Preparation and Self-assembly of Zirconia Nanoparticles via Hydrothermal Method

Zirconia nanoparticles were synthesized via hydrothermal method without any additives. This work focuses on the effect of preparation conditions1 such as the precursor preparation condition and crystallization time of nanocrystallite in autoclave on the properties of as-prepared products. The results indicated that the amount of tetragonal zirconia varied with the preparation conditions. It increased with the increase of the concentration of KOH solution in precursor producing process and reduced with the prolongation of crystallization time. At the same time, the particle size and morphology were also affected by the preparation conditions. In addition, the self-assembled spindle- like aggregates were observed in present works.

Structural,Optical,Antibacterial and Antifungal Properties of Zirconia Nanoparticles by Biobased Protocol

Biological entities and inorganic materials have been in constant touch with each other ever since inception of life on earth.This method has lots of merits such as not requiring complex procedures,template supporting etc.In this work,Aloe vera plant mediated synthesis of tetragonal zirconia nanoparticles has been performed and thermogravimetric and differential thermal analysis（TG/DTA）,X-ray diffraction（XRD）,scanning electron microscopy（SEM） with energy dispersive X-ray spectroscopy（EDX）,atomic force microscopy（AFM）,ultraviolet—visible（UV—VIS） technique and Fourier transform infrared spectroscopy（FTIR） have been provided for characterizing the nanoparticles.Formation of homogeneously distributed spherical zirconia nanoparticles of 50—100 nm in size is predicted.The antimicrobial and antifungal properties are also investigated for synthesis of zirconia nanoparticles and the treated cotton by agar diffusion method against Staphylococcus aureus and Escherichia coli bacterial pathogens and fungal strains Candida albicans and Aspergillus niger,respectively.

Nanocrystalline Growth Activation Energy of Zirconia Polymorphs Synthesized by Mechanochemical Technique

The synthesis of ZrO2 by mechanochemical reaction using ZrCI4 and CaO as raw materials and subsequent annealing of the products were investigated. The effect of thermal treatment on the structural evolution and morphological characteristics of the nanopowders was studied by X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, differential thermal analysis and Rietveld refinement. The results showed that the average crystallite size of Zr02 was less than 100 nm up to around 1100 ℃. The activation energy for ZrO2 nanocrystallite growth during calcination was calculated to be about 13,715 and 27,333 J/too Mechanism of the nanocrysta for tetragonal （t-ZrO2） and monoclinic （m-Zr02） polymorphs, respectively. ite growth of the ZrO2 polymorphs during annealing is primarily investigated.

A Highly Efficient ZrO2 Nanoparticle Based Electrochemical Sensor for the Detection of Organophosphorus Pesticides

A sensitive electrochemical method for square-wave voltammetric detection of organophosphate （OP） com- pounds was developed based on zirconia （ZrO2） nanoparticles modified electrode. The electrode was fabricated us- ing electrochemical deposition and characterized by scanning electron microscopy （SEM）, which confirmed the successful formation of nanoparticles. Due to the strong affinity of ZrO2 with the phosphoric group, OPs can strongly bind to the surface of ZrO2 nanoparticles （ZrO2NPs）. Under optimized operational conditions, SWV was employed for Omethoate （a model of OP compounds） detection with 5 min absorption, which showed a wide detec- tion range from 98.5 pmoloL-x to 985 nmol·L^1, with a detection limit as low as 52.5 pmol·L^-1. This electrochemi- cal sensor has good selectivity, stability and reproducibility, and great potential in the detection of OP compounds in agriculture area.

Release of ZrO2 nanoparticles from ZrO2/Polymer nanocomposite in wastewater treatment processes

The widespread use of nano-enabled water treatment composites(NWTCs)can result in the release of nanoparticles(NPs)into environmental waters.Studying the release of NPs from NWTCs is of great significance for evaluating the material stability,and environment and biological safety.This work evaluated the amount and species of Zr released from a NWTC,a ZrO2/polymer composite(HZO@D201),during the treatment of electroplating wastewater.About 5 g of the HZO@D201 particles,consisting of porous spheres(0.8 mm in diameter)loaded with ZrO2 NPs,were packed into a glass column(130 mm in length and20 mm in diameter)and treated with wastewater at a flow rate of 25 mL/hr.The release of Zr occurred mainly in the initial stages of water treatment,decreased with the increase of treatment volume,and approached an equilibrium value of approximately 3.79μg/L at the treatment volume of about 800 bed volumes.The total amount of Zr released in the effluent was in the range of 2.62-140μg/L,which was mainly present in the form of ZrO2 NPs.The amounts of Zr released under acidic and alkaline conditions were markedly higher than that under neutral conditions,while the presence of humic acid significantly inhibited the release of Zr.Our study implied that the NWTCs could be a source of engineered NPs in environmental waters,and should be considered in evaluating the safety of ZrO2/polymer composites in water treatment.