS nanoparticles were synthesized via the precipitation method. The construction of a homojunction was completed by incorporating CdS nanoparticles on CdS thin films deposited via CBD. CdS nanoparticles were deposited using the spin coating technique, and the effect of thermal annealing on the deposited films was investigated. In the modified thin films with nanoparticles, a transmittance of about 70% and a band gap between 2.12 eV and 2.35 eV were obtained. The two characteristic phonons of the CdS were observed via Raman spectroscopy, and the CdS thin films/CdS nanoparticles showed a hexagonal and cubic crystalline structure with average crystallite size of 21.3-28.4 nm, where hexagonal is the most stable for optoelectronic applications, with roughness less than 5 nm, indicating that CdS is relatively smooth, uniform and highly compact. In addition, the characteristic curves of current-voltage for as-deposited and annealed thin films showed that the metal-CdS with the CdS nanoparticle interface exhibits ohmic behavior.

S-Scheme TiO2/CuNb2O6 Nanocomposite Photocatalyst with Enhanced H2 Evolution Activity from Aqueous Glycerol Solution

Steering of photoexcitons via interface engineering of semiconductor photocatalysts is key to achieving a stable and efficient photocatalyst for continuous hydrogen production. Among them, the development of 1D nanostructures with several advantageous properties such as wide surface area, effective light harvesting, and increased electron moving kinetics has received special attention. In this work, 1D titania nanobars were successfully synthesized via the methanol-assisted solvothermal method, in which alcohol formed hydrogen bonds with nuclei, which consequently encouraged the growth of nanobars. Following this, the titania nanobars were integrated with solvothermally synthesized monoclinic CuNb2O6 nanoparticles. TEM analysis revealed the formation of TiO2 nanobars and their uniform interaction with CuNb2O6 nanoparticles. A S-scheme heterojunction is formed at the interface of TiO2 nanobars and CuNb2O6 nanoparticles. 1D morphology of titania and CuNb2O6 plays a key role in light absorption and boosts the photocatalytic activity by promoting the separation and transfer of photoexcited charge carriers. The electrons at the TiO2 conduction band and holes at the valance band of CuNb2O6 facilitated recombination at the heterojunction. The remaining electrons at the conduction band of CuNb2O6 and holes at the valance band of TiO2 tend to participate in redox reactions at their terminals. As the loading of CuNb2O6 increases, the rate of activity initially increases and then decreases, which is consistent with the trend for light penetration-dependent photocatalytic hydrogen evolution. The band edge potentials of TiO2 and CuNb2O6 were also revealed using VB-XPS and UPS analysis. In addition to catalytic stability, the effect of glycerol concentration, catalyst loading, time on stream, recyclability, and parametric analysis which aided in the discovery of ideal experimental conditions is revealed. Under optimal conditions, the photocatalyst showed an enhanced rate of H2 generation (146 mmol h–1 gcat–1) under simulated solar light irradiation. The solar to H2 conversion efficacy is also discussed with comparison.

Engineering the Interface of Ceria and Silver Janus Nanoparticles for Enhanced Catalytic Performance in 4-Nitrophenol Conversion

Engineering the Interface of Ceria and Silver Janus Nanoparticles for Enhanced Catalytic Performance in 4-Nitrophenol Conversion

Surface plasmon enhanced fluorescence: self-consistent classical treatment in the quasi-static limit

The problem of enhanced molecular emission in close proximity to dielectric and metallic interfaces is of great importance for many physical and biological applications. Here we present an exact treatment of the problem from the view point of classical electromagnetism. Self-consistent analytical theory of the surface enhanced fluorescence (SEF) is developed for configurations consisting of an emitter in proximity to core–shell metal-dielectric nanoparticles. The dependence of the fluorescence enhancement on the excitation laser and fluorescence frequencies and distance of the emitter to the nanoparticle interface are studied. The developed theory predicts enhanced fluorescence at intermediate distances as well as emission quenching into non-radiative surface plasmon (SP) modes dominating the response for short distances. The conditions for optimal emission enhancement for two core–shell configurations are determined and a comparison to published experimental data is performed showing a good correspondence between theory and experiment. The developed model can be applied toward analyzes and optimizations of various applications related to SP enhance fluorescence spectroscopy.

Electrooxidation of CO on Platinum Nanoparticles Supported on NiO Thin Films

In this article, we report on a robust experimental model to investigate strong metal–support interactions (SMSI) and their effect on electrocatalytic reactions in the absence and presence of direct contact between the nanoparticles (NPs) and the metal oxide thin film. Specifically, we describe beneficial interactions between Ni0.9O thin film supports and PtNPs toward the CO electrooxidation reaction. The metal oxide layer (Ni0.9O) is prepared by atomic layer deposition and characterized using X-ray photoelectron spectroscopy (XPS). PtNPs, containing an average of either 55 (Pt55) or 140 (Pt140) atoms, were synthesized using a dendrimer encapsulation method. The results indicate negative shifts of ∼100 and ∼60 mV of the CO electrooxidation peak potential when Ni0.9O thin films are in contact with Pt55 NPs and Pt140 NPs, respectively. Additionally, the oxygen evolution reaction (OER) is suppressed only when the PtNPs are in contact with the Ni0.9O thin film. Density functional theory (DFT) calculations indicate that both the CO electrooxidation enhancement and suppression of the OER can be attributed to a 1.23 eV decrease of the CO* binding energy and a 0.35 eV increase of the OH* binding energy at a NiO(111)/Pt55 NP interface compared to isolated Pt55 NPs.

Synthesis and Biological Activity Evaluations of Green ZnO-Decorated Acid-Activated Bentonite-Mediated Curcumin Extract (ZnO@CU/BE) as Antioxidant and Antidiabetic Agents

Green ZnO-decorated acid-activated bentonite-mediated curcumin extract (ZnO@CU/BE) was prepared as a multifunctional antioxidant and antidiabetic agent based on the extract of curcumin, which was used as a reducing and capping reagent. ZnO@CU/BE showed notably enhanced antioxidant properties against nitric oxide (88.6 ± 1.58%), 1,1-diphenyl-2-picrylhydrazil (90.2 ± 1.76%), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (87.3 ± 1.61%), and superoxide (39.5 ± 1.12%) radicals. These percentages are higher than the reported values of ascorbic acid as a standard and the integrated components of the structure (CU, BE/CU, and ZnO). This signifies the impact of the bentonite substrate on enhancing the solubility, stability, dispersion, and release rate of the intercalated curcumin-based phytochemicals, in addition to enhancing the exposure interface of ZnO nanoparticles. Therefore, effective antidiabetic properties were observed, with significant inhibition effects on porcine pancreatic α-amylase (76.8 ± 1.87%), murine pancreatic α-amylase (56.5 ± 1.67%), pancreatic α-glucosidase (96.5 ± 1.07%), murine intestinal α-glucosidase (92.5 ± 1.10%), and amyloglucosidase (93.7 ± 1.55%) enzymes. These values are higher than those determined using commercial miglitol and are close to the values measured using acarbose. Hence, the structure can be applied as an antioxidant and antidiabetic agent.

An additively manufactured heat-resistant Al-Ce-Sc-Zr alloy: Microstructure, mechanical properties and thermal stability

In this study, a high-strength and heat-resistant Al–Ce–Sc–Zr alloy was designed and fabricated by additive manufacturing. The as-built alloy shows an excellent combination of strength and ductility compared to other Al–Ce-based alloys, including an ultimate tensile strength of 445 MPa, a yield strength of 344 MPa and an elongation of 10%. Even at 300 °C, the alloy still retains a superb tensile yield strength of 233 MPa, which is the best among the high-temperature aluminum alloys reported so far. The excellent performance is mainly attributed to a significant amount of fine, homogeneous and coarsening-resistant Al11Ce3 intermetallic nanoparticles formed during the rapid solidification process of laser additive manufacturing. The formation of coherent Al3(Sc, Zr) nano-precipitates and interfacial segregation at the interface of intermetallic nanoparticles during high temperature exposure further improve the high temperature properties of the alloy. Our work has the potential to provide design concepts for the development of novel high temperature aluminum alloys.

Photocatalytic activity of biosynthesized silver nanoparticle fosters oxidative stress at nanoparticle interface resulting in antimicrobial and cytotoxic activities.

Inside the biological milieu, nanoparticles with photocatalytic activity have potential to trigger cell death non-specifically due to production of reactive oxygen species (ROS) upon reacting with biological entities. Silver nanoparticle (AgNP) possessing narrow band gap energy can exhibit high light absorption property and significant photocatalytic activity. This study intends to explore the effects of ROS generated due to photocatalytic activity of AgNP on antimicrobial and cytotoxic propensities. To this end, AgNP was synthesized using the principle of green chemistry from the peel extract of Punica granatum L., and was characterized using UV-Vis spectroscope, transmission electron microscope and x-ray diffraction, and so forth. The antimicrobial activity of AgNP against studied bacteria indicated that, ROS generated at AgNP interface develop stress on bacterial membrane leading to bacterial cell death, whereas Alamar Blue dye reduction assay indicated that increased cytotoxic activity with increasing concentrations of AgNP. The γH2AX activity assay revealed that increasing the concentrations of AgNP increased DNA damaging activity. The results altogether demonstrated that both antimicrobial and cytotoxic propensities are triggered primarily due interfacial ROS generation by photocatalytic AgNP, which caused membrane deformation in bacteria and DNA damage in HT1080 cells resulting in cell death.

Self-powered dual-wavelength polarization-sensitive photodetectors based on ZnO/BiFeO3 heterojunction

The ferroelectric-photovoltaic (FE-PV) devices have received growing attention for the FE polarization-induced internal electric field to facilitate the separation and transport of the photogenerated electron-hole (e-h) pairs in the FE semiconductors. However, the low photocurrent output of the FE-PV devices is still a key challenge for the application and development of these devices. Here, ZnO/BiFeO3 (BFO) heterojunction photodetectors (PDs) are designed to utilize the built-in electric field at the heterojunction interface of ZnO nanoparticles (NPs)/BFO and the spontaneous FE polarization field of BFO to promote the separation and transport of the photogenerated carriers. ZnO nanorod arrays (NRs) grown on ZnO NPs provide a directional transport channel for the photogenerated electrons. ZnO/BFO heterojunction devices demonstrate a self-powered photoresponse in the ultraviolet (UV) and visible (vis) dual-wavelength. The devices show a responsivity of 1.32 mA/W, response time (τrise/τdecay) of 12.6/44.9 ms at 420 nm light illumination. In addition, the polarization imaging function of ZnO/BFO PDs is explored by extending the polarization photocurrent mapping values of a single PD unit to a complex array of optical information image processing utilizing the polarization-sensitive properties of BFO without external bias.

Effect of structure of Pd@Fe core–shell cubes on the enhancement of H2 conversion in direct reaction of H2 and O2

Structure engineering is an integrated strategy to regulate the performance of nanoparticles for various catalytic reactions, since the nanoparticle composition, shape, and interface affect the reaction activity and selectivity. Herein, we report a simple synthesis of clear core–shell structured Pd@Fe nanocubes with different shell thicknesses, which exhibit higher H2 conversion efficiency in direct hydrogen peroxide generation compared with ordinary Pd cubes. This result can be attributed to two main reasons: (i) the conformal growth of the Fe oxide shell consisting of loose structured Fe3O4 favors H2 penetration, and (ii) the capping agent (Br−) on the Pd–Fe3O4 interface that blocks the Pd active sites is removed during the shell formation. Therefore, the Fe oxide shell of the Pd@Fe nanoparticles not only helps maintaining the morphology of the nanoparticles but also increases the number of active sites on the inner core surface, confirming the advantage of the core–shell structure.

Room Temperature Synthesized TiO2 Nanoparticles for Two-Folds Enhanced Mechanical Properties of Unsaturated Polyester.

Using of nano-inclusion to reinforce polymeric materials has emerged as a potential technique to achieve an upper extreme of specific strength. Despite the significant improvement of mechanical properties via nano-reinforcements, the commercial application of such nano-composites is still restricted, due to high cost and unwanted aggregation of nanoparticles in the polymer matrix. To address these issues, here we proposed a scalable and economical synthesis of TiO2 at low temperatures, resulting in self-dispersed nanoparticles, without any surfactant. As lower energy is consumed in the synthesis and processing of such nanoparticles, so their facile gram-scale synthesis is possible. The defect-rich surface of such nanoparticles accommodates excessive dangling bonds, serving as a center for the functional groups on the surface. Functional surface enables high dispersion stability of room temperature synthesized TiO2 particles. With this motivation, we optimized the processing conditions and concentration of as-synthesized nano-particles for better mechanical properties of unsaturated polyester (UP) resin. The composite structure (UP-TiO2) showed nearly two folds higher tensile, flexural, and impact strength, with 4% content of nanoparticles. Characterization tools show that these better mechanical properties are attributed to a strong interface and superior dispersion of nanoparticles, which facilitate better stress distribution in the composite structure. In addition, the crack generation and propagation are restricted at a much smaller scale in nanocomposites, therefore significant improvement in mechanical properties was observed.

Effects of nanoparticle types and internal phase content on the properties of W/O emulsions based on dual stabilization mechanism

In this study, water-in-oil (W/O) Pickering emulsions stabilized by different interfacial nanoparticles (ethyl cellulose-EC, whey protein isolate-WPI, Zein) and oleogel networks (glycerin monostearate) were constructed. The influence mechanism of different nanoparticles and oleogel networks under different internal phase fractions on the properties of emulsions was explored. Among different nanoparticles, EC nanoparticle had the smallest particle size (187.03 ± 2.23 nm) and highest contact angle (64.63 ± 2.94°), while Zein and WPI nanoparticles had bigger particle size (287.00 ± 5.54 nm and 213.77 ± 12.90 nm) and lower contact angle (59.71 ± 3.22° and 62.76 ± 1.47°). Microstructural observation revealed that the nanoparticles were located at the interface and in the water droplets, and the nanoparticles could aggregate into network structures. The oil phase had compact gel structures, which surrounded the water droplets. FTIR further proved that the interaction between interfacial particles and oleogel network was dominated by hydrogen bonding and hydrophobic interaction. Both nanoparticle type and water volume affected the rheological properties of the emulsions. Comparatively, EC-based emulsions had the highest shearing viscosity, creep recovery rate and storage modulus. The increase in water phase volume led to higher viscoelasticity, higher centrifugal stability and oil holding capacity of the emulsions. Upon heating, Zein-based emulsions presented the most significant phase separation and decrease in storage modulus. These findings suggested a dual stabilization mechanism for W/O emulsions, and both the nanoparticles and oleogel networks assisted in stabilizing the emulsions. The knowledge obtained in this study would be helpful in developing functional low-fat food and hydrophilic ingredient delivery systems.