Synthesis of novel morphology-controlled Bi(OH)CrO4 with high visible light photocatalytic activity

Bi(OH)CrO4 photocatalyst excited by visible-light was successfully synthesized by the hydrothermal method, and the morphologies were well controlled via different hydrothermal temperatures and time. The Bi(OH)CrO4 was characterized in detail, and the photocatalytic activity was investigated by decolorization of methylene blue. The results showed that only orthorhombic crystal is observed for the Bi(OH)CrO4 prepared at 180 °C for 24 h, whereas the samples prepared under other conditions display monoclinic crystal. The Bi(OH)CrO4 prepared at 160 °C, 180 °C and 200 °C for 24 h display regular strips, hexagon and irregular shape, respectively. The hydrothermal time also has a significant influence on the morphology of the photocatalyst. The absorption wavelength of the photocatalyst is lower than 590 nm. The Bi(OH)CrO4 prepared at 180 °C for 24 h has the most excellent visible-light photocatalytic activity. The mechanisms of the photocatalytic reaction were also discussed.