title: Surface passivation of undoped hematite nanorod arrays via aqueous solution growth for improved photoelectrochemical water splitting.
abstract: A facile solution-based strategy was found to be effective for surface passivation of undoped hematite nanorod photoanodes by adding noble-metal chlorides such as HAuCl4 and H2PtCl6 in the Fe(3+) precursor solution. XPS and Raman spectra revealed that noble-metal ions would not be doped into, but lead to surface disorder of hematite. Incident photon to current efficiency (IPCE) of the hematite photoanode grown in HAuCl4 and H2PtCl6 contained precursor solution was increased from 3.6% to 11.5% and 12.9%, respectively, at 365 nm and 1.23 V vs. RHE (reversible hydrogen electrode). This photoelectrochemical (PEC) enhancement was ascribed to the surface passivation, which resulted in a reduced recombination of photogenerated carriers, as confirmed by ultrafast transient absorption spectroscopy.
authors.affiliation: International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China; Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, United States. Electronic address: shshen_xjtu@mail.xjtu.edu.cn.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Shen
authors.affiliation: International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
authors.forename: Mingtao
authors.initials: M
authors.lastname: Li
authors.affiliation: International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
authors.forename: Liejin
authors.initials: L
authors.lastname: Guo
authors.affiliation: International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Shaanxi 710049, China.
authors.forename: Jiangang
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Mechanical Engineering, University of California at Berkeley, Berkeley, CA 94720, United States.
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Mao
keywords: Hematite; Photoelectrochemical water splitting; Surface passivation