Novel ternary metal oxide nanoparticles (La2Cu0.8Zn0.2O4) as a potential photocatalyst for visible light photocatalytic degradation of methylene blue and desulfurization of dibenzothiophene

Abstract

In this work we present the preparation of novel ternary metal oxide nanoparticles, La2Cu0.8Zn0.2O4 (LCZO), using a simple co-precipitation method. The crystalline structure, morphology and composition of the prepared LCZO nanoparticles were characterized by x-ray diffraction, scanning electron microscopy and energy-dispersive x-ray analysis. The diffuse reflectance spectrum investigation showed that LCZO nanoparticles have considerable light absorption in the visible light region. Also, the LCZO nanoparticles possess a band-gap energy of 2.82 eV. To investigate the visible light photocatalytic potential of the prepared LCZO nanoparticles, two photocatalytic reactions were conducted, namely degradation of methylene blue (MB) solution and desulfurization of dibenzothiophene (DBT). In the presence of a 3:1 molar ratio of H2O2/DBT, a high photocatalytic desulfurization rate of DBT (93.7%) was obtained over 0.2 g of LCZO photocatalyst. In addition, the photocatalytic degradation rate of MB solution was 91.4%. The mechanisms of both photocatalytic reactions were studied using different radical scavenging agents, which showed that hydroxyl radicals are responsible for highly efficient desulfurization and degradation reactions. Moreover, reusability experiments reveal that the prepared LCZO photocatalyst has great stability and recyclability for both desulfurization of DBT and degradation of MB after six reaction cycles.