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-Bi 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-Bi 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.