Influence of Structural Defects on Biomineralized ZnS Nanoparticle

United States. Environ. Sci. Technol. , 2018, 52 (3), pp 1139–1149. DOI: 10.1021/acs.est.7b04343. Publication Date (Web): December 19, 2017. Cop...
0 downloads 10 Views 4MB Size
Subscriber access provided by READING UNIV

Article

Influence of Structural Defects on Biomineralized ZnS Nanoparticle Dissolution: An In-Situ Electron Microscopy Study Jeremy R. Eskelsen, Jie Xu, Michelle Y. Chiu, Ji-Won Moon, Branford O Wilkins, David E Graham, Baohua Gu, and Eric M. Pierce Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b04343 • Publication Date (Web): 19 Dec 2017 Downloaded from http://pubs.acs.org on December 22, 2017

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 31

Environmental Science & Technology

3

Influence of Structural Defects on Biomineralized ZnS Nanoparticle Dissolution: An In-Situ Electron Microscopy Study

4 5

Jeremy R. Eskelsena, Jie Xub, Michelle Chiua, Ji-Won Moonc, Branford Wilkinsa, David E. Grahamc, Baohua Gua, Eric M. Piercea‡*

1 2

6 7 8 9 10 11

a

Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, MS 6038, Oak Ridge, TN 37831 b

Geological Sciences, University of Texas at El Paso, 500 West University Ave, El Paso, TX 79968 c

Biosciences Division, Oak Ridge National Laboratory, P.O. Box 2008, MS 6038, Oak Ridge, TN 37831

12

13 14

KEYWORDS1: liquid cell electron microscopy, metal sulfides, nanoparticles, dissolution, structural defect, sphalerite, zinc blende, wurtzite.

15 16

*

Corresponding Author: Eric M. Pierce

17

Phone: (865) 574-9968

18

Fax: (865) 576-8646

19

Email: [email protected]

20

21

1

This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-publicaccess-plan).

1

ACS Paragon Plus Environment

Environmental Science & Technology

22

ABSTRACT: The dissolution of metal sulfides, such as ZnS, is an important biogeochemical

23

process affecting fate and transport of trace metals in the environment. However, currently

24

studies of in-situ dissolution of metal sulfides and the effects of structural defects on dissolution

25

are lacking. Here we have examined the dissolution behavior of ZnS nanoparticles synthesized

26

via several abiotic and biological pathways. Specifically, the biogenic ZnS nanoparticles were

27

produced by an anaerobic, metal-reducing bacterium Thermoanaerobacter sp. X513 in a Zn-

28

amended, thiosulfate-containing growth medium either in the presence or absence of silver (Ag),

29

whereas the abiogenic ZnS nanoparticles were produced by mixing an aqueous Zn solution with

30

either H2S-rich gas or Na2S solution. The size distribution, crystal structure, aggregation

31

behavior, and internal defects of the synthesized ZnS nanoparticles were examined using high-

32

resolution transmission electron microscopy (TEM) coupled with X-ray energy dispersive

33

spectroscopy. The characterization results show that both the biogenic and abiogenic samples

34

were dominantly composed of sphalerite. In the absence of Ag, the biogenic ZnS nanoparticles

35

were significantly larger (i.e., ~10 nm) than the abiogenic ones (i.e., ~3–5 nm) and contained

36

structural defects (e.g., twins and stacking faults). The presence of trace Ag showed a restraining

37

effect on the particle size of the biogenic ZnS, resulting in quantum-dot-sized nanoparticles (i.e.,

38

~3 nm). In situ dissolution experiments for the synthesized ZnS were conducted with a liquid-

39

cell TEM (LCTEM), and the primary factors (i.e., the presence or absence structural defects)

40

were evaluated for their effects on the dissolution behavior using the biogenic and abiogenic ZnS

41

nanoparticle samples with the largest average particle size. Analysis of the dissolution results

42

(i.e., change in particle radius with time) using the Kelvin equation shows that the defect-bearing

43

biogenic ZnS nanoparticles (γ = 0.799 J/m2) have a significantly higher surface energy than the

44

abiogenic ZnS nanoparticles (γ = 0.277 J/m2). Larger defect-bearing biogenic ZnS nanoparticles 2

ACS Paragon Plus Environment

Page 2 of 31

Page 3 of 31

Environmental Science & Technology

45

were thus more reactive than the smaller quantum-dot-sized ZnS nanoparticles. These findings

46

provide new insight into the factors that affect the dissolution of metal sulfide nanoparticles in

47

relevant natural and engineered scenarios, and have important implications for tracking the fate

48

and transport of sulfide nanoparticles and associated metal ions in the environment. Moreover,

49

our study exemplified the use of an in-situ method (i.e., LCTEM) to investigate nanoparticle

50

behavior (e.g., dissolution) in aqueous solutions.

51 52

INTRODUCTION Solid–fluid interfacial reactions that govern the formation of fine-grained nanoparticulate

53

metal sulfides have relevance to a range of areas with energy and industrial applications (e.g.,

54

sedimentary sulfide ore deposit formation, geochemical cycling of elements in the earth’s crust,

55

contaminated site remediation, and semiconductor research).1,

56

perspective, the influence that the formation of fine-grained metal sulfides can have on the

57

world’s aquatic resources and the geochemical cycling of elements cannot be overstated. For

58

example, the bioavailability and transport of metals ions (e.g., Fe, Zn, and Hg) in anoxic

59

environments—such as marine ecosystems near hydrothermal vents, stream biofilms, acid mine

60

drainage, and the pores of anaerobic sediments—is directly controlled by the production of

61

sulfides by sulfate-reducing bacteria.3-9 Sulfate-reducing bacteria are ubiquitous in natural

62

systems, where they obtain electrons by oxidizing organic carbon compounds to reduce sulfate to

63

sulfide, which is the dominant process for sulfide production in low-temperature (