Photocatalytic activity of GO-doped bismuth-based photocatalyst for Methyl Orange decolorization under visible light irradiation

It was aimed to investigate the photocatalytic activity of GO-doped BiVO4 nanocomposite (m-BVG) as novel visible-light bismuth-based photocatalyst for decolorization of a selected azo dye (methyl orange, MO) from water. According to the obtained results, the synthesized m-BVG represented a better photocatalytic performance and exhibited higher decolorization rate and efficiency at any given time of the test in comparison with the synthesized BiVO4 nanoparticles. Owing to GO electrical conductivity, reduction of the recombination rate of electron–hole pairs resulted in more efficient performance for the m-BVG. The solution permeability to light, which is a function of both m-BVG dosage and dye concentration, was distinguished as a predominant controlling factor of the decolorization efficiency. Applying H2O2 (at the content of 2 wt.%) as an external electron acceptor in association with m-BVG, dramatically enhanced the decolorization rate. Presence of H2O2 eliminated the necessity of going through the long pre-required pathway (comprising of six successive reactions) for the subsequent OH’ generating reactions. Under this circumstance and owing to the synergistic performance of H2O2/m-BVG composite, around 98% MO decolorization was achieved over only 10 min of irradiation while it lasted about 330 and 60 min for m-BVG and H2O2, orderly, to gain the same decolorization efficiency when they were used individually.