Heterostructure engineering, combining dissimilar materials into a single substrate, allows the alteration of the optical, electrical, and electrochemical properties of photoelectrodes for photoelectrochemical (PEC) water splitting. Herein, we successfully synthesized a novel dual-textured BiVO4 / Sb:SnO2 heterostructure as a photoanode for PEC water-splitting devices. Sb:SnO2 (ATO) nanorods (NRs) with a [0 0 1] growth orientation were first grown on a fluorine-doped tin oxide substrate by a hydrothermal method. Subsequently, the BiVO4 (BVO) seed layer was deposited on the ATO NRs using a solution spin-coating followed by a second hydrothermal growth to synthesize the dual-textured BVO/ATO heterostructure (dt-BAH). The resultant dt-BAH photoanode was composed of (0 0 1)-textured BVO on the [0 0 1]-oriented single-crystalline ATO NRs, and their interface exhibited intimate junctions. In addition, the textured BVO exhibited two different facets of (0 0 1) and (1 0 1). Notably, the synthesized dt-BAH photoanode showed a considerable enhancement in charge collection performance, resulting in a photocurrent density approximately four times higher than that of the textured BVO grown on the randomly oriented ATO nanoparticle film (single-textured BAH). Our results provide new insights into heterostructure design for the development of efficient photoelectrodes.
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea, funded by the Ministry of Science, ICT, and Future Planning (Grant Numbers NRF-2019R1A2C2002024 and 2021R1A4A1031357).
