Cleaning Up Water Pollution Using Light

By Dean Williams on March 23, 2017

In their latest article, part of the JPhysD special issue on biological applications of electromagnetically active nanoparticles, authors Miguel Comesaña and colleagues working in Spain describe a potential solution for tackling polluted wastewater using photocatalytic degradation:

Since the beginning of modern industrialization, human activities have had an enormous impact in water quality, leading to the pollution and degradation of aquatic ecosystems worldwide. Among the different water polluters, polycyclic aromatic molecules derived from agricultural and textile industries are particularly dangerous, given their known or presumed carcinogenic potential. Thus, important efforts are currently under way in order to minimize the negative effects that such hazardous species may have over the environment and, by extension, on public health.

Our approach to tackle this issue relies on the formation of a nanocomposite capable of (1) efficiently degrading water contaminants by using the sun as a sustainable source of energy, and (2) selectively targeting particular contaminants in complex environments, such as those found in wastewater treatment plants. Along these lines, we have developed a hybrid nanostructure that results from the combination of two materials: one capable of catalyzing the degradation of water pollutants through UV light (the semiconductor) and other that can extend such catalytic properties to a broader range of the solar radiation spectrum (the photosensitizer).

More precisely, the hybrid composite presented in our work consists in the decoration of sodium titanate nanotubes with plasmonic gold nanoparticles, so that the selective photocatalytic properties of the former and the ability to absorb visible and NIR light of the latter can be synergistically merged. The obtained results show the great potential that this combination represents for the development of selective environmental remediation technologies.

Figure 1. (a) Schematic representation of the synthetic and photocatalytic mechanism, (b) electron microscopy characterization of the hybrid nanocomposite, and (c) selective photocatalytic degradation of polycyclic aromatic contaminants. Images taken from Waleed M A El Rouby et al 2017 J. Phys. D: Appl. Phys. 50 144002, © IOP Publishing, All Rights Reserved.

TeamNanoTech is a research group based at Universidade de Vigo (Spain) engaged in the design and synthesis of novel hybrid nanomaterials, as well as their application in a broad range of fields such as catalysis, theranostics and energy.

About the authors

Waleed M. A. El Rouby received his PhD degree in Physical Chemistry from Beni-Suef University (Egypt) in 2011. In 2015, he joined TeamNanoTech (TNT) at Universidade de Vigo (Spain) as a postdoctoral researcher. Currently, he is a lecturer at the Department of Materials Science and Nanotechnology, Faculty of Postgraduate Studies for Advanced Sciences (PSAS), Beni-Suef University (Egypt). His research interests focus on the synthesis and characterization of semiconductor nanomaterials, graphene, carbon nanotubes, and their application in catalysis.

Miguel Comesaña-Hermo obtained his PhD degree in Chemistry and Physics from Université de Toulouse (France) and Universität Duisburg-Essen (Germany) in 2011. After that, he held a postdoctoral position at the Centre de Recherche Paul Pascal in Bordeaux (France). He is currently a postdoctoral fellow at Universidade de Vigo (Spain). His research interests focus on the synthesis and characterization of multifunctional nanohybrids.

Martín Testa-Anta obtained his BSc (Hons) (2015) and MSc (2016) in Chemistry at Universidade de Vigo (Spain). He is currently a PhD student at the Department of Applied Physics at Universidade de Vigo. His research interests focus on the synthesis, characterization and analysis of the magnetic behavior of nanocrystals.

Enrique Carbó-Argibay received his PhD degree in Physical Chemistry from the Universidade de Vigo in June 2011. In April 2013, he joined the International Iberian Nanotechnology Laboratory (Braga, Portugal) as a postdoctoral researcher. Currently, he is an Electron Microscopy Facility Manager in the Department of Advanced Electron Microscopy, Imaging and Spectroscopy of the same Institution, working on extracting structural and chemical information from nanomaterials by means of advanced electron microscopy imaging (aberration-corrected TEM and aberration-corrected STEM) and spectroscopy (EELS, EDX) techniques.

Verónica Salgueiriño received her PhD degree in Chemistry from Universidade de Vigo (Spain) in 2003. Then, she worked as a postdoctoral researcher at Universität Duisburg-Essen (Germany), Arizona State University (USA) and Universidade de Santiago de Compostela (Spain) until joining the Department of Applied Physics at Universidade de Vigo. Her current research focuses on the development and physical and chemical characterization of new magnetic nanoparticles and nanocomposites, with particular interest on interfaces between transition metal oxides.

Moisés Pérez-Lorenzo obtained his PhD in Chemistry from Universidade de Vigo (Spain) in 2004. Then, he performed postdoctoral stays at the University of California at Santa Cruz (USA) and Universidade de Santiago de Compostela (Spain) working on the fields of physical and mechanistic organic chemistry as well as chemical kinetics in colloidal systems. After this period, he joined the Department of Physical Chemistry at Universidade de Vigo. His current research interests focus on the design of plasmonic nanoplatforms and their applications in catalysis, sensing and drug delivery.

Miguel A. Correa-Duarte received his PhD degree in Chemistry from Universidade de Vigo (Spain) in 2002. Then, he held postdoctoral positions at the Center of Advanced European Studies and Research, CAESAR (Germany) and Arizona State University (USA). He is currently an Associate Professor at the Department of Physical Chemistry of Universidade de Vigo and Group Leader of TeamNanoTech, a recently established research group engaged in the design and synthesis of nanomaterials toward the development of novel applications as well as their implementation in devices.