1. Introduction Recently, extensive research has been conducted on the synthesis and characterization of zinc oxide (ZnO) and titanium oxide (TiO 2 ) due to their electric, optical, catalytic, magnetic, and biochemical properties as well as owing to their good chemical and thermal stability. Most of the obtained results are summarized in the review by Carp et al. [1] and in the Ozgur’s monograph [2]. In our previous investigations submicron ZnO/TiO 2 powders were obtained by hydrolytic sol-gel method and their photocatalytic and antibacterial properties against E. Coli were studied [3-5]. Several authors established that the method of synthesis and morphology of the nanoparticles have an essential impact on the photocatalytic processes [6,7]. Recently, the combustion synthesis (CS) became more popular and has emerged as an important technique for the synthesis and processing of oxide and non-oxide advanced materials [8]. This method has many potential advantages, such as low-processing cost, energy effciency, and high production rate. Several books [9-12] and review articles [13-19] have been published on this subject in recent years. By combustion synthesis, TiO 2 , nanoparticles sized from 100 nm to 1000 nm were very quickly obtained through gasifcation, nucleation, and crystal growth [20,21]. Zinc oxide (ZnO) powders with different types of morphology were Central European Journal of Chemistry Photocatalytic properties of ZnO/TiO 2 powders obtained via combustion gel method * E-mail: albenadb@svr.igic.bas.bg Received 18 July 2012; Accepted 18 October 2012 Abstract: © Versita Sp. z o.o. Keywords: Precursor • Gel combustion method • TiO 2 /ZnO composites 1 Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofa, Bulgaria 2 Medical University, 5800 Pleven, Bulgaria 3 University of Chemical Technology and Metallurgy, 1756 Sofa, Bulgaria 4 University of Mining and Geology “St. Ivan Rilski”, Sofa 1700, Bulgaria Albena D. Bachvarova-Nedelcheva 1* , Reni S. Iordanova 1 , Angelina M. Stoyanova 2 , Radka D. Gegova 1 , Yanko B. Dimitriev 3 , Alexandre R. Loukanov 4 Research Article The present study is a continuation of our previous investigations on the ZnO-TiO 2 system. By applying different sol-gel methods we proved that the type of precursor and the order of adding the components infuence the microstructure of the fnal product. This study focuses on the combustion sol-gel synthesis and photocatalytic properties of nanosized (∼7-20 nm) ZnO-TiO 2 powders. The photocatalytic tests were performed toward two model organic dyes, Malachite Green and Reactive Black 5, in the UV and Vis region. For synthesis of ZnO/TiO 2 powders, different precursors such as Zn(NO 3 ) 2 •6H 2 O, Zn(CH 3 COO) 2 •2H 2 O, Ti(OC 2 H 5 ) 4 and Ti(OC 4 H 9 ) 4 were used. During the combustion process various phases (ZnO, TiO 2 – anatase and rutile, ZnTiO 3 ) were obtained. The structure and morphology of the resulting particles were characterized by XRD and SEM analysis. All samples exhibited a good photocatalytic activity in both UV and Vis regions. 364 Cent. Eur. J. Chem. • 11(3) • 2013 • 364-370 DOI: 10.2478/s11532-012-0167-2