Controlling the Structure and Photoelectrochemical Performance of BiVO4 Photoanodes Prepared from Electrodeposited Bismuth Precursors: Effect of Zinc Ions as Directing Agent

A facile and green method was developed to control the structure of the prevailing BiVO4 photoanodes derived from electrodeposited Bi precursors, in which Zn2+ ions were added as a directing agent to tune the deposition of Bi particles. The particle size and density of the Bi precursors were affected by the amount (or concentration) of Zn2+ ions added. The structural evolution of BiVO4 was consistent with that of the Bi precursor particles. An optimal concentration of Zn2+ ions resulted in smaller particle sizes and produced appropriate interparticle spacing of BiVO4 photoanodes, which possessed enhanced photocurrent and improved charge separation efficiency. The enhancement is mostly ascribed to the suppression of carrier recombination in the bulk This work demonstrates an effective way to adjust the structure and the subsequent photoelectrochemical performance of BiVO4 photoanodes by a cation-tuned Bi precursor strategy without the use of hard templates or complex directing agents.