Enhanced photocatalytic activity of CdWO4/BaTiO3 heterostructure for dye degradation

• Published in: New journal of chemistry 2021-11, Vol.45 (42), p.19723-19732
• Main Authors: Sai Sushma, S P, Swarupa, G, Nagesh, T, Pola, Someshwar, Rajitha, P, B Vijaya Kumar, Upender, G
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Barium titanates; Catalytic activity; Charge transfer; Degradation; Dyes; Ferroelectricity; Fourier transforms; Heterostructures; Infrared spectroscopy; Irradiation; Methylene blue; Photocatalysis; Photoelectrons; Photoluminescence; Spectrum analysis; Ultraviolet radiation; X ray photoelectron spectroscopy
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/d1nj01556g

The novel UV active photocatalysts of (1 − x)CdWO4–xBaTiO3 (where x = 10, 30, 50 and 70 wt%) heterostructures were synthesized using the hydrothermal technique. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence (PL) techniques. The photocatalytic activities of BaTiO3, CdWO4 along with all CdWO4/BaTiO3 heterostructures were evaluated for the degradation of methylene blue (MB) dye in an aqueous solution under UV irradiation and it was found that the CdWO4/BaTiO3 (70 : 30 wt%) heterostructure exhibited the highest photocatalytic activity within 45 minutes compared to BaTiO3 and CdWO4. The scavenger tests confirmed that OH·, O2·− and h+ radicals were the main species for the MB degradation. The calculated redox potentials of both BaTiO3, CdWO4 semiconductors indicated that the charge transfer between these two is responsible for the enhanced photocatalytic activity of CdWO4/BaTiO3 heterostructures. Accordingly, the possible mechanisms of the separation of photo-induced electron–hole pairs and charge transfer and also the generation of radicals for MB degradation under UV irradiation were proposed in detail. Our findings clearly suggest that the integration of ferroelectric BaTiO3 with semiconducting CdWO4 could be an effective way to expedite MB dye degradation.