Browsing by Author "Ayvacikli, M"
Now showing 1 - 20 of 95
Results Per Page
Sort Options
Item Microstructural and Radioluminescence Characteristics of Nd3+ Doped Columbite-Type SrNb2O6 PhosphorEkmekçi, MK; Ilhan, M; Ege, A; Ayvacikli, MUndoped and different concentration Nd3+ doped SrNb2O6 powders with columbite structure were synthesized by molten salt process using a mixture of strontium nitrate and niobium (V) oxide and NaCl-KCl salt mixture as a flux under relatively low calcining temperature. X-ray diffraction analysis results indicated that SrNb2O6 phases found to be orthorhombic columbite single phase for undoped, 0.5 and 3 mol% Nd3+ doping concentrations. Phase composition of the powders was examined by SEM-EDS analyses. Radioluminescence properties of Nd3+ doped samples from UV to near-IR spectral region were studied. The emissions increased with the doping concentration of up to 3 mol%, and then decreased due to concentration quenching effect. There is a sharp emission peak around 880 nm associated with F-4(5/2) -> I-4(9/2) transition in the Nd3+ ion between 300 and 1100 nm. The broad emission band intensity was observed from 400 to 650 nm where the peak intensities increased by increasing Nd3+ doping concentration. All the measurements were taken under the room temperature.Item Synthesis and competitive luminescence quenching mechanism of Ca3Al2O6Ln3+(Ln: Dy and Sm) phosphorsBakr, M; Kaynar, ÜH; Ayvacikli, M; Benourdja, S; Karabulut, Y; Hammoudeh, A; Can, NSm3+ and Dy3+ activated Ca3Al2O6 phosphors were produced through a gel combustion method using Urea + beta-Alanine, Urea, and Urea + Glycine as fuels. The crystal structure and the phase purity of the obtained materials were characterized by X-ray powder diffraction (XRD). Ca3Al2O6 :Sm3+ phosphor shows characteristic emission lines (565 nm, 602 nm, 649 nm, and 714 nm) in the orange red region assigned to (4)G(5/2) -> H- 6(J) (J = 5/2, 7/2, 9/2, 11/2) transitions of Sm3+. The strongest peak is located at 602 nm. Emission spectra of Ca3Al2O6 :Dy3+ show that there are two dominant peaks centered at 480 nm and 573 nm emitting blue and yellow light. Optimum doping concentrations of Sm(NO3)(3) and Dy(NO3)(3) are 0.01 % and 0.03 %, respectively. The concentration quenching mechanism is verified to be a dipole-dipole interaction as the type of energy transfer among Sm3+-Sm3+ and Dy3+-Dy3+ ions. The critical distance is also calculated to be 24.19 angstrom and 16.77 angstrom, respectively.Item Phase transition and luminescence characteristics of dysprosium doped strontium stannate phosphor synthesized using hydrothermal methodKaynar, H; Coban, MB; Madkhli, AY; Ayvacikli, M; Can, NA series of strontium stannate (SrSnO3) doped with Dy3+ ions at various wt % concentrations (1, 2, 3 and 5) were synthesized via hydrothermal reaction and analysed using X-ray diffraction (XRD), energy dispersive spectros-copy (EDS), environmental electron scanning microscope (ESEM), photoluminescence (PL) and, cath-odoluminescence (CL). The XRD results confirmed that all samples were assigned to cubic perovskite-type SrSnO3 structured with the Pm3m space group. The PL emission spectrum of Dy3+ activated samples consisted of some characteristic peaks located at 481 nm, 572 nm, 660 nm and 753 nm, corresponding to (4F9/2 -> 6H15/2, blue), (4F9/2 -> 6H13/2, yellow), 660 nm (4F9/2 -> 6H11/2, red) and 753 nm (4F9/2 -> 6H9/2, red) transitions. The PL emission line intensity is gradually enhanced with an increase in doping concentration up to 3 wt %, followed by concentration quenching. The confinement effects of localized resonant energy transfer might cause higher concentration quenching. PL emission spectra were affected by the temperature range from 10 K to 300 K. PL emission anomalies at 270 K in SrSnO3:Dy3+ have been reported to be consistent with a structural phase tran-sition at this temperature. This work confirms Singh et al.'s observation, revealing that SrSnO3 has a phase transition at 270 K.Item Dy3+and Eu3+co-activated gadolinium aluminate borate phosphor: Synthesis, enhanced luminescence, energy transfer and tunable colorMadkhali, O; Kaynar, UH; Kaynar, SC; Ayvacikli, M; Can, NThe synthesis of GdAl3(BO3)4 phosphors incorporated with activators of Dy3+ and Dy3+/ Eu3+was successful and achieved through the gel combustion method. Powder X-ray diffraction (XRD) was employed to identify phase purity and the effects of dopant concentration on the crystallographic structure. The results of Photo-luminescence (PL) measurements revealed that the intensity and lifetime of luminescence properties varied depending on the concentrations of Dy3+ and Eu3+ ions. The dependence of luminescence intensity on doping concentration is investigated with respect to the energy transfer process between Eu3+ and Dy3+ ions. A decrease in luminescence lifetime occurs with increasing concentrations of Eu3+ co-doping. The energy transfer was also investigated using decay curve analysis. The co-doping of Eu3+ significantly boosts the energy transfer efficiency from 26% to 84%. These findings make GdAl3(BO3)4: Dy3+, Eu3+ phosphors an ideal choice for LED applications in solid state lighting and displays.Item Characterization and thermoluminescence behavior of beta irradiated NaBaBO3 phosphor synthesized by combustion methodOglakci, M; Akça, S; Halefoglu, YZ; Dogan, T; Ayvacikli, M; Karabulut, Y; Topaksu, M; Can, NNaBaBO3 host material was synthesized using the combustion method. In order to optimize the performance of the material, effects of sintering temperatures varying from 600 degrees to 1000 degrees C were investigated. The sintering temperature and dwell time were found to have pronounced effects on the pure NaBaBO3 material. X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques were used to confirm the phase formation and examine the surface morphology of the prepared powder material, respectively. TL behavior of NaBaBO3 was studied at various beta doses. It is seen that the sample exhibits well resolved TL glow peak at a peak temperature about 175 degrees C and corresponding TL intensity increases with the increasing beta dose. However, TL glow peak slightly shifts to lower temperature with the increasing beta dose level. This is the first TL report of a phosphor with a NaBaBO3 host. The TL kinetic parameters were estimated by the peak shape (PS) method and CGCD software. TL glow curves of NaBaBO3 consist of several traps and exhibited second order kinetics. A possible TL mechanism was also discussed using the energy level model. The obtained results can provide valuable knowledge related to the investigation of the intrinsic nature characteristics of NaBaBO3 in research fields pertaining to dosimetry.Item Thermoluminescence glow curve analysis of Ca3Y2B4O12 phosphor prepared using combustion methodHakami, J; Sonsuz, M; Kaynar, UH; Ayvacikli, M; Oglakci, M; Yüksel, M; Topaksu, M; Can, NCa3Y2B4O12 (CBYO) phosphor was synthesized using a gel combustion method. X-ray diffraction (XRD) measurement confirmed a single-phase structure (space group Pnma (62)) of synthesized compound. TL measurements were conducted between room temperature (RT) and 450 degrees C at a heating rate of 2 degrees Cs-1. Significant glow peaks were observed at 64, 116, and 242 degrees C in CYBO phosphor sample exposed to different beta doses. In the range of 0.1-100 Gy, the TL intensity of the glow peak displayed good linearity. Different methods were employed to determine the number of peaks, the trap structure, and the kinetic parameters of the thermoluminescence glow curve of CBYO; the Hoogenstraaten method, various heating rates (VHR), and glow curve deconvolution method (CGCD) implemented through tgcd:An R package. Currently available findings confirm that CYBO host is a promising candidate for environmental studies because one exhibits adequate TL dose response coupled with a good sensitivity and linearity.Item Thermoluminescence characterization and kinetic parameters of Dy3+ activated Ca3Y2B4O12Hakami, J; Sonsuz, M; Kaynar, UH; Ayvacikli, M; Oglakci, M; Topaksu, M; Can, NIn this study, thermoluminescence (TL) characteristics of Ca3Y2B4O12:xDy (0 < x < 0.07) phosphor samples were studied. The samples were exposed to beta irradiation in the dose range from 0.1 Gy to 100 Gy to investigate TL dose response. The concentration of Dy3+ in Ca3Y2B4O12 phosphor was optimized and found to be 1 mass % in terms of TL signal quality. The TL glow curve appears to be consisted of three peaks which were discernible at 72 degrees C, 280 C and 376 degrees C. The trapping parameters (E, b, and s) were calculated using initial rise (IR), and variable heating rate (VHR) techniques. The trapping parameters, order of kinetics, frequency factor, and figure of merit have been all determined by means of the Glow Curve Deconvolution (GCD) method (tgcd:An R package). Ca3Y2B4O12:Dy phosphor displays efficient thermoluminescence properties.Item Radioluminescence and thermoluminescence of albite at low temperatureCan, N; Garcia-Guinea, J; Kibar, R; Çetin, A; Ayvacikli, M; Townsend, PDFeldspar as an archaeological and geological natural material for dating and retrospective dosimetry is receiving more and more attention because of its useful luminescence properties. In this study, the 25-280 K thermoluminescence (TL) and radioluminescence (RL) spectra in albite, which is a component of the two main feldspar series, the alkali feldspar (Na, K)AlSi(3)O(8) and the plagioclases (NaAlSi(3)O(8)-CaAl(2)Si(2)O(8)) have been presented for aliquots along (001) and (010) crystallographic orientations. There are four main emission bands that are considered to arise from complexes of intrinsic defects linked in larger complexes with impurities such as Na(+), Mn(2+) or Fe(3+) ions. The consequence of their association is to produce different luminescence efficiencies that produce wavelength sensitive TL curves. Radioluminescence data at low temperature for albites is distorted by contributions from the TL sites, even when the RL is run in a cooling cycle. This indicates the potential for a far more general problem for analysis of low temperature RL in insulating materials. (C) 2011 Elsevier Ltd. All rights reserved.Item Thermally stimulated luminescence glow curve structure of β-irradiated CaB4O7:DyAkin, A; Ekdal, E; Arslanlar, YT; Ayvacikli, M; Karali, T; Can, NThermally stimulated luminescence glow curves of CaB4O7:Dy samples after beta-irradiation showed glow peaks at similar to 335, 530 and 675 K, with a heating rate of 2 K/s. The main peak at 530 K was analyzed using the T-max-T-stop method and was found to be composed of at least five overlapping glow peaks. A curve-fitting program was used to perform computerized glow curve deconvolution (CGCD) analysis of the complex peak of the dosimetric material of interest. The kinetic parameters, namely activation energy (E) and frequency factor (s), associated with the main glow peak of CaB4O7:Dy at 520 K were evaluated using peak shape (PS) and isothermal luminescence decay (ILD) methods. In addition, the kinetics was determined to be first order (b = 1) by applying the additive dose method. The activation energies and frequency factors obtained using PS and ILD methods are calculated to be 0.72 and 0.72 eV and 8.76 x 10(5) and 1.44 x 106/s, respectively. Copyright (C) 2014 John Wiley & Sons, Ltd.Item Luminescence of undoped and Eu3+activated zinc gallate phosphor: Synthesis, unusual intense 5D0 → 7F4 red emissionSouadi, G; Kaynar, ÜH; Ayvacikli, M; Can, NA series of Eu3+-doped ZnGa2O4 samples were synthesized via the urea-glycine combustion route. Powder X-ray diffraction (XRD) was used to investigate the crystallinity of the samples, energy dispersive spectroscopy (EDS) to explore the elemental composition, Fourier transform infrared (FTIR), to observe the vibrational modes of the samples, photoluminescence (PL) to determine the luminescence properties. The XRD data prove that the samples remain single cubic structure even at high concentrations of Eu3+, enabling the formation of a unique emission spectrum. The active ion concentration was varied to examine the influence of concentration on luminescent properties. This study revealed a 5D0 & RARR;7F4 transition located at 700 nm with unusual intensity that has not been documented in the literature, which suggests that the active ion concentration can influence the luminescent characteristics of the phosphors. The increasing Eu3+ content increases the number of Eu3+ ions in ZnGa2O4 host lattice, which enhances the luminescence efficiency of the phosphor. However, beyond a certain level of Eu3+content (i.e., 3 wt% Eu3+), the number of Eu3+ ions becomes excessive, resulting in a reduction in luminescence efficiency due to concentration quenching. The dipole dipole interaction is elucidated to play a prominent role in the mechanism of Eu3+ quenching in the ZnGa2O4. An assessment of color coordinates based on emission spectra reveals that the coordinates shift from blue to the white light region, and then to red as Eu3+ content increases. This suggests that there is a substantial relationship between the Eu3+ concentration and the measured color coordinates.Item Synthesis and optical properties of Er3+ and Eu3+ doped SrAl2O4 phosphor ceramicAyvacikli, M; Ege, A; Yerci, S; Can, NWe report, for the first time on luminescence from a Er3+ doped SrAl2O4 phosphor. Effects of Eu3+ doping were also studied. The influence of rare-earth doping in crystal structure and its optical properties were analysed by means of X-ray diffraction (XRD), Raman scattering, optical absorption, excitation and emission (PL) spectroscopy, thermally stimulated luminescence (TSL) and scanning electron microscope (SEM). Luminescence spectra and luminescence decay curves for Er3+ transitions in the near infrared region were recorded. The PL maximum for Eu doped SrAl2O4 is obtained at 620 nm and corresponds to the orange region of the spectrum. Diffraction patterns reveal a dominant phase, characteristic of the monoclinic SrAl2O4 compound and the presence of dopants has no effect on the basic crystal structure of SrAl2O4. The shapes of the glow curves are different for each dopant irradiated with either a Sr-90-Y-90 beta source, or UV light at 311 nm, and in detail the TL signals differ somewhat between Er and Eu dopants. (C) 2011 Elsevier B.V. All rights reserved.Item Photoluminescence investigations of Li2SiO3:Ln (Ln=Er3+, Eu3+, Dy3+, Sm3+) phosphorsSabikoglu, I; Ayvacikli, M; Bergeron, A; Ege, A; Can, NIn this study, we report a comprehensive structural and photoluminescence (PL) study on lithium metasilicate (Li2SiO3) phosphor ceramics doped with four rare earth (RE) ions. X-ray diffraction (XRD) patterns show a dominant phase, characteristic of the orthorhombic structure Li2SiO3 compound and the presence of dopants has no effect on the basic crystal structure of the material. The first excited state Er3+ luminescence at 1.54 mu m arises from a sharp atomic-like radiative transition between the I-4(13/2) state and the I-4(15/2) state (ground level) under a 532 nm line of an Ar ion laser excitation. Sm doped samples showed Sm3+ emission characteristics corresponding to the some (4)G(5/2) -> H-6(j) (j = 5/2.9/2,11/2) transitions indicating a strong crystal-field effect. PL spectra of Eu doped material exhibited peaks corresponding to the D-5(0) -> F-7(j) (j similar or equal to 0,1,2,3 and 4) transitions under 405 nm excitation. The dominant red color emission at 612 nm from the hypersensitive (D-5(0) -> F-7(2)) transition of Eu3+ indicates the inversion antisymmetry crystal field around Eu3+ ion, which is favorable to improve the red color purity. Dy doped samples showed the Dy3+ emission characteristic due to the F-4(9/2) -> H-6(13/2) transition. Their relative intensity ratios also suggested the presence of a symmetric environment around the metal ion. We suggest that lithium metasilicate has enough potential candidates to be a phosphor material. (C) 2012 Elsevier B.V. All rights reserved.Item Structural and luminescence characterization of Ce3+ and Mn2+ co-activated zinc silicate nanocrystal obtained by gel combustion synthesisPortakal-Uçar, ZG; Oglakci, M; Yüksel, M; Ayvacikli, M; Can, NThe structural, morphological, and luminescence properties, including photoluminescence (PL) and thermoluminescence ('FL), of newly produced Zn2SiO4:Ce co-activated by Ce3+ and Mn2+ ions using the gel-combustion synthesis, are investigated in deep. To determine the co-dopant effect precisely, non-doped, Ce3+ doped, and Ce3+ and Mn2+ double doped Zn2SiO4:Ce phosphors are evaluated. The fluorescence decay curves indicate that a shorter decay time at relatively high Mn concentrations takes place. The TL glow curve readouts observed by applying the dose range between 0.1 and 2000 Gy after 150 degrees C preheat are performed at a linear heating rate of 2 degrees C/s from room temperature (RT) to 500 degrees C. An anomalous heating rate behavior is observed when the influence of different heating rates on TL characteristics is reported. An excellent agreement is found between the TL kinetic parameters analyzed by the initial rise (IR) with T-M-T(stop )analysis and computerized glow curve deconvolution (CGCD) methods.Item Luminescence behavior and Raman characterization of jade from TurkeyArslanlar, YT; Garcia-Guinea, J; Kibar, R; Çetin, A; Ayvacikli, M; Can, NResults are presented for the cathodoluminescence (CL), radioluminescence (RL) and thermoluminescence (TL) of jade from Turkey. Jade samples show broad band luminescence from green to red, which, using lifetime-resolved CL, reveals seven overlapping emissions, of which two are dominant. Green emission obtained using spatially resolved CL was associated with Mn2+ and emission bands centered near at 480 and 530 nm were attributed to P-3(0)-H-3(4) and D-1(2)-H-3(4) transitions of Pr3+, respectively. Different shifts of the peak-wavelengths for 326 and 565 nm were observed with varying jade compositions. The incorporation of the larger K ion causes non-linear variations of the cell dimensions and therefore changes in the Fe-O band distance. We suggest that stress of the jade structure can be linked to the luminescence emission at 326 nm. Raman spectra have also been recorded in order to provide an unequivocal identification of the type of jade. The mechanism for the luminescence of the jade is considered. (C) 2011 Elsevier Ltd. All rights reserved.Item Influence of laser excitation power on temperature-dependent luminescence behaviour of Ce- and Tb-incorporated BaMgAl10O17 phosphorsKaynar, ÜH; Kaynar, SC; Ayvacikli, M; Karabulut, Y; Souadi, GO; Can, NBaMgAl10O17 (BAM) is a highly suitable host lattice for various rare earth ions with excellent luminescence properties in different spectral regions, including a strong photoluminescence (PL) emission from the visible spectral region. A new Ce- and Tb-incorporated BaMgAl10O17 phase was synthesized successfully using a wet combustion method and it was studied as a function of the temperature and laser excitation power. We further characterize the obtained phosphors with X-ray diffraction at room temperature. Different fuel/oxidant (f/o) ratios were introduced to investigate the optimum synthesis conditions for the BAM phosphors and optimum ratio was found out to be 8. The photoluminescence (PL) spectra were collected under the excitation light generated by a Nd:YLF pulse laser at 349 nm as the temperature was increased from 10 K to 300 K. A strong green emission of Tb3+ was observed in the green region of the spectrum due to the D-5(4)-> F-7(J) transition. We also observed a wide emission band from the Ce3+ ion in the wavelength range of 350-650 nm. The luminescence intensities of all phosphors exhibited different patterns with an increase in the temperature. We also evaluated how the PL spectrum of the rare earth-activated BAM host matrix shifts under various laser excitation powers. The PL intensity of Ce-activated BAM significantly shifted (similar to 30 A) to the blue region of the spectrum with an increase in the laser excitation power, however we did observed no shift forTb(3+) activated BAM. The present findings suggest that Tb-incorporated BaMgAl10O17 can be effective as a green phosphor candidate material with a wide range of applications.Item Luminescence and micro-Raman investigations on inclusions of unusual habit in chrysoprase from TurkeyAyvacikli, M; Garcia-Guinea, J; Jorge, A; Akalin, I; Kotan, Z; Can, NChemical analyses performed on chrysoprase from Turkey have shown many trace elements as well as rare earth impurities. Quantitative chemical analyses of inclusions in minerals can improve our understanding of the chemistry of surface. The environmental scanning electron microscope (ESEM) with an attached X-ray energy dispersive system (EDS) is capable of producing rapid and accurate major element chemical analyses of individual inclusions in crystals larger than about 30 mu m in diameter. The samples were examined with lifetime-resolved and spatially-resolved cathodoluminescence (CL), and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Spatially resolved CL results at room temperature were recorded for two different areas. Bulk area displays with low CL emission and pores contain iron phases such as chromite, hematite and anatase which cause the green color. For the raw data in the lifetime resolved CL spectrum, at least three broad emission bands were detected in a yellow band of the highest intensity at about 550 nm, a weaker orange band at about 650 nm, and a red band at 720 nm. It is assumed that there are links between the CL emissions and the presence of some transition metal and REE elements, but it is obvious that all trace elements do not play a direct role. Micro-Raman measurements were performed on chrysoprase and these showed a characteristic intensive Raman band peaked at 464 cm(-1) which can be inferred to nu(2) doubly symmetric bending mode of [SiO4/M] centers. Raman spectrum of all inclusions found in the material are also given and discussed in detail. (C) 2012 Elsevier B.V. All rights reserved.Item Spectral emission of rare earth (Tb, Eu, Dy) doped Y2Sn2O7 phosphorsEge, A; Ayvacikli, M; Dinçer, O; Satilmis, SURadioluminescence (RL) characterization of the yttrium stannate (Y2Sn2O7) phosphors doped with 1 mol % Tb, Eu and Dy was carried out and significant electronic transitions corresponding to doped rare earth ions were observed. It was seen that all parts of these rare earth ions are included in the phosphor material in their trivalent state. The RL measurement indicates that the series of the emission-state D-5(4)-> F-7(6), D-5(4)-> F-7(4), D-5(4)-> F-7(3), corresponding to the characteristic 4f -> 4f intra-configuration forbidden transitions of Tb(3+)are appeared and that main emission peak occurs at about 542 nm. There are in fact multiple emission lines at each of these due to the crystal field splitting of the ground state of the emitting ions. Eu-doped Y2Sn2O7 sample displayed intense and predominant emission peaks located at 580-650 nm corresponding to the D-5(0)->(7)Fj (j=1, 2, 3 and 4) transitions. Red emission coming from the hypersensitive Dy doped phosphor presented luminescence emissions with dominating transitions at (4)Fw(9/1) -> H-6(j)(j=9/2, 11/2,13/2 and 15/2). The sharp emission properties show that the Y2Sn2O7 is a suitable host for rare-earth ion doped phosphor material. (C) 2013 Elsevier B.V. All rights reserved.Item Characterization of a Green-Emitting Copper-Doped Barium Aluminate PhosphorAyvacikli, MA novel green-emitting phosphor copper-doped barium aluminate was synthesized by the conventional ceramic method. The crystallographic phase and microstructure identification were performed by powder X-ray diffraction and scanning electron microscopy. The X-ray diffraction pattern of the sample confirms the formation of the phosphor, and the scanning electron microscope image was recorded to observe the surface morphology. Differential thermal analysis results show that the initiatory decomposition temperature of barium carbonate starts at about 728 degrees C. Cathodoluminescence studies have been undertaken to ensure the successful incorporation of copper ions in the barium aluminate host lattice. Under the excitation of the electron beam, the phosphor can efficiently display a broad green emission centered at 490nm, corresponding to the transition from the conduction band edge to the excited state of copper in the barium aluminate host. However, there are no data available on copper luminescence in barium aluminate. New results on 3d activators of copper emission in the barium aluminate host are reported in this article, thus extending the list of copper-activated phosphors. These results strongly indicate that the copper-activated barium aluminate is a potential material used as a new high-brightness green phosphor for ultraviolet light-emitting diode and display devices.Item Radioluminescence of SrAl2O4:Ln3+ (Ln = Eu, Sm, Dy) phosphor ceramicAyvacikli, M; Ege, A; Can, NPhosphors for radiation detection require efficient energy transfer from the ionization track to the luminescent centers. In this work, the radioluminescence (RL) spectra of SrAl2O4 phosphor ceramics doped with individual trivalent rare earth element (REE) ions (Sm, Eu and Dy) are reported at the room temperature. Although there is some intrinsic UV/blue emission from the host lattice, the dominant signals are from the rare-earth sites, with signals characteristic of the REE2+ and REE3+ states. The shapes of the emission bands are different for each dopant. The sharp emission properties show that the SrAl2O4 is a suitable host for rare-earth ion doped phosphor material. (C) 2011 Elsevier B.V. All rights reserved.Item Removal of thorium (IV) ions from aqueous solution by a novel nanoporous ZnO: Isotherms, kinetic and thermodynamic studiesKaynar, ÜH; Ayvacikli, M; Hiçsönmez, U; Kaynar, SCThe adsorption of thorium (IV) from aqueous solutions onto a novel nanoporous ZnO particles prepared by microwave assisted combustion was studied using batch methods under different experimental conditions. The effect of contact time, solution pH, initial concentration and temperature on adsorption process was studied. The ability of this material to remove Th (IV) from aqueous solution was characterises by Langmuir, Freunlinch and Temkin adsorption isotherms. The adsorption percent and distribution coefficient for nanoporous ZnO powders in optimum conditions Were 97% +/- 1.02; 8080 L kg(-1) for Th (IV), respectively. Based on the Langmuir model, the maximum adsorption capacity of nanoporous ZnO for Th (IV) was found to be 1500 g kg(-1). Thermodynamic parameters were determined and discussed. The results indicated that nanoporous ZnO was suitable as sorbent material for recovery and adsorption of Th (IV) ions from aqueous solutions. The radioactive Th (VI) in surface water, sea water and waste waters from technologies producing nuclear fuels, mining (uranium and thorium) and laboratories working with radioactive materials (uranium and thorium) can be removed with this nanoporous ZnO. (C) 2015 Elsevier Ltd. All rights reserved.