Factorial electrochemical design for tailoring of morphological and optical properties of Cu2O

[EN] The electrodeposition of cuprous oxide (Cu2O) onto FTO-coated glass substrate was studied by using a statistical approach in order to control the Cu2O morphology and optical properties. The factorial design considered four electrodeposition conditions at two representative levels as input variables (electrolyte temperature and pH, deposition potential and duration) and the deposition charge and morphology of obtained Cu2O as the output variables. The morphology analysis showed the highest influence on crystal shape was exhibited by electrolyte temperature and pH, reaching significance levels of 95 and 98%, respectively. Temperature as low as 35°C and pH 12.2 results in cubic morphology, while other parameters result in octahedron shape. The highest absorbance was exhibited by the Cu2O with cubic morphology.AP acknowledges financial support from Romanian National Authority for Scientific Research and Innovation, CNCS - UEFISCDI (project number PN-II-RU-TE-2014-4-0806].Cembrero-Coca, P.; Cembrero Cil, J.; Busquets Mataix, DJ.; Pérez Puig, MA.; Marí, B.; Pruna, AI. (2017). Factorial electrochemical design for tailoring of morphological and optical properties of Cu2O. Materials Science and Technology. 33(17):2102-2109. https://doi.org/10.1080/02670836.2017.1349595S210221093317Rakhshani, A. E. (1987). Measurement of dispersion in electrodeposited Cu2O. Journal of Applied Physics, 62(4), 1528-1529. doi:10.1063/1.339619Chen, L.-C. (2013). Review of preparation and optoelectronic characteristics of Cu2O-based solar cells with nanostructure. Materials Science in Semiconductor Processing, 16(5), 1172-1185. doi:10.1016/j.mssp.2012.12.028Hsu, Y.-K., Lin, H.-H., Wu, J.-R., Chen, M.-H., Chen, Y.-C., & Lin, Y.-G. (2014). Electrochemical growth and characterization of a p-Cu2O thin film on n-ZnO nanorods for solar cell application. RSC Advances, 4(15), 7655. doi:10.1039/c3ra47188hChou, S.-M., Hon, M.-H., Leu, I.-C., & Lee, Y.-H. (2008). Al-Doped ZnO∕Cu[sub 2]O Heterojunction Fabricated on (200) and (111)-Orientated Cu[sub 2]O Substrates. Journal of The Electrochemical Society, 155(11), H923. doi:10.1149/1.2980424Siegfried, M. J., & Choi, K.-S. (2004). Electrochemical Crystallization of Cuprous Oxide with Systematic Shape Evolution. Advanced Materials, 16(19), 1743-1746. doi:10.1002/adma.200400177Siegfried, M. J., & Choi, K.-S. (2005). Directing the Architecture of Cuprous Oxide Crystals during Electrochemical Growth. Angewandte Chemie International Edition, 44(21), 3218-3223. doi:10.1002/anie.200463018Yang, W.-Y., Kim, W.-G., & Rhee, S.-W. (2008). Radio frequency sputter deposition of single phase cuprous oxide using Cu2O as a target material and its resistive switching properties. Thin Solid Films, 517(2), 967-971. doi:10.1016/j.tsf.2008.08.184Reddy, A. S., Uthanna, S., & Reddy, P. S. (2007). Properties of dc magnetron sputtered Cu2O films prepared at different sputtering pressures. Applied Surface Science, 253(12), 5287-5292. doi:10.1016/j.apsusc.2006.11.051Laik, B., Poizot, P., & Tarascon, J.-M. (2002). The Electrochemical Quartz Crystal Microbalance as a Means for Studying the Reactivity of Cu[sub 2]O toward Lithium. Journal of The Electrochemical Society, 149(3), A251. doi:10.1149/1.1445430Fu, L. J., Gao, J., Zhang, T., Cao, Q., Yang, L. C., Wu, Y. P., … Wu, H. Q. (2007). Preparation of Cu2O particles with different morphologies and their application in lithium ion batteries. Journal of Power Sources, 174(2), 1197-1200. doi:10.1016/j.jpowsour.2007.06.030Zhou, Y., & Switzer, J. A. (1998). Electrochemical Deposition and Microstructure of Copper (I) Oxide Films. Scripta Materialia, 38(11), 1731-1738. doi:10.1016/s1359-6462(98)00091-8Budevski, E., Staikov, G., & Lorenz, W. J. (2000). Electrocrystallization. Electrochimica Acta, 45(15-16), 2559-2574. doi:10.1016/s0013-4686(00)00353-4Morales, J., Sánchez, L., Bijani, S., Martı́nez, L., Gabás, M., & Ramos-Barrado, J. R. (2005). Electrodeposition of Cu[sub 2]O: An Excellent Method for Obtaining Films of Controlled Morphology and Good Performance in Li-Ion Batteries. Electrochemical and Solid-State Letters, 8(3), A159. doi:10.1149/1.1854126Holzschuh, H., & Suhr, H. (1990). Deposition of copper oxide (Cu2O, CuO) thin films at high temperatures by plasma-enhanced CVD. Applied Physics A Solids and Surfaces, 51(6), 486-490. doi:10.1007/bf00324731Jeong, S., & Aydil, E. S. (2009). Heteroepitaxial growth of Cu2O thin film on ZnO by metal organic chemical vapor deposition. Journal of Crystal Growth, 311(17), 4188-4192. doi:10.1016/j.jcrysgro.2009.07.020Pruna, A., Pullini, D., & Busquets, D. (2015). Effect of AZO film as seeding substrate on the electrodeposition and properties of Al-doped ZnO nanorod arrays. Ceramics International, 41(10), 14492-14500. doi:10.1016/j.ceramint.2015.07.087Pruna, A., Pullini, D., Tamvakos, D., Tamvakos, A., & Busquets-Mataix, D. (2015). Effect of tin-doped indium oxide film on electrodeposition of ZnO nanostructures. Materials Science and Technology, 31(14), 1794-1799. doi:10.1179/1743284715y.0000000016Pruna, A., Reyes-Tolosa, M. D., Pullini, D., Hernandez-Fenollosa, M. A., & Busquets-Mataix, D. (2015). Seed-free electrodeposition of ZnO bi-pods on electrophoretically-reduced graphene oxide for optoelectronic applications. Ceramics International, 41(2), 2381-2388. doi:10.1016/j.ceramint.2014.10.052Cembrero, J., Pruna, A., Pullini, D., & Busquets-Mataix, D. (2014). Effect of combined chemical and electrochemical reduction of graphene oxide on morphology and structure of electrodeposited ZnO. Ceramics International, 40(7), 10351-10357. doi:10.1016/j.ceramint.2014.03.008Prună, A., Pullini, D., & Mataix, D. B. (2012). Influence of Deposition Potential on Structure of ZnO Nanowires Synthesized in Track-Etched Membranes. Journal of The Electrochemical Society, 159(4), E92-E98. doi:10.1149/2.003205jesJiang, X., Zhang, M., Shi, S., He, G., Song, X., & Sun, Z. (2014). Microstructure and optical properties of nanocrystalline Cu2O thin films prepared by electrodeposition. Nanoscale Research Letters, 9(1), 219. doi:10.1186/1556-276x-9-219Yu, X., Li, X., Zheng, G., Wei, Y., Zhang, A., & Yao, B. (2013). Preparation and properties of KCl-doped Cu2O thin film by electrodeposition. Applied Surface Science, 270, 340-345. doi:10.1016/j.apsusc.2013.01.026Bijani, S., Schrebler, R., Dalchiele, E. A., Gabás, M., Martínez, L., & Ramos-Barrado, J. R. (2011). Study of the Nucleation and Growth Mechanisms in the Electrodeposition of Micro- and Nanostructured Cu2O Thin Films. The Journal of Physical Chemistry C, 115(43), 21373-21382. doi:10.1021/jp208535

Electrochromic switching of electrodeposited ZnO+Zn5(OH) 8Cl2 films

This study reports the effect of optical switching of electrodeposited ZnO + Zn5(OH)8Cl2 films on a gold electrode in a bath of 0.05 M Zn(NO3)2 + 0.1 M KCl. The coating turns black when cathodic polarization is applied yet when the current is removed the electrode immediately returns to a white colour. This optical effect is reversible and can be switched through various cycles.The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Rayón Encinas, E.; Cembrero Cil, J.; Marí Soucase, B. (2011). Electrochromic switching of electrodeposited ZnO+Zn5(OH) 8Cl2 films. Materials Letters. 65(23):3424-3426. doi:10.1016/j.matlet.2011.07.052S34243426652

Photoluminescent properties of electrochemically synthetized ZnO nanotubes

ZnO nanotubes were prepared by a sequential combination of electrochemical deposition, chemical attack and regeneration. ZnO nanocolumns were initially electrodeposited on conductive substrates and then converted into nanotubes by a process involving chemical etching and subsequent regrowth. The morphology of these ZnO nanocolumns and derived nanotubes was monitored by Scanning Electron Microscopy and their optical properties was studied by photoluminescence spectroscopy. Photoluminescence were measured as a function of temperature, from 6 to 300 K, for both nanocolumns and nanotubes. In order to study the behaviour of induced intrinsic defect all ZnO films were annealed in air at 400 °C and their photoluminescent properties were also registered before and after annealing. The behaviour of photoluminescence is explained taking into account the contribution of different point defects. A band energy diagram related to intrinsic defects was proposed to describe the behaviour of photoluminescence spectraThis work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat Valenciana (Prometeus 2014/044).Gracia Jimenez, JM.; Cembrero Cil, J.; Mollar García, MA.; Marí Soucase, B. (2016). Photoluminescent properties of electrochemically synthetized ZnO nanotubes. Materials Characterization. 119:152-158. https://doi.org/10.1016/j.matchar.2016.07.022S15215811

Improving the properties of Cu2O/ZnO heterojunction for photovoltaic application by graphene oxide

[EN] A p-Cu2O/n-ZnO heterojunction grown on fluorine-doped tin oxide (FTO) substrate is reported by a combined low-cost approach employing tape-casting of ZnO layer and subsequent electrochemical deposition of Cu2O layer. Graphene oxide (GO) nanosheets were employed as nanofiller for the ZnO matrix. Moreover, a ZnO buffer layer was inserted at the interface between the Cu2O and ZnO layers. The morphological, structural and photoelectrical characteristics of these heterojunction layers were investigated by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Raman spectroscopy and photoelectrical current-voltage measurements. The results confirmed that the morphology and structure of ZnO layer were affected by the incorporation of GO nanosheets while the presence of buffer layer influenced the growth of Cu2O layer. This work shows the addition of GO and the use of ZnO buffer layer represent a viable approach towards improving the photoelectrical properties of the Cu2O/ZnO heterojunction cell.Financial support from Escuela Politecnica Nacional, Ecuador (project number PIMI 15-09) and Secretaria de Education Superior, Ciencia, Tecnologia e Innovation (SENESCYT) and Romanian National Authority for Scientific Research and Innovation, Romania CNCS - UEFISCDI (project number PN-III-P1-1.1-TE-2016-1544) is gratefully acknowledged.Rosas-Laverde, NM.; Pruna, AI.; Busquets Mataix, DJ.; Marí, B.; Cembrero Cil, J.; Salas Vicente, F.; Orozco-Messana, J. (2018). Improving the properties of Cu2O/ZnO heterojunction for photovoltaic application by graphene oxide. Ceramics International. 44(18):23045-23051. https://doi.org/10.1016/j.ceramint.2018.09.107S2304523051441

Ciencia de los materiales : reforma de las enseñanzas medias : segundo ciclo

Programa para el desarrollo de la asignatura de ciencias de los materiales de segundo ciclo del bachillerato técnico industrial. Se exponen la justificación, los objetivos, las actividades y la programación. Dicho programa se estructura en trece partes con distintos temas cada uno. La bibliografía se refiere a cada una de las partes.ValenciaBiblioteca de Educación del Ministerio de Educación, Cultura y Deporte; Calle San Agustín 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]

Effect of combined chemical and electrochemical reduction of graphene oxide on morphology and structure of electrodeposited ZnO

This study reports a novel method of tailoring the properties of ZnO nanostructures by electrodeposition in presence of chemically-reduced graphene oxide (rGO). The coupled electrochemical and chemical reduction of graphene oxide resulted in few-layer graphene-based material. The presence of rGO in the electrolytic bath showed a marked influence on the morphology and structure of the hybrid nanostructures. The results indicated the presence of 5 mg L 1 rGO results in a 42.9% decrease in resistivity of the hybrid material with respect to the pure ZnO. The proposed approach shows very promising for the fabrication of transparent conductive oxide electrodes.Financial support is gratefully acknowledged from the European Commission (Project no. NMP3-SL-2010-246073) and Romanian Authority for Scientific Research - UEFISCDI (Project no. PN-II-RU-PD-2012-3-0124). The authors would like to thank the support given by the Microscopy Service and Institute of Chemical Technology (ITQ) from the Universidad Politecnica de Valencia (Spain).Cembrero Cil, J.; Pruna, AI.; Pullini, D.; Busquets Mataix, DJ. (2014). Effect of combined chemical and electrochemical reduction of graphene oxide on morphology and structure of electrodeposited ZnO. Ceramics International. (7):10351-10357. https://doi.org/10.1016/j.ceramint.2014.03.008S1035110357

INTRODUCCIÓN A LA NANOTECNOLOGÍA. DESARROLLO DE UN PROCESO TEÓRICO PRÁCTICO MEDIANTE LA TÉCNICA DE ELECTRODEPOSICIÓN

Con esta publicación los autores exponen su experiencia científica adquirida en el trascurso de su actividad docente e investigadora como miembros de la Universitat Politècnica de València. El libro presenta una breve descripción de los campos donde actualmente la nanotecnología está más implantada. Se describe la estructura del material a nivel atómico, se estudian las superficies y los sustratos ya que muchos de los procesos nanotecnológicos son procesos de superficie. Este contenido se complementa con un estudio de los materiales semiconductores que se están desarrollando con esta tecnología y, con la descripción de los principales equipos existentes para la elaboración y caracterización, ya que se consideran un factor importante que ha posibilitado que la nanotecnología avance tan rápidamente. Finalmente, se realiza el desarrollo de un proceso nanotecnológico utilizando todos los recursos necesarios en cualquier investigación. En esta propuesta de estudio de la Nanotecnología, los autores proponen algunos ejercicios y trabajos que ayudarán a comprender los temas tratados.Cembrero Cil, J.; Pérez Puig, MA.; Rayón Encinas, E.; Cembrero Coca, P.; Pascual Guillamón, M.; Marí Soucase, B.; Busquets Mataix, DJ. (2013). INTRODUCCIÓN A LA NANOTECNOLOGÍA. DESARROLLO DE UN PROCESO TEÓRICO PRÁCTICO MEDIANTE LA TÉCNICA DE ELECTRODEPOSICIÓN. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/71971EDITORIA

Problemas de ciencia de materiales II

Este texto está basado en la resolución de problemas adaptados, que pueden ser utilizados en el aprendizaje de diversos Grados de Ingeniería (Mecánica, Tecnologías industriales, Organización, Eléctrica, Energética etc.), así como aplicable también a procesos industriales en las ramas de Pulvimetalurgia, Tratamientos térmicos, Ensayos no Destructivos (US, RX) u otras. En primer lugar se describe la resolución de una serie de problemas relacionados con la fractura y fatiga de los materiales y las causas que pueden originar sus roturas.En segundo lugar, encontramos problemas propuestos en la resolución de procesos de obtención de piezas por compactación de polvos y las distintas variables que pueden surgir inherentes al producto obtenido.En tercer lugar, tenemos los problemas resueltos que están relacionados con la obtención de productos en los que intervienen procesos de colada en molde desechable o permanente así como los tratamientos térmicos que puedan aplicarse a distintos tipos de aceros, con el fin de variar su comportamiento mecánico y estructural.Pascual Guillamón, M.; Pérez Puig, MA.; Cembrero Cil, J.; Salas Vicente, F.; Pascual Martínez, R.; Cárcel Carrasco, FJ. (2017). Problemas de ciencia de materiales II. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/83675EDITORIA

Problemas de tecnología de materiales

Este libro está dedicado a la resolución de problemas destinados al aprendizaje en distintos grados de ingeniería (Mecánica, Tecnología industrial,Organización, Energética, etc), así como a la enseñanza de los procesos industriales de pulvimetalúrgia, tratamientos térmicos, ensayos no destructivos (ultrasonidos y radiografía) u otros Los problemas resueltos en él contenidos son fruto de la experiencia docente que durante años han acumulado los autores como profesores del área de materiales de la Universidad Politécncia de Valencia y están especialmente pensados para proporcionar al estudiante un imprescindible complemento que le permita aplicar el contenido teórico de la materia a casos prácticos y asegurar que se alcanza el nivel requerido de comprensión Cada uno de los problemas propuestos en el libro se ha resuelto de forma detallada con el fin de que se pueda seguir sin problemas el proceso seguido. Además,se proporciona al principio de cada capítulo un resumen de las fórmulas y variables usadas en la resolución de los problemasPascual Guillamón, M.; Salas Vicente, F.; Pérez Puig, MA.; Cembrero Cil, J.; Pascual Martínez, R.; Cárcel Carrasco, FJ. (2018). Problemas de tecnología de materiales. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/113120EDITORIA