Photoelectrocatalytic activity of methylene blue using chemically sprayed Bi2WO6 photoanode under natural sunlight

Abstract

In this work, Bi2WO6 thin films are deposited using a simple chemical spray pyrolysis technique at different substrate temperatures. The physicochemical behavior of the films was evaluated by analysing photoelectrochemical, optical, morphological, and structural properties. The Rietveld refinement study confirms the orthorhombic crystal structure of Bi2WO6 thin films. The film deposited at 325 °C shows maximum photocurrent density under illumination. The large area (10 ×10 cm2) Bi2WO6/FTO thin film electrode is used further for photocatalytic, electrocatalytic, and photoelectrocatalytic degradation of methylene blue. The effective separation of photogenerated charge carriers is carried out by applying a bias potential of 1 V. In comparison with photocatalytic and electrocatalytic degradation, the photoelectrocatalytic degradation of methylene blue shows enhanced performance with 90% degradation efficiency under solar radiation. The quenching experiment confirmed major contribution of hole in dye degradation. These outcomes can help researchers to explore the photocatalytic behaviour of different ternary metal oxides based on Bi2WO6.