Room-temperature synthesis of three-dimensional porous ZnO@CuNi hybrid magnetic layers with photoluminescent and photocatalytic properties

Abstract

A facile synthetic approach to prepare porous ZnO@CuNi hybrid films is presented. Initially, magnetic CuNi porous layers (consisting of phase separated CuNi alloys) are successfully grown by electrodeposition at different current densities using H₂ bubbles as a dynamic template to generate the porosity. The porous CuNi alloys serve as parent scaffolds to be subsequently filled with a solution containing ZnO nanoparticles previously synthesized by sol-gel. The dispersed nanoparticles are deposited dropwise onto the CuNi frameworks and the solvent is left to evaporate while the nanoparticles impregnate the interior of the pores, rendering ZnO-coated CuNi 3D porous structures. No thermal annealing is required to obtain the porous films. The synthesized hybrid porous layers exhibit an interesting combination of tunable ferromagnetic and photoluminescent properties. In addition, the aqueous photocatalytic activity of the composite is studied under UV−visible light irradiation for the degradation of Rhodamine B. The proposed method represents a fast and inexpensive approach towards the implementation of devices based on metal-semiconductor porous systems, avoiding the use of post-synthesis heat treatment steps which could cause deleterious oxidation of the metallic counterpart, as well as collapse of the porous structure and loss of the ferromagnetic properties.

Keywords:

• Porous nanocomposite
• CuNi alloy
• ZnO nanoparticles
• ferromagnetism
• photoluminescence

Classification:

• 40 Optical, magnetic and electronic device materials
• 102 Porous / Nanoporous / Nanostructured materials
• 100 Materials
• 103 Composites
• 205 Catalyst / Photocatalyst / Photosynthesis
• 200 Applications
• 203 Magnetics / Spintronics / Superconductors

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplemental data

The supplemental material for this paper is available online at http://dx.doi.org/10.1080/14686996.2016.1165583

Acknowledgements

This work has been funded by the Generalitat de Catalunya [project 2014-SGR-1015] and the Spanish Ministerio de Economía y Competitividad (MINECO) [projects MAT2014-57960-C3-1-R and MAT2014-57960-C3-3-R]. Partial funding from the European Research Council [Consolidator Grant, project number 648454, SPIN-PORICS] is acknowledged. E. Pellicer is grateful to MINECO for the ‘Ramón y Cajal’ contract [RYC-2012-10839]. J. Zhang is grateful to the China Scholarship Council (CSC) for the PhD grant. M. Guerrero acknowledges the support of the Secretary for Universities and Research of the Government of Catalonia and the COFUND Programme of the Marie Curie Actions of the 7th R&D Framework Programme of the European Union for the ‘Beatriu de Pinos’ contract [2013 BP-B 00077].