title: A nanostructured hematite film prepared by a facile "top down" method for application in photoelectrochemistry.
abstract: To overcome tough conditions currently used for the preparation of nanostructured hematite films on a conducting substrate, a rational and easy method of chemical etching involving Fe3+release and material growth in the presence of OH-has been developed. By carefully tuning the parameters influencing the morphologies of hematite, including the synthetic procedure, the concentration of etching solution, temperature, etching time and the morphology controlling surfactant, hematite films grown on iron foil with various morphologies (e.g. nanorod, nanowire, ultrathin nanoflake and cauliflower-like shape) have been achieved. In particular, it is found that F-is an effective surfactant to control the morphology as well as the crystallization process of hematite. Ultrathin nanoflakes having a minimized feature size exhibit the best photocurrent of 0.5 mA cm-2(1.23 V vs. RHE, RHE is reversible hydrogen electrode) among the samples tested as a result of facilitated hole diffusion to the electrolyte and thus lowered carrier recombination. Compared with pristine hematite, a nearly tripled photocurrent is observed when H2O2is added in the electrolyte as a hole scavenger, suggesting the presence of a charge injection barrier in the surface of samples. According to this, the strategy of Co2+treatment is utilized and the improved photocurrent is seen, likely due to the improved water oxidation kinetics and surface state passivation. We believe that this convenient and economical method can be extended to the synthesis of other alkaline metal oxide nanomaterials as long as the redox potential of S2O82-/SO42-is higher than Mn+/M (M refers to metal).
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Dong-Dong
authors.initials: DD
authors.lastname: Qin
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Xing-Ming
authors.initials: XM
authors.lastname: Ning
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Qiu-Hong
authors.initials: QH
authors.lastname: Wang
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Cai-Hua
authors.initials: CH
authors.lastname: He
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Jing-Jing
authors.initials: JJ
authors.lastname: Quan
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.affiliation: School of Physical Science and Technology, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China. taochl@lzu.edu.cn.
authors.forename: Ying-Tao
authors.initials: YT
authors.lastname: Li
authors.affiliation: Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, People's Republic of China. qindd05@gmail.com luxq@nwnu.edu.cn.
authors.forename: Xiao-Quan
authors.initials: XQ
authors.lastname: Lu
authors.affiliation: School of Physical Science and Technology, Lanzhou University, Lanzhou, Gansu 730000, People's Republic of China. taochl@lzu.edu.cn.
authors.forename: Chun-Lan
authors.initials: CL
authors.lastname: Tao