标题: Facet-preferential reduction of hematite nanocrystals by Shewanella oneidensis MR-1: An iron isotope tracer study

作者: Hua, J (Hua, Jian); Feng, CH (Feng, Chunhua); Sun, J (Sun, Jing); Wu, F (Wu, Fei); Wu, F (Wu, Feng); Liu, CS (Liu, Chengshuai)

来源出版物: CHEMICAL GEOLOGY 卷: 614 文献号: 121166 DOI: 10.1016/j.chemgeo.2022.121166 出版年: DEC 30 2022

摘要: Coexistence of crystals with multiple facets on an individual particle or different crystals is prevalent in real environments. However, the reduction efficiency of individual crystal facets in facet-combined system is still enigmatic. This study aimed to determine the reduction efficiencies of different facets of hematite by Shewanella oneidensis MR-1. An iron isotope tracer was used to distinguish Fe(II) produced from reduction of the combined and separate hematite {001} and {100} facets, i.e., Hem {001} nanoplates and Hem {100} nanorods. Hem {001} nanoplates was reduced 1.8 times more significantly than Hem {100} nanorods when the two facets combined, whereas Hem {001} nanoplates was reduced only 1.2 times more significantly than Hem {100} nanorods in separate reactors. Initial - 72% and final - 63% of reduced atoms from Hem {001} nanoplate demonstrated the facet-preferential reduction of hematite crystal when the facets combined. The pseudo-first-order rate constants (k) of reduced Fe(II) for Hem {001} nanoplates and {100} nanorods were 3.2 and 2.0 x 10-2 d-1, respectively. We attributed the more efficient reduction of Hem {001} nanoplates than Hem {100} nanorods to their differences in surface hydroxyl groups, surface charges, ligand-bound conformation and steric effects. These findings provide new insights into microbe-mineral interaction based on the crystal facet and the overall role of Fe oxides nanocrystals in the environments.

作者关键词: Microbially mediated reduction; Facet-combined environment; Hematite crystal facet; 57Fe-Mo?ssbauer spectrum; Fe isotope tracer

地址: [Hua, Jian; Wu, Feng] Wuhan Univ, Sch Resources & Environm Sci, Wuhan, Peoples R China.

[Hua, Jian; Liu, Chengshuai] Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China.

[Hua, Jian; Liu, Chengshuai] Guangdong Acad Sci, Inst Eco Environm & Soil Sci, Natl Reg Joint Engn Res Ctr Soil Pollut Control &, Guangdong Key Lab Integrated Agroenvironm Pollut C, Guangzhou 510650, Peoples R China.

[Feng, Chunhua] South China Univ Technol, Sch Environm & Energy, Guangzhou 510006, Peoples R China.

通讯作者地址: Wu, F (通讯作者)，Wuhan Univ, Sch Resources & Environm Sci, Wuhan, Peoples R China.

Liu, CS (通讯作者)，Chinese Acad Sci, Inst Geochem, State Key Lab Environm Geochem, Guiyang 550081, Peoples R China.

电子邮件地址: fengwu@whu.edu.cn; liuchengshui@vip.gyig.ac.cn

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