Hexagonal Nanoplatelets Research Articles

High Thermal Conductivity Polyelectrolyte Nanocomposite Electrical Insulation Thin Films

AbstractHigh‐power electronics require thin, conformal insulation that resists dielectric breakdown, while promoting removal of heat from the device. Recently, polyelectrolytes have shown promise in creating dielectric thin films, but their thermal conductivity remains relatively low (<1 W m−1 K−1). In this work, the layer‐by‐layer (LbL) assembly of polyethylenimine, mica clay, poly(acrylic acid), and hexagonal boron nitride is exploited to create a thin film dielectric material with relatively high thermal conductivity (through‐plane thermal conductivity of 1.87 ± 0.03 W m−1 K−1) and strong electrical insulation (breakdown strength of 152 kV mm−1). High thermal conductivity is obtained due to mica and hexagonal boron nitride nanoplatelets stretching through multiple layers. The performance benefits of this nanocomposite are demonstrated with a partial motor, where the nanocomposite greatly reduces the peak temperature of the motor when compared to state‐of‐the‐art polyimide insulation. This remarkable combination of thermal conductivity and dielectric breakdown strength represents a significant advancement in the electrical and thermal protection of high voltage devices.

Microstructure and mechanical properties of hybrid hexagonal BN nanotube and nanoplatelet reinforced AZ91 Mg matrix composites

In this research, we report fabrication of AZ91 (Mg–Al–Mn–Zn) matrix composites reinforced with a hybrid of hexagonal boron nitride nanoplatelets (BNNP) and nanotubes (BNNT) using spark plasma sintering (SPS) and hot isostatic pressing (HIP). The resultant composites present dense microstructure featured by the refined α-Mg grains decorated with eutectic along the α-Mg grain boundaries, and trace amounts of in-situ interfacial-reaction products such as Mg3N2 and MgB2 are observed to serve as chemical anchors for stronger interface. More importantly, the AZ91 composites reinforced with a hybrid of 0.4 wt% BNNPs-0.1 wt% BNNTs displays ∼209 MPa of compressive yield strength, ∼329 MPa of ultimate compressive strength and ∼19.4% of elongation, achieving satisfactory balance of strength and ductility when compared to the AZ91 composite reinforced with sole BNNPs. This improvement can be attributed to the unique three-dimensional hybrid structure, where BNNPs maintain their high specific surface area, and the de-bundled BNNTs extend like tentacles, further contributing to their interfacial adhesion with the matrix. This research is expected to pave the way for the development of Mg-based composites with an optimal balance of strength and ductility.

Heterogeneous nucleation of polyethylene crystals on binary hexagonal nanoplatelets

Crystal nucleating agents offer an effective strategy for controlling the morphology, dimensional stability and rate of solidification of polymers during processing. Molecular dynamics (MD) simulation can shed light on nucleation behavior at the nanoscopic length and time scales over which nucleation occurs. In this work, crystal nucleation of a polyethylene oligomer, n-pentacontane, on three graphene-like substrates, hexagonal boron nitride (hBN), molybdenum disulfide (MoS2), and tungsten disulfide (WS2), was simulated, and the thermodynamic efficiencies of these substrates as nucleating agents were determined. Experimental measurements of heterogeneous nucleation of a high-density polyethylene on nanoparticles of these three graphene-like materials were performed using the method of dispersed microdroplets in an immiscible polystyrene matrix. Qualitative agreement between simulations and experiments was observed for trends in nucleation rate, J, and interfacial free energy difference, Δσ, with JhBN>JMoS2>JWS2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$J_{\ ext{hBN}} > J_{\ ext{MoS}_{2}} > J_{\ ext{WS}_{2}}$$\\end{document}. The simulations are then used to gain additional insight into the mechanisms of nucleation. Epitaxy is confirmed in all systems, with small mismatches in lattice spacing being accommodated by strain in the oligomer crystal. However, epitaxy alone is insufficient to explain the observed trends. The strength of interaction between the nucleating agent and the polyethylene oligomer is found to be the strongest predictor of nucleating agent efficiency. The strength of interaction is in turn related to the density of interaction sites at the interface: hBN has the highest density, and thus the fastest nucleation rate.

Temperature-controlled morphology and enhanced functionalities of hydrothermally synthesized SrFe2O4 nanostructures for multifaceted applications

In this study, we investigate the effect of synthesis temperature on the morphology and properties of spinel strontium ferrite (SrFe2O4) nanostructures, synthesized using a surfactant-free hydrothermal method. We demonstrate that by varying the temperature from 85 °C to 160 °C, we can control the morphology of SrFe2O4, transitioning from nanoribbons to dendritic structures, and finally to hexagonal nanoplatelets. These morphological changes correspond to significant enhancements in both magnetic and photocatalytic performance. The saturation magnetization (Ms) notably increases by up to 70 % at higher synthesis temperatures. Additionally, these nanostructures show improved efficiency in photocatalytic degradation of methylene blue dye, indicating their potential for environmental remediation. The dielectric properties of the various morphologies were also characterized, suggesting applications in electronics and energy storage. This study establishes a clear link between synthesis conditions, resulting structures, and functional performance in SrFe2O4 nanostructures, contributing to the development of advanced materials.

Hexagonal nanoplatelets of Ni–Mn oxide implanted reduced graphene oxide for high response in humidity sensing

Hexagonal nanoplatelets of Ni–Mn oxide implanted reduced graphene oxide for high response in humidity sensing

Mg2-xCaxAl layered double hydroxide-derived mixed metal oxide porous hexagonal nanoplatelets for CO2 sorption.

Porous hexagonal nanoplatelets of mixed metal oxide (MMO) derived from the calcination of MgAl layered double hydroxide exhibits a CO2 sorption capacity of 1.99 mmol g-1 at 30 °C, with a retention of 87% sorption capacity over 10 carbonation-decarbonation cycles and a CO2 sorption capacity of 1 mmol g-1 at 200 °C with a 40% increase in capacity over 10 cycles. The high sorption capacity is attributed to the porous nanoplatelet structure of the MMO with a BET surface area of 115 m2 g-1, which enables increased CO2 diffusion. Upon partially replacing magnesium with calcium (33, 50 and 66 mol%), the CO2 sorption capacity of the MMO increases with an increase in temperature. MMO derived from LDH, in which 66% of magnesium is replaced by calcium (MgCaAl-66), delivers CO2 sorption capacities of 1.38, 1.31, 2.50, 4.85 and 7.75 mmol g-1 at 200, 300, 350, 400 and 600 °C, respectively, which is significant for application in the sorption-enhanced water gas shift (SEWGS) process. MgCaAl-66 MMO exhibits a sorption capacity of 1 mmol g-1, which is stable over 10 cycles at 200 °C, and a sorption capacity of 3.68 mmol g-1 at 400 °C with 85% capture efficiency retention over 10 cycles. While the incorporation of Ca2+ serves multiple purposes such as increasing basic defect sorption sites and improving stability to repress the sintering-induced limitation of MMO over sorption cycles, the porous nanoplatelets act as individual sorbent units resisting volume changes through carbonation-decarbonation cycles.

Facile preparation of polymer-based heat dissipation composite coating with enhanced thermal conductivity via optimizing synergistic effect of multi-scale fillers

Aluminum radiator plays a significant role in thermal managing system of passive heat dissipation for high power consuming microelectronic devices. Although inspiring strategies have been proposed to design and prepare polymer-based composites with high thermal conductivity in previous reports, it remains urgent to develop practical techniques for economically fabricating thermally conductive composite coatings in large-scale. To construct efficient heat dissipation film, two-dimensional (2D) graphene nanoplatelets (GNPs)/hexagonal boron nitride nanoplatelets (BNNPs) hybrid fillers are dispersed in polydimethylsiloxane (PDMS) solution with branch-like porous magnéli-phase Ti4O7 microparticles as heat conducting paths, and fabricated via convenient spray-coating. Thermal conductivity of the cured coating presents two-fold increase to 5.339 W m−1 K−1 as compared to the coating without Ti4O7, and a heat dissipation ratio of 13.96 %. Furthermore, the composite coating demonstrates excellent corrosion resistance under neutral salt solution spray. The as-prepared composite coating is of great potential to be applied as protective coating for aluminum radiators.

Growth of high carrier mobility 2-Dimensional hexagonal Bi2Te3-xSex nanoplatelets and its thermoelectric performance studies

Morphologically controlled growth of selenium-doped 2-Dimensional (2D) Bi2Te3-xSex nanoplatelets have been optimized by solvothermal synthesis using polyvinyl-pyrro-lidone (PVP) surfactant from the pre-optimized growth conditions of 2D-Bi2Te3 hexagonal nanoplatelet. An optimization was carried out using the Se-doping of x = 0.3 under variable growth durations of 4 h, 8 h, and 12 h. X-ray powder diffraction studies confirmed the complete crystallization with a pure phase of 2D-Bi2Te3-xSex at an extended duration of 12 h synthesis. Crystallization with defined hexagonal morphology was confirmed by FESEM analysis. Selenium doping into the 2D-Bi2Te3-xSex lattice from x = 0.1 to x = 0.4 indicates a step-by-step shift in the 2θ value of the (015) predominant peak towards higher 2θ values. Raman analysis revealed the alteration of the appearance of A1u2 to A1g2 upon the lattice inclusion of “Se” in the place of “Te”. Hall measurements on the consolidated pellet of 2D-Bi2Te3-xSex resulted in the highest electron mobility of 1675 cm2V−1s−1 with carrier concentration of 2.9 × 1018 cm−3 for Se-doping x = 0.2. Thermal conductivity analysis in comparison with the total thermal conductivity and the calculated electronic thermal conductivity revealed the lowest lattice thermal conductivity of 0.17 Wm−1K−1 for the Se-doping x = 0.2 after the correction for structural anisotropy factor (f). The highest thermoelectric figure of merit of 0.74 was achieved in this course of work.

Investigation of the synergetic effect of hybrid fillers of hexagonal boron nitride, graphene nanoplatelets and short basalt fibers for improved properties of polyphenylene sulfide composites

Investigation of the synergetic effect of hybrid fillers of hexagonal boron nitride, graphene nanoplatelets and short basalt fibers for improved properties of polyphenylene sulfide composites

Europium (III) doped bismuth telluride decorated on carbon-based materials for enhancing thermoelectric performance

Scalable synthetic approach for superior performance of thermoelectric (TE) materials is a crucial step for the TE technology progress. Herein, reduced graphene oxide (RGO), carbon nitride (g-C 3N4) and europium (Eu) are utilized as additives to bismuth telluride (Bi2Te3) matrix to prepare various novel nanocomposites (NCs): (RGO@Bi1.8Te3Eu0.2) and (RGO-g-C3N4@Bi1.8Te3Eu0.2) with an enhanced TE performance. The novel NCs were synthesized via solvothermal method, physiochemically characterized and consolidated into pellets of 1 mm thickness to measure their TE properties. The new additives potentially affected the physicochemical and TE properties of Bi2Te3. Nanostructured hexagonal nanoplatelets with 12.5 nm thickness were observed by scanning and transmission electron microscopy (SEM and TEM) of the synthesized Bi2Te3. This thickness shrinked to 5.7 and 5.2 nm upon the formation of (RGO@Bi1.8Te3Eu0.2) and (RGO-g-C3N4@Bi1.8Te3Eu0.2) NCs, respectively. Energy dispersive X-ray Spectroscopy (EDS) of NCs proved the existence of Bi, Te, C, Eu and N atoms. Raman and Fourier-transform infrared (FT-IR) spectra confirmed the NC formation that led to narrowing the energy band gap of Bi2Te3 as displayed by UV–Vis spectra. Brunauer–Emmett–Teller showed specific surface area expansion of Bi2Te3 from 6.78 to 19.00 and 16.75 m2g-1 of (RGO@Bi1.8Te3Eu0.2) and (RGO-g-C3N4@Bi1.8Te3Eu0.2) NCs, respectively. The electrical conductivity of Bi2Te3 rose by 56 and 69 times, whereas its thermal conductivity significantly dropped by 1.6 and 1.7 times upon (RGO@Bi1.8Te3Eu0.2) and (RGO-g-C3N4@Bi1.8Te3Eu0.2) NCs formation. Owing to extra channels of carrier transfer and phonon scattering induced by NCs heterointerfaces. Novel combination of carbon-based materials and Eu with Bi2Te3 matrix boosts its TE performance resulting in a worthy candidate for power generation applications at room-temperature.

Functionalized hexagonal boron nitride nanoplatelets for advanced cementitious nanocomposites

Portland cement-based nanocomposites were successfully fabricated with low volume fractions of hexagonal boron nitride (hBN) nanoplatelets, exfoliated and functionalized using a combination of ball milling and sonicated-assisted dispersion. Surface topography, thickness, lateral dimension, and number of layers of the hBN nanoplatelets were evaluated by AFM and Raman analysis. The identification of functional groups attached onto the functionalized hBN was performed through FTIR. The results show that the functionalization successfully exfoliates the hBN nanoplatelets to few-layer thicknesses, resulting in suspensions with high colloidal stability. The grafted hydroxyl and carboxyl groups on the hBN surface interact with the Ca2+ ions of calcium silicate hydrates (CSH), improving the load-transfer efficiency from the cement matrix to the hBN nanoplatelets. Overall, the hBN reinforced cementitious composites demonstrated significant enhancement in flexural strength by ∼50%, compressive strength by ∼17%, Young's modulus by ∼56%, and fracture energy by ∼76%.

Multifunctional steel surface through the treatment with graphene and h-BN

The search for improved surface properties of engineering alloys is always a matter of interest. Herein, we introduce a surface treatment based on depositing a non-continuous layer of two-dimensional (2D) nanomaterials via a simple and scalable method. 2D nanosheets of hexagonal boron nitride (h-BN) and graphene nanoplatelets (GNP) were sprayed on mild steel, followed by mild heat treatment. The nanosheets are strongly attached to the surfaces and even diffused to submicron under the surface, as proved by various analytical techniques. The mechanical, tribological and corrosion evaluations show significant simultaneous enhancement in a set of surface properties. From the friction tests with sliding steel-steel tribo-pairs under dry conditions, the graphene treatment decreases the friction coefficient and wear area by 21% and 31%, respectively. Interestingly, it is revealed that under dry and lubricated conditions, graphene-doped h-BN exhibits outstanding anti-wear properties synergistically compared to stand-alone 2D materials. The possible wear mechanism is investigated and found to be based on the formation of a tribofilm.

Bismuth Telluride (Bi2Te3) nanocrystallites: Studies on growth morphology and its influence on the thermoelectric properties

Growth of Bismuth Telluride (Bi2Te3) nanocrystallites by solvothermal method resulted in an incomplete hexagonal flake-like (BTFL) structure for surfactant-free growth and complete hexagonal morphologies (BTHP) for the PVP surfactant mixed growth respectively identified through FESEM studies. XRD characterization revealed the crystallization of pure phase of Bi2Te3 at 210 °C for PVP-free growth and at 200 °C for PVP-assisted growth. Raman studies shows a noticeable difference in the appearance of peak positions for hexagonal nanoplatelets. Laser flash measurement of total thermal conductivity (κtot) resulted in the lowest value of 0.39 Wm−1K−1 for the BTFL pellet and 0.44 Wm−1K−1 for BTHP. Estimated lattice thermal conductivity resulted in 0.16 Wm−1K−1 for BTFL pellet and 0.25 Wm−1K−1 for the BTHP pellet. Temperature-dependent electrical conductivity studies reveal semiconductor behaviour for BTFL pellet and semi-metallic behaviour for BTHP pellet. Calculation of figure of merit (ZT) based on the measured values exhibits ZT value of 0.76 for BTFL and 0.64 for BTHP pellet. Details are presented in this paper.

2D hexagonal yttrium doped SnO2 nanoplatelets for photocatalytic degradation

In this study, simple morphological and structural evolutions of two-dimensional hexagonal nanoplatelets were investigated. XRD analysis of SnO2 and SnO2:Y has revealed a tetragonal structure and photoluminescence spectra exhibited a visible emission broadband peak around 464 nm and 528 nm. The photoluminescence spectra of SnO2:Y (7 wt.%) confirm the increased charge separation, which inhibits electron–hole recombination. Raman spectra validated the presence of oxygen vacancies in SnO2:Y (7 wt.%) nanoplatelets. It has been shown that hexagonal SnO2:Y (7 wt.%) nanoplatelets perform better in photocatalytic degradation than conventional spherical nanoparticles. EIS measurements were performed to investigate the charge carrier movement of SnO2 and SnO2:Y nanoparticles. Our study is the first to illustrate the two-dimensional morphology of SnO2:Y (7 wt.%) hexagonal nanoplatelets and their application as a photocatalytic material.

Exploring a balance between strength and ductility of hexagonal BN nanoplatelet reinforced ZK61 magnesium composite

The practical applications of magnesium (Mg) alloys are usually beset by their relatively low strength and limited ductility. Herein we attempt to fabricate hexagonal BN nanoplatelet (BNNP) reinforced ZK61 magnesium composites using a combination of spark plasma sintering and friction stir processing. The resulting composites exhibit microstructural characteristics of homogeneous dispersion of BNNP in Mg matrix with refined equiaxed grains and (0002) basal texture roughly surrounding the pin column surface. Transmission electron microscopy observation illustrates that trace amounts of Mg3N2 and MgB2 form at BNNP-Mg interface, in which Mg3N2 locates at the basal plane of a BNNP and MgB2 grows at its open edge. The spatial distribution of Mg3N2 and MgB2 facilitates interfacial wetting and stronger BNNP-Mg interface in such a way that interfacial products act as anchors bonding between them. In comparison with monolithic ZK61 alloy, the BNNP/ZK61 composites display simultaneous improvements in yield strength, hardness and ductility, achieving good strength-ductility balance. This research is expected to shed some light on BNNP potentials for designing and producing magnesium composites with high strength and good ductility.

Peculiarities of erbium incorporation into ZnO microrods at high doping level leading to upconversion and the morphology change. Influence on excitonic as well as shallow donor states

Heavily Er-doped zinc oxide (ZnO) microrods with nominal compositions, ZnO:Er(2, 10, 30%), were prepared by the hydrothermal growth method. The crystallographic phases present in the as grown and annealed materialswere determined. The presence of the hexagonal Wurtzite ZnO phase in the form of the hexagonal shape nanoplatelets and microrods was confirmed. Moreover, the Er2O3phase in the form of nanosheets has been revealed as well. Erbium is partly incorporated into the ZnO hosts. It was thinning upon erbium doping level contributing to erbium oxide. This effect was even more pronounced upon annealing in air. Moreover, the influence of erbium doping and annealing on paramagnetic shallow donor centers has been studied. There were two types of these centers, both affected by the erbium presence. The increase of the neutral zinc vacancies amount upon erbium doping has been proven. Annealing in air moderated the charge distribution between them. Moreover, upconversion processes between the two erbium ions were observed and explained. The surface distribution of excitonic emission centers was studied. The larger the erbium content the weaker the exciton luminescence. The smaller the ZnO microrods the stronger the exciton emission.

Interfacial reaction induced synergetic strengthening effects on the plasma sprayed Ni3Al composite coating reinforced with hexagonal boron nitride nanoplatelets

Ni3Al has shown great potential in high-performance wear-resistant coating material for lots of tribological machinery components working in extremely aggressive environments owing to its anomalous strength-temperature dependence and coexistent atomic bonds (covalent and metallic bonds) in nature. In this research, hexagonal boron nitride nanoplatelet (BNNP) reinforced Ni3Al composite coatings are fabricated on Ti6Al4V substrate using plasma spray. The added BNNP can survive the harsh high-temperature conditions and are homogeneously distributed in the composite coatings. Trace amounts of in-situ synthesized AlN and AlB2 and local diffusion layer are found to form a stronger BNNP-Ni3Al interface in such a way that BNNPs act as anchors bonding Ni3Al matrix during rapid solidification. These BNNPs either locating within a splat or being sandwiched by the adjacent splats exert synergetic strengthening effects on individual splats and splat boundaries, imparting the lamellar structural composite coatings with noticeably improved mechanical and tribological properties. As compared with Ni3Al coating, BNNP/Ni3Al composite coatings showed an improvement in tensile strength, elongation, toughness, and wear resistance by 24.6 %, 21.4 %, 52.5 %, and 77 %, respectively. This research is expected to shed some light on BNNP potentials for designing and producing high-performance composite coatings using plasma spray.

Hierarchical Fe2O3 hexagonal nanoplatelets anchored on SnO2 nanofibers for high-performance asymmetric supercapacitor device

Metal oxide heterostructures have gained huge attention in the energy storage applications due to their outstanding properties compared to pristine metal oxides. Herein, magnetic Fe2O3@SnO2 heterostructures were synthesized by the sol–gel electrospinning method at calcination temperatures of 450 and 600 °C. XRD line profile analysis indicated that fraction of tetragonal tin oxide phase compared to rhombohedral hematite was enhanced by increasing calcination temperature. FESEM images revealed that hexagonal nanoplatelets of Fe2O3 were hierarchically anchored on SnO2 hollow nanofibers. Optical band gap of heterogeneous structures was increased from 2.06 to 2.40 eV by calcination process. Vibrating sample magnetometer analysis demonstrated that increasing calcination temperature of the samples reduces saturation magnetization from 2.32 to 0.92 emu g-1. The Fe2O3@SnO2-450 and Fe2O3@SnO2-600 nanofibers as active materials coated onto Ni foams (NF) and their electrochemical performance were evaluated in three and two-electrode configurations in 3 M KOH electrolyte solution. Fe2O3@SnO2-600/NF electrode exhibits a high specific capacitance of 562.3 F g-1 at a current density of 1 A g-1 and good cycling stability with 92.8% capacitance retention at a high current density of 10 A g-1 after 3000 cycles in three-electrode system. The assembled Fe2O3@SnO2-600//activated carbon asymmetric supercapacitor device delivers a maximum energy density of 50.2 Wh kg-1 at a power density of 650 W kg-1. The results display that the Fe2O3@SnO2-600 can be a promising electrode material in supercapacitor applications.

(Digital Presentation) OER Catalysts Supported on Layered Zirconium Phosphate Nanomaterials

Learning from nature, instead of using expensive catalysts such as platinum for splitting water, cheaper alternatives (such as cobalt, iron, or nickel) could be used for the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Hydrogen solar fuel produced in artificial photosynthesis schemes for water splitting could be used in fuel cells. However, obtaining efficient catalysts based on earth-abundant materials is still difficult, particularly for the OER. Recent theory has shown that nanoscopic confinement of catalysts increases the stability and efficiency of catalysts for OER. We have designed and develop earth-abundant electrocatalysts for oxygen reduction and water splitting using nanostructured layered inorganic materials of zirconium phosphate (ZrP). We have demonstrated improved electrocatalytic activity of ZrP nanomaterials loaded with metal ions suitable for the OER of water splitting. Adsorbing Co or Ni catalysts on the ZrP nanoparticles surface proved to improved OER activity compared to intercalated catalysts. A comparison between adsorbed Co or Ni catalysts and those catalysts on exfoliated ZrP hexagonal nanoplatelets proved that those on exfoliated nanoplatelets were more active, with diminished overpotentials and reduced Tafel plot slopes as well as higher mass activities. More recently, comparison between Co and Ni catalyst on ZrP particles with different morphologies (hexagonal platelets, rods, cubes, and spheres) revealed that the more active Co catalysts are those on hexagonal ZrP platelets, whereas the best Ni catalysts are those on ZrP spheres. Finally, encouraging recent results with a cobalt porphyrin catalyst and bimetal catalysts will be presented, as well as recent XAS operando results. These results demonstrate that ZrP nanoparticles are suitable supports for electrocatalysis of the OER and water splitting.Sponsored by the NSF-PREM Center for Interfacial Electrochemistry for Energy Materials (CIE2M) grant DMR-1827622.

Influence of Structural Disorders on the Tribological Behavior of Phosphate-Intercalated Layered Double Hydroxide Additives in Polyalphaolefin.

In this work, several phosphate-intercalated Mg-Al layered double hydroxides (LDHs) were synthesized and evaluated as solid lubricant additives in polyalphaolefin (PAO-4) by means of tribotesting on coupled GCr15/cast iron contacts. The effects of test parameters such as normal loads, additive concentrations, and substrate surface roughness were investigated, while the LDH crystal structure received considerable attention. Several types of structural disorder after anion exchange were identified based on X-ray diffraction (XRD) analysis. The unstable structures promote feasible shearing during sliding to improve friction and wear. In addition, antiwear properties correlate well with the anion charge number or the quantity of anion in the interlayer region. Overall, the tribological performance increased in the order HPO42--LDH < PO43--LDH < P2O74--LDH < (PO3)66--LDH. (PO3)66--LDH demonstrated the best antiwear performance with a reduction of 69% of the ball volume loss compared to PAO-4 oil due to the synergy of the disordered stacking LDH sheets and flexible ring structure of the (PO3)66- anion. Furthermore, on polished surfaces, the coefficient of friction (COF) of the (PO3)66--LDH sample dropped significantly by 26%, while the wear loss reduction of more than 80% was also substantial compared to the base oil sample. A performance comparison between the best-performing LDH additive was also conducted against popular nanomaterials, such as hexagonal boron nitride (BN), graphene nanoplatelets (GNPs), and titanium oxide (TiO2). The performance of (PO3)66--LDH was close to that of GNPs.