Title: X-ray and neutron scattering study of the formation of core–shell-type polyoxometalates

Abstract

A typical type of core-shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo₇₂Fe₃₀}. Small angle X-ray scattering is used to study the structural features and stability of the core-shell structures in aqueous solutions. Time-resolved small angle X-ray scattering is applied to monitor the synthetic reactions and a three-stage formation mechanism is proposed to describe the synthesis of the core-shell polyoxometalates based on the monitoring results. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core-shell structures and two different types of water molecules, the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures. A typical type of core shell polyoxometalates can be obtained through the Keggin-type polyoxometalate-templated growth of a layer of spherical shell structure of {Mo₇₂Fe₃₀}. Small-angle X-ray scattering is used to study the structural features and stability of the core shell structures in aqueous solutions. Time-resolved small-angle X-ray scattering is applied to monitor the synthetic reactions, and a three-stage formation mechanism is proposed to describe the synthesis of the core shell polyoxometalates based on the monitoringmore » results. New protocols have been developed by fitting the X-ray data with custom physical models, which provide more convincing, objective, and completed data interpretation. Quasi-elastic and inelastic neutron scattering are used to probe the dynamics of water molecules in the core shell structures, and two different types of water molecules, the confined and structured water, are observed. These water molecules play an important role in bridging core and shell structures and stabilizing the cluster structures.« less

Authors:

Yin, Panchao ^[1]; Wu, Bin ^[2]; Mamontov, Eugene ^[1]; Daemen, Luke L. ^[1]; Cheng, Yongqiang ^[1]; Li, Tao ^[3]; Seifert, Soenke ^[3]; Hong, Kunlun ^[1]; Bonnesen, Peter V. ^[1]; Keum, Jong Kahk ^[1]; Ramirez-Cuesta, Anibal J. ^[1]

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+ Show Author Affiliations

1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Univ. of Tennessee, Knoxville, TN (United States)
3. Argonne National Lab. (ANL), Argonne, IL (United States)

Publication Date:

Fri Feb 05 00:00:00 EST 2016

Research Org.:

Argonne National Laboratory (ANL), Argonne, IL (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1340274

Alternate Identifier(s):

OSTI ID: 1240563

Grant/Contract Number:  

AC02-06CH11357; AC05-00OR22725; DE-AC02- 06CH11357

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the American Chemical Society

Additional Journal Information:

Journal Volume: 138; Journal Issue: 8; Journal ID: ISSN 0002-7863

Publisher:

American Chemical Society (ACS)

Country of Publication:

United States

Language:

English

Subject:

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE