Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25. | Journal of Science and Technology 54 (4B) (2016) 42-47 SOLVOTHERMAL SYNTHESIS OF BI2WO6 AND ITS PHOTOCATALYTIC ACTIVITY UNDER VISIBLE LIGHT IRRADIATION Trinh Duy Nguyen1, *, Van Thi Thanh Ho2, Long Giang Bach1 1 NTT Institute of High Technology, Nguyen Tat Thanh University, 298-300A, Nguyen Tat Thanh, Ho Chi Minh City, Vietnam 2 Hochiminh City University of Natural Resources and Environment, Vietnam * Email: nguyenduytrinh86@ Received: 15 August 2016; Accepted for publication: 10 November 2016 ABSTRACT Flower-like Bi2WO6 were successfully synthesized using the solvothermal method at different temperatures and characterized by XRD, FE-SEM, and DRS. We also investigated the photocatalytic activity of Bi2WO6 for the decomposition of rhodamine B under visible light irradiation. From XRD and SEM results, the reaction temperature has significant effects on the morphologies of the samples. From DRS results, Bi2WO6 samples displayed the absorption spectrum up to the visible region and then they showed the high photocatalytic activity under visible light irradiation, as a comparison with TiO2-P25. Keywords: Bi2WO6, solvothermal method, rhodamine B, visible light irradiation. 1. INTRODUCTION Bismuth tungstate (Bi2WO6), an Aurivillius-phase perovskite, has been extensively used in photocatalytic applications [1 - 3]. Bi2WO6 is a typical n-type direct band gap semiconductor with a band gap of eV, and thus it exhibits high photooxidative capacity as a catalyst for water splitting processes and degradation of organic pollutions under visible light irradiation [1]. It is a well-known fact that Bi2WO6 has two types of crystal structures: orthorhombic (space group B2cb, with a = , b = , c = , Z = 4) and monoclinic (space group structure. Monoclinic structure existed at a high-temperature phase (> 960 oC) while orthorhombic structures existed at a low and intermediate temperatures (< 960 oC) [4 – 6]. However, the orthorhombic phase was usually .
