TY - JOUR
T1 - Engineering disorder at a nanoscale: a combined TEM and XAS investigation of amorphous versus nanocrystalline sodium birnessite
AU - Hocking, Rosalie Katherine
AU - King, Hannah J
AU - Hesson, Aimee
AU - Bonke, Shannon
AU - Johannessen, Bernt
AU - Fekete, Monika
AU - Spiccia, Leone
AU - Chang, Lan-Yun Shery
PY - 2015
Y1 - 2015
N2 - The term amorphous metal oxide is becoming widely used in the catalysis community. The term is generally used when there are no apparent peaks in an X-ray diffraction pattern. However, the absence of such features in X-ray diffraction can mean that the material is either truly amorphous or that it is better described as nanocrystalline. By coprecipitating a sodium birnessite-like phase with and without phosphate (1.5%), we are able to engineer two very similar but distinct materials - one that is nanocrystalline and the other that is amorphous. The two closely related phases were characterized with both Mn K-edge X-ray absorption spectroscopy and high-resolution transmission electron microscopy. These structural results were then correlated with catalytic and electrocatalytic activities for water oxidation catalysis. In this case, the amorphous phosphate-doped material was less catalytically active than the nanocrystalline material
AB - The term amorphous metal oxide is becoming widely used in the catalysis community. The term is generally used when there are no apparent peaks in an X-ray diffraction pattern. However, the absence of such features in X-ray diffraction can mean that the material is either truly amorphous or that it is better described as nanocrystalline. By coprecipitating a sodium birnessite-like phase with and without phosphate (1.5%), we are able to engineer two very similar but distinct materials - one that is nanocrystalline and the other that is amorphous. The two closely related phases were characterized with both Mn K-edge X-ray absorption spectroscopy and high-resolution transmission electron microscopy. These structural results were then correlated with catalytic and electrocatalytic activities for water oxidation catalysis. In this case, the amorphous phosphate-doped material was less catalytically active than the nanocrystalline material
UR - http://www.publish.csiro.au/?act=view_file&file_id=CH15412.pdf
U2 - 10.1071/CH15412
DO - 10.1071/CH15412
M3 - Article
VL - 68
SP - 1715
EP - 1722
JO - Australian Journal of Chemistry
JF - Australian Journal of Chemistry
SN - 0004-9425
IS - 11
ER -