Synthesis and characterization of nanocrystalline zirconia powder by simple sol–gel method with glucose and fructose as organic additives

Experimental and computational study of metal oxide nanoparticles for the photocatalytic degradation of organic pollutants: a review

Photocatalysis is a more proficient technique that involves the breakdown or decomposition of different organic contaminants, various dyes, and harmful viruses and fungi using UV or visible light solar spectrum. Metal oxides are considered promising candidate photocatalysts owing to their low cost, efficiency, simple fabricating method, sufficient availability, and environment-friendliness for photocatalytic applications. Among metal oxides, TiO2 is the most studied photocatalyst and is highly applied in wastewater treatment and hydrogen production. However, TiO2 is relatively active only under ultraviolet light due to its wide bandgap, which limits its applicability because the production of ultraviolet is expensive. At present, the discovery of a photocatalyst of suitable bandgap with visible light or modification of the existing photocatalyst is becoming very attractive for photocatalysis technology. However, the major drawbacks of photocatalysts are the high recombination rate of photogenerated electron-hole pairs, the ultraviolet light activity limitations, and low surface coverage. In this review, the most commonly used synthesis method for metal oxide nanoparticles, photocatalytic applications of metal oxides, and applications and toxicity of different dyes are comprehensively highlighted. In addition, the challenges in the photocatalytic applications of metal oxides, strategies to suppress these challenges, and metal oxide studied by density functional theory for photocatalytic applications are described in detail.

Yolk@Wrinkled-double shell smart nanoreactors: new platforms for mineralization of pharmaceutical wastewater

Nanomaterials with "yolk and shell" "structure" can be considered as "nanoreactors" that have significant potential for application in catalysis. Especially in terms of electrochemical energy storage and conversion, the nanoelectrode has a large specific surface area with a unique yolk@shell structure, which can reduce the volume change of the electrode during the charging and discharging process and fast ion/electron transfer channels. The adsorption of products and the improvement of conversion reaction efficiency can greatly improve the stability, speed and cycle performance of the electrode, and it is a kind of ideal electrode material. In this research, heterojunction nanoreactors (FZT Y@WDS) Fe3O4@ZrO2-X@TiO2-X were firstly synthesized based on the solvothermal combined hard-template process, partial etching and calcination. The response surface method was used to determine the performance of the FZT Y@WDS heterojunction nanoreactors and the effects of four process factors: naproxen concentration (NAP), solution pH, the amount of charged photocatalyst, and the irradiation time for photocatalytic degradation of NAP under visible light irradiation. To maximize the photocatalytic activity, the parameters of the loaded catalyst, the pH of the reaction medium, the initial concentration of NAP, and the irradiation time were set to 0.5 g/L, 3, 10 mg/L, and 60 min, respectively, resulting in complete removal of NAP and the optimum amount was calculated to be 0.5 g/L, 5.246, 14.092 mg/L, and 57.362 min, respectively. Considering the promising photocatalytic activity of FZT Y@WDS under visible light and the separation performance of the nanocomposite, we proposed this photocatalyst as an alternative solution for the treatment of pharmaceutical wastewater.

Zirconia-based nanomaterials: recent developments in synthesis and applications

In the last decade, the whole scientific community has witnessed great advances and progress in the various fields of nanoscience. Among the different nanomaterials, zirconia nanomaterials have found numerous applications as nanocatalysts, nanosensors, adsorbents, etc. Additionally, their exceptional biomedical applications in dentistry and drug delivery, and interesting biological properties, viz. anti-microbial, antioxidant, and anti-cancer activity, have further motivated the researchers to explore their physico-chemical properties using different synthetic pathways. With such an interest in zirconia-based nanomaterials, the present review focuses systematically on different synthesis approaches and their impact on the structure, size, shape, and morphology of these nanomaterials. Broadly, there are two approaches, viz., chemical synthesis which includes hydrothermal, solvothermal, sol-gel, microwave, solution combustion, and co-precipitation methods, and a greener approach which employs bacteria, fungus, and plant parts for the preparation of zirconia nanoparticles. In this review article, the aforementioned methods have been critically analyzed for obtaining specific phases and shapes. The review also incorporates a detailed survey of the applications of zirconia-based nanomaterials. Furthermore, the influence of specific phases, morphology, and the comparison with their counterpart composites for different applications have also been included. Finally, the concluding remarks, prospects and possible scope are given in the last section.

Photocatalytic activity of ZrO2/TiO2/Fe3O4 ternary nanocomposite for the degradation of naproxen: characterization and optimization using response surface methodology

In this study, ZrO₂, TiO₂, and Fe₃O₄ components were synthesized by co-precipitation, sol–gel, and co-precipitation methods, respectively. In addition, solid-state dispersion method was used for synthesizing of ZrO₂/TiO₂/Fe₃O₄ ternary nanocomposite. The ZrO₂/TiO₂/Fe₃O₄ nanocomposite was characterized by different techniques including XRD, EDX, SEM, BET, FTIR, XPS, EELS, and Photoluminescence (PL). The FTIR analysis of ZrO₂/TiO₂/Fe₃O₄ photocatalyst showed strong peaks in the range of 450 to 700 cm⁻¹, which represent stretching vibrations of Zr–O, Ti–O, and Fe–O. The results of FTIR and XRD, XPS analyses and PL spectra confirmed that the solid-state dispersion method produced ZrO₂/TiO₂/Fe₃O₄ nanocomposites. The EELS analysis confirmed the pure samples of Fe₃O₄, TiO₂ and ZrO₂. The EDAX analysis showed that the Zr:Ti:Fe atomic ratio was 0.42:2.08:1.00. The specific surface area, pores volume and average pores size of the photocatalyst were obtained 280 m²/g, 0.92 cm³/g, and 42 nm respectively. Furthermore, the performance of ZrO₂/TiO₂/Fe₃O₄ nanocomposite was evaluated for naproxen removal using the response surface method (RSM). The four parameters such as NPX concentration, time, pH and catalyst concentration was investigated. The point of zero charge of the photocatalyst was 6. The maximum and minimum degradation of naproxen using photocatalyst were 100% (under conditions: NPX concentration = 10 mg/L, time = 90 min, pH = 3 and catalyst concentration = 0.5 g/L) and 66.10% respectively. The stability experiment revealed that the ternary nanocatalyst demonstrates a relatively higher photocatalytic activity after 7 recycles.

Drug infused Al2O3-bioactive glass coatings toward the cure of orthopedic infection

A unique implant coated substrate with dual-drug-eluting system exhibiting antibacterial, anti-inflammatory, and bone regenerative capacity has been fabricated using spray pyrolysis deposition (SPD) method. Bioglass (BG) and BG-alumina (BG-Al) composites coatings with different concentrations of Al incorporated on BG network over the Cp-Ti substrate were fabricated using SPD technique. Phase purity of BG and BG-Al composites were analyzed by XRD in which Na₂Ca₂Si₃O₉ and β-Na₂Ca₄(PO₄)₂SiO₄) and Na_7.15(Al_7.2Si_8.8O₃₂) phases were formed. Surface morphology of the coated substrates was analyzed by SEM. Uniformity of the coatings were evaluated by surface profilometer and the uniform distribution the nanoparticles were confirmed with Elemental mapping. Systematically, each apatite layer formation on coated substrate was confirmed by immersing the samples for 1, 3, and 7 days in simulated body fluid and the needle-like structure was characterized using SEM. Cumulative release of Tetracycline hydrochloride (Tet) antibiotic and Dexamethasone (Dex) anti-inflammatory drug-loaded BG-Al and BG-Al composite-coated substrate were studied for 24 h. Antibacterial activity of the coated substrates were evaluated by time-dependent growth inhibition and minimal inhibitory concentration (MIC) assays in which BG-Al and BG-Al composite loaded with Tet showed considerable growth inhibition against S. aureus. Osteoblast-like cells (MG-63) exhibited profound proliferation with no cytotoxic effects which was due to release of Dex drug-coated substrates. Thus, surface modification of Cp-Ti substrate with BG, BG-Al composites coatings loaded with Tet and Dex drug can be considered for post-operative orthopedic implant infection application.

Enhanced acetic acid sensing of MOF-derived α-Fe2O3/ZrO2 arising from phase junction and defects

The coexistence of phase junction, heterojunction and defects allows α-Fe2O3/ZrO2 to display an significant response towards acetic acid.

Zirconia Reduced Graphene Oxide Nano-Hybrid Structure Fabricated by the Hydrothermal Reaction Method

In this work, we report an available technique for the effective reduction of graphene oxide (GO) and the fabrication of nanostructured zirconia reduced graphene oxide powder via a hydrothermal method. Characterization of the obtained nano-hybrid structure materials was carried out using a scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). The confirmation that GO was reduced and the uniform distribution of zirconia nanoparticles on graphene oxide sheets during synthesis was obtained due to these techniques. This has presented new opportunities and prospects to use this uncomplicated and inexpensive technique for the development of zirconia/graphene nanocomposite powders.

Solvothermal Preparation and Electrochemical Characterization of Cubic ZrO₂ Nanoparticles/Highly Reduced Graphene (HRG) based Nanocomposites

A single-step solvothermal approach to prepare stabilized cubic zirconia (ZrO₂) nanoparticles (NPs) and highly reduced graphene oxide (HRG) and ZrO₂ nanocomposite (HRG@ZrO₂) using benzyl alcohol as a solvent and stabilizing ligand is presented. The as-prepared ZrO₂ NPs and the HRG@ZrO₂ nanocomposite were characterized using transmission electron microscopy (TEM) and X-ray diffraction (XRD), which confirmed the formation of ultra-small, cubic phase ZrO₂ NPs with particle sizes of ~2 nm in both reactions. Slight variation of reaction conditions, including temperature and amount of benzyl alcohol, significantly affected the size of resulting NPs. The presence of benzyl alcohol as a stabilizing agent on the surface of ZrO₂ NPs was confirmed using various techniques such as ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), Raman and XPS spectroscopies and thermogravimetric analysis (TGA). Furthermore, a comparative electrochemical study of both as-prepared ZrO₂ NPs and the HRG@ZrO₂ nanocomposites is reported. The HRG@ZrO₂ nanocomposite confirms electronic interactions between ZrO₂ and HRG when compared their electrochemical studies with pure ZrO₂ and HRG using cyclic voltammetry (CV).

A simple method for the sonochemical synthesis of PVA/ZrO2-vitamin B1 nanocomposites: Morphology, mechanical, thermal and wettability investigations

Poly(vinyl alcohol) (PVA) based nanocomposites (NCs) filled by various weight percent of modified ZrO₂ nanoparticles (NPs) with vitamin B₁ (VB₁) up to 7wt% were fabricated via ultrasonication method then was cast to thin films. The ultrasonication was applied for the preparation and modification process asan easy, safe and fast method. Ultrasonic was responsible for great homogeneities of NPs into PVA matrix, which could not be achieved by mechanical or magnetically stirring. The creation of polymer NCs and changes in the structural properties were examined by X-ray diffraction. FT-IR spectroscopy indicated the possible interactions of the ZrO₂-VB₁ NPs with the PVA backbones and also, existence of absorption bands related to PVA and ZrO₂ NPs in the NC structures. The distribution of nano-fillers and uniform morphology of the NCs showed that the ZrO₂-VB₁ NPs were homogeneously dispersed in the polymer matrix in the nanosized scale. UV-Vis analysis shown that the the optical absorption were improved by evolution of ZrO₂-VB₁ NPs content. The tensile strength of PVA film was increased significantly with increasing the ZrO₂-VB₁ NPs content. Thermal gravimetric analysis confirmed that NCs displayed higher thermal stability than the pristine PVA. Also, water contact angle analysis indicated that the hydrophilicity of NC films was enhanced with increasing the concentration of ZrO₂ NPs.

The synthesis of poly(vinyl chloride) nanocomposite films containing ZrO2 nanoparticles modified with vitamin B1 with the aim of improving the mechanical, thermal and optical properties

In the present investigation, solution casting method was used for the preparation of nanocomposite (NC) films. At first, the surface of ZrO₂ nanoparticles (NPs) was modified with vitamin B₁ (VB₁) as a bioactive coupling agent to achieve a better dispersion and compatibility of NPs within the poly(vinyl chloride) (PVC) matrix. The grafting of modifier on the surface of ZrO₂ was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis (TGA). Finally, the resulting modified ZrO₂ (ZrO₂–VB₁), was used as a nano-filler and incorporated into the PVC matrix to improve its mechanical and thermal properties. These processes were carried out under ultrasonic irradiation conditions, which is an economical and eco-friendly method. The effect of ZrO₂–VB₁ on the properties and morphology of the PVC matrix was characterized by various techniques. Field emission scanning electron microscopy and transmission electron microscopy analyses showed a good dispersion of fillers into the PVC matrix with the average diameter of 37–40 nm. UV–Vis spectroscopy was used to study optical behavior of the obtained NC films. TGA analysis has confirmed the presence of about 7 wt% VB₁ on the surface of ZrO₂. Also, the data indicated that the thermal and mechanical properties of the NC films were enhanced.

Synthesis and characterization of ZrO2 nanoparticles-antimicrobial activity and their prospective role in dental care

Nanomaterials are exerting a pull on deal with biological and pharmaceutical applications. Biomedical grade of zirconia reveals potential mechanical features of oxide ceramics. In this study, antimicrobial activity and anti-tooth decay applications of the synthesized NPs of ZrO₂ were determined. The as-prepared ZrO₂ NPs were characterized by UV-vis spectroscopy, FTIR and XRD, which determined the formation of ZrO₂NPs and their crystalline nature. SEM analysis further revealed spherical shaped NPs and TEM analysis determined the size of the particles in the range of 15-21 nm, respectively. The antimicrobial activity of different concentrations of the synthesized ZrO₂NPs was examined against gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa), respectively. The synthesized ZrO₂NPs displayed a better inhibitory action against Pseudomonas aeruginosa (inhibition zone size of 20 mm) at the concentration of 100 μg/ml compared to other bacteria due to the negatively charged P. aeruginosa cell wall readily attracting positively charged ZrO₂NPs and thereby inhibiting microbial actions. Moreover, the concentration of ZrO₂NPs was directly proportional to their inhibitory actions against the tested microorganisms. Finally, the preventive role of ZrO₂NPs in a tooth decay pathway has been elucidated. Hence, it could be concluded that the as-prepared ZrO₂NPs possess viable biomedical applications.

Photocatalytic activity against azo dye and cytotoxicity on MCF-7 cell lines of zirconium oxide nanoparticle mediated using leaves of Lagerstroemia speciosa

Metal oxide nanoparticles are gaining interest in recent years. The present paper explains about the green synthesis of zirconium oxide nanoparticles (ZrO NPs) mediated from the leaves of Lagerstroemia speciosa. The prepared ZrO NPs were characterized by UV-vis spectroscopy, FT-IR, X-ray diffraction analysis (XRD), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX) and Thermogravimetric Analysis (TGA). The photocatalytic activity of ZrO NPs was studied for azo dye by exposing to sunlight. The azo dye was degraded up to 94.58%. Also the ZrO NPs were studied for in vitro cytotoxicity activity against breast cancer cell lines-MCF-7 and evaluated by MTT assay. The cell morphological changes were recorded by light microscope. The cells viability was seen at 500μg/mL when compared against control. Hence the research highlights, that the method was simple, eco-friendly towards environment by phytoremediation activity of the azo dye and cytotoxicity activity against MCF-7 cell lines. Hence the present paper may help to further explore the metal nanoparticle for its potential applications.

Sol–gel synthesis of mesoporous spherical zirconia

Mesoporous spherical zirconia (ZrO₂) with a surface area of 113 m²g⁻¹and average pore size of 5.0 nm is prepared by a sol–gel method with ZrOCl₂·8H₂O precursors and Sodium Dodecyl Sulfonate (SDS) templates with subsequent annealing at 500 °C in air.

Defluoridation using biomimetically synthesized nano zirconium chitosan composite: kinetic and equilibrium studies

The present study reports a novel approach for synthesis of Zr nanoparticles using aqueous extract of Aloe vera. Resulting nanoparticles were embedded into chitosan biopolymer and termed as CNZr composite. The composite was subjected to detailed adsorption studies for removal of fluoride from aqueous solution. The synthesized Zr nanoparticles showed UV-vis absorption peak at 420nm. TEM result showed the formation of polydispersed, nanoparticles ranging from 18nm to 42nm. SAED and XRD analysis suggested an fcc (face centered cubic) Zr crystallites. EDAX analysis suggested that Zr was an integral component of synthesized nanoparticles. FT-IR study indicated that functional group like NH, CO, CN and CC were involved in particle formation. The adsorption of fluoride on to CNZr composite worked well at pH 7.0, where ∼99% of fluoride was found to be adsorbed on adsorbent. Langmuir isotherm model best fitted the equilibrium data since it presented higher R(2) value than Freundlich model. In comparison to pseudo-first order kinetic model, the pseudo-second order model could explain adsorption kinetic behavior of F(-) onto CNZr composite satisfactorily with a good correlation coefficient. The present study revealed that CNZr composite may work as an effective tool for removal of fluoride from contaminated water.