BiOI–BiVO 4 photoanodes with significantly improved solar water splitting capability: p–n junction to expand solar adsorption range and facilitate charge carrier dynamics

• DOI: 10.1016/j.nanoen.2015.10.018
• Publication Date: 2015-10-31T14:01:31Z
• Authors: Kai-Hang Ye; Zhisheng Chai; Jiuwang Gu; Xiang Yu; Chuanxi Zhao; Yuanming Zhang; Wenjie Mai
• Keywords: Photocurrent; Charge carrier; p–n junction

Abstract Herein, we report an effective synthesis method of BiOI/BiVO 4 p–n junction that greatly improves the performance of BiVO 4 for photoelectrochemical water splitting due to a synergistic effect. The photocurrent density of BiOI/BiVO 4 photoanodes achieved 3.27 mA cm 2 at 1.23 V vs. RHE, which is much higher than those of pristine BiVO 4 and BiOI (1.23 mA cm 2 and 0.15 mA cm 2 at 1.23 V vs. RHE, respectively). At 0.68 eV vs. RHE, BiOI/BiVO 4 shows the maximum of applied bias photo-to-current efficiency of 0.97% at 0.68 V vs. RHE. This new BiOI/BiVO 4 p–n junction not only facilitates the separation and transfer of photo-generated charges, but also expands the light absorption range, which is the origin for this synergistic effect. The BiOI/BiVO 4 p–n junction materials with excellent solar water splitting capability should shed light on designing and fabricating the next-generation photocatalysts.