NANOMATERIALS

Watching metal nanoparticle exsolution

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Science  15 Nov 2019:
Vol. 366, Issue 6467, pp. 834-835
DOI: 10.1126/science.366.6467.834-d

3D model of a nickel nanoparticle grown under vacuum on perovskite

IMAGE: NEAGU ET AL., ACS NANO 10.1021/ACSNANO.9B05652 (2019)

Metal nanoparticles (NPs) grown from complex oxides through exsolution can be better anchored to their support in “sockets” than ones deposited on the surface. Neagu et al. followed the formation of nickel NPs from two perovskites, La0.43Ca0.37Ni0.06Ti0.94O3 and La0.8Ce0.1Ni0.4Ti0.6O3. An environmental transmission electron microscope enabled kinetics and structural studies of powder samples exposed to reducing gases [hydrogen (H2) and carbon monoxide (CO)] at high temperatures (650° to 1000°C). Different atmospheric conditions changed NP shape—exposure to H2 formed rounder NPs, NPs formed in vacuum were more faceted, and exposure to CO formed cubic NPs. NP growth was not monotonic but occurred in a stepwise manner, alternating between growth spurts and periods of quiescence.

ACS Nano 10.1021/acsnano.9b05652 (2019).

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