Facile synthesis of Bi/BiVO4 composite ellipsoids with high photocatalytic activity

Abstract

BiVO₄-based composites have been extensively investigated as promising photocatalysts due to their strong visible-light absorption. In this work, novel Bi/BiVO₄ composites with excellent photocatalytic performance were firstly fabricated via a simple hydrothermal method, using BiVO₄ as a self-sacrificing template and N₂H₄·H₂O as a reductant. In the hydrothermal process, partial BiVO₄ was reduced to form metallic Bi nanoparticles, which were deposited on the surface of BiVO₄. The Bi content in the Bi/BiVO₄ composites could be easily tuned by controlling the concentration of the N₂H₄·H₂O solution. The photocatalytic performance of the Bi/BiVO₄ composites was examined by studying the photodecomposition of RhB under visible-light illumination. The experimental results revealed that the Bi/BiVO₄ composites exhibit high visible-light photocatalytic activity for the photodegradation of RhB compared with that of pure BiVO₄. This enhanced photocatalytic activity likely originates from the strong visible-light absorption and high separation efficiency of photogenerated electron–hole pairs by Bi nanoparticles. This work presents a new approach for the development of Bi/BiVO₄ composite photocatalysts with high activity and stability.