66 research outputs found

    Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst

    Full text link
    [EN] Bimetallic iron and copper oxide nanoparticles (NPs) supported on hydroxylated diamond (D3) exhibits an improved activity for the heterogeneous Fenton phenol degradation under natural or simulated sunlight irradiation with respect to analogous monometallic samples or than analogous FeCu NPs on graphite, activated carbon and P25 TiO2 semiconductor. FeCu/D3 catalyst exhibits good recyclability and stability especially working at pH 6. Overall, the high activity of the Fe20Cu80(0.2 wt%)/D3 catalyst is mainly due to the combination of the high activity of reduced copper species decomposing H2O2 to HO center dot radical, while Fe2+ allows the regeneration of these reduced copper species.S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016), Ministerio de Ciencia, Innovacion y Universidades RTI2018-099482-A-I00 project and Generalitat Valenciana grupos de investigacion consolidables 2019 (ref: AICO/2019/214) project. H.G. thanks financial support by the Spanish Ministry of Science and Innovation (Severo Ochoa SEV2016 and RTI2018-890237-CO2-1) and Generalitat Valenciana (Prometeo 2017/083) is also gratefully acknowledged.Manickam-Periyaraman, P.; Espinosa, JC.; Ferrer Ribera, RB.; Subramanian, S.; Alvaro RodrĂ­guez, MM.; GarcĂ­a GĂłmez, H.; NavalĂłn Oltra, S. (2020). Bimetallic iron-copper oxide nanoparticles supported on nanometric diamond as efficient and stable sunlight-assisted Fenton photocatalyst. Chemical Engineering Journal. 393:1-11. https://doi.org/10.1016/j.cej.2020.124770S111393Malato, S., FernĂĄndez-Ibåñez, P., Maldonado, M. I., Blanco, J., & Gernjak, W. (2009). Decontamination and disinfection of water by solar photocatalysis: Recent overview and trends. Catalysis Today, 147(1), 1-59. doi:10.1016/j.cattod.2009.06.018Pera-Titus, M., Garcı́a-Molina, V., Baños, M. A., GimĂ©nez, J., & Esplugas, S. (2004). Degradation of chlorophenols by means of advanced oxidation processes: a general review. Applied Catalysis B: Environmental, 47(4), 219-256. doi:10.1016/j.apcatb.2003.09.010Pignatello, J. J., Oliveros, E., & MacKay, A. (2006). Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry. Critical Reviews in Environmental Science and Technology, 36(1), 1-84. doi:10.1080/10643380500326564Rahim Pouran, S., Abdul Aziz, A. R., & Wan Daud, W. M. A. (2015). Review on the main advances in photo-Fenton oxidation system for recalcitrant wastewaters. Journal of Industrial and Engineering Chemistry, 21, 53-69. doi:10.1016/j.jiec.2014.05.005Cheng, M., Zeng, G., Huang, D., Lai, C., Xu, P., Zhang, C., & Liu, Y. (2016). Hydroxyl radicals based advanced oxidation processes (AOPs) for remediation of soils contaminated with organic compounds: A review. Chemical Engineering Journal, 284, 582-598. doi:10.1016/j.cej.2015.09.001Garrido-RamĂ­rez, E. G., Theng, B. K. ., & Mora, M. L. (2010). Clays and oxide minerals as catalysts and nanocatalysts in Fenton-like reactions — A review. Applied Clay Science, 47(3-4), 182-192. doi:10.1016/j.clay.2009.11.044Klavarioti, M., Mantzavinos, D., & Kassinos, D. (2009). Removal of residual pharmaceuticals from aqueous systems by advanced oxidation processes. Environment International, 35(2), 402-417. doi:10.1016/j.envint.2008.07.009Bokare, A. D., & Choi, W. (2014). Review of iron-free Fenton-like systems for activating H2O2 in advanced oxidation processes. Journal of Hazardous Materials, 275, 121-135. doi:10.1016/j.jhazmat.2014.04.054Chiron, S. (2000). Pesticide chemical oxidation: state-of-the-art. Water Research, 34(2), 366-377. doi:10.1016/s0043-1354(99)00173-6Chong, M. N., Jin, B., Chow, C. W. K., & Saint, C. (2010). Recent developments in photocatalytic water treatment technology: A review. Water Research, 44(10), 2997-3027. doi:10.1016/j.watres.2010.02.039Herney-Ramirez, J., Vicente, M. A., & Madeira, L. M. (2010). Heterogeneous photo-Fenton oxidation with pillared clay-based catalysts for wastewater treatment: A review. Applied Catalysis B: Environmental, 98(1-2), 10-26. doi:10.1016/j.apcatb.2010.05.004Wang, C., Liu, H., & Sun, Z. (2012). Heterogeneous Photo-Fenton Reaction Catalyzed by Nanosized Iron Oxides for Water Treatment. International Journal of Photoenergy, 2012, 1-10. doi:10.1155/2012/801694Ramirez, J. H., Maldonado-HĂłdar, F. J., PĂ©rez-Cadenas, A. F., Moreno-Castilla, C., Costa, C. A., & Madeira, L. M. (2007). Azo-dye Orange II degradation by heterogeneous Fenton-like reaction using carbon-Fe catalysts. Applied Catalysis B: Environmental, 75(3-4), 312-323. doi:10.1016/j.apcatb.2007.05.003Navalon, S., Sempere, D., Alvaro, M., & Garcia, H. (2013). Influence of Hydrogen Annealing on the Photocatalytic Activity of Diamond-Supported Gold Catalysts. ACS Applied Materials & Interfaces, 5(15), 7160-7169. doi:10.1021/am401489nEspinosa, J. C., NavalĂłn, S., Álvaro, M., & GarcĂ­a, H. (2015). Silver Nanoparticles Supported on Diamond Nanoparticles as a Highly Efficient Photocatalyst for the Fenton Reaction under Natural Sunlight Irradiation. ChemCatChem, 7(17), 2682-2688. doi:10.1002/cctc.201500458Espinosa, J. C., NavalĂłn, S., Álvaro, M., & GarcĂ­a, H. (2016). Copper nanoparticles supported on diamond nanoparticles as a cost-effective and efficient catalyst for natural sunlight assisted Fenton reaction. Catalysis Science & Technology, 6(19), 7077-7085. doi:10.1039/c6cy00572aEspinosa, J. C., CatalĂĄ, C., NavalĂłn, S., Ferrer, B., Álvaro, M., & GarcĂ­a, H. (2018). Iron oxide nanoparticles supported on diamond nanoparticles as efficient and stable catalyst for the visible light assisted Fenton reaction. Applied Catalysis B: Environmental, 226, 242-251. doi:10.1016/j.apcatb.2017.12.060Garrido-RamĂ­rez, E. G., Marco, J. F., Escalona, N., & Ureta-Zañartu, M. S. (2016). Preparation and characterization of bimetallic Fe–Cu allophane nanoclays and their activity in the phenol oxidation by heterogeneous electro-Fenton reaction. Microporous and Mesoporous Materials, 225, 303-311. doi:10.1016/j.micromeso.2016.01.013Karthikeyan, S., Pachamuthu, M. P., Isaacs, M. A., Kumar, S., Lee, A. F., & Sekaran, G. (2016). Cu and Fe oxides dispersed on SBA-15: A Fenton type bimetallic catalyst for N,N -diethyl- p -phenyl diamine degradation. Applied Catalysis B: Environmental, 199, 323-330. doi:10.1016/j.apcatb.2016.06.040Martin, R., Navalon, S., Delgado, J. J., Calvino, J. J., Alvaro, M., & Garcia, H. (2011). Influence of the Preparation Procedure on the Catalytic Activity of Gold Supported on Diamond Nanoparticles for Phenol Peroxidation. Chemistry - A European Journal, 17(34), 9494-9502. doi:10.1002/chem.201100955Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption.Dhakshinamoorthy, A., Navalon, S., Alvaro, M., & Garcia, H. (2012). Metal Nanoparticles as Heterogeneous Fenton Catalysts. ChemSusChem, 5(1), 46-64. doi:10.1002/cssc.201100517Burkitt, M. J., & Mason, R. P. (1991). Direct evidence for in vivo hydroxyl-radical generation in experimental iron overload: an ESR spin-trapping investigation. Proceedings of the National Academy of Sciences, 88(19), 8440-8444. doi:10.1073/pnas.88.19.8440Li, K., Zhao, Y., Janik, M. J., Song, C., & Guo, X. (2017). Facile preparation of magnetic mesoporous Fe3O4/C/Cu composites as high performance Fenton-like catalysts. Applied Surface Science, 396, 1383-1392. doi:10.1016/j.apsusc.2016.11.17

    Engineering of activated carbon surface to enhance the catalytic activity of supported cobalt oxide nanoparticles in peroxymonosulfate activation

    Full text link
    [EN] Commercial activated carbon has been functionalized by chemical or thermal treatments to introduce surface oxygen functional groups able to anchor small cobalt nanoparticles with superior catalytic activity for peroxymonosulfate activation. The resulting activated carbon supports where characterized by combustion elemental analysis, Fourier-transformed infrared spectroscopy, Raman spectroscopy, isothermal N-2 adsorption, temperature programmed desorption/mass spectrometry, X-ray diffraction and scanning electron microscopy. Activated carbon functionalization by nitric acid resulted the most appropriated method to provide a higher population of oxygenated functional groups able to anchor small cobalt nanoparticles. The catalytic activity of supported oxidized metal nanoparticles (4.7 +/- 0.05 nm) was higher than analogous non-oxidized cobalt nanoparticles (2.9 +/- 0.14 nm). The use of analogous supported oxidized iron or copper nanoparticles resulted in lower catalytic activity. Importantly, the supported oxidized cobalt nanoparticles at 0.2 wt% loading exhibit higher activity than benchmark catalysts such as unsupported Co3O4 solid or even homogeneous Co2+ ions. This is a reflection of the relatively low estimated activation energy for both processes, peroxymonosulfate decomposition and phenol degradation. The estimated activation energy values are about 30 and 32 kJ mol(-1). The stability of the most active catalyst was assessed by performing eight consecutive uses without observing decrease of catalytic activity, neither metal leaching or metal nanoparticle aggregation. Turnover numbers/turnover frequencies values as high as 440(5)/8.10(5)h(-1) for peroxymonosulfate activation and 39.10(3)/68.10(3) h(-1) for phenol degradation at pH 7 and 20 degrees C have been estimated, respectively. Electron paramagnetic resonance measurements and selective quenching experiments revealed that the generated sulfate radicals from peroxymonosulfate rapidly are transformed in highly reactive hydroxyl radicals. In excellent agreement with previous reports, this work demonstrates the importance of an adequate activated carbon functionalization to obtain superior and stable catalysts for peroxymonosulfate activation.Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, CTQ2015-65963-CQ-R1) and CTQ2014-53292-R is gratefully acknowledged. Generalitat Valenciana is also thanked for funding (Prometeo 2017/083). S.N. thanks financial support by the Fundacion Ramon Areces (XVIII Concurso Nacional para la Adjudicacion de Ayudas a la Investigacion en Ciencias de la Vida y de la Materia, 2016).Espinosa-LĂłpez, JC.; Manickam-Periyaraman, P.; Bernat-Quesada, F.; Sivanesan, S.; Alvaro RodrĂ­guez, MM.; GarcĂ­a GĂłmez, H.; NavalĂłn Oltra, S. (2019). Engineering of activated carbon surface to enhance the catalytic activity of supported cobalt oxide nanoparticles in peroxymonosulfate activation. Applied Catalysis B Environmental. 249:42-53. https://doi.org/10.1016/j.apcatb.2019.02.043S425324

    ΕυρΔτÎčÎșές Ï€ÏÎżÏƒÎ”ÎłÎłÎŻÏƒÎ”Îčς Ï„ÎżÏ… ÎŒÎżÎœÎ±ÎŽÎčÎŹÏƒÏ„Î±Ï„ÎżÏ… Ï€ÏÎżÎČÎ»ÎźÎŒÎ±Ï„ÎżÏ‚ παÎșÎ”Ï„ÎżÏ€ÎżÎŻÎ·ÏƒÎ·Ï‚

    Get PDF
    Article 59.1, of the International Code of Nomenclature for Algae, Fungi, and Plants (ICN; Melbourne Code), which addresses the nomenclature of pleomorphic fungi, became effective from 30 July 2011. Since that date, each fungal species can have one nomenclaturally correct name in a particular classification. All other previously used names for this species will be considered as synonyms. The older generic epithet takes priority over the younger name. Any widely used younger names proposed for use, must comply with Art. 57.2 and their usage should be approved by the Nomenclature Committee for Fungi (NCF). In this paper, we list all genera currently accepted by us in Dothideomycetes (belonging to 23 orders and 110 families), including pleomorphic and non-pleomorphic genera. In the case of pleomorphic genera, we follow the rulings of the current ICN and propose single generic names for future usage. The taxonomic placements of 1261 genera are listed as an outline. Protected names and suppressed names for 34 pleomorphic genera are listed separately. Notes and justifications are provided for possible proposed names after the list of genera. Notes are also provided on recent advances in our understanding of asexual and sexual morph linkages in Dothideomycetes. A phylogenetic tree based on four gene analyses supported 23 orders and 75 families, while 35 families still lack molecular data

    The role of solvent on the base stacking properties of the stacked cytosine dimer

    No full text
    The role of solvent on the base stacking of cytosine dimers is analyzed with the help of the Onsager reaction field model in the framework of Hartree–Fock theory. In this Letter, it has been found that the total energy of the base stacked cytosine dimer depends on the twist angle. The inclusion of solvent in the calculation, destabilizes the parallelly stacked cytosine dimer (twist angle equals 0°) by ∌22.4 kcal/mol. The dipole moment of the anti-parallelly stacked cytosine dimer (twist angle equals 180°) is zero and hence, this conformer is not influenced by the presence of the solvent environment

    Electronic structure of Ne–H–Cl and Ne–Cl–H using the G1, G2 and MP4 methods

    No full text
    The potential energy surface for the Ne–HCl Van der Waals complex is calculated using fourth-order Mþller–Plesset perturbation theory (MP4) employing both 6-311G**, cc-pVDZ and AUG-cc-pVDZ basis sets. The global minimum occurs at the linear Ne–H–Cl configuration. The binding energy of the linear Ne–H–Cl and Ne–Cl–H configurations has also been calculated using G1, G2 and MP4 methods. The G1 and G2 methods cannot predict the relative stability of the complexes, since the difference in the calculated binding energies is small. In all the calculations, the binding energy of the Ne–H–Cl and Ne–Cl–H complex is low compared to that of the Ar–HCl Van der Waals complex for which D<SUB>e</SUB>=2.096 kJ/mol

    Quantification of reactive sites in DNA bases using condensed Fukui functions

    No full text
    The Fukui function values of various atoms in DNA bases have been computed with a view to understand their reactivity. Since reactivity of DNA bases depends on the surrounding solvent medium, the effect of incorporation of bulk solvent around the bases has also been studied using self consistent reaction field approach with in the frame work of Hartree–Fock theory

    Solvent effect on DNA base stacked dimers: an isodensity polarizable continuum model approach

    No full text
    The role of solvent on the base stacking properties of various stacked dimers has been analyzed. Ab initio calculations have been performed on the various stacked dimers using the isodensity polarizable continuum model (IPCM), in the framework of the HF/6-31G** level. It is observed that the stacked dimers undergo different levels of stabilization for different rotated conformations, and the total energy of stacked dimers depends on the twist angle. The results reveal that DNA stacked dimers prefer the twisted (rotated conformation) conformation in water environment, so as to escape from water, due to their hydrophobic nature. In addition, the presence of solvent stabilizes the stacking interaction between bases

    Effect of water continuum on the interaction energy of DNA base- pairs: a Hartree-Fock self-consistent reaction field study

    Get PDF
    The stability of several base-pairs has been calculated in water medium using self-consistent reaction field theory (SCRF) in the framework of Hartree-Fock (HF) theory formalism. The nomenclature used by Sponer etal. (J phys Chem, 100(1996) 1965) have been used for all the base- pairs investigated in this work. The binding energy is found to increase for TAH, GT2, GC1, GA4, and GG3 basepairs whereas, it decreases for GCWC, GCNEW, TARH, AC1, GT1, and TT1 base- pairs in solvent environment. The polarizing cavity around the base -pairs influences the primary electrostatic contribution arising from dipole-dipole interaction and charge distribution

    Effect of water continuum on the interaction energy of DNA base- pairs: A Hartree-Fock self-consistent reaction field study

    No full text
    132-138The stability of several base-pairs has been calculated in water medium using self-consistent reaction field theory (SCRF) in the framework of Hartree-Fock (HF) theory formalism. The nomenclature used by Sponer etal. (J phys Chem, 100(1996) 1965) have been used for all the base- pairs investigated in this work. The binding energy is found to increase for TAH, GT2, GC1, GA4, and GG3 basepairs whereas, it decreases for GCWC, GCNEW, TARH, AC1, GT1, and TT1 base- pairs in solvent environment. The polarizing cavity around the base -pairs influences the primary electrostatic contribution arising from dipole-dipole interaction and charge distribution
    • 

    corecore