Issue 9, 2020

Facet-dependent reductive dissolution of hematite nanoparticles by Shewanella putrefaciens CN-32

Abstract

Dissimilatory iron-reducing processes can be influenced by the physicochemical properties of iron (Fe) oxides; however, little is known about the effect of the exposed facets of these oxides on the reductive dissolution process. In this work, kinetic studies showed that the reduction rate of hematite {001} by Shewanella putrefaciens CN-32 was faster than that of hematite {100}. XRD, HR-TEM, electrochemistry, and time-resolved ATR-FTIR spectroscopy combined with 2D-COS were used to investigate the interaction of CN-32 and different facets of hematite. Results showed that hematite {001} exhibited higher conductivity and lower resistance than hematite {100}, and therefore hematite {001} was more favorable for Fe bioreduction. This result was additionally supported by the higher current density observed in the DPV and Tafel results. The number of surface hydroxyl groups and the bacterial adsorption capacity of hematite {001} were both higher than the counterpart values of hematite {100}, and the redox potential of hematite {001} was more positive than that of hematite {100}. Hence, the more surface reaction sites and stronger oxidizing surface of hematite {001} accounted for higher iron reduction rates. During the biotransformation process, the produced Fe(II) was mainly distributed in the solution and adsorbed onto the Fe oxides. The adhesion amount of CN-32 on hematite {001} was higher than that on hematite {100}. Phosphorus functional groups play an important role in the adhesion of CN-32 on the facet-dependent hematite nanoparticles, and hematite {001} with its positive charges exhibited a stronger affinity to the CN-32 cell surfaces than hematite {100} with negative charges. Furthermore, the adhesion sequence of the bacterial functional groups on the hematite nanoparticles was influenced by the exposed facets of Fe oxides. This study advanced our understanding of the underlying mechanism for the microbe–Fe mineral interaction at the molecular scale.

Graphical abstract: Facet-dependent reductive dissolution of hematite nanoparticles by Shewanella putrefaciens CN-32

Supplementary files

Article information

Article type
Paper
Submitted
26 মে 2020
Accepted
04 আগ. 2020
First published
05 আগ. 2020

Environ. Sci.: Nano, 2020,7, 2522-2531

Facet-dependent reductive dissolution of hematite nanoparticles by Shewanella putrefaciens CN-32

S. Hu, Y. Wu, Z. Ding, Z. Shi, F. Li and T. Liu, Environ. Sci.: Nano, 2020, 7, 2522 DOI: 10.1039/D0EN00555J

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements