Optimization of photodegradation of methylene blue over modified TiO2/BiVo4 photocatalysts: effects of total TiO2 loading and different type of co-catalyst

The photocatalytic degradation of BiVO4 photocatalyst via removal of methylene blue under visible light irradiation was explored by adding different co-catalysts namely TiO2, Ag, Pt, Ni and reduced graphene oxide (RGO). The effect of the total amount of co-catalysts loading on the removal of methylene blue was investigated by varying the amount of TiO2 loading (0.1, 0.8, 1.0 and 1.2 wt%). The physicochemical properties of as-prepared TiO2/BiVO4 photocatalysts were explored by Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and Field-Emission Scanning electron Microscope (FESEM) micrograph analysis. The TiO2/BiVO4 heterostructure photocatalyst with 1% TiO2 loading exhibited better photodegradation performance with 100% removal rate within 150 minutes. A high performance of this heterostructure photocatalyst is accredited to higher BET specific surface area and intimate contact between BiVO4 and TiO2 nanoparticles shown by FESEM images which resulted in more available of active reaction site for photodegradation activity. A comparison between 1 wt% of TiO2 co-catalyst and the rest of co-catalysts confirmed that the addition of 1wt% of RGO loaded onto BiVO4 displayed 100% removal rate within 135 minutes. This work demonstrates the optimization of BiVO4 via optimum total loading and different type of co-catalysts has the promising potential in the wide range of practical photodegradation applications such as degradation of organic and inorganic pollutants. (C) 2018 Elsevier Ltd. All rights reserved.