Pure ZrO2 Research Articles

Tuning the crystallite size of monoclinic ZrO2 to reveal critical roles of surface defects on m–ZrO2 catalyst for direct synthesis of isobutene from syngas

• A series of monoclinic ZrO 2 catalysts with different crystalline size was prepared. • ZrO 2 with small crystalline size owned higher activity and isobutene selectivity. • Higher concentrations of surface defects on ZrO 2 was vital for isobutene synthesis. The effects of crystallite size on the physicochemical properties and surface defects of pure monoclinic ZrO 2 catalysts for isobutene synthesis were studied. We prepared a series of monoclinic ZrO 2 catalysts with different crystallite size by changing calcination temperature and evaluated their catalytic performance for isobutene synthesis from syngas. ZrO 2 with small crystalline size showed higher CO conversion and isobutene selectivity, while samples with large crystalline size preferred to form dimethyl ether (DME) instead of hydrocarbons, much less to isobutene. Oxygen defects (O Defects ) analyzed by X-ray photoelectron spectroscopy (XPS) provided evidence that more O Defects occupied on the surface of ZrO 2 catalysts with smaller crystalline size. Electron paramagnetic resonance (EPR) and ultraviolet–visible diffuse reflectance (UV–vis DRS) confirmed the presence of high concentration of surface defects and Zr 3+ on m -ZrO 2 -5.9 sample, respectively. In situ diffuse reflectance infrared Fourier transform spectroscopy ( in situ DRIFTS) analysis indicated that the adsorption strength of formed formate species on catalyst reduced as the crystalline size decreased. These results suggested that surface defects were responsible for CO activation and further influenced the adsorption strength of surface species, and thus the products distribution changed. This study provides an in-depth insight for active sites regulation of ZrO 2 catalyst in CO hydrogenation reaction.

Reactive crystallization in HfO2 exposed to molten silicates

Hafnia is of interest in thermal and environmental barrier coatings, but little is known about its response to molten silicate attack. This article investigates that response using two model silicate melts, compares it with pure ZrO2 and examines the effect of YO1.5 additions. HfO2 was found to form HfSiO4 with acidic melts but undergoes grain boundary penetration in basic melts, which do not exhibit reactive crystallization. The latter can be exacerbated by microcracking resulting from the thermal expansion anisotropy of monoclinic HfO2. Y additions generally degrade the ability to form hafnon (and zircon), and exacerbate grain boundary penetration, especially in HfO2 where Y is present as a fluorite second phase. The fluorite controls grain growth in monoclinic HfO2 and suppresses microcracking, but dissolves faster, especially in basic melts. The results are presented in the context of the relevant thermodynamics and kinetics. The implications for coating applications are discussed.

Compositional and phase dependence of elastic modulus of crystalline and amorphous Hf1-xZrxO2 thin films

The elastic moduli of amorphous and crystalline atomic layer-deposited Hf1-xZrxO2 (HZO, x = 0, 0.31, 0.46, 0.79, 1) films prepared with TaN electrodes on silicon substrates were investigated using picosecond acoustic measurements. The moduli of the amorphous films were observed to increase between 211 ± 6 GPa for pure HfO2 and 302 ± 9 GPa for pure ZrO2. In the crystalline films, it was found that the moduli increased upon increasing the zirconium composition from 248 ± 6 GPa for monoclinic HfO2 to 267 ± 9 GPa for tetragonal ZrO2. Positive deviations from this increase were observed for the Hf0.69Zr0.31O2 and Hf0.54Zr0.46O2 compositions, which were measured to have moduli of 264 ± 8 GPa and 274 ± 8 GPa, respectively. These two compositions contained the largest fractions of the ferroelectric orthorhombic phase, as assessed from polarization and diffraction data. The biaxial stress states of the crystalline films were characterized through sin2(ψ) x-ray diffraction analysis. The in-plane stresses were all found to be tensile and observed to increase with the increasing zirconium composition, between 2.54 ± 0.6 GPa for pure HfO2 and 5.22 ± 0.5 GPa for pure ZrO2. The stresses are consistent with large thermal expansion mismatches between the HZO films and silicon substrates. These results demonstrate a device-scale means to quantify biaxial stress for investigation on its effect on the ferroelectric properties of hafnia-based materials.

Ferroelectric properties of pure ZrO2 thin films by chemical solution deposition

Ferroelectricity in pure zirconia (ZrO2) thin films, manufactured on Si (100) substrates via the chemical solution deposition method using all-inorganic aqueous salt precursor, has been demonstrated for the first time. The influence of thickness on the crystalline structure and ferroelectric properties of the thin films were measured and showed that they were strongly affected by the film thickness. The structural data indicated that as the film thickness increased from 30 nm to 50 nm, the m-phase fraction increased, and a phase transition from orthorhombic to cubic and then tetragonal occurred near the main diffraction peak of 30.7°. The lowest m-phase fraction of 15.4% was obtained in the pure ZrO2 film with a thickness of 30 nm, and after 103 field cycling, it exhibited the highest relative permittivity of 39.6 as well as the highest residual polarization of 8.5 μC/cm2.

New insight into sequential of silica-zirconia precursors in stabilizing silica-doped tetragonal zirconia nanoparticles for enhanced photoactivity

Silica-doped tetragonal zirconia nanoparticles (SiO2-ZrO2) catalysts were synthesized with the addition of ZrO2 prior to SiO2 by the microwave-assisted method and compared with a different sequence of ZrO2 and SiO2 (ZrO2-SiO2). The catalysts were characterized by X-ray diffraction, nitrogen adsorption-desorption, transmission electron microscopy, Fourier-transform infrared, electron spin resonance, ultraviolet–visible diffuse reflectance spectroscopy and photoluminescence analyses. The catalyst phase was pure tetragonal ZrO2 (t-ZrO2) with nano in size (9–10 nm). The sequential of SiO2 and ZrO2 precursors significantly affected the catalyst framework and led to a different number of pore volume and defect sites, including oxygen vacancies (OV), metal defects site (MDS) and Si-O-Zr bonds, which altered their behaviour towards t-ZrO2 stabilization and applications. It was found that the synergistic effect between nanocrystals and the appropriate amount of defect sites influenced the stabilization of t-ZrO2. The catalytic activity towards photodegradation of 2-chlorophenol (2-CP) are in the following order: SiO2-ZrO2 (92%) > ZrO2-SiO2 (59%) > ZrO2 (50%) > SiO2 (20%). The highest photoactivity of SiO2-ZrO2 is due to the large pore volume, which offered good surface contact with light. Besides, the higher crystallinity, Si-O-Zr bonds, and OV and MDS also could contribute to the excellent performance in 2-CP degradation. The abovementioned properties provided good electron-hole pair mobility and electron trapping for enhanced photoactivity.

Synthesis, characterization, photocatalytic, and antimicrobial activity of ZrO2 nanoparticles and Ag@ZrO2 nanocomposite prepared by the advanced oxidative process/hydrothermal route

ZrO2 nanoparticles (ZrO2 NPs) and Ag@ZrO2 nanocomposite (Ag@ZrO2 NCs) were prepared from zirconium (IV) butoxide in the absence of base or acid mineraliser by the advanced oxidation processes (AOP) and subsequent hydrothermal treatment. Samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), Raman, Photoluminescence (PL), Fourier transform infrared (FTIR), and diffuse reflectance spectroscopy (DRS). XRD and Raman analyses confirmed ZrO2 NPs and Ag@ZrO2 NCs tetragonal crystalline phase synthesized at 200 °C for 1 h. HRTEM images of ZrO2 NPs and Ag@ZrO2 NCs after treatment at 200 °C indicated small nanoparticles with characteristic size of 5–8 nm (ZrO2) and 40–50 nm (Ag NPs). It was found that Ag@ZrO2 NCs showed outstanding photocatalytic activity in photodegradation Rhodamine B dye compared with pure ZrO2 NPs. Antibacterial activity tests of ZrO2 NPs and Ag@ZrO2 NCs were carried out using E. coli and S. aureus as model strains of Gram-negative and Gram-positive bacteria, respectively. Ag@ZrO2 NCs were capable of efficiently growth inhibition of bacteria cultures in more than 75% E. Coli compared to ZrO2 NPs that exhibited <10% instead. However, at the same concentration (for example 0.25 mg/mL) we found that both ZrO2 NPs and Ag@ZrO2 NCs were significantly more effective against S. aureus in comparison with E. coli showing bacterial growth inhibition higher than 90% for S. aureus. Morphological observation of bacterial cells by scanning electron microscopy (SEM) revealed that nanoparticles and nanocomposite caused irreversible damage to the cell membrane.

Effect of zirconia on low cycle fatigue and energy absorption of molybdenum alloy

Pure molybdenum and ZrO2 dispersion strengthened Mo alloy were prepared by liquid-liquid doping method. The effects of adding ZrO2 on their microstructure and properties were investigated by tensile test and low cycle fatigue (LCF) test at room temperature, and the fracture mode and energy absorption were analyzed. The research shows that ZrO2 can refine the grain size and increase the recrystallization temperature of molybdenum alloy. The enhancement of yield strength by ZrO2 is mainly reflected in grain boundary strengthening. The tensile fracture mode is related to grain size, and changes from transgranular fracture to transgranular-intergranular fracture with the decrease of grain size. At the initial stage of the cycle, the increase of strain amplitude changes the cyclic hardening into cyclic softening, and the addition of ZrO2 accelerates the cyclic hardening/softening. With the increase of strain amplitude, the loading energy and absorption energy of a single stable cycle increase, while the unloading energy is basically unchanged. ZrO2 can increase the total fatigue absorption energy of molybdenum alloy at the same strain amplitude, and the single cycle absorption energy is lower than that of pure Mo, thus increasing the fatigue life.

Sub-7-nm textured ZrO2 with giant ferroelectricity

An ~6.5 nm pure ZrO2 thin film with a giant ferroelectric remanent polarization (Pr) of ~50 μCcm−2 and an effective piezoelectric coefficient (d33) of 7−9 pm/V is reported. The film was prepared on a (111)-oriented Pt electrode using plasma-enhanced atomic layer deposition at 300 °C, followed by annealing at 400 °C, and exhibited a preferred orientation of the orthorhombic (111) planes in the in-plane direction. The Pr value of ~50 μCcm−2 is the largest reported to date for both perovskite and fluorite nanoscale ferroelectric thin films (< 120 nm) on a Pt electrode. Furthermore, the processing temperature of 300−400 °C is the lowest reported to date to produce a Pr of ~50 μCcm−2 in nanoscale ferroelectrics on a Pt electrode. The giant Pr, ascribed to the preferred crystal orientation, was confirmed by the positive-up negative-down (PUND) polarization measurement with a long delay time to allow the relaxation of polarization. The effective d33 was obtained using piezoresponse force microscopy with an interferometric displacement sensor to minimize the frequency-dependent artifacts and the effects of cantilever dynamics. The low-temperature preparation of the textured ZrO2 ultrathin film with a giant Pr is extremely advantageous for device scaling and process integration in advanced nanoelectronics.

Visible-Light-Driven Methane Conversion with Oxygen Enabled by Atomically Precise Nickel Catalyst

It remains an extreme challenge to activate thermodynamically unfavorable, chemically inert methane molecules under mild conditions. Herein, we report a molecular-like nickel-thiolate hexameric clu...

Investigation of optical and magnetic properties of Mn-doped tetragonal ZrO2 nanocrystals

Pure and Mn-doped ZrO2 nanocrystals (Zr1-xMnxO2) with varying Mn concentrations (x ​= ​0.02, 0.04, 0.06, and 0.08) have been synthesized using sol-gel method. The effect of Mn doping concentration on structural, optical and magnetic properties has been investigated. X-ray diffraction data and SAED analysis revealed that all Zr1-xMnxO2 nanocrystals have a tetragonal structure without any secondary phase. The average crystallite size obtained from XRD decreases (within the experimental uncertainty) with increased Mn concentration. Magnetic measurements have revealed that Zr0.98Mn0.02O2 nanocrystalline sample exhibits both low and room temperature ferromagnetism. The origin of ferromagnetism is attributed to the anionic vacancies created due to Mn doping in ZrO2. Higher Mn concentrations shows superparamagnetism whereas pure ZrO2 displayed diamagnetic behavior. The UV–Vis absorption spectra showed a wide absorption peak at 200–330 ​nm, and a redshift was observed in the bandgap with an increase in the concentration of Mn2+.

Copper sulphide-Zirconium dioxide nanocomposites photocatalyst with enhanced UV-light photocatalysis efficiency: structural and methodology

ABSTRACT To plan great photocatalytic performance, fast photo-generated charge recombination in nanocatalysts should be repressed. Thus, copper sulphide-Zirconium dioxide (CuS-ZrO2) nanocomposites were synthesised via a facile chemical method. The field-emission scanning electron microscopy (FESEM) results indicated that a heterojunctions interface among CuS and ZrO2. XRD analysis showed optimum CuS-ZrO2 photocatalyst with an average diameter of 42.58 nm were found. The UV–vis diffuse reflection spectroscopy (DRS) illustrated that the synthesised CuS-ZrO2 nanocomposites owned the highest absorption intensity in the UV-light range compared with pure ZrO2 nanoparticles. The bandgap (Eg) values of ZrO2 nanoparticles and CuS-ZrO2 nanocomposites were found 3.55 eV, and 2.65 eV, respectively. These characteristic structural and optical property consequence showed that the CuS-ZrO2 nanocomposites with great photocatalysis progress for degradation of tetracycline. Among the different ratio nanocomposites, CuS-ZrO2-2 indicates the highest photocatalytic efficiency (97.15%) in acidic pH and 60 min. Photocatalytic was optimised by response surface methodology with the Box-Behnken model. The study provides a promising photocatalyst to be used for organic pollutant removal in a large scale.

Rapid Sintering and Synthesis of Nanocrystalline Ta-ZrO&lt;sub&gt;2&lt;/sub&gt; Composite

ZrO&lt;sub&gt;2&lt;/sub&gt; is a promising candidate for knee and hip joint replacements due to its excellent combination of low density, corrosion resistance and biocompatibility. Nevertheless, a low fracture toughness of pure ZrO&lt;sub&gt;2&lt;/sub&gt; at room temperature limits its wider application in the industry. One of the most obvious ways to solve the problem is to add a reinforcing phase, to produce a nanocrystalline composite material. Nanomaterials have been widely studied in recent years because they can improve hardness and fracture toughness. To produce nanocrystalline materials, the pulsed current activated sintering method has the advantage of simultaneously applying mechanical pressure and pulsed current during sintering. As a result, nanocrystalline materials can be produced within a very short time. Ta and ZrO&lt;sub&gt;2&lt;/sub&gt; nanopowders were mechanically synthesized from Ta&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; and 2.5Zr powders according to the reaction (Ta&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;5&lt;/sub&gt; + 5/2Zr → 2Ta + 5/2ZrO&lt;sub&gt;2&lt;/sub&gt;). The synthesized powders were then sintered using pulsed current activated heating under 80 MPa uniaxial pressure within two minutes. Hardness and fracture toughness were measured using a Vickers hardness tester. The average hardness and fracture toughness of the nanocrystalline 2Ta-5/2ZrO&lt;sub&gt;2&lt;/sub&gt; composite sintered at 1350 &lt;sup&gt;o&lt;/sup&gt;C were 1008 kg/mm&lt;sup&gt;2&lt;/sup&gt; and 10 MPa·m&lt;sup&gt;1/2&lt;/sup&gt;, respectively. Both the hardness and fracture toughness of the composite were higher than monolithic ZrO&lt;sub&gt;2&lt;/sub&gt;. The microstructure and phase of the composite was also investigated by FE-SEM and XRD.

Short-range order and electronic structure of radiation-damaged zircon according to X-ray photoelectron spectroscopy

Core-level and valence-band X-ray photoelectron spectroscopy was employed to study the dose-dependent radiation effects in the short-range order and the electronic structure of natural U, Th-bearing zircon near-surface layers. Single crystals from different localities (Ratanakiri, Cambodia; Mud Tank, Australia; Highlands, Sri Lanka) exhibiting wide variations in the accumulated radiation dose D≈(0 ÷ 9.2)·1018 α-decays/g was investigated. The dose values obtained by electron probe microanalysis and Raman micro-spectroscopy were used to correlate the samples with the two percolation transitions (p1, p2) in the amorphous-crystalline structure of damaged zircon. The dose-dependent variations in Eb (530.9–531.3, 101.7–102.4, 182.8- 183.3 eV) and FWHM (1.32–2.57, 1.47–1.77, 1.16 -1.55 eV) of the O1s, Si2p, and Zr3d5/2 core levels, respectively, were attributed to changes in the ensemble of non-equivalent short-range order structures. An increase in the dose resulted in the complication of the oxygen sublattice, with the following nearest environments of O atoms: (1) O (Si, [8]Zr, [8]Zr), Eb = 530.8–531.2 eV, the amount of > ~3.5 apfu (at D p2). For the first time, under an increase in the radiation dose, the oppositely directed changes in the effective charges of Si and Zr cations were detected in damaged zircon. This phenomenon was assigned to an increase in the content of the short-range order fragments characteristic of pure oxides SiO2 (namely, Si-O-Si) and ZrO2 (namely, [7]Zr) as well as to the influence of the anions O (Si, Si, [8]Zr), and the assignment was independently confirmed by the valence band analysis. The sequence of transformations in the Si-O and Zr-O sublattices was shown to be not concurrent: a partial polymerization of SiO4 tetrahedra occurs mainly at low and medium doses (D p2) in the amorphous fraction.

Effect of Ni Doping on the Structural and Optical Properties of ZrO2 Thin Films

Transparent thin films of pure and nickel-doped ZrO2 with doping levels of 0, 1, 3 and 5 molar percentage were deposited through sol–gel dip coating and subsequently annealed at 500°C. Surface morphology and film thickness were examined through field emission scanning electron microscopy, which revealed a smooth surface morphology of the synthesized film, while elemental dot-mapping confirmed uniform distribution of nickel in the film. X-ray diffraction analysis revealed tetragonal crystalline structure of the deposited films. The structure exhibited a change in crystallite size upon varying the doping concentration. UV–Visible spectroscopy was employed for determining the optical band gap and transmittance. All the specimens were found to exhibit transmittance above 80%. Surface defects and oxygen vacancies were analyzed through photoluminescence spectroscopy. The photoluminescence peak intensities were observed to decrease upon increasing the nickel doping beyond 1% molar ratio, which was found to be in accordance with the change in optical band gap determined through UV–Visible spectroscopy. Fourier transform infrared spectroscopy revealed a strong absorption peak corresponding to Zr–O vibrational mode, while another peak corresponding to Ni–O vibrational mode was observed for nickel-doped samples, thereby implying replacement of some Zr4+ ions by Ni2+ ions in the lattice.

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.

Comparative study of the efficiency of different noble metals supported on zirconium oxide in the catalytic wet air oxidation of bisphenol-A solution

Noble metals supported on ZrO2 catalysts were elaborated using sol-gel and impregnation methods then studied for catalytic wet air oxidation of bisphenol-A (BPA) in water. The prepared solids were characterized by N2-physisorption at 77 k, XRD, TEM, TGA/TDA, FTIR spectroscopy, XPS and H2-TPR techniques. BPA solution of 10 mg/L was successfully oxidized at 100 °C and Pair = 20 bar. For pure ZrO2, a conversion of 49% was obtained within 5 h. The catalytic activity was improved by adding noble metals resulting in a BPA conversion surpassing 90% for 3%Ru/ZrO2 after 3 h. No catalyst deactivation was reported.

Ion-beam induced luminescence and optical response measurement setup at IGCAR: First experimental results

A multipurpose novel experimental setup has been developed for the in situ measurements of ion-beam induced luminescence, optical response, and time-resolved photoluminescence spectroscopy of materials. A low-energy ion accelerator (terminal voltage of 150 kV) has been coupled with the spectrometer for the experiments. Measurements show a drastic increase in the luminescence intensity at 425 nm with the maximum fluence of 120 keV He+ ion irradiation on pure monoclinic ZrO2 samples. The maximum luminescence intensity is found to increase systematically with the ion fluences. An excess of oxygen defects in irradiated ZrO2 samples is thought to be the reason for the increase in the luminescence intensity. In addition, the He+ ion-beam induced increase in optical responses at 425 nm in Ag+ ion-exchanged soda glass samples, for example, has been observed on ion irradiation. The unique in situ experimental setup demonstrates and opens new opportunities to study irradiation controllable defects in materials and ion-beam induced optical responses in glass samples.

High-temperature mass spectrometric study of thermodynamic properties in the UO2 -ZrO2 system.

The UO2 -ZrO2 solid solution at high temperatures is the key system of modern nuclear science and technology in the context of the safety operation of nuclear cycles, the consequences of severe accidents, and the incorporation of nuclear waste. Urgent needs of the continuation of experimental studies of this system at temperatures up to 3000 K are aimed at preventing severe accidents similar to Chernobyl and Fukushima when the thermodynamic approach is used for the prediction of high-temperature behavior of materials. This investigation was carried out using the Knudsen effusion mass spectrometric method using the MS-1301 magnetic sector mass spectrometer. The samples in the UO2 -ZrO2 system were vaporized from a tungsten effusion cell. Vapor species effusing from the cell were ionized at an electron ionization energy of 70 eV. The vaporization and thermodynamics of pure UO2 and ZrO2 as well as of the samples in the UO2 -ZrO2 system were studied in the range 2000-2730 K. The temperature dependences of the partial vapor pressures of UO and UO2 over pure UO2 were obtained at 2060-2456 K, which agreed with the literature results. The partial vapor pressures of UO, UO2 , ZrO, and ZrO2 , the vaporization rates, and the UO2 and ZrO2 activities in the UO2 -ZrO2 solid solutions were determined at 2370, 2490, 2570, and 2730 K. The component activities and excess Gibbs energies of the UO2 -ZrO2 system indicated a change in deviations from the ideal behavior from positive to negative with the temperature increase from 2370 to 2730 K. The thermodynamic functions of formation from the oxides of the solid solutions in the UO2 -ZrO2 system such as Gibbs energies as well as the enthalpies and entropies of formation were obtained for the first time at 2550 K in the composition range 0.89-1.00 ZrO2 mole fraction.

Co doped ZrO2 nanoparticles: An efficient visible light triggered photocatalyst with enhanced structural, optical and dielectric characteristics

In this work ZrO2 and Co doped ZrO2 (tetragonal) nanoparticles (NPs) were prepared via facile co-precipitation method. Multivalent Co-ZrO2 NPs were investigated for structural, optical, magnetic, dielectric and photocatalytic applications. A detailed structural analysis confirmed successful substitution of dopant ions in zirconia lattice with an average crystallite size of 18.0 ± 1.7 nm. SEM analysis depicted narrow, spherical like morphology for both pure ZrO2 and Co-ZrO2 NPs. DRS spectra revealed substantial tuning of band gap from 3.7 to 2.12 eV with Co doping owing to crystal defects. Moreover, incorporation of Co contents in ZrO2 matrix had significantly enhanced the dielectric constant up to 2.8 × 104 with a very low loss, which is attributed to the size of the nanoparticles along with presence of localized states between valence band and conduction band. The room temperature ferromagnetism (RTF), driven by creation of oxygen vacancies coupled with dopant concentration in the host lattice, enhanced the degradation process. Interestingly, Co-ZrO2 NPs have shown effective visible light triggered photocatalytic activity against methylene blue (MB). The significant removal of MB (96.5%) was achieved using 10% Co doped ZrO2 NPs, which was consigned to the efficient control on the recombination rate. These findings illustrate that Co-ZrO2 NPs can be a profound alternate for futuristic high frequency devices, and waste water treatment processes.

Ni-dopant concentration effect of ZrO2 photocatalyst on photoelectrochemical water splitting and efficient removal of toxic organic pollutants

Recent years, metal oxide semiconductor photoelectrochemical (PEC) and photocatalytic technology is a compassionate of eco-friendly methods that has displayed significant consideration in the environmental and energy fields. Ni-doped ZrO2 has studied several studies but its PEC water splitting and organic pollutant dye degradation have not been exploited yet. Hence, in the present study, we prepared the Ni-doped ZrO2 (0.1, 0.3 and 0.5 mol %) photocatalyst using a simple hydrothermal technique and studied their PEC water splitting and methyl (MB) blue organic pollutant dye degradation under visible light irradiation. Compared with pure ZrO2 photocatalyst, the Ni-doped photocatalysts displayed extra-prolonged light response and greater separation rate of photo-generated charge carrier’s. The optimized doped (0.3 mol %) photocatalyst showed higher photocurrent (~89 times) density and lesser charge resistance over pure photocatalyst. Moreover, the optimized doped photocatalyst showed 90.2% degradation of methyl blue dye under 100 min of visible light irradiation.