Bivo4 Photoanode Modification by Synergic Dual-Conjugated Organic Materials

Abstract

Organic conjugated materials have presented considerable application potential in the field of photoelectrochemical (PEC) water splitting. In this study, two organic conjugated materials, two dimension carbon nitride (2D-C 3 N 4 ) and organic cobalt molecular catalyst ((H 3 O) 6 ·[Co 4 (H 2 O) 4 (HPMIDA) 2 (PMIDA) 2 )]·2H 2 O) (OCM), are fabricated in turn on the surface of bismuth vanadate (BiVO 4 ) photoanode. Basing on the synergistic effect of 2D-C 3 N 4 and OCM, the PEC property of the modified BiVO 4 photoanode increases three times higher than that of bare BiVO 4 photoanode at 1.23 V vs. RHE by reaction active surface increasing, charge separation promoting, and reaction overpotential reducing. This study shows that organic conjugated materials can not only form an effective heterojunction system with semiconductor materials and improve surface catalytic activity, but also assemble easily by the strong affinity between g-C 3 N 4 and OCM. Therefore, this research provides a novel and efficient modification method by dual-conjugated organic materials to improve the PEC performance of photoelectrodes.

Keywords: bismuth vanadate photoanode, organic conjugated material, carbon nitride, organic cobalt molecular catalyst, synergistic effect