Photocatalytic Degradation of Rhodamine-B Under UV-Visible Light Irradiation Using Different Nanostructured Catalysts
María del C. Cotto-Maldonado *
School of Science and Technology, Universidad del Turabo, 00778-PR, USA
Teresa Campo
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
Eduardo Elizalde
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
Arancha Gómez-Martínez
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
Carmen Morant
Departamento de Física Aplicada C-XII, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain
Francisco Márquez
School of Science and Technology, Universidad del Turabo, 00778-PR, USA
*Author to whom correspondence should be addressed.
Abstract
Aims: The goal of this research is to determine the efficiency of different catalysts for the degradation of organic compounds as possible alternative for wastewater treatments. To reach this goal, many objectives should be previously satisfied including the synthesis of different catalysts and the catalytic tests for the different processes.
Study Design: A multifactorial design was used for the experimental study.
Place and Duration of Study: The present study was conducted between January 2011 to December 2011 at the School of Science and Technology, Universidad del Turabo and the Department of Applied Physics at the Universidad Autónoma de Madrid, Spain.
Methodology: Different catalysts were synthesized and the photocatalytic activity was measured. Catalysts were characterized by XRD, FE-SEM, SBET and TGA. For the photocatalytic activity a cylindrical reactor with continuous stirring was used. The dye (10-5 M) was previously dissolved in water and 0.6g L-1 of the corresponding catalyst was added to the reaction mixture. An irradiation of 60 watts was applied. An aliquot of 10 mL was taken every 10 min during a period of an hour from the solution and diluted for characterizing by UV-vis and fluorescence spectroscopies and TOC.
Results: The catalytic tests indicate that TiO2NWs is the most efficient catalyst and eventually could be used for alternative wastewater treatments.
Conclusion: Synthesized (TiO2NWs, TiO2@MWCNTs and ZnO) and commercial catalysts were fully characterized by FE-SEM, TGA, specific surface area (BET) and XRD. The most efficient catalyst was TiO2NWs (with approximately 96.44% of degradation). All catalysts used were able to degrade the Rhodamine-B and could eventually be used to removal pollutants from water.
Keywords: Photocatalysis, Rhodamine-B, TiO2, nanowires, advanced oxidation process, pollutants