Synthesis and Photocatalytic Properties of Silver Niobate

The interaction between silver nitrate and niobium pentoxide has been studied under conventional thermal treatment (TT) as well as mechanochemical and sonochemical treatment (MChT and UST, respec-tively). The products of reaction have been investigated using XRD, DTA-TG, Raman spectroscopy, adsorp-tion of nitrogen. MChT and UST promote lowering the temperature of silver niobate (SN) formation. The formed SN possesses higher specific surface area and photocatalytic activity. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3527

Модифікування та дослідження властивостей оксиду та оксигідроксиду олова (IV)

Чотири серії зразків оксиду та оксигідроксиду олова (IV) було модифіковано за допомогою меха- нохімічної та мікрохвильової обробки. Досліджено фізико-хімічні властивості всіх зразків за допо- могою рентгенофазового аналізу, диференційного термічного аналізу, методів дослідження порува- тої структури, електронної (UV-Vis) спектроскопії. Фотокаталітичні властивості дослідних зраз- ків вивчалися в реакціях фотодеструкції водних розчинів барвників (Cафранін Т, Родамін Б) при опроміненні у видимій області. Дослідження показали, що після проведення механохімічної обробки перших трьох серій зразків в атмосфері повітря питома поверхня знижується, а у воді залишаєть- ся майже незмінною. У результаті мікрохвильової обробки питома поверхня зростає, спостеріга- ється упорядкування кристалічної структури. В усіх випадках формується мезо-макропорувата структура. Усі зразки показали високу фото- каталітичну активність при фотодеструкції Родаміну Б та Сафраніну Т.Four series of tin (IV) oxide and oxo-hydroxide samples were modified by using microwave and mechanochemical treatments. Physical-chemical properties of all samples were studied by using the following techniques: XRD, differential thermal analysis, nitrogen adsorption-desorption, UV-Vis spectroscopy. The estimation of photocatalytic activity under visible irradiation was carried out by using degradation of textile dyes (safranin T, rhodamine B) in aqueous medium. Investigations have shown that a specific surface area decreases as a result of mechanochemical treatment of samples of the first three series in air, and remains almost unchanged after milling in water. The specific surface area increases and the crystal structure of the latter are improved as a result of microwave treatment. Meso-macroporous structure is formed in all cases. All samples showed high photocatalytic activity in the degradation of rhodamine B and safranin T

On the utility of Transcarpathian Clinoptylolite in the adsorption of chloroform from aqueous solutions

The objective of the study was to determine the sorbing capacity of the transcarpathian clinophylolite ( Ukraine ) when applied to chloroform separation from aqueous solutions. Analyses and measurements included the chemical parameters and porosity of the mineral, as well as the effect of processing temperature, grain size distribution and pH ( of the agueous solution ) on the sorbing properties with respect to water and chloroform.The efficiency of chloroform sorption from the agueous solution ranged from 97 to 99%.This is an indication that the clinoptylolite has a great potential for being effectively used as a sorbend in the concentration of chloroform occuring in agueous solutions.The properties of the clinoptylolite make it applicable not only to analytical procedures,but also to water treatment

On the utility of transcarpthian clinoptylolite in the adsarption of Hg(II),Cr(III) and Ni(II) ionsfrom aqueous solutions

The objective of the study was to assess the usefulness of the Transcarpatien zeolite-clinoptylolite ( Sokirnica,Ukraine) when applied to the removal of Hg(II),Ni(II) and Cr(III) ions from aqueous solutions.The experiments were carried out with three types of clinoptylolite samples-natural,after thermal processing ( 300 and 500.o C),and after chemical modification (with NH4Cl or HCl).Thus,natural clinoptylolote adr clinoptylolite modifical with 3N NH4Cl were found to have a high sorbing capacity.Maximum adsorption of Hg(II) ions (amounting to 4.7 mg/g was achieved within two hours.The adsorption of Ni(II) ions was alamost complete wilin on hour.The efficiency of Cr(III), ion adsorption amounted to 70%. These data indicate that the investigated clynoptilolite has a potential for being effectively used in water treatment for drunking purposes.Ist properties make in also applicable to the removal of heavy metals from wasterwater. A low initial concentrations of Ni(II) and Cr(III), a good treatment effect conbe achieved within a comparatively short time of contact,ar a result of filtration on the clinoptylolite bed