Perovskite Type B-CaTiO3 Coupled with Graphene Oxide as Efficient Bifunctional Composites for Environmental Remediation

Abstract

To prepare boron doped perovskite CaTiO3 nanocubes coupled with graphene oxide (B-CaTiO3/GO), B-CaTiO3 photocatalyst was initially synthesized by the solvothermal method and subsequently attached on GO by a simple hydrothermal process. The phase structure and optical features of the prepared materials were efficiently characterized by several techniques. The XRD patterns indicated that boron doping could not give rise to lattice disruption of CaTiO3. The results of XPS, HRTEM and Raman measurements revealed that the presence of B-CaTiO3 is anchored on the surface of GO effectively. The morphology of the B-CaTiO3/5GO was nanocube particles. The photocatalytic capacity of B-CaTiO3/GO nanocomposites was determined by investigating the degradation of a model dye, methylene blue (MB). Their degradation performance could be enhanced by altering the ratio between B-CaTiO3 and GO. The most effective GO incorporation is 5 wt%, and at this loading percentage, B-CaTiO3/GO nanocomposite showed improved photocatalytic activity compared with CaTiO3 and B-CaTiO3 photocatalyst, which could be attributed to the synergistic efficacy of the adsorbed MB molecule on the GO followed by their degradation after 180 min of visible light. Additionally, the active species trapping tests confirm the dominant role performed by ·OH and O2·− during the degradation of MB. The presence of HCO3− and Cl− indicated moderate prohibitive effect on the degradation of MB, while NO3− and SO42− negatively affected the catalytic activity in a non-significant way. In brief, the results of this study show that boron doped perovskite-type semiconductor catalysts by combining with graphene has significant efficiency in the removal of MB from aqueous solution, which can be employed as effective photocatalyst materials for the treatment of other organic pollutants.