Doped Zirconia Research Articles

Efficient Photocatalytic Degradation of Rhodamine B Dye by Undoped and Zinc Doped Zirconium Dioxide NPs

Efficient Photocatalytic Degradation of Rhodamine B Dye by Undoped and Zinc Doped Zirconium Dioxide NPs

Effect of (Zr, Ta) doping on electronic and magnetic properties of zinc-blende MgTe DMS compound: AB-initio approach

This study utilizes density functional theory (DFT) and the Korringa-Kohn-Rostoker coherent potential approximation (KKR-CPA) to explore the effects of zirconium (Zr) and tantalum (Ta) doping on the electronic and magnetic properties of zinc-blende MgTe. The electronic configurations of Mg1-x(TM)xTe (TM = Zr, Ta) were analyzed, revealing that Zr induces magnetic behavior with near-total spin polarization, while Ta doping leads to metallic behavior with partial polarization. The variations in magnetic moments are largely determined by impurity concentrations, with ferromagnetic stability in both systems driven by a double exchange interaction mechanism. Additionally, Curie temperatures exceeding room temperature were observed for specific doping concentrations. These results suggest significant potential for MgTe-based materials in spintronic applications. The findings further illustrate that Zr-doped alloys display half-metallicity, making them especially promising for future spintronics device development. KEY WORDS: DMS, KKR-CPA, Polarization, Metallic behavior, Curie temperature, Double exchange, Spintronic Bull. Chem. Soc. Ethiop. 2025, 39(1), 153-164. DOI: https://dx.doi.org/10.4314/bcse.v39i1.13

Synthesis, optimization, electrochemical and electrochromic properties of Zr-doped NiO films by chemical spray pyrolysis

Zirconium (Zr)-doped NiO films with different contents were successfully synthesized via the chemical spray pyrolysis technique. The structure, morphology, optical and electrochemical behaviors of these films were investigated by X-ray diffraction (XRD), Raman spectrometer, scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), UV–Vis-NIR spectrophotometry, cyclic voltammetry (CV), and chronoamperometry (CA). XRD results suggested that the synthesized samples have the cubic crystal structure and a preferred orientation along the plane (111). Raman spectra further confirmed the successful incorporation of zirconium ions into the NiO films. SEM images explained that the surfaces of the doped films were composed of uniform and dense nanoparticles. EDS analysis suggested that Zr, Ni and O elements were uniformly distributed on the films. The optical results showed that the band gap decreases from 3.53 eV to 3.47 eV as the increase of zirconium doping content. The electrochemical analysis suggested that zirconium doping improved the specific capacitance of the NiO films (the NiO film with the Zr amount of 7 %, 59 F/g at 6 mV/s). In addition, the NiO film with 5 % Zr doped amount exhibited the largest ΔOD (81 %), the largest CE (60.37 cm2/C), and the fastest coloring time (tc =2.1 s) and bleaching time (tb = 2.4 s). These results showed that this film had the excellent electrochromic properties, suggesting that the optimal Zr doped amount of NiO films is 5 %. As a novel kind of electrochromic material, the Zr-doped NiO film has broad application prospects in smart windows, green buildings and energy efficient utilization fields.

Revisiting the validity of the ‘Garvie criterion’ for the stabilization of doped tetragonal zirconia systems

Revisiting the validity of the ‘Garvie criterion’ for the stabilization of doped tetragonal zirconia systems

Enhanced the stability and efficiency of CoxSy/PMS degradation towards metronidazole: Zirconium doping and vacancy engineering

This study designed a vacancy-decorated bimetallic sulfide catalyst, Zr-CoxSy-V, for the removal of metronidazole (MTZ) from aqueous solutions through PMS oxidation. By integrating the zirconium (Zr) species into CoxSy and employing sulfur vacancies (SVs) regulation, the Zr-CoxSy-V/PMS system showed a significant enhancement on the catalytic kinetic, with the reaction rate constant of 0.3326 min−1, approximately 15.8 times higher than that of the CoxSy/PMS system (0.0210 min−1). Moreover, this system inhibited the cobalt (Co) ion leaching to 0.57 mg/L, marking an 83.3 % decrease compared to the CoxSy-V/PMS system (3.41 mg/L). Zr doping elevates the proportion of low-valent Co species and mitigates Co ion leaching. The presence of SVs significantly enhances the catalytic performance of the material. Sulfate radicals (SO4•−) serve as the primary active oxygen species and singlet oxygen (1O2) also plays a certain role in the system. The catalyst functions effectively across a broad pH range and exhibits potential for multiple reuses. Interference studies indicate that most background constituents minimally impact MTZ removal, except for chloride ions (Cl-) and humic acid (HA), which significantly inhibit it. Through LC-MS/MS analysis, the degradation intermediates of MTZ were identified, enabling the proposal of a degradation pathway and the ecotoxicological assessment of the intermediates. This study presents a viable new approach for MTZ removal from aqueous solutions.

Compositional and Fabrication Cycle Optimization of Ceria-Zirconia-Supported Mo-Based Catalysts for NH3-SCR NOx Reduction

The reduction of nitrogen oxides (NOx), critical pollutants from stationary to mobile sources, mainly relies on the selective catalytic reduction (NH3-SCR) method, employing ammonia to reduce NOx into nitrogen and water. However, conventional catalysts, while effective, pose both environmental and operational challenges. This study investigates ceria-zirconia-supported molybdenum-based catalysts, exploring the effects of zirconium doping and different catalyst synthesis techniques, i.e., co-precipitation and impregnation. The catalytic performance of the differently prepared samples was significantly influenced by the molybdenum incorporation method and the zirconium content within the ceria-zirconia support. Co-precipitation at higher temperatures resulted in catalysts with better structural attributes but slightly lower catalytic activity compared to those prepared via impregnation. Optimal NOx reduction (close to 100%) was observed at a 15 mol% zirconium doping level when using the impregnation method.

Spin dynamics investigation and structural analysis of ambient scalable Sr2+ doped zirconium ferrite nanoparticles synthesized by low temperature auto combustion route

Microwave spin resonance behaviour of Sr2+ doped Zirconium ferrite Zr1-xSrxFe2O4; (0 ≤ x ≥ 0.20) nanoparticles synthesized by auto combustion route has been investigated by electron paramagnetic resonance (EPR) which show a broad ferromagnetic resonance signal with a superimposed hump signal which is attributed to ferrite Fe3+ ions and oxygen vacancies which is in agreement with XRD and XPS. EPR shows low spin concentration and smaller relaxation time for Zr0.80Sr0.20Fe2O4 which can be used for hyperthermia and for use as a MRI contrast agent. EDS and XPS confirms the presence of Zr, Sr, Fe, O, and C and HRTEM images confirm growth along (220) and (311) with an interatomic distance of 0.3327 nm and 0.2622 nm respectively, thus, authenticating the formation of spinel structure in agreement with FTIR studies. The magnetic behaviour (M − H loop) shows high saturation magnetization and higher value of effective magnetocrystalline anisotropy (Keff) for Zr0.80Sr0.20Fe2O4.

Polypyrrole doped zirconium dioxide composite as electrode material for super-capacitor applications

Polypyrrole doped zirconium dioxide composite as electrode material for super-capacitor applications

Zirconium doping facilitates a vertically aligned NiCoZr-layered hydroxide nanoneedle arrays electrode for hybrid supercapacitors exhibiting a 90,000 cycle durability

LDHs (Layered Double Hydroxides) are a kind of promising cathode material for high-performance hybrid supercapacitor. Nevertheless, it suffers quick capacitance decay after only thousands of cycles, which greatly prevents it from further application. In this contribution, zirconium (Zr) is introduced to the host layer of NiCo-LDH via a simple one-pot hydrothermal process. Owing to the strong bonding energy of ZrO (760 kJ mol−1) and special electronic structure (fully empty 4d orbits), the doped Zr could not only act as a structural stabilized element, but also change the mechanism of the energy storage process to alleviate the Jahn-Teller distortion of NiCo-LDH. Moreover, the introduction of Zr boosts an orderly growth of the LDHs, changing from disorder stack structure to vertically aligned nanoneedle arrays, which improve their structural stability. By controlling a varying level of Zr content, the electrode NiCoZr-LDH@CC with a Zr content ratio of 6.4 % delivers the best comprehensive electrochemical performance with a specific capacitance of 1758 F g−1 and good rate performance (73 % capacitance retention at 10 A g−1). The assembled asymmetric supercapacitor shows a highest energy density of 42.3 Wh kg−1 at 504 W kg−1 and an ultralong cycling lifespan beyond 90,000 cycles with a 97 % capacitance retention. The results exhibit the great potential of NiCoZr-LDH as a qualified candidate for high-performance hybrid supercapacitors.

Zirconium tungstate (Zr4W8O32)-doped zirconium dioxide (ZrO2) for gamma ray shielding: an in-depth examination of fabrication, characterizations, and gamma ray attenuation properties

Zirconium tungstate (Zr4W8O32)-doped zirconium dioxide (ZrO2) for gamma ray shielding: an in-depth examination of fabrication, characterizations, and gamma ray attenuation properties

Synergy of atom doping and defect construction in marigold-like Zn3In2S6 for improved photocatalytic hydrogen production

Atom doping and defect construction are effective strategies to enhance the performance of photocatalysts. Herein, zirconium (Zr) doping and sulfur vacancies (Vs) are introduced on marigold-like Zn3In2S6 (Zr-ZIS-Vs) by controlling the amount of sulfur precursors and ZrCl4 via a one-pot hydrothermal process. Remarkably, the optimized Zr-ZIS-Vs catalyst exhibits excellent photocatalytic activity, giving a photocatalytic hydrogen evolution rate of 9.44 mmol g−1 h−1, which is 10.73, 4.39 and 2.37 times higher than pure Zn3In2S6 (ZIS, 0.88 mmol g−1 h−1), Zn3In2S6 with sulfur vacancies alone (ZIS-Vs, 2.15 mmol g−1 h−1), and Zn3In2S6 with Zr doping alone (Zr-ZIS, 3.98 mmol g−1 h−1). The apparent quantum efficiency (AQE) of Zr-ZIS-Vs achieves 27.15 % and 4.90 % at λ = 370 and 456 nm, respectively. Experimental results and theoretical simulations reveal the behavioral mechanisms of the deletion of S atoms and the tendency of Zr to replace In, indicating that the defective and reference strategies can narrow the band gap, provide abundant active sites, enhance the effective transport and separation of photogenerated carriers, and modulate the transfer of active sites to empirical site S atoms to achieve the synergistic thermodynamic and kinetic interactions, which effectively enhances the performance of photocatalytic hydrogen production.

Optical, structural, and electrical performance of CsPbIBr2 perovskites with zirconium doping and bilayer ETLs

This work studies the optoelectronic, and structural characteristics of CsPbIBr2 perovskite solar cells (PSCs) improved by 4 % Zirconium (Zr) doping and a bilayer electron transport layers (ETLs) composed of TiO2 and Zr-doped WO3. X-ray diffraction (XRD) examination of pure and Zr-doped CsPbIBr2 films revealed increased crystal size (39.2–41.2 nm) and lowered lattice constant following Zr doping, suggesting better crystallinity. The calculated energy band gap of pristine and Zr-doped CsPbIBr2 film decreases (1.986–1.926 eV), which improves the light absorption efficiency, while the increase in the refractive index implies that light is slowed down more as it passes through the material, which increases light trapping and absorption within the material. The XRD of Zr-WO3 ETL indicated a monoclinic crystal structure and increased lattice constant, allowing charge carrier transmission. Raman spectroscopy confirms the structural integrity of Zr-WO3. UV–Vis absorption spectra suggest enhanced absorption in the visible region and higher bandgap compared to Zr-doped CsPbIBr2. J-V tests reveal an efficiency rise from 8.54 % to 10.20 % with the proposed of double ETLs, exhibiting substantial breakthroughs in PSCs performance.

Cu–ZrO2@GO scaffold: Visible spectrum triggered caffeine degradation and microbial inactivation

Consumption of beverages with caffeine has increased in last decade and has led to increase in the concentration of caffeine in various water bodies, placing it in the category of emerging contaminants (ECs). Sewage treatment plants are incapable of completely removing ECs and therefore use of photocatalysis as tertiary treatment is the need of the hour. Reported is a visible light active Copper doped Zirconium oxide loaded Graphene oxide based (Cu–ZrO2@GO) composite using co-precipitation method for photocatalytic degradation of caffeine. The composite was characterized using physiochemical techniques such as FTIR, XPS, XRD, FE-SEM, HR-TEM, UV-DRS, PL, and BET for its successful synthesis confirming distribution of Cu–ZrO2 (5–40 nm) over GO matrix. With the band gap energy of 2.5 eV, Cu–ZrO2@GO could effectively degrade 81.18% for caffeine in 240 min (min) under optimum conditions (pH 3, dose 70 mg) due to its high surface area (80.57 m2 g−1) with pore diameter of 37.4 Ao mainly by the hydroxyl radical as reactive oxygen species (ROS). Proposed degradation mechanism for caffeine is supported by LC/MS analysis. Cu–ZrO2@GO could degrade 78% of caffeine in tea extract (real sample) as confirmed by HPLC studies. Reported composite also depicted antibacterial activity against Gram-positive staphylococcus aureus (S. Aureus) and Gram-negative Escherichia Coli (E. coli) bacteria and could be recycled upto four cycles. Cu–ZrO2@GO can effectively be used for wastewater remediation.

Zr and V-doped effect on Martensitic transformations and magnetic properties of NiMnIn shape memory alloy

In this study, the elements vanadium (V) and zirconium (Zr) were doped separately as a fourth element to the ternary NiMnIn Heusler magnetic shape memory alloy and the alloys were produced as ingots by arc-melting method. The shape memory properties, microstructures, magnetic and microstructural changes of these new alloys were investigated in detail. The vanadium (V) and zirconium (Zr) elements doped into the alloy caused a decrease in the transformation temperature values of the alloy, but did not cause a significant change in its magnetic properties. The master sample, which has low hysteresis, undergoes a phase transition from the martensite phase to the austenite phase due to an increase in the nucleation of austenite phases at the twinning boundaries. Here, the vanadium and zirconium doping of the alloy caused an increase in the strength and ductility values of the alloy and this caused the formation of the second phase. Due to the increase of this phase formation in the alloy, it can be said that there is a slight decrease in the shape retention of the alloy.

Unlocking the superior flexibility and enhanced catalytic oxidation performance of CoTiO3 nanofibrous membranes through zirconium doping

The development of continuous CoTiO3 (CTO) fibers with prominent catalytic oxidation activity, tunable fibrous structures, and improved recyclability is appealing for application in efficient organic wastewater treatment; however, inescapable flaws remain, such as their inherent brittleness and adverse operability. Herein, a facile and effective strategy is proposed for the fabrication of flexible and mechanically robust CTO nanofibrous membranes through a combination of element doping and sol–gel-assisted electrospinning. Compared with pristine CTO fibers, the resulting zirconium-doped CoTiO3 (ZCTO) nanofibrous membranes displayed remarkably enhanced flexibility and tensile mechanics, which were attributed to their lower crystallinity, smaller grain size, and fewer fiber surface defects. The developed ZCTO fibrous membrane demonstrated exceptional resistance to bending fatigue, retaining a polymer-like bending rigidity of approximately 25 mN even after undergoing 200 reciprocating bending cycles. Furthermore, the incorporation of zirconium into CTO clearly had an advantageous effect on the formation of oxygen vacancies, thereby enhancing the surface adsorption of peroxymonosulfate (PMS), accelerating the electron transfer process, and weakening the peroxy bonds. The tetracycline degradation efficiency of the ZCTO fibers remained at 81.4% within 10 min after 5 continuous cycles. Benefiting from their robust mechanical properties and excellent catalytic activity, the fabricated membranes demonstrated outstanding dynamic catalytic performance under gravity-driven conditions. More importantly, the reported strategy might be adopted and extended to develop a wide range of ceramic fibers with enhanced flexibility and mechanics for catalytic oxidation.

Investigation on preparation and tribology of poly ether ether ketone nanocomposite with transition metal doped zirconium dioxide

Composite materials are currently one of the most active study fields in modern technology. Their promising properties make them appropriate for a wide range of industrial applications including aerospace, automotive, construction, sports, bio-medical, and many more. These materials have amazing structural and mechanical features such as high strength-to-weight ratio, resistance to chemicals, fire, corrosion, and wear, as well as being cost-effective to produce. Poly-ether-ether-ketone (PEEK), a high performance polymeric materials, is increasingly being employed to replace metal elements in car engines and transmissions. Zirconium oxide (ZrO2), often known as zirconia, is a high-tech ceramic substance that is widely employed in the manufacture of various hard ceramics. The various physical and chemical properties of ZrO2 have been properly tailored for a given use by inserting transition metals (dopants) into the ZrO2 crystalline structure. In this work, the nano-composite of PEEK and transition metal doped Zirconium Dioxide is prepared. The composite was subsequently subjected to vital characterizations and tribological testing. The characterization validated the amalgam of modified ZrO2 with PEEK. The investigation has shown that PEEK reinforcement with modified ZrO2 has desired qualities for use in tribological applications

Novel Photoluminescence and Optical Thermometry of Solvothermally Derived Tetragonal ZrO2:Ti4+,Eu3+ Nanocrystals

In this paper, we report on the solvothermal preparation and detailed characterization of pristine and intentionally doped zirconium dioxide (ZrO2) nanocrystals (NCs, ~5 nm) with Eu3+ or Ti4+/Eu3+ ions using alkoxide precursors. The results indicated that the ZrO2 NCs were dominantly of a tetragonal phase (t-ZrO2) with a small proportion of monoclinic ZrO2 (m-ZrO2). The high purity of t-ZrO2 NCs could be synthesized with more Eu3+ doping. It was found that the as-obtained ZrO2 NCs contain some naturally present Ti4+ ions originating from precursors, but were being overlooked commonly, and some carbon impurities produced during synthesis. These species showed distinct photoluminescence (PL) properties. At least two types of Eu3+, located at low- and high-symmetry sites (probably sevenfold and eightfold oxygen coordination), respectively, were demonstrated to build into the lattice structure of t-ZrO2 NCs together. The cationic dopants were illustrated to be distributed non-randomly over the sites normally occupied by Zr, while Ti impurities preferentially occupied the sites near the low-symmetry site of Eu3+, yielding efficient energy transfer from the titanate groups to the neighboring Eu3+. Luminescence nanothermometry could measure temperature in a non-contact and remote way and could find great potentials in micro/nano-electronics, integrated photonics, and biomedicine. On the basis of the dual-emitting combination strategy involving the white broadband CT (Ti3+→O−) emissions of the titanate groups and red sharp Eu3+ emissions, t-ZrO2:Eu3+ nanophosphors were demonstrated to be ratiometric self-referencing optical thermometric materials, with a working range of 130–230 K and a maxima of relative sensitivity of ~1.9% K−1 at 230 K.

Boosting Blue Self-Trapped Exciton Emission in All-Inorganic Zero-Dimensional Metal Halide Cs2ZnCl4 via Zirconium (IV) Doping.

Low-dimensional metal halides with efficient luminescence properties have received widespread attention recently. However, nontoxic and stable low-dimensional metal halides with efficient blue emission are rarely reported. We used a solvothermal synthesis method to synthesize tetravalent zirconium ion-doped all-inorganic zero-dimensional Cs2ZnCl4 for the first time. Bright blue emission in the range of 370 nm-700 nm with a emission maximum at 456 nm was observed in Zr4+:Cs2ZnCl4 accompanied by a large Stokes shift, which was due to self-trapped excitons (STEs) caused by the lattice vibrations of the twisted structure. Simultaneously, the PLQY of Zr4+:Cs2ZnCl4 achieve an impressive 89.67%, positioning it as a compelling contender for future applications in blue-light technology.

Optimization of mesoporous magnesium ferrite hydroelectric cells for sustainable green electricity generation via Zirconium doping

Novel hydroelectric cells exploit porosity and structural defects to dissociate deionized water for hydroelectricity generation. In the present study, these essential attributes have been engineered using Zr4+ doping in MgFe2O4 using the facile sol-gel method. Comprehensive structural analysis performed using modern analytical techniques such as X-ray Diffraction (XRD) and Raman Spectroscopy ascertained the pure spinel cubic phase of the synthesized nanoparticles. Morphologically, the material was probed using Field-Emission Scanning Electron Microscopy (FESEM) analysis, identifying highly porous and agglomerated spherical grains. The mesoporous structure of the samples was further determined using Brunauer-Emmett-Teller (BET) surface examination. An inclusive evaluation employing Photoluminescence (PL) examination in the UV spectral region revealed the existence of oxygen-deficient sites and intrinsic defects inside the doped magnesium ferrites. These results were further validated using X-ray Photoelectron Spectroscopy (XPS). Significant lattice strain (≈2.5 × 10−3) and the presence of oxygen vacancies, defects, and mesoporosity influence water dissociation at the ferrite surface. These attributes were utilized to facilitate the generation of hydroelectric current. The maximum short circuit current values recorded for MgZr0.05Fe1.95O4 (ZMF-1) and MgZr0.10Fe1.90O4 (ZMF-2) were observed to be 6.3 and 11.6 mA, respectively, with corresponding output voltages of 0.77 V and 0.89 V. The incorporation of Zirconium (Zr) dopant not only enhances the hydroelectric current but also contributes to sustained current generation over extended periods.

Zirconium Doping to Enable High-Efficiency and Stable CsPbI2Br All-Inorganic Perovskite Solar Cells.

All-inorganic wide-bandgap perovskite CsPbI2Br has attracted much attention because of its inherent thermal stability and ideal bandgap for the front subcell of tandem solar cells (TSCs). However, the low power conversion efficiency (PCE) and poor moisture stability of CsPbI2Br still restrict its future commercialization. Herein, zirconium tetrachloride (ZrCl4) was doped into CsPbI2Br films to modulate the crystal growth and improve the film quality. The partial substitution of the B-site Pb2+ of CsPbI2Br with Zr4+ suppresses the unwanted phase conversion from the crystallized black α-phase to the δ-phase, resulting in improved phase stability. Consequently, the humidity and thermal stability of the film are greatly improved. Additionally, the incorporation of ZrCl4 suppresses nonradiative recombination and forms a matched energy-level alignment with the hole-transport layer (Spiro-OMeTAD). Benefiting from these features, the ZrCl4-doped CsPbI2Br perovskite solar cell (PSC) shows an outstanding efficiency of 16.60% with a high open-circuit voltage of 1.29 V. The unencapsulated devices simultaneously show excellent humidity and thermal stability, retaining over 91% of PCEinitial after 1000 h of aging in ambient air conditions and 92% PCEinitial after 500 h of continuous heating at 85 °C in a nitrogen environment, respectively. Furthermore, ZrCl4-doped CsPbI2Br was employed as the front subcell of perovskite/organic TSCs and achieved a remarkable PCE of 19.42%, showing great potential for highly efficient and stable TSCs.