Monoclinic ZrO2 Phase Research Articles

Development of step-wise functionally graded materials nano (3YPSZ/Al2O3) with improved fracture toughness and low thermal degradation for hip joint replacements

In this work high order (10 layers) step – wise functionally graded materials (FGM) of nano 3Y- tetragonal zirconia poly crystals (3YPSZ) and nano alumina (Al2O3) successfully prepared by powder technology technique. “Fracture toughness and hardness were measured by using indentation methods”. Low thermal degradation (LTD) was done at 134 ºC and 0.2 bar in autoclave, the amount of monoclinic phase of ZrO2 (m – phase) on the exposed surface was calculated by X-ray’s diffraction (XRD). Results showed prevent of m – t transformation after 40 hr in all FGM specimens, high fracture toughness along cross – section of specimens due to increase of zirconia content, which tetragonal phase is toughening agent. SEM observations and EDS analytic a long cross – section of specimen showed good distributed of 3YPSZ from EDS analytic and there were no agglomerates, some pores appear due to binder material that was used in pressing process.

Preparation of Magnesia Partially Stabilized Zirconia Nanomaterials from Zirconium Hydroxide and Magnesium Carbonate Precursors Using PEG as a Template

Stabilized zirconia is a promising material due to its great physical and chemical properties, and thermal stability. In this work, MgO was used as a stabilizer in ZrO2 to obtain Magnesia Partially Stabilized Zirconia (MSZ) nanomaterials assisted with PEG as a template through conventional mixing process. Zirconium hydroxides prepared from local zircon and MgCO3 were used as MSZ precursors. Meanwhile, the stabilizer concentration was varied from 1 to 4 wt% of ZrO2. The effect of the stabilizer concentration and the calcination temperature to the crystallinity and the morphological properties of the MSZ nanoparticles were studied using X-ray diffraction and scanning and transmission electron microscopy. The ZrO2 content in the zirconium hydroxides precursors is accounting 89.52 wt% of the total and exhibits the dominant m-phase at 1000 °C. Meanwhile, the tetragonal and the monoclinic phases were formed in all MSZ samples at a temperature of 800–1000 °C. The as-synthesized MSZ samples show typical FT-IR spectra, consisting of the metal–oxygen bonds at below 500 cm−1 and the organic functional groups ranging at 1000–3000 cm−1. The ZrO2 morphologies exhibit spherical-like shapes with elongated agglomeration at 800 °C. In addition, the average particle sizes of the final product ranges from 20 to 50 nm. At a sintering temperature of 1500 °C, MSZ samples show the monoclinic phase of ZrO2 and densities in the range of 3.95–4.14 g/cm3.

Orientations and seed type effect on Al2O3-YAG-ZrO2 eutectic microstructure solidified from the melt by the micro-pulling down technique

Al2O3-YAG-ZrO2 eutectic ceramic rods of 5 mm in diameter were grown by micro-pulling down technique. The seeding and the solidification rate affect microstructure, morphology, crystallography, and thermal stress of the solidified ceramics. The ternary eutectic grown through zirconia (111) seed had inhomogeneous and irregular cellular microstructures. At the stationary stable regime, the microstructure spacing (λ) depends on the pulling rate (v). Under solidification rate of 0.5 mm.min−1, the rods grown by using eutectic poly-crystal, (100), (111) YAG, and c(0001), A(1−210), M(10−10) sapphire seeds, the YAG and ZrO2 phases are oriented along the <100> direction parallel to the growth direction. The zirconia (111) seeding X-ray diagram eutectic presents additional peaks and the monoclinic ZrO2 phase appears at the solidification rate of 1 mm.min-1. The rods grown through ZrO2 seeding are more stressed than those solidified by using eutectic, YAG and sapphire seeds, respectively.

CO2 Hydrogenation to Methanol on ZnO/ZrO2 Catalysts: Effects of Zirconia Phase

AbstractZnO/ZrO2 samples were obtained by impregnation ZnO on three different ZrO2 polymorphic phases: monoclinic, tetrahedral and amorphous. The catalysts were tested for CO2 hydrogenation to methanol and the structure was determined using nitrogen physisorption, scanning electron microscope (SEM), Fourier transform infrared (FT‐IR) pyridine adsorption, hydrogen temperature‐programmed desorption (H2‐TPD), CO2‐TPD and X‐ray photoelectron spectroscopy (XPS). The results showed that the ZnO/tm‐ZrO2‐500 catalyst, with a mixture of both tetrahedral and monoclinic ZrO2 phases, had the highest CH3OH yield among all the samples. The yield of methanol is correlated to the lattice oxygen content for all the catalysts. During the reaction, formate and methoxy species seemed to be the active intermediate species.

Thermal stability of atmospheric pressure plasma jet-deposited ZrO2 top coats and sputtered RuAl/RuAlZr/Ru bond coats on Inconel 617

In this study, the feasibility of using ZrO2 coatings, fabricated through the atmospheric pressure plasma jet technique, as top coats in thermal barrier systems was explored. Inconel 617 was used as the substrate material, and sputtered laminated RuAl/RuAlZr/Ru was used as the bond coat. >20-μm-thick ZrO2 coatings were deposited through several iterations of deposition at 500 °C and annealing at 600 °C; here, ZrO2 existed in the tetragonal phase. The tetragonal ZrO2 was stable after annealing at up to 700 °C but transformed into a mixture of tetragonal and monoclinic ZrO2 phases when annealed at >800 °C. The thermal stability of the ZrO2/RuAl/RuAlZr/Ru/Inconel 617 assembly was evaluated at 800–900 °C in air. The variations in volumetric fractions of the tetragonal and monoclinic ZrO2 phases were recorded; 44% of the tetragonal phase remained after 100 h of annealing at 800 °C, whereas 80% of the tetragonal phase had transformed into the monoclinic phase after 4 h of annealing at 900 °C. Observation of BC after annealing at 800 °C indicated that a dense thermally grown oxide scale, comprising O and Al, formed between the ZrO2 and RuAl layers, which impeded the inward diffusion of O. The inhibition of O diffusion declined with the crystallization of the thermally grown oxide scale into the δ-Al2O3 phase when the annealing time was extended.

Catalytic Performance of Lanthanum Promoted Ni/ZrO2 for Carbon Dioxide Reforming of Methane

Nickel catalysts supported on zirconium oxide and modified by various amounts of lanthanum with 10, 15, and 20 wt.% were synthesized for CO2 reforming of methane. The effect of La2O3 as a promoter on the stability of the catalyst, the amount of carbon formed, and the ratio of H2 to CO were investigated. In this study, we observed that promoting the catalyst with La2O3 enhanced catalyst activities. The conversions of the feed, i.e., methane and carbon dioxide, were in the order 10La2O3 &gt; 15La2O3 &gt; 20La2O3 &gt; 0La2O3, with the highest conversions being about 60% and 70% for both CH4 and CO2 respectively. Brunauer–Emmett–Teller (BET) analysis showed that the surface area of the catalysts decreased slightly with increasing La2O3 doping. We observed that 10% La2O3 doping had the highest specific surface area (21.6 m2/g) and the least for the un-promoted sample. The higher surface areas of the promoted samples relative to the reference catalyst is an indication of the concentration of the metals at the mouths of the pores of the support. XRD analysis identified the different phases available, which ranged from NiO species to the monoclinic and tetragonal phases of ZrO2. Temperature programmed reduction (TPR) analysis showed that the addition of La2O3 lowered the activation temperature needed for the promoted catalysts. The structural changes in the morphology of the fresh catalyst were revealed by microscopic analysis. The elemental compositions of the catalyst, synthesized through energy dispersive X-ray analysis, were virtually the same as the calculated amount used for the synthesis. The thermogravimetric analysis (TGA) of spent catalysts showed that the La2O3 loading of 10 wt.% contributed to the gasification of carbon deposits and hence gave about 1% weight-loss after a reaction time of 7.5 h at 700 °C.

Surface plasmon resonance effect, nonlinearity and faraday rotation properties of magneto optical glass: Influence of diamagnetic Ag@ZrO2 nanoparticles

In this study, for the first time we report the influence of Ag@ZrO2 nanocomposites to diamagnetic glass forming ability, structure, Plasmon, nonlinear, hardness and Faraday rotation properties. Spherical Ag@ZrO2 nanocomposites with average 50 nm size were synthesized and well dispersed without oxidation of silver. XRD, XPS, FT-IR and Raman spectra displayed the pure Ag0 and monoclinic ZrO2 phases with typical ZrO2 (m) vibration modes. Due to the high polarizability and large mass, high valence Zr4+ existed in glass as ZrO4 which strengthened the glass network, so good quality and transparent glasses were obtained for 0–3% Ag@ZrO2 doping amount. 3% Ag/ZrO2 containing glass presented strong SPR effect, the biggest hardness of 497HV, giant nonlinear refractive index of 3.44×10−17 m2/W and the highest Verdet constant of 0.2002 min/G.cm which make the glass most suitable for magneto optical, nonlinear and photonic applications.

Hot corrosion behavior of ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3 TBCs in CMAS: CaO-MgO-Al2O3-SiO2

Improvement of hot corrosion resistance in calcium-magnesium-aluminosilicate (CMAS: CaO-MgO-Al2O3-SiO2) environments is one of the main goals in the development of aero-engines especially in their thermal barrier coatings (TBCs). In this regard, this study aims to improve the quality and efficiency of the yttria-stabilized ZrO2 (8YSZ) TBCs by substitution of new coatings such as ZGYbY: ZrO2 9.5Y2O3 5.6Yb2O3 5.2Gd2O3. For this purpose, 8YSZ and ZGYbY topcoats with CoNiCrAlY bond coat were applied on IN738LC substrates using atmospheric plasma spray (APS) technique. Hot corrosion behavior of the coatings was investigated in CMAS environment by a furnace method at 1150 °C in the 4-h cycles. Phase and microstructural investigations of the coatings by XRD and FESEM/EDS methods before and after the hot corrosion test indicated the better performance of ZGYbY coating (relative to 8YSZ) in preventing from the diffusion of the CMAS particles. This could be due to the formation of the impermeable apatite compounds (i.e., Ca4Y(Yb/Gd)6O(SiO4)6). Furthermore, the destruction of the TBCs in CMAS environment can be attributed to the diffusion of molten silicates through the pores and micro-cracks of the ceramic top layer to the TBC and then release of the ZrO2 stabilizer and finally the tetragonal to monoclinic ZrO2 phase transformation.

Synthesis nanocompsite TiO2-ZrO2 for photocatalic degration of phenol and methylene blue (MB)

A series of TiO2-ZrO2 binary oxide samples with various TiO2-ZrO2 content (90-10, 80-20, 70-30, 60-40, 50-50 mol %) were prepared by the co-precipitation method. The obtained samples were characterized by XRD, SEM, EDX, UV-vis, IR spectroscopy and BET. XRD data identified the anatase phase of the TiO2 and tetragonal, monoclinic phases of ZrO2 in all obtained samples. The average crystallite size of the samples was between 16 to 21 nm. As UV-Vis spectra, the band gaps of TiO2-ZrO2 composites vary from 2,5 eV to 3,1 eV. The photocatalytic reactions confirmed that the nanocomposite sample showed higher photocatalytic activity than the pure oxides samples for the degradation of phenol and methylene blue (MB) under 100 W incandescent lamp. Among the prepared samples, the best sample for photocatalytic degration of MB is the ĐKT9-1 which contains 90% TiO2 and 10% ZrO2 with a percentage 95% after 180 minutes. The ĐKT8-2 which contains 80% TiO2 and 20% ZrO2 shows the best phenol removal efficiency of 97% after 30 minutes. This indicates that the materials are capable of treating MB and phenol in wastewater.

Evolution of the residual stress in porous ceramic abradable coatings under thermal exposure

Porous dysprosium-stabilized zirconia (DySZ) based abradable coatings were fabricated on DD5 superalloy by atmospheric plasma spraying technique (APS). The residual stress of the porous coating after thermal aging at 1100 °C was characterized using Raman spectroscopy and Photoluminescence piezo-spectroscopy (PLPS) techniques. The results indicated that the residual stress of the porous topcoat was smaller than the theoretically predicted due to a large number of pores and cracks inside the coating. Based on the stress evolution behavior of the porous coating exposed to thermal aging, a rational failure threshold stress was suggested. In addition, the effect of coating depth, pores and monoclinic ZrO2 phase on the stress distribution were analyzed on the polished cross-section specimens. Meanwhile, the stress distribution along the TGO direction showed a strong correlation with the local geometry, and the number of points showing tensile stress increased with prolongation of thermal exposure. Evidence revealed that the initiation and propagation of micro-cracks prefer to occur at locations with high curvature and tip edge of the convex area. The research in this paper provides enlightenment for life prediction and structural optimization.

Whether Ge-Rich ZrO2 and Ge-Rich HfO2 Materials Have Similar Reaction on Annealing Treatment?

The properties of Ge-HfO2 and Ge-ZrO2 films were studied versus Ge content and annealing temperature by means of Raman scattering, FTIR and X-ray diffraction methods. Ge-HfO2 films with [Ge]<5 at.% were polycrystalline, whereas higher Ge content stabilized amorphous structure that was stable for T<600°C. The T increase caused the formation of Ge clusters and tetragonal HfO2 phase. This latter appeared at T=600-670°C, while the Ge clusters crystallized at T=700-800°C. Unlike to Ge-rich HfO2 films, as-deposited Ge-ZrO2 films and those annealed at T≤600°C were amorphous. In these films, formation of Ge clusters and their crystallization occurred at T=640-700°C depending on Ge content, whereas ZrO2 phase crystalized at T=680-700°C that allowed to form Ge nanocrystals in amorphous matrix at T=640-680°C. For T>800°C, the films showed appearance of monoclinic HfO2 or ZrO2 phases that was explained by the Ge content decrease via volatile GeO formation. Obtained results supported theoretical prediction of the stability of tetragonal phases in these oxides via Ge doping. However, our results showed also some difference in the phase separation process of Ge-rich HfO2 and Ge-rich ZrO2 upon thermal treatment.

Carboxylate-assisted synthesis of highly-defected monoclinic zirconia nanoparticles

Zirconia (ZrO2) nanoparticles were prepared by hydrothermal route using zirconium oxychloride (ZrOCl2) as a single precursor with different sodium carboxylates as mineralizers. The structure, morphology and defects of the nanoparticles were characterized by XRD, HRTEM and ATR-FTIR spectroscopy. X-ray diffraction studies revealed that the as-synthesized zirconia was pure monoclinic ZrO2 phase. The crystallite sizes were in the range 8.9–19.5 nm. The defects and microstrains of ZrO2 nanoparticles were greatly influenced by the type of sodium carboxylate. Apparently, there was a direct correlation between the stability constant of Zr(IV)-carboxylate complex and the amount of defects in the produced ZrO2. Sodium tartrate produced semicrysalline ZrO2 nanoparticles with microstarin that were 5 times greater than that produced without any carboxylate salt. ZrO2 nanoparticles with increased defects and microstarins were found to be rich with surface hydroxide groups. Designing monoclinic ZrO2 with controlled defects and degree of hydroxylation may have a great impact in heterogonous organic catalysis.

Corrosion resistance of sol-gel ZrO2 coatings deposited on stainless steel

Corrosion-resistant ZrO2 coatings were deposited on stainless steel plates using organic (A) and inorganic (B) Zr precursors containing polyethylene glycol as structure directing agent. The dipping-drying cycles were repeated five times; the coatings were then treated at 500 °C. The samples were studied by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and by automated contact-angle goniometry. The corrosion resistance of the ZrO2 coatings were examined in NaCl and artificial sea water. The XRD analyses revealed a crystallized monoclinic ZrO2 phase. The AFM observation proved that after the corrosion attack the surface had no signs of corrosion (scratches or cracks). The A and B coatings had corrosion rates of 4×10−5 and 2×10−4 g/m2 h, respectively. The A coatings possessed a fine grained structure and a lower wettability (contact angle of 107°) and a lower oxygen content than the B coatings, which determined their better corrosion properties in both corrosive media.

Photocatalytic degradation of methylene blue dye by fluorite type Fe2Zr2-xWxO7 system under visible light irradiation.

Nano-sized Fe2Zr2-xWxO7 system was prepared using the Pacini method where x=0, 0.05, 0.1 and 0.15. All the samples were characterized using chemical analysis, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), UV-vis diffuse reflectance measurements (DRS) and surface area measurements. The undoped Fe2Zr2O7 was crystallised in the cubic fluorite phase as a major phase in addition to rhombohedral phase of Fe2O3 and monoclinic phase of ZrO2 as the minor phases. Meanwhile, single cubic fluorite phase was defined for Fe2Zr0.85W0.15O7 sample. The last has the lowest band gap (1.69eV) and the highest surface area (106m2/g). From TEM, the average particle size of the prepared samples was in the range of (3-7nm). The photocatalytic efficiency of the prepared Fe2Zr2-xWxO7 system was manifested by the degradation of methylene blue and real textile wastewater of blue colour. Ascending degradation efficiency was exhibited with increasing tungsten concentration which is in accordance with their band gap as well as their surface area values. The degradation rate using Fe2Zr0.85W0.15O7 sample obeys the pseudo-first order kinetic at the optimum degradation conditions (1.5g/L catalyst and pH11). Fe2Zr0.85W0.15O7 showed promising photocatalytic activity for real textile wastewater where the 69% COD removal was obtained under the same conditions used for methylene blue degradation.

Microstructure and synthesis mechanism of dysprosia-stabilized zirconia nanocrystals via chemical coprecipitation

In this study, zirconia (ZrO2) and dysprosia-stabilized zirconia (DySZ) nanocrystals were synthesized using a chemical coprecipitation method. The crystal structure and micromorphology of the as-synthesized powders, as well as the structural evolution from precursors to oxides were investigated, and the synthesis mechanism was also examined. Results show that pure ZrO2 powders mainly comprise the monoclinic ZrO2 phase with trace tetragonal ZrO2, while the DySZ powders exhibit a tetragonal ZrO2 structure. In addition, the crystal growth rate of DySZ is far slower than that of the pure ZrO2 under elevated calcination temperature. The addition of Dy could significantly improve the phase stability of DySZ powder and effectively inhibit the crystal growth of DySZ. In the DySZ precursor, the binding energy of chemical bonds is significantly difference than in the ZrO2 precursor. A composite hydroxide can be formed with -Zr-OH-Dy- and -Zr-OH-Zr- units in the tetramer structure because of the in-situ substitution of Zr by Dy atoms. Both the ZrO2 and DySZ precursors exhibit analogous dehydration and crystallization behaviours in calcination process. Dy-doping plays a significant role in stabilizing both the intermediate product and the DySZ crystal.

Highly enhanced aging resistance of rapidly solidified zirconia toughened alumina bioceramics with refined eutectic microstructure

A novel zirconia toughened alumina bioceramic (ZTA) with a unique microstructure was prepared by rapid solidification with laser floating melting zone technique. The magnitude of microstructure dimension of the solidified samples is refined at the level of the submicron scale (150 nm∼630 nm). The aging behavior of as-solidified ZTA bioceramic is investigated. The monoclinic ZrO2 phase content of the solidified samples after 145 h of aging decreases from 30 % to 5.3 % when the solidification rate increases from 8 μm/s to 100 μm/s, lower than that of the sintered sample with the same composition. The growth rate (αd) and the nucleation rate (Nr) of monoclinic phase of the solidified samples are lower than the sintered sample and the former is the dominant factor determining the aging behavior. Therefore, the solidified ZTA bioceramics exhibit excellent aging resistance that may cast light on extending the clinical application of all-ceramic dental prosthesis.

The study of chromium oxide loading on platinum chromium oxide zirconia catalyst for n-dodecane and 1,4-diisopropylbenzene hydrocracking

Hydrocracking reaction is one of the major processes in petroleum refining. To date, the exploration of a suitable catalyst for hydrocracking reaction remains challenging. The presence of Pt loaded on Cr2O3-ZrO2 promotes the catalytic activity and stability of Cr2O3-ZrO2. While, zirconia has an interesting thermal and mechanical properties which make it as a support material. Therefore, in this study, platinum chromium oxide zirconia catalyst (Pt/Cr2O3-ZrO2) with different Cr2O3 loading (1, 4, 8, and 12 wt%) were prepared by impregnation method. The physical and chemical properties will be characterized by the XRD and FTIR analysis whereas catalytic testing will be analyzed by n-dodecane and 1,4-diisoproylbenzene hydrocracking. The XRD results showed that the peak intensity of the tetragonal phase of ZrO2 and bulk crystalline of Cr2O3 increased with the increase in the Cr2O3 loading from 1 to 12 wt%. The FTIR KBr analysis showed the presence of monoclinic and tetragonal phase of ZrO2 and none or only negligible amount of coke formed during the reaction. The 2,6-lutidine adsorbed FTIR analysis showed that six bands located at 1675, 1660, 1650, 1640, 1630 and 1625 cm−1 corresponding to the Bransted acid sites whereas the Lewis acid sites located at 1608, 1603, 1593, 1580, 1565 and 1560 cm−1. For n-dodecane and 1,4-diisoproylbenzene hydrocracking, all catalysts showed 100% conversion except for Pt/12Cr2O3-ZrO2. Hence, the presence of tetragonal phase and Lewis acid sites play an important role for catalytic activity of n-dodecane and 1,4-diisoproylbenzene hydrocracking.

Occurrence of Ferromagnetic Behavior in ZrO2 by Ni Substitution Beyond x = 0.01

A series of Zr1-xNixO2 nanocrystalline powders were synthesized by chemical route and then calcined at 750 °C for 5 h. A mixed phase of monoclinic and tetragonal phase of ZrO2 has been observed in XRD patterns and Raman studies. The tetragonal phase of ZrO2 increases up to a Ni concentration of x = 0.025 and thereafter suppression of the tetragonal phase is observed with the increase in monoclinic phase of ZrO2. At lower concentration of Ni of x = 0.01, the material manifests with diamagnetic property and then a diamagnetic to ferromagnetic transition is established at above than x = 0.01. The saturation magnetization increases with increase in Ni concentration up to x = 0.025 and then decreases for Ni concentration of x = 0.03 in Ni substituted ZrO2. The sudden fall in saturation magnetization in Zr0.97Ni0.03O2 arises due to the superexchange interactions between two neighboring Ni2+ ions which lead to antiferromagnetism in the material and suppress the ferromagnetic ordering.

The controlled preparation and stability mechanism of partially stabilized zirconia by microwave intensification

Partially stabilized zirconia (PSZ) occupies an important application portion in ceramics materials and refractories materials. In this work, calcium oxide-partially stabilized zirconia (CaO-PSZ) ceramics were prepared from fused zirconia by microwave sintering, with its microstructure and stability properties characterized by XRD and SEM. Results indicated that the heating rate, cooling rate, quenching temperature and isothermal treatment time rendered different influence on the stability properties, which was mainly ascribed to the reversible martensitic transformation of zirconia ceramics. Additionally, a mixed-phase composed by cubic phase ZrO2 (c-ZrO2) and monoclinic phase ZrO2 (m-ZrO2) appeared after fused zirconia treated by microwave sintering at 1450 °C for 2 h, indicating the formation of CaO-PSZ ceramics, which the finding was consistent with the SEM and EDAX analysis. Meanwhile, CaO stabilizer precipitated behavior at the crystal boundary, with the formation of acicular grains and fine particles, further rendering a toughening effect to CaO-PSZ ceramics. This work can provide important theoretical and practical significance for applications of microwave sintering to prepare CaO-PSZ ceramics material, even extending further applications in functional materials and structural materials.

Photocatalytic removal of 4-chlorophenol present in water using ZrO2/LDH under UV light source

The influence of ZrO2 semiconductor content (0.3–5 wt%) supported on a Layered Double Hydroxides (LDH) system for photodegradation of 4-chlorophenol (4-CP) in water was studied. Complete removal of 4-CP is achieved in two stages: first, 4-CP was adsorbed on the photocatalyst in darkness, until equilibrium was reached. Afterwards, the light was turned on, and the photodegradation process started. Adsorption and photodegradation were analyzed both individually, and combined. The adsorption process of 4-CP on the synthesized samples is well described by fitting a pseudo-second-order equation. The UV photodegradation rates were 2.6 times higher than the 4-CP removal rates achieved by adsorption. The photodegradation process was analyzed by means of hydroxyl radical production displaying zeroth order behavior. The photocatalyst with 1 wt% ZrO2/LDH had the highest hydroxyl radical production rate, achieving 99 % of 4-CP degradation and 87 % of mineralization, while maintaining its photocatalytic activity during ten reaction cycles. At wt%ZrO2/ LDH higher than 1 wt%, clustering is observed, promoting charge recombination, hindering photodegradation efficiency and thus, decreasing mineralization rates. The monoclinic phase of ZrO2, identified by XRD, was responsible for the high photocatalytic activity. The distances between cations within the LDH layers were not modified after ZrO2 impregnation, thus suggesting that zirconia was supported on the external surface of LDH. Characterization was done by N2 physisorption, TGA, XRD, AAS, UV-DRS TEM, and SEM-EDS.