ABSTRACT
The effective utilization of visible light is required for exploiting photocatalytic reactions in indoor and outdoor environments. In this study, Pd-supported BiVO4 microspheres (Pd-BiVO4) were prepared for visible light-induced photocatalytic reactions. Under irradiation with a white light-emitting diode, the obtained Pd-BiVO4 composite exhibited considerably improved catalytic activity for the decomposition of an organic dye compared with other BiVO4 catalysts. The Pd-BiVO4 composite was also effective for catalytic organic transformation via the visible light-induced Suzuki-Miyaura coupling reaction. The photogenerated electrons in the conduction band of BiVO4 flowed to the Pd nanoparticles and amplified cross-coupling reaction. The influence of the crystal structure and grain size of BiVO4 and the role of the deposited Pd nanoparticles were fully investigated to elucidate the visible light activity of the catalyst. This system highlights the possibility of an indoor light source with low energy density for sustainable organic transformations.
ABSTRACT
A BiVO4/Bi2S3 composite comprising Bi2S3 nanowires on top of a BiVO4 film was prepared via hydrothermal reaction. Because additional Bi3+ ions were not delivered during the reaction, BiVO4 served as the Bi3+ ion source for the development of Bi2S3. A detailed growth mechanism of the nanowire was elucidated by an analysis of the concentration gradient of Bi3+ and S2- ions during the reaction. The in situ growth was followed by the etching of BiVO4 to Bi3+ and VO43- ions and regrowth to Bi2S3, which resulted in the rapid evolution of nanowires on the BiVO4 substrate. The fabricated BiVO4/Bi2S3NW composite exhibited an improved photoelectrochemical activity compared to other Bi2S3 samples. The improved efficiency was mainly attributed to both improved charge separation and effective adhesion obtained by the in situ growth.
