SONOPHOTOCATALYTIC DEGRADATION OF ACID BLUE 113 IN THE PRESENCE OF RARE EARTH IONS LOADED TIO 2 NANOPHOTOCATALYSTS Panneerselvam Sathishkumar 1,2* , Ramalinga Viswanathan Mangalaraja 1, * , Oscar Rozas 3 , Héctor D. Mansilla 3 , M. Gracia-Pinilla 4 , Sambandam Anandan 5 (1) Advanced Ceramics and Nanotechnology Laboratory, Department of Materials Engineering, Faculty of Engineering, University of Concepcion, Concepcion 407-0409, Chile (2) Department of Chemistry, Periyar Maniammai University, Thanjavur – 613 403, Tamil Nadu, India (3) Facultad de Ciencias Químicas, Universidad de Concepción, Casilla 160-C, Concepción, Chile (4) (a) Universidad Autónoma de Nuevo León, Facultad de Ciencias Físico-Matemáticas, Av. Universidad, Cd. Universitaria, San Nicolás de los Garza, N.L. México. (b) Universidad Autónoma de Nuevo León, Centro de Investigación e Innovación en Desarrollo de Ingeniería y Tecnología. PIIT. Km 10, Carretera al Aeropuerto, Apodaca N.L. México (5) Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Trichy 620 015, India * Presenting author: Email: sathish_panner2001@yahoo.com (P. Sathishkumar); * Corresponding Author: E-mail:mangal@udec.cl (R.V.Mangalaraja) Keywords: 42 kHz Ultrasound, Rare earth loaded TiO 2 , Visible light, Sonophotocatalysis. ABSTRACT In this study, we report a simple, convenient and one-step sonochemical method for the loading of rare earth clusters into the TiO 2 for the enhanced degradation of Acid Blue 113 (AB113). The synthesized nanophotocatalysts were characterized by diffuse reflectance UV-Vis (DR- UV-Vis) spectra for the optical properties. The observed decrease in the band gap (2.90, 2.92 and 2.90 eV) for Sm 3+ , Er 3+ , Pr 3+ loaded TiO 2 when compared with bare TiO 2 (3.2 eV) clearly illustrates that the visible light is appropriate for the band gap excitation of the sonochemically prepared nanophotocatalysts. The sonolytic, sonocatalytic and sonophotocatalytic degradation of AB113 was carried out by a 42 kHz commercial sonicator. The commercial 42 kHz sonicator and visible light excitation of the semiconductor materials significantly reduces the cost of the sonophotocatalytic processes. The synergy index for the combination of two AOPs was calculated using the observed rate constants for the individual and combined AOPs. 1. INTRODUCTION The combination of advanced oxidation processes (AOPs) enhances the degradation of non-biodegradable recalcitrant pollutants [1]. Among various AOPs, the combination of sonolysis with photocatalysis received much attention from the environmental perspectives [2]. The extreme conditions produced during the sonication are of current interest for the degradation of environmental contaminants [3]. However, the electrical consumption during sonication makes the process expensive compared to other technologies and also the equipment which producing higher ultrasonic irradiation is costly. Therefore to avoid the usage of high-frequency ultrasound, a low cost and commercially available device producing low frequency