Preparation of Manganese Phthalocyanine Modified Nano-BiVO4 Photocatalyst with Perforated Hollow Morphology and Its Catalytic Performances

Abstract

Nano-BiVO4 was successfully modified by manganese phthalocyanine (MnPc) with high photocatalytic activity through a simple hydrothermal path. The perforated hollow morphology of BiVO4 was maintained after the modification, which was profitable for the photocatalytic activity. The MnPc was physically combined with BiVO4 through weak links such as the Coulomb force or hydrogen bond, other than chemical bound. The band gap of the modified BiVO4 was successfully narrowed by MnPc to cause the redshift of the modified BiVO4, which provided larger visible light absorption. Therefore the MnPc-modified BiVO4 obtained improved photocatalystic activity. On the conditions of the hydrothermal temperature of 180 °C, pH of 7.5, hydrothermal time of 4 h, 3.30 mmol of EDTA, and the MnPc amount of 0.20 wt%, the band gap of the BiVO4 catalyst was narrowed to 2.40 eV. Under the catalysis of the MnPc-modified BiVO4, the discoloration rate of methylene blue reached 98.44% in the simulated sunlight. A synergistic effect between MnPc and BiVO4 appeared through our hydrothermal synthesis process. Such a successful modification design could be extended to other photocatalyst systems with phthalocyanine compounds and transition metal oxides.