InVO<inf>4</inf>–BiVO<inf>4</inf>composite films with enhanced visible light performance for photodegradation of methylene blue

Abstract

© 2016 Elsevier B.V. The InVO4, BiVO4, and InVO4–BiVO4films were fabricated by a simple doctor blading coating technique. The film thickness of the as-prepared samples was varied to one, two and three layers. The prepared InVO4–BiVO4composite films were characterized in detail by various analytical techniques that reveal the well crystallinity with orthorhombic structure of InVO4and monoclinic structure of BiVO4for the as-prepared material. The as-synthesized photocatalyst films were used as the efficient photocatalysts for the photocatalytic degradation of methylene blue (MB) under visible light illumination. It was found that the three-layered 0.2InVO4–0.8BiVO4film presented better photocatalytic activity than that of pure phase InVO4and BiVO4. About 70% of the 1 × 10−5 g L−1MB was degraded within 120 min catalyzed by the three-layered 0.2InVO4–0.8BiVO4films. Interestingly, an obvious synergy between two catalysts was observed and corresponding mechanism based on facilitated transfer of electrons and holes as a result of a suitable energy level alignment was suggested. Fluorescence method with terephthalic acid (TA) as the probe was employed for the quantification of hydroxyl production.