title: Iron Oxide with Different Crystal Phases (α- and γ-Fe2O3) in Electroanalysis and Ultrasensitive and Selective Detection of Lead(II): An Advancing Approach Using XPS and EXAFS.
abstract: Iron oxide with different crystal phases (α- and γ-Fe2O3) has been applied to electrode coatings and been demonstrated to ultrasensitive and selective electrochemical sensing toward heavy metal ions (e.g., Pb(II)). A range of Pb(II) contents in micromoles (0.1 to 1.0 μM) at α-Fe2O3 nanoflowers with a sensitivity of 137.23 μA μM(-1) cm(-2) and nanomoles (from 0.1 to 1.0 nM) at γ-Fe2O3 nanoflowers with a sensitivity of 197.82 μA nM(-1) cm(-2) have been investigated. Furthermore, an extended X-ray absorption fine structure (EXAFS) technique was applied to characterize the difference of local structural environment of the adsorbed Pb(II) on the surface of α- and γ-Fe2O3. The results first showed that α- and γ-Fe2O3 had diverse interaction between Pb(II) and iron (hydro)oxides, which were consistent with the difference of electrochemical performance. Determining the responses of Cu(II) and Hg(II) as the most appropriate choice for comparison, the stripping voltammetric quantification of Pb(II) with high sensitivity and selectivity at γ-Fe2O3 nanoflower has been demonstrated. This work reveals that the stripping performances of a nanomodifier have to be directly connected with its intrinsic surface atom arrangement.
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.|Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Shan-Shan
authors.initials: SS
authors.lastname: Li
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.|Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Li
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.|Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Tian-Jia
authors.initials: TJ
authors.lastname: Jiang
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.|Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Zhong-Gang
authors.initials: ZG
authors.lastname: Liu
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Huai-Ping
authors.initials: HP
authors.lastname: Cong
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.
authors.forename: Jin-Huai
authors.initials: JH
authors.lastname: Liu
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201204, People's Republic of China.
authors.forename: Yu-Ying
authors.initials: YY
authors.lastname: Huang
authors.affiliation: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences , Shanghai 201204, People's Republic of China.
authors.forename: Li-Na
authors.initials: LN
authors.lastname: Li
authors.affiliation: Nanomaterials and Environmental Detection Laboratory, Institutes of Intelligent Machines, Chinese Academy of Sciences , Hefei 230031, People's Republic of China.|Department of Chemistry, University of Science and Technology of China , Hefei 230026, People's Republic of China.
authors.forename: Xing-Jiu
authors.initials: XJ
authors.lastname: Huang
mesh_terms: D003460:Crystallization; D055664:Electrochemical Techniques; D005290:Ferric Compounds / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D056951:Photoelectron Spectroscopy; D056928:X-Ray Absorption Spectroscopy
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide; D007854:Lead