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Lazaratou CV, Panagopoulos SD, Vayenas DV, Panagiotaras D, Papoulis D. Thermally Modified Palygorskite Usage as Adsorbent in Fixed-Bed Reactor for High Concentration NH 4+-N Removal and Further Application as N-Fertilizer in Hydroponic Cultivation. Materials (Basel) 2022; 15:6541. [PMID: 36233891 PMCID: PMC9573168 DOI: 10.3390/ma15196541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/12/2022] [Accepted: 09/18/2022] [Indexed: 06/16/2023]
Abstract
Palygorskite sample (Pal) underwent thermal treatment at 400 °C (T-Pal) to be used as adsorbent for the removal of 200 mg NH4+-N/L from artificial solution. After thermal treatment, the sample was characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM). For NH4+-N removal, T-Pal was added as a bed matrix in fixed-bed reactor experiments and the effect of flow rate was determined. It was indicated that with the flow rate increase from 10 mL/min to 50 mL/min, fewer liters of the solution were purified, rendering a longer residual time of interactions, which is optimal for NH4+-N removal from T-Pal. The maximum removed amount was calculated at 978 mg NH4+-N (qtotal), suggesting T-Pal is a promising ammonium adsorbent. The data of kinetic experiments were applied to Clark, Yoon-Nelson, and Thomas kinetic models, with Clark having the best fit, highlighting a heterogenous adsorption. At the end of kinetic experiments, T-Pal applied in hydroponic cultivations and presented a sufficient release rate, which was found utilizable for saturated T-Pal usage as N fertilizer that satisfactory results were deemed concerning lettuces characteristics and growth.
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Affiliation(s)
| | | | - Dimitrios V. Vayenas
- Department of Chemical Engineering, University of Patras, GR-26504 Patras, Greece
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology, GR-26504 Patras, Greece
| | - Dionisios Panagiotaras
- Department of Environment, Ionian University, M. Minotou-Giannopoulou 26, GR-29100 Zakynthos, Greece
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Lazaratou CV, Triantaphyllidou IE, Pantelidis I, Chalkias DA, Kakogiannis G, Vayenas DV, Papoulis D. Using raw and thermally modified fibrous clay minerals as low concentration NH 4+-N adsorbents. Environ Sci Pollut Res Int 2022; 29:17737-17756. [PMID: 34676475 DOI: 10.1007/s11356-021-17107-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/14/2021] [Indexed: 06/13/2023]
Abstract
Raw and modified fibrous clay minerals palygorskite (Pal) and sepiolite (Sep) were tested for their ability to remove ammonium from ammonium polluted water. Palygorskite and sepiolite underwent thermal treatment at 400°C (T-Pal and T-Sep respectively). Raw and thermally treated samples were characterized using XRD, SEM, BET, FTIR, TGA, zeta potential, and XRF. The techniques verified the effect of thermal treatment on sample structures and the enhancement of negative charge. Both raw and thermally activated materials were applied in batch kinetic experiments, and found to be efficient adsorbents in their raw forms, since Pal and Sep achieved 60 and 80% NH4+-N removal respectively within 20 min of contact for initial NH4+-N concentration of 4 mg/L. Similar removal rates were gained for other concentrations representative of contaminated aquifers that were examined, ranging from 1 to 8 mg/L. Results for the modified T-Pal and T-Sep minerals showed up to 20% higher removal rate. Saturation tests indicated the positive effect of thermal treatment on the minerals since T-Pal and T-Sep removal efficiency reached 85% and remained stable for 24 h. However, competitive ions in real water samples can influence the NH4+-N removal efficiency of the examined samples. At almost all the examined samples, the nonlinear Freundlich isotherm and linear pseudo-second kinetic models showed better fitted all examined samples thus indicating heterogeneous chemisorption.
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Affiliation(s)
| | | | | | - Dimitris A Chalkias
- Nanotechnology & Advanced Materials Laboratory, Department of Electrical and Computer Engineering, University of Peloponnese, GR-26334, Patras, Greece
| | | | - Dimitrios V Vayenas
- Department of Chemical Engineering, University of Patras, GR-26504, Patras, Greece
- Institute of Chemical Engineering Sciences, Foundation for Research and Technology, PO Box 1414, 26504, Patras, GR, Greece
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Mavrikos A, Papoulis D, Todorova N, Papailias I, Trapalis C, Panagiotaras D, Chalkias D, Stathatos E, Gianni E, Somalakidi K, Sygkridou D, Komarneni S. Synthesis of Zn/Cu metal ion modified natural palygorskite clay – TiO2 nanocomposites for the photocatalytic outdoor and indoor air purification. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113568] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Mavrikos A, Pospíšil M, Gianni E, Lazaratou CV, Pšenička M, Papoulis D. Interactions among TiO2 and palygorskite revealed: Boost for stability of well-known photocatalyst. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Gianni E, Lazaratou CV, Panagopoulos G, Sarantari P, Martsouka F, Papagiannopoulos K, Panagiotaras D, Papoulis D. Raw and modified palygorskite in water treatment applications for low-concentration ammonium removal. Water Environ Res 2021; 93:1979-1994. [PMID: 33835675 DOI: 10.1002/wer.1570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/22/2021] [Accepted: 04/01/2021] [Indexed: 06/12/2023]
Abstract
Raw palygorskite (Pal) samples went under acid (H-Pal), NaCl (Na-Pal), and CaCl2 treatment (Ca-Pal) in order to be examined as ammonium (NH4 + ) sorbents from aqueous solutions. The samples were characterized by XRD and FT-IR techniques to examine potential structural differences after modifications, and batch kinetic experiment series were applied to determine the optimal conditions for NH4 + removal. According to thermodynamic analysis, the removal reaction for sodium- and calcium-treated samples was endothermic (ΔΗ0 > 0, 1.65 kJ/mol and 24.66 kJ/mol, respectively), in contrast with the exothermic reactions of raw and acidic-treated palygorskite samples (ΔΗ0 < 0, -37.18 kJ/mol and -27.56 kJ/mol respectively). Moreover, each sample presented a different order of sorbed ions preference, whereas the strong affinity for Ca2+ sorption was common in all cases since the NH4 + removal inhibited. Nevertheless, a similar pattern was followed for raw and modified samples at isotherm study, rendering the linear form of Freundlich isotherm to express better the NH4 + sorption on palygorskite sample, indicating that it is a heterogeneous procedure. In all cases, the NH4 + maximum uptake was within 15 min using 8 g/L of each sorbent, especially for the Na-Pal sample, which could reach almost 100% removal of low concentration NH4 + . PRACTITIONER POINTS: Modified palygorskite samples were tested for NH4 + removal from aqueous solutions. NaCl-treated palygorskite had the higher removal efficiency, which could reach almost 100% removal of low concentration NH4 + . NH4 + maximum uptake was within 15 minutes using 8 g/L of each sorbent. NH4 + adsorption was an endothermic reaction for NaCl- and CaCl2 -treated palygorskite sorbents. NH4 + adsorption was an exothermic reaction for raw and acid-treated palygorskite sorbents.
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Affiliation(s)
- Eleni Gianni
- Department of Geology, University of Patras, Patras, Greece
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Martsouka F, Papagiannopoulos K, Hatziantoniou S, Barlog M, Lagiopoulos G, Tatoulis T, Tekerlekopoulou AG, Lampropoulou P, Papoulis D. The Antimicrobial Properties of Modified Pharmaceutical Bentonite with Zinc and Copper. Pharmaceutics 2021; 13:pharmaceutics13081190. [PMID: 34452151 PMCID: PMC8399475 DOI: 10.3390/pharmaceutics13081190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/30/2023] Open
Abstract
Pharmaceutical grade bentonite, containing a high amount of montmorillonite, enriched with zinc (Zn) or copper (Cu) (ZnBent and CuBent, respectively) was used as the main component for the creation of formulations for cutaneous use and tested for their antimicrobial capacity. Bentonite (Bent) with added phenoxyethanol (PH) as a preservative and unmodified bentonite were used as control groups. The mineralogical composition, structural state, and physical or chemical properties, before and after the modification of the samples, were characterized utilizing X-ray Diffraction Analysis (XRD), Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Fluorescence (XRF) techniques, and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM, SEM-EDS) analyses. In addition, the profile of zinc and copper concentration from two types of surfaces ZnBent and CuBent, and into Phosphate-Buffered Saline (PBS) are discussed. Finally, the formulations in the form of basic pastes were challenged against bacteria, molds, and yeasts, and their performance was evaluated based on the European Pharmacopeia criteria. The Cu-modified bentonite performed excellently against bacteria and yeasts, while the Zn-modified bentonite only showed great results against yeasts. Therefore, Cu-modified bentonite formulations could offer antimicrobial protection without the use of preservatives.
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Affiliation(s)
- Fotini Martsouka
- Department of Geology, University of Patras, 26504 Patras, Greece; (K.P.); (P.L.); (D.P.)
- Correspondence: ; Tel.: +30-697-755-0907
| | | | | | - Martin Barlog
- Institute of Inorganic Chemistry, Slovak Academy of Sciences (SAS), Dúbravská Cesta 9, 845 36 Bratislava, Slovakia;
| | - Giorgos Lagiopoulos
- Microbiology Department, Quality Assurance and Control Systems—QACS Labs, Antigonis 1, Metamorfosis, 14451 Athens, Greece;
| | - Triantafyllos Tatoulis
- Department of Environmental Engineering, University of Patras, 2 G. Seferi Str., 30100 Agrinio, Greece; (T.T.); (A.G.T.)
| | - Athanasia G. Tekerlekopoulou
- Department of Environmental Engineering, University of Patras, 2 G. Seferi Str., 30100 Agrinio, Greece; (T.T.); (A.G.T.)
| | - Paraskevi Lampropoulou
- Department of Geology, University of Patras, 26504 Patras, Greece; (K.P.); (P.L.); (D.P.)
| | - Dimitrios Papoulis
- Department of Geology, University of Patras, 26504 Patras, Greece; (K.P.); (P.L.); (D.P.)
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Martsouka F, Papagiannopoulos K, Hatziantoniou S, Barlog M, Lagiopoulos G, Tekerlekopoulou AG, Papoulis D. Evaluation of the Antimicrobial Protection of Pharmaceutical Kaolin and Talc Modified with Copper and Zinc. Materials (Basel) 2021; 14:1173. [PMID: 33801536 PMCID: PMC7958952 DOI: 10.3390/ma14051173] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 02/17/2021] [Accepted: 02/25/2021] [Indexed: 12/21/2022]
Abstract
Six pharmaceutical pastes were prepared using chemically modified kaolin and talc powders. Tests were conducted to determine their structural and chemical characteristics as well as their antimicrobial protection, thus rendering them suitable for cosmetic and pharmaceutical uses. Kaolin and talc were treated chemically via the cation exchange method to load the clay particles with copper and zinc ions, two cations well known for their antimicrobial properties. Mineralogical analyses were conducted by using X-ray diffraction (XRD) before and after the modification, confirming the mineralogical purity of the samples. Scanning electron microscopy was also used in conjunction with energy dispersed spectroscopy (SEM-EDS) to obtain chemical mapping images, revealing the dispersion of the added metals upon the clay minerals surfaces. Moreover, chemical analysis has been performed (XRF) to validate the enrichment of the clays with each metal utilizing the cation exchange capacity. All modified samples showed the expected elevated concentration in copper or zinc in comparison to their unmodified versions. From the X-ray photoelectron spectroscopy (XPS), the chemical state of the samples' surfaces was investigated, revealing the presence of salt compounds and indicating the oxidation state of adsorbed metals. Finally, the resistance of pastes in microbial growth when challenged with bacteria, molds, and yeasts was assessed. The evaluation is based on the European Pharmacopeia (EP) criteria.
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Affiliation(s)
- Fotini Martsouka
- Department of Geology, University of Patras, 26504 Patras, Greece; (K.P.); (D.P.)
| | | | | | - Martin Barlog
- Institute of Inorganic Chemistry, Slovak Academy of Sciences (SAS), Dúbravská cesta 9, 845 36 Bratislava, Slovakia;
| | - Giorgos Lagiopoulos
- Microbiology Department, Quality Assurance and Control Systems—QACS Labs, Antigonis 1, 14451 Metamorfosis, Greece;
| | | | - Dimitrios Papoulis
- Department of Geology, University of Patras, 26504 Patras, Greece; (K.P.); (D.P.)
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Siakavella IK, Lamari F, Papoulis D, Orkoula M, Gkolfi P, Lykouras M, Avgoustakis K, Hatziantoniou S. Effect of Plant Extracts on the Characteristics of Silver Nanoparticles for Topical Application. Pharmaceutics 2020; 12:pharmaceutics12121244. [PMID: 33371293 PMCID: PMC7767050 DOI: 10.3390/pharmaceutics12121244] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 12/10/2020] [Accepted: 12/18/2020] [Indexed: 11/16/2022] Open
Abstract
Silver nanoparticles (AgNPs) were synthesized using hydroalcoholic extracts of dittany (Origanum dictamnus), sage (Salvia officinalis), sea buckthorn (Elaeagnus rhamnoides, syn. Hippophae rhamnoides), and calendula (Calendula officinalis) as reducing agents. AgNPs synthesized using NaBH4 and citric acid were used as control. The impact of the origin of the extract and preparation conditions (light, temperature, reaction time) on the properties of the synthesized AgNPs was investigated. The structure, morphology, composition, physicochemical characteristics, and colloidal stability were characterized using dynamic laser scattering (DLS), ultraviolet-visible spectrophotometry (UV–/Vis), XRD, X-ray fluorescence (XRF), TEM, and FTΙR. The reduction of total phenolic and flavonoid content of the extracts after the reaction of AgNPs synthesis was also determined. Low IC50 values for all types of AgNPs revealed good antioxidant activity, attributable to the phenolic and flavonoid content of their surface. The results suggest that plant extract selection is important to the green synthesis of AgNPs because it affects the kinetics of their synthesis as well as their morphology, physicochemical characteristics, and colloidal stability. In vitro permeation studies on porcine skin revealed that AgNPs remained at the upper layers of stratum corneum and did not penetrate the skin barrier after 4 h of cutaneous application suggesting the safety of their application on intact skin for a relatively short time.
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Affiliation(s)
- Ioanna K. Siakavella
- Laboratory of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece; (I.K.S.); (K.A.)
| | - Fotini Lamari
- Laboratory of Pharmacognosy & Chemistry of Natural Products Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece;
| | | | - Malvina Orkoula
- Laboratory of Instrumental Pharmaceutical Analysis, Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece; (M.O.); (M.L.)
| | - Patroula Gkolfi
- Department of Chemistry, University of Patras, 26504 Patras, Greece;
| | - Michail Lykouras
- Laboratory of Instrumental Pharmaceutical Analysis, Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece; (M.O.); (M.L.)
| | - Konstantinos Avgoustakis
- Laboratory of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece; (I.K.S.); (K.A.)
| | - Sophia Hatziantoniou
- Laboratory of Pharmaceutical Technology, Department of Pharmacy, School of Health Sciences, University of Patras, 26504 Patras, Greece; (I.K.S.); (K.A.)
- Correspondence:
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Gianni E, Avgoustakis K, Papoulis D. Kaolinite group minerals: Applications in cancer diagnosis and treatment. Eur J Pharm Biopharm 2020; 154:359-376. [PMID: 32745710 DOI: 10.1016/j.ejpb.2020.07.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/23/2020] [Accepted: 07/27/2020] [Indexed: 12/26/2022]
Abstract
The clay minerals are characterized as important minerals due to their specific properties. One of the most important groups of the clay minerals is the kaolinite's group minerals due to their morphology, availability and range of potential applications. Halloysite and kaolinite are investigated here for their pharmaceutical applications and especially for their potential in cancer treatment. This review study is focusing on the potential applications of the kaolinite's group minerals in cancer diagnosis and monitoring, cancer treatment, the avoidance of metastasis, and the relief of cancer pains. Anticancer drug-loaded formulations based on these minerals show high potential for the treatment of various types of cancer as they have been shown to exhibit high anticancer activity in cancer cell lines and cancer animal models, high biocompatibility, low side effects, and high drug bioavailability.
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Affiliation(s)
- Eleni Gianni
- Department of Geology, University of Patras, Rio 26504, Patras, Greece.
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Gianni E, Avgoustakis K, Pšenička M, Pospíšil M, Papoulis D. Halloysite nanotubes as carriers for irinotecan: Synthesis and characterization by experimental and molecular simulation methods. J Drug Deliv Sci Technol 2019. [DOI: 10.1016/j.jddst.2019.05.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Papoulis D, Tzortzakaki O, Avramidis P, Mentis P, Lampropoulou P, Iliopoulos G. Mineralogical and textural characteristics of nest building geomaterials used by three sympatric mud-nesting hirundine species. Sci Rep 2018; 8:11050. [PMID: 30038225 PMCID: PMC6056552 DOI: 10.1038/s41598-018-29307-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 07/04/2018] [Indexed: 11/09/2022] Open
Abstract
Many hirundine species construct their nests by carrying mud particles from adjacent areas. This study aimed to investigate for the first time the materials that mud-nesting hirundines choose for nest construction from a mineralogical and sedimentological perspective. For this purpose, we sampled nests of three sympatric species, namely the Barn Swallow (Hirundo rustica), the Red-rumped Swallow (Cecropis daurica) and the House Martin (Delichon urbicum), from southeastern Europe. Our results showed that all species tend to use clay minerals as a cement and especially smectite and illite and if these minerals are not present in the adjacent area, they use halloysite, kaolinite or chlorite. The amounts of clay minerals in the nests are generally low indicating that the studied species can accurately identify the properties of the nesting materials. Most of the non clay minerals that they use are the common, easily accessible colourless or white minerals with low specific gravity values such as quartz, feldspars and calcite. Grain size distribution analysis revealed that the amount of clay sized grains in the mud nests of all three species is relatively low, while the amount of larger grain particles decreases when the size of the non clay minerals is small. The Red-rumped Swallow showed an increasing preference for larger grain size particles and quartz, the Barn Swallow for finer grain size particles and calcite, and the preferences of the House Martin are in between the other two species. The three hirundine species present different nest building strategies and depending on the nest architecture, each of them seems to show preference for specific minerals and specific grain sizes.
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Affiliation(s)
- Dimitrios Papoulis
- Department of Geology, University of Patras, Rio - Patras, 26504, Greece
| | - Olga Tzortzakaki
- Department of Biology, University of Patras, Rio - Patras, 26504, Greece
| | - Pavlos Avramidis
- Department of Geology, University of Patras, Rio - Patras, 26504, Greece
| | - Panagiotis Mentis
- Department of Geology, University of Patras, Rio - Patras, 26504, Greece
| | | | - George Iliopoulos
- Department of Geology, University of Patras, Rio - Patras, 26504, Greece.
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Christoforidis KC, Melchionna M, Montini T, Papoulis D, Stathatos E, Zafeiratos S, Kordouli E, Fornasiero P. Solar and visible light photocatalytic enhancement of halloysite nanotubes/g-C3N4 heteroarchitectures. RSC Adv 2016. [DOI: 10.1039/c6ra15581b] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The charged surface of HNTs allows efficient charge separation and increased pollutant adsorption, enhancing the overall photocatalytic performance of the HNTs/g-C3N4 heteroarchitectures.
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Affiliation(s)
- K. C. Christoforidis
- Department of Chemical and Pharmaceutical Sciences
- ICCOM-CNR Trieste Research Unit and INSTM Research Unit
- University of Trieste
- 34127 Trieste
- Italy
| | - M. Melchionna
- Department of Chemical and Pharmaceutical Sciences
- ICCOM-CNR Trieste Research Unit and INSTM Research Unit
- University of Trieste
- 34127 Trieste
- Italy
| | - T. Montini
- Department of Chemical and Pharmaceutical Sciences
- ICCOM-CNR Trieste Research Unit and INSTM Research Unit
- University of Trieste
- 34127 Trieste
- Italy
| | - D. Papoulis
- Department of Geology
- University of Patras
- 26504 Patras
- Greece
| | - E. Stathatos
- Department of Electrical Engineering
- Technological Educational Institute (TEI) of Western Greece
- 26334 Patras
- Greece
| | - S. Zafeiratos
- Institut de Chimie et Procédés Pour l'Energie
- l'Environnement et la Santé
- (ICPEES) ECPM
- University of Strasbourg
- 67087 Strasbourg
| | - E. Kordouli
- Department of Chemistry
- University of Patras
- 26504 Patras
- Greece
| | - P. Fornasiero
- Department of Chemical and Pharmaceutical Sciences
- ICCOM-CNR Trieste Research Unit and INSTM Research Unit
- University of Trieste
- 34127 Trieste
- Italy
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Huang D, Ma J, Yu L, Wu D, Wang K, Yang M, Papoulis D, Komarneni S. AgCl and BiOCl composited with NiFe-LDH for enhanced photo-degradation of Rhodamine B. Sep Purif Technol 2015. [DOI: 10.1016/j.seppur.2015.11.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Stathatos E, Papoulis D, Aggelopoulos CA, Panagiotaras D, Nikolopoulou A. TiO2/palygorskite composite nanocrystalline films prepared by surfactant templating route: synergistic effect to the photocatalytic degradation of an azo-dye in water. J Hazard Mater 2012; 211-212:68-76. [PMID: 22177018 DOI: 10.1016/j.jhazmat.2011.11.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 10/28/2011] [Accepted: 11/16/2011] [Indexed: 05/31/2023]
Abstract
Microfibrous palygorskite clay mineral and nanocrystalline TiO(2) are incorporating in the preparation of nanocomposite films on glass substrates via sol-gel route at 500°C. The synthesis involves a simple chemical method employing nonionic surfactant molecule as pore directing agent along with the acetic acid-based sol-gel route without direct addition of water molecules. Drying and thermal treatment of composite films lead to the elimination of organic material while ensure the formation of TiO(2) nanoparticles homogeneously distributed on the surface of the palygorskite microfibers. TiO(2) nanocomposite films without cracks consisted of small crystallites in size (12-16 nm) and anatase crystal phase was found to cover palygorskite microfibers. The composite films were characterized by microscopy techniques, UV-vis, IR spectroscopy, and porosimetry methods in order to examine their structural properties. Palygorskite/TiO(2) composite films with variable quantities of palygorskite (0-2 w/w ratio) were tested as new photocatalysts in the photo-discoloration of Basic Blue 41 azo-dye in water. These nanocomposite films proved to be very promising photocatalysts and highly effective to dye's discoloration in spite of the small amount of immobilized palygorskite/TiO(2) catalyst onto glass substrates. 3:2 palygorskite/TiO(2) weight ratio was finally the most efficient photocatalyst while reproducible discoloration results of the dye were obtained after three cycles with same catalyst. It was also found that palygorskite showed a positive synergistic effect to the TiO(2) photocatalysis.
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Affiliation(s)
- E Stathatos
- Electrical Engineering Department, Technological-Educational Institute of Patras, GR-26334 Patras, Greece.
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