ZrO2 Nanoparticles Research Articles

Unlocking a Dual‐Channel Pathway in CO2 Hydrogenation to Methanol over Single‐Site Zirconium on Amorphous Silica

AbstractConverting CO2 into methanol on a large scale is of great significance in the sustainable methanol economy. Zirconia species are considered to be an essential support in Cu‐based catalysts due to their excellent properties for CO2 adsorption and activation. However, the evolution of Zr species during the reaction and the effect of their structure on the reaction pathways remain unclear. Herein, single‐site Zr species in an amorphous SiO2 matrix are created by enhancing the Zr−Si interaction in Cu/ZrO2‐SiO2 catalysts. In situ X‐ray absorption spectroscopy (XAS) reveals that the coordination environment of single‐site Zr is sensitive to the atmosphere and reaction conditions. We demonstrate that the CO2 adsorption occurs preferably on the interface of Cu and single‐site Zr rather than on ZrO2 nanoparticles. Methanol synthesis in reverse water‐gas‐shift (RWGS)+CO‐hydro pathway is verified only over single‐dispersed Zr sites, whereas the ordinary formate pathway occurs on ZrO2 nanoparticles. Thus, it expands a non‐competitive parallel pathway as a supplement to the dominant formate pathway, resulting in the enhancement of Cu activity sixfold and twofold based on Cu/SiO2 and Cu/ZrO2 catalysts, respectively. The establishment of this dual‐channel pathway by single‐site Zr species in this work opens new horizons for understanding the role of atomically dispersed oxides in catalysis science.

Soy protein isolate amyloid fibril-coated ZrO2 nanoparticles anchored in the polyurethane sponge for rapid and effective fluoride adsorption in the wide pH range

Fluoride ion contamination remains a key challenge for water scarcity. ZrO2 has a good affinity for fluoride ions, but the narrow pH range of application and agglomeration limit its further development. In this work, soybean isolate protein-coated ZrO2 nanoparticles were immobilized into polyurethane sponge to obtain a macroscopic adsorbent (PU-ZrSAF). PU-ZrSAF exhibited fast kinetics (∼30 min), high adsorption capacity (95.24 mg/g), excellent selectivity and resistance to extreme pH. Especially at pH= 3–8, the PU-ZrSAF could still maintain approximately 100% fluoride removal effectiveness. The complexation, electrostatic interaction, and hydrogen bonding interaction between the oxygen and nitrogen functional groups of amyloid fibrils and fluoride ions were major mechanism of fluoride ions adsorption. The secondary conformation of proteins also changed during synthesis and adsorption. The strategy of synthesizing protein by-product based composites with environmentally friendly in this study can be extended to remove other contaminants from water.

Strong Metal‐Support Interactions in ZrO2‐Supported IrOx Catalyst for Efficient Oxygen Evolution Reaction

AbstractThe use of ZrO2 as a support material for IrOx‐based catalysts in oxygen evolution reaction (OER) electrocatalysis was studied using ex‐situ characterization and rotating disk electrode electrochemical testing of supported IrxZr(1‐x)O2 on ZrO2 of varying sizes. The catalyst exhibited high OER mass (specific) activity (712 A ) and intrinsic activity (4.8 mA ) at 1.6 VRHE, attributed to IrxZr(1‐x)O2 alloy formation, an interconnected network of Irx Zr(1‐x)O2 nanoparticles and the presence of Ir(III)/Ir(IV) species throughout the bulk. It also appears to be resistant to Ir dissolution; however, accumulation of O2 bubbles in the catalyst microstructure and minor phase transformation of Ir(III)/Ir(IV) species during OER cause deactivation. Temperature‐programmed desorption indicated a possible link between the observed high activity and higher amounts of adsorbed H2O and desorbed O2 species.

Synthesis of Poly(ethylene furanoate) Based Nanocomposites by In Situ Polymerization with Enhanced Antibacterial Properties for Food Packaging Applications.

Poly(ethylene 2,5-furandicarboxylate) (PEF)-based nanocomposites containing Ce-bioglass, ZnO, and ZrO2 nanoparticles were synthesized via in situ polymerization, targeting food packaging applications. The nanocomposites were thoroughly characterized, combining a range of techniques. The successful polymerization was confirmed using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, and the molecular weight values were determined indirectly by applying intrinsic viscosity measurements. The nanocomposites' structure was investigated by depth profiling using time-of-flight secondary ion mass spectrometry (ToF-SIMS), while color measurements showed a low-to-moderate increase in the color concentration of all the nanocomposites compared to neat PEF. The thermal properties and crystallinity behavior of the synthesized materials were also examined. The neat PEF and PEF-based nanocomposites show a crystalline fraction of 0-5%, and annealed samples of both PEF and PEF-based nanocomposites exhibit a crystallinity above 20%. Furthermore, scanning electron microscopy (SEM) micrographs revealed that active agent nanoparticles are well dispersed in the PEF matrix. Contact angle measurements showed that incorporating nanoparticles into the PEF matrix significantly reduces the wetting angle due to increased roughness and introduction of the polar -OH groups. Antimicrobial studies indicated a significant increase in inhibition of bacterial strains of about 9-22% for Gram-positive bacterial strains and 5-16% for Gram-negative bacterial strains in PEF nanocomposite films, respectively. Finally, nanoindentation tests showed that the ZnO-based nanocomposite exhibits improved hardness and elastic modulus values compared to neat PEF.

The multifunctional performance of the laser powder bed fusion 316L stainless steel matrix composite reinforced with the CNT-ZrO2 nanohybrid

The effects of CNT-ZrO2 nanohybrid reinforcement on the microstructure features, mechanical properties, wear behavior, and corrosion resistance of laser powder bed fusion (LPBF) stainless steel 316L (SS 316L) were analyzed. X-ray diffraction, scanning electron microscopy, Raman analysis, tensile, pin-on-disk, and potentiodynamic polarization tests were conducted to determine the function of the CNT-ZrO2 nanohybrid reinforcement in enhancing the properties of the fabricated LPBF SS 316L matrix composite. The hardness, tensile properties, wear behavior, and corrosion resistance of the LPBF composites with various wt.% of the CNT-ZrO2 nanohybrid were compared with those of the unreinforced SS 316L and the SS 316L matrix composite containing detached CNTs and ZrO2 nanoparticles. The outcomes demonstrated a synergistic influence between the CNT and ZrO2 in an integrated nanosystem in improvement in the hardness, strength, wear behavior, and corrosion resistance of prepared composites.

Performance of composite ZrO2/MoDTC nanolubricant as an effective anti-friction and - Wear oil-based additive

Nanolubricants are the preferred method for improving the anti-friction and -wear performance of the moving components of machines. However, the lubrication performance requires further improvement. In this study, the tribological performances of ZrO2/MoDTC (BZM) nanolubricants with various mass ratios and concentrations were systematically evaluated using a pin-on-disc tribotester with a steel-steel contact pair. Subsequently, comparative analyses with lubricants containing only pure base oil (BO), pure ZrO2 (BZ) nanoparticles, and pure MoDTC (BM) additives were performed. The results validate the excellent anti-friction and -wear performances of BZM nanolubricants compared with individual BO, BZ, and BM lubricants, even in cases of high load and varied velocity. The optimal mixing ratio and concentration of BZM nanolubricant are 1:2 and 0.25–0.75 wt%, respectively. The friction coefficient of BZM (1:2) decreased by 71.64%, 67.80%, and 47.22%, respectively, compared with those of pure BO, BZ, and BM lubricants separately. The exceptional tribological performance of the BZM nanolubricants is ascribed to the structural advantages and physical synergistic lubricating actions of the ZrO2 nanoparticles and MoDTC additives during the friction process.

The Contact Interface Electronic Coupling of Cobalt and Zirconia Enables Stable and Highly Efficient 4e- Oxygen Reduction ReactionCatalysis.

Cobalt (Co) is an efficient oxygen reduction reaction (ORR) catalyst but suffers from issues of easy deactivation and instability. Here, it shows that ZrO2 can stabilize Co through interface electron coupling and enables highly efficient 4e- ORR catalysis. Porous carbon nanofibers loaded with dispersed Co-nanodots (≈10nm, 9.63wt%) and ZrO2 nanoparticles are synthesized as the catalyst. The electron transfer from the metallic Co to ZrO2 causes interface-oriented electron enrichment that promotes the activation and conversion of O2, improving the efficiency of 4e- transfer. Moreover, the simulation results show that ZrO2 acts like an electron reservoir to store electrons from Co and slowly release them to the interface, solving the easy deactivation problem of Co. The catalyst exhibits a high half-wave potential (E1/2) of 0.84V, which only decreases by 3.6mV after 10000 cycles, showing great stability. Particularly, the enhanced spin polarization of Co in a magnetic field reinforces the interface electron coupling that increases the E1/2 to 0.864V and decreases the energy barrier of ORR from 0.81 to 0.63eV, confirming that the proposed strategy is effective for constructing efficient and stable ORR catalysts.

Viscoelastic and vibrational studies of nano hybrid fibre metal laminates

Employment of distinct fibres (glass/carbon etc.) in Fibre Metal Laminates (FMLs) is one way of enhancing the durable life of an FML and its performance under dynamic loads. In the present work, carbon fibre is employed in GLARE (Glass/Aluminium laminated epoxy) to enhance the vibration (natural frequency) and viscoelastic (storage modulus ( E′), loss modulus ( E″) and Tan δ) properties. Similarly, the influence of 1 wt% of Al2O3 (alumina), ZrO2 (zirconium oxide) and TiO2 (titanium oxide) nano particles are also studied in hybrid (carbon/glass) FML. The mean particle size of Al2O3 (5.1 nm), ZrO2 (25.3 nm) and TiO2 (63.2 nm) were estimated using the Scherer equation with the aid of X-ray diffractometer analysis. Hybridisation resulted in a 22%, 10% and 2% increase of natural frequencies from mode 1 to mode 3 and 36.3%, 15% and 13.2% of E′, E″ and Tanδ, respectively, when compared to GLARE (glass fibre reinforced aluminium laminated epoxy). TiO2-reinforced hybrid FML shows the highest natural frequencies among all nanohybrid FMLs. The results summarise that natural frequencies and viscoelastic properties of nanohybrid FMLs are sensitive to the type of fibre, nano particle reinforcement and its size. A stereo microscope and a scanning electron microscope (SEM) were used to analyse the defects at the interface and the nanoparticle dispersion in the matrix, respectively. Further, a numerical model was developed to perform free vibration analysis, and it was noticed that the results were similar to experimental values.

Enhanced visible-light photocatalytic activity of ZrO2/gCN composite by introducing nitrogen vacancies with H2 plasma treatment

The abuse of tetracycline antibiotics (TCs) has caused serious environmental pollution problems in recent years due to excessive use of biomedicine, healthcare, animal husbandry and other fields. How to effectively remove TCs contaminants from water has been one of research emphasis on environment protection. In this work, we have successfully prepared a composite photocatalyst (P16-ZrO2/gCN) by physical mixing method and H2 plasma treatment at room temperature. The ZrO2 nanoparticles and H2 plasma treatment have synergetic effects on photocatalytic performance of gCN for degradation of TCs, and the highest degradation rate is achieved with 16 mins plasma treatment. According to BET, XPS and EPR results, more mesopores and nitrogen vacancies (NVs) are introduced by H2 plasma treatment. Furthermore, In-situ TRPL spectra illustrate that ZrO2 nanoparticles and H2 plasma treatment facilitate charge transfer process of catalysts. Overall, this work firstly reports utilizing ZrO2 nanoparticles/H2 plasma treatment together to boost photocatalytic performance of gCN and provides a low-cost approach for preparation of other photocatalysts.

Enhancing significantly the strength and tribological response of Al7075 alloy using nano-ZrO2 reinforcement

Ball milling is an effective method for developing a homogenous and refined microstructure for composites. In this study, we synthesized ultrahigh strength Al7075/xZrO2 alloy nanocomposites. These nanocomposites were specially fabricated by the in-situ powder metallurgy technique from high-purity elemental powders through a multi-step process, which included ball milling, uniaxial cold compaction, traditional sintering in an inert atmosphere, and hot extrusion. The ZrO2 nanoparticles with varying volume percentages (x vol.% = 0, 1.25, 2.53, 3.84, and 5.19) were used as a reinforcement. Ball milling was performed to mechanically alloy the elemental powders that reduce the grain size of the powder and homogeneously disperse the nano ZrO2 in the matrix. The physical, mechanical, microstructural, and tribological properties of the nanocomposites were determined. The results showed that adding 2.53 vol.% ZrO2 nanoparticles considerably improved the mechanical and tribological properties. The tensile strength and yield strength of the 2.53 vol.% alloy nanocomposites increased significantly. The wear resistance of the nanocomposite increased up to 5.19 vol.% ZrO2. The results obtained from the newly developed composites were compared with those of Al7075 alloy composites produced earlier.

Strength-enhanced Sn–In low-temperature alloy with surface-modified ZrO2 nanoparticle addition

Low-temperature packaging is essential for the widespread use of flexible electronic devices, and Sn–In eutectic alloys have attracted considerable attention because of their low melting temperatures. However, these alloys have a lower strength compared with other types of solder alloys. This study aimed to investigate the effect of adding nanoparticles on the mechanical strength of Sn–In eutectic alloys while keeping their melting temperature unchanged. ZrO2 nanoparticles coated with NiO (NiO/ZrO2 nanoparticles) were utilized to strengthen Sn–In eutectic alloys with a high dispersity. Sn–In composite alloys reinforced with NiO/ZrO2 nanoparticles were fabricated, and tensile strength evaluation and microstructure observations were conducted. The experimental results showed that the addition of nanoparticles to the Sn–In eutectic alloys did not change their melting behavior. The tensile strength of the Sn–In composite alloys reinforced with NiO/ZrO2 nanoparticles increased by up to 35.6%, which was attributed to grain refinement and dispersion strengthening. Even after thermal aging at 60 ºC, the Sn–In composite alloys reinforced with NiO/ZrO2 nanoparticles showed a 1.11 times higher ultimate tensile strength than that of the non-aged, non-reinforced eutectic alloy, despite grain coarsening. This was attributed to the contribution of dispersion strengthening. These results indicate that the addition of NiO/ZrO2 nanoparticles is an effective method to improve the strength of low-melting-temperature alloys.

Experimental approach on the effect of ZrO2/DW nanofluid on flat plate solar collector thermal and exergy efficiencies

Recently, many studies have increasingly dedicated have paid considerable attention to how nanofluids affect the efficiency of renewable energy systems. In this study, the effectiveness of ZrO2–distilled water (DW) nanofluid effectiveness on a solar thermal collector (FPSC) in Hungary, Gödöllő, was studied. First, four different volume fractions of 20 nm ZrO2 nanoparticles (0.025 %, 0.05 %, 0.075 % and 0.1 %) were added to DW-based nanofluids, and the stability and nanofluids characteristics were examined using various measurement instruments. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM), were used in the analysis of structural and morphological characteristics. The efficiency of a solar collector powered via nanofluids was then examined at various flow rates: 0.025, 0.033 and 0.041 kg/s. Findings showed that adding nanoparticles improved the FPSC’s efficiency to 72.1 %, and thermal efficiency of the FPSC increased by 26.2 % relative to that of water at 0.1% concentration and 0.041 kg/s flow. The proposed FPSC system in the nanofluid showed greater exergy efficiency than the system in DW, and a considerable in exergy efficiency (∼16.05 %) was observed when the nanoparticle concentration in the working fluid was 0.1 % ZrO2–DW. The system yielded maximum exergy efficiency. This study demonstrated the significant potential of ZrO2 nanoparticles for the application of solar energy.

ZrO2 modification of homogeneous nitrogen-doped oxide MgTa2O6−xNx for promoted photocatalytic water splitting

Homogeneous nitrogen-doped oxides are of wide visible light utilization for promising photocatalytic water splitting to produce hydrogen, but currently the poor charge separation severely limits their photocatalytic performances. In this work, a homogeneous nitrogen-doped tunneled oxide of MgTa2O6−xNx with an absorption edge of 570 nm was selected as a prototype to investigate the influence of ZrO2 modification on the charge separation as well as photocatalytic performance. It is interesting to observe that the formation of the reduced tantalum species, regarded as recombination centers, in the MgTa2O6−xNx sample could be effectively inhibited via the surface passivation with ZrO2 nanoparticles, based on which the photocatalytic water reduction and oxidation half-reaction activities could be remarkably promoted. Together with modification of the deposited Pt cocatalyst, the optimized H2 evolution rate over Pt-ZrO2/MgTa2O6−xNx (Zr/Ta = 0.10) photocatalyst was almost 4.5 times as high as that of the pristine Pt-MgTa2O6−xNx sample free of ZrO2 modification, whose apparent quantum yield at 420 nm (± 15 nm) achieved herein was superior to those of other reported homogeneous nitrogen-doped photocatalysts. The improved charge separation probably attributes to the introduction of Zr–O–Ta bond after ZrO2 modification, which is helpful to stabilize the tantalum species at more cationic state and inhibit the formation of the reduced tantalum species. This work extends the application territory of ZrO2 modification to the homogeneous nitrogen-doped oxide photocatalysts, and demonstrates its feasibility and effectiveness for remarkably enhanced photocatalytic water splitting performance.

Visible Light-Driven Photocatalytic Degradation of Tetracycline Using p-n Heterostructured Cr2O3/ZrO2 Nanocomposite

Antibiotic pollution beyond the safety limits poses a significant threat to the environmental sustainability and human health which necessitates the development of efficient methods for reducing antibiotics in pharmaceutical wastewater. Photocatalysis is a proven technology which has drawn considerable attention in semiconductor photocatalysts. Our study aims to develop a highly efficient Cr2O3/ZrO2 photocatalyst for the degradation of tetracycline (TCL) under visible light. The synthesized catalyst was well characterized by XRD, HR-TEM-SAED, XPS, FT-IR, BET and UV-Vis-DRS methods. The effects of various parameters on photocatalytic degradation were evaluated in detail, showing that 97.1% of 50 mgL−1 tetracycline concentrations could be degraded within 120 min at pH 5 with a 0.1 gL−1 photocatalyst-loading concentration under visible light (300 W Xe lamp). The uniform distribution of spherical ZrO2 nanoparticles on the surface of the Cr2O3 nano-cubes efficiently reduced the recombination rate with an energy bandgap of 2.75 eV, which provided a faster photodegradation of tetracycline under visible light. In addition, a plausible degradation pathway and photoproducts generated during the photocatalytic degradation of TCL are proposed based on the LC-ESI/MS results, which suggested that efficient photodegradation was achieved during the visible light irradiation. Thus, our study reveals that the cost-effective Cr2O3-based photocatalyst with multi-reusability and efficient energy consumption could be an efficient photocatalyst for the rapid degradation of TCL during the wastewater treatment process.

Regulating the electronic structure of Ir single atoms by ZrO2 nanoparticles for enhanced catalytic oxidation of formaldehyde at room temperature

Developing low-loading single-atom catalysts with superior catalytic activity and selectivity in formaldehyde (HCHO) oxidation at room temperature remains challenging. Herein, ZrO2 nanoparticles coupled low-loading Ir single atoms in N-doped carbon (Ir1-N-C/ZrO2) was prepared. The optimal Ir1-N-C/ZrO2 with 0.25 wt% Ir loading delivers the high HCHO removal and conversion efficiency (>95%) at 20 °C, which is higher than that over Ir1-N-C with the same Ir loading. The specific rate can reach 1285.6 mmol gIr−1 h−1, surpassing the Ir based catalysts reported to date. Density functional theory calculation results and electron spin resonance spectra indicate that the introduction of ZrO2 nanoparticles modulate the electronic structure of the Ir single atoms, promoting O2 activation to •O2–. Moreover, the Ir-C-Zr channel is favorable for the dissociation of •O2– to active oxygen atom (*O), and further accelerates the transformation of HCHO and intermediates (dioxymethylene and formates) to CO2 and H2O. This work provides a facile strategy to design low-loading single-atom catalysts with high catalytic activity toward HCHO oxidation.

Biosynthesis, Characterization, Adsorption and Antimicrobial studies of zirconium oxide Nanoparticles Using Punica Granatum Extract

In this study we using zirconium sulfate, Punica granatum plant extract, and an alkaline medium, to created ZrO2 nanoparticles. They were then characterized using a variety of techniques, including FT-IR, UV-visible, atomic force microscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The Debye-Scherrer equation was used to calculate the crystal size in X-ray diffraction and found to be 27.82 nm. The particle size of ZrO2 nanoparticles was determined using atomic force microscopy, scanning electron microscopes, and transmission electron microscopy. Utilizing ZrO2 NPs, the metal ions M (II) = Co, Ni, and Cu were successfully adsorbed, proving that the three metal ions could be removed from the water at the same time. Over the time frame and under the circumstances, Ni(II) has the highest rate of adsorption. Co, Ni, and Cu ions had removal efficiencies of 32.79%, 75.00%, and 30.20%, respectively. Three concentrations of the ZrO2 nanoparticles were tested against two types of bacteria, Escherichia coli and staphylococcus, and one type of fungus, Candida, in various concentrations of (25, 50, and 75) mg/L. The outcomes were contrasted with those attained using the medications Amoxicillin and Metronidazole.

Zirconium Dioxide Nanoparticles Effect on the Color Stability of Maxillofacial Silicone after Outdoor Weathering

Background: Maxillofacial prostheses made of silicone elastomers tend to lose color. Despite advances in materials and processes, color change over time remains a challenge. Objective: This in vitro study aimed to observe how zirconium dioxide (ZrO2) nanoparticles impact the color stability of M511 heat temperature vulcanizing (HTV) silicone elastomer following outdoor weathering. Methods: ZrO2 nanoparticles were added in concentrations of 1%, 2%, and 3% by weight to the M511 HTV silicone elastomer. Brilliant red- and mocha-pigmented silicone pigments were utilized, along with colorless silicone as a base control. A total of 90 disk-shaped specimens were fabricated and divided into nine experimental groups, each containing ten samples (n = 10). All specimens were subjected to 6 months of outdoor weathering. A colorimeter was used to measure the values of L*a*b* according to the CIELab system. The 50:50% perceptibility threshold (∆E* = 1.1) and acceptability threshold (∆E* = 3.0) were used to interpret recorded color differences. At the 0.05 level of significance, the 1-way ANOVA and the Tukey post hoc test were used in the statistical analysis. Results: All evaluated specimen groups experienced a chromatic alteration (∆E* > 0). The ∆E* values exceeded the perceptible threshold in all groups (1.1 units). The ∆E* value of the colorless group and the red pigment with and without ZrO2 nanoparticles were both above the acceptable threshold (p < 0.001). Mocha control was also above the acceptable level but was not statistically significant (p > 0.99). ZrO2 nanoparticles showed a reduction in color change. Conclusion: According to this in vitro study, all specimens underwent color changes. Even colorless silicone exhibited a significant color change. The red pigment showed a highly significant chromatic alteration. ZrO2 nanoparticles showed important protection and a reduction in color change. Its protecting action increased with an increase in the concentration of ZrO2 nanoparticles (3% ZrO2 > 2% ZrO2 > 1% ZrO2).

Characterization, rheological behaviour, and dynamic viscosity of ZrO2-SiC (50–50)/DW hybrid nanofluid under different temperatures and solid volume fractions: An experimental study and proposing a new correlation

Researchers, engineers, scientists, and other professionals have been focusing on the exploitation of nanotechnology with specific attention to nanofluids and their property of dynamic viscosity that can do wonders in the field of engineering. This study was aimed at determining the dynamic viscosity of the given hybrid nanofluid (distilled water based ZrO2/SiC) by studying the nanofluid's rheology. In this regard, a two-step method was employed for the dispersal of nanoparticles in the base fluid. The nano-powder was composed of ZrO2 and SiC in a ratio of 1:1 (50% - 50%). The dynamic viscosity of solid volume fractions 0.025% - 0.1% was measured in temperatures 20–60 °C by using DV2TRVTBG Brookfield digital viscometer. The research indicated the association between the nanofluid's viscosity and the factors of temperature and solid volume fraction. At first, in order to assessment the characteristics and stability of nanoparticles into the base fluid, XRD, TEM, FESEM, EDX, UV–vis spectrometer, DLS, and zeta potential test were used on ZrO2 and SiC nanoparticles. The results indicated an increase in dynamic viscosity at higher solid concentrations and falling temperatures. The dynamic viscosity increase of the nanofluid was recorded at 20 and 60 °C, which showed a 29.6% and 64.2% rise in the viscosity respectively in the presence of 0.025% of nanoparticles in the nanofluid. This implies that the viscosity of nanoparticles becomes more sensitive at high temperatures. The experiment showed a maximum viscosity rise of 169.4%. The experiments also discovered that ZrO2-SiC /DW hybrid nanofluid can be successfully used in different devices as a Newtonian fluid since it depicts Newtonian properties at various temperatures. In addition, the study put forward a new correlation for determining the dynamic viscosity of hybrid nanofluid using the experimental data (temperature and solid volume fraction). The value of mathematical correlation accuracy was 98.92%. During the experiment, the sensitivity of viscosity in response to a rise in solid volume fraction was evaluated. Lastly, an acceptable level of accuracy of the correlation outputs was seen when the theoretical and practical values were contrasted.

Nitrogen-doped carbon aerogel framework with in situ encapsulated ZrO2 nanoparticles as pseudocapacitive anode for phosphorus uptake

Phosphorus reduction is crucial for controlling eutrophication and protecting the aquatic environment. Nonetheless, traditional methods suffer from secondary pollution and high costs. Capacitive deionization (CDI) is a novel electrochemical approach for phosphorus removal, which is low-cost and environmentally friendly. Its performance is highly correlated with the electrode material. Herein, a novel nitrogen-doped carbon aerogel framework encapsulated with ZrO2 nanoparticles (ZrNC) was rationally fabricated and employed as an anode for phosphorus removal. The experimental results revealed that the N site and ZrO2 could enhance the physicochemical properties, electrochemical activity, and additional pseudocapacitive contribution, thus raising the phosphorus removal capacity. The optimal ZrNC-3 electrode demonstrated superior phosphorus capture (18.26 mg P/g), low energy consumption at 1.2 V (0.0256 kWh/m3 and 4.159 kWh/kg), outstanding phosphorus selectivity, and excellent stability. Mechanism investigation suggested phosphorus can form mono- or bi-dentate inner-sphere complexes (Zr–O–P) by ligand exchange with ZrO2 sites under an electric field and combined with unsaturated Zr sites and N species by electrostatic attraction. This study presents a promising conception for designing and applying metal oxide/carbon complexes in selective phosphorus uptake electrodes.

Diamond-like carbon films doped with ZrO2 nanoparticles: Improving antimicrobial properties

Diamond-like carbon films doped with zirconium oxide nanoparticles were developed as a nanocomposite, seeking better antibacterial properties for medical applications. Monoclinic zirconium oxide nanoparticles were heated and sonicated at 700 W to obtain a suspension with a particle size with low polydispersity in hexane as a solvent. There were no appreciable changes, neither in the surface organic functional groups nor in the crystalline structure with the heating process. The suspension was introduced into a reaction chamber to generate a carbon plasma in a deposition process. Ti6Al4V was used as a substrate in order to obtain acceptable adherence values close to 22 N. Diamond-like carbon films doped with zirconium oxide nanoparticles were obtained via PECVD and an additional cathode technique. The bactericidal and fungicidal properties of the films were evaluated by direct and non-direct contact. Non-contact results showed films with good bactericidal properties, close to 95 % after 6 h and 36 % after 18 h. Fungicidal properties were at 65 % and 50 %, respectively, under the same test conditions. These results suggested that the nanoparticles helped to maintain quasi-constant damage in C. albicans, in contrast to E. coli, where the properties decreased considerably. So, the death mechanism caused by zirconium oxide nanoparticles is more effective long-term against C. albicans than E. coli. When there is direct contact, the nanoparticle agglomerates acted as a poison in the cell, causing degeneration in geometry and continuity of the cells.