Multifunctional BaTi0.98M0.02O3 (M = V, Co, Mo) compositions: High dye-photodegradation and relative permittivity characteristics

Abstract

In this study, the relative permittivity and photocatalytic properties of BaTi0.98M0.02O3 (M = V, Co, Mo) compositions have been investigated. Polycrystalline BaTiO3, BaTi0.98V0.02O3 BaTi0.98Co0.02O3 and BaTi0.98Mo0.02O3 powders were synthesized by solid state reaction method. The X-ray diffraction analysis of all samples confirmed the formation of tetragonal BaTiO3 phase without any impurities. The scanning electron microscope images showed the formation of irregular grains for BaTiO3 and BaTi0.98V0.02O3 samples while BaTi0.98Co0.02O3 and BaTi0.98Mo0.02O3 powders revealed spongy and uniform crystalline grains shapes, respectively. Remarkably, the incorporation of V, Co and Mo ions was reduced the UV band gap energy of BaTiO3 from 3.25 eV to 2.96, 2.98 and 2.92 eV, respectively. These results verify that V, Co and Mo doped BaTiO3 samples have the ability to absorb the visible light spectrum compared to pure one. The study of the dielectric properties showed that the BaTi0.98V0.02O3 and BaTi0.98Mo0.02O3 samples have a colossal relative permittivity of 14263 and 1658, respectively. Besides, BaTi0.98Mo0.02O3 as a photocatalyst exhibits superior photodegradation efficiencies of 90 and 100% towards 10 ppm Congo red solution under sunlight irradiation during 20 and 60 min, respectively. For 50 ppm CR, the photocatalytic activity of this catalyst was reached to 53% and 70% in 20 and 60 min, respectively. The highest performance of BaTi0.98Mo0.02O3 catalyst can be ascribed to high crystallinity, formation of oxygen vacancies, well charge separation and visible light absorption.