| 초록 |
Porous hematite (α-Fe2O3) films doped with Sn(IV) and coated with an ultrathin (~2 nm thick) Nb2O5 passivation layer were synthesized, and the photoelectrochemical (PEC) water oxidation performance and durability of the hematite were examined in detail. As compared to hematite samples modified by either doping or passivation, dual-modified hematite exhibited a promising PEC water oxidation performance (i.e., an onset potential of ~0.7 V vs. RHE and a photocurrent density of ~2 mA cm-2 at 1.23 V vs. RHE in the presence of Co2+) under AM 1.5 irradiation. A stable photocurrent was maintained under prolonged irradiation over 24 h, while O2 was produced from water with a Faradaic efficiency of over 80% without showing any sign of deactivation. This performance and durability could be decoupled into separate effects of Sn doping and Nb2O5 layer via in-depth surface characterization and electrochemical analyses. |
