The impact of iron–boron electrocatalysts on the charge transport and oxygen evolution reaction of bismuth vanadate photoanodes

Abstract

BiVO₄ possesses a suitable band gap for photoelectrochemical (PEC) water splitting to produce hydrogen; however, the performance of BiVO₄ is limited by several adverse factors. The bulk charge recombination and the slow surface water oxidation reaction of BiVO₄ are main unfavorable factors. In view of these disadvantages, an Fe–B_i electrocatalyst is loaded on BiVO₄ to improve the PEC performance of BiVO₄. After modification, the onset potential of BiVO₄ shifts negatively by 60 mV, and the saturated photocurrent is greatly increased. Systematic studies demonstrate that the Fe–B_i electrocatalyst not only enhances the bulk charge separation, but also accelerates the surface water oxidation rate of BiVO₄ and greatly reduces the resistance of the reaction interface.