In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy

Handle URI:
http://hdl.handle.net/10754/626002
Title:
In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy
Authors:
LAGROW, A.P. ( 0000-0002-3306-6458 ) ; AlYami, Noktan; LLOYD, D.C.; Bakr, Osman M. ( 0000-0002-3428-1002 ) ; BOYES, E.D.; GAI, P.L. ( 0000-0003-3837-7148 )
Abstract:
Understanding the oxidation and reduction mechanisms of transition metals, such as nickel (Ni), is important for their use in industrial applications of catalysis. A powerful technique for investigating the redox reactive species is in situ environmental transmission electron microscopy (ETEM), where oxidation and reduction can be tracked in real time. One particular difficulty in understanding the underlying reactions is understanding the underlying morphology of the starting structure in a reaction, in particular the defects contained in the material, and the exposed surface facets. Here-in, we use a colloidal nanoparticle synthesis in a continuous flow reactor to form nanoplates of nickel coated with oleylamine as a capping agent. We utilise an in situ heating procedure at 300 °C in vacuum to remove the oleylamine ligands, and then oxidise the Ni nanoparticles at 25 °C with 2 Pa oxygen, and follow the nanoparticles initial oxidation. After that, the nanoparticles are oxidised at 200 and 300 °C, making the size of the oxide shell increase to ∼4 nm. The oxide shell could be reduced under 2 Pa hydrogen at 500 °C to its initial size of ∼1 nm. High temperature oxidation encouraged the nanoparticles to form pure NiO nanoparticles, which occurred via the Kirkendall effect leading to hollowing and void formation.
KAUST Department:
Physical Sciences and Engineering (PSE) Division
Citation:
LAGROW AP, ALYAMI NM, LLOYD DC, BAKR OM, BOYES ED, et al. (2017) In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy. Journal of Microscopy. Available: http://dx.doi.org/10.1111/jmi.12621.
Publisher:
Wiley-Blackwell
Journal:
Journal of Microscopy
Issue Date:
29-Aug-2017
DOI:
10.1111/jmi.12621
Type:
Article
ISSN:
0022-2720
Sponsors:
P.L.G. and E.D.B. thank the EPSRC (UK) for a critical mass Grant EP/J0118058/1, a postdoctoral research assistantship (PDRA) for A.P.L., and a PhD CASE studentship in association with Johnson Matthey plc, for D.C.L. We thank Ian Wright for expert technical assistance.
Additional Links:
http://onlinelibrary.wiley.com/doi/10.1111/jmi.12621/abstract
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorLAGROW, A.P.en
dc.contributor.authorAlYami, Noktanen
dc.contributor.authorLLOYD, D.C.en
dc.contributor.authorBakr, Osman M.en
dc.contributor.authorBOYES, E.D.en
dc.contributor.authorGAI, P.L.en
dc.date.accessioned2017-10-30T08:39:49Z-
dc.date.available2017-10-30T08:39:49Z-
dc.date.issued2017-08-29en
dc.identifier.citationLAGROW AP, ALYAMI NM, LLOYD DC, BAKR OM, BOYES ED, et al. (2017) In situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopy. Journal of Microscopy. Available: http://dx.doi.org/10.1111/jmi.12621.en
dc.identifier.issn0022-2720en
dc.identifier.doi10.1111/jmi.12621en
dc.identifier.urihttp://hdl.handle.net/10754/626002-
dc.description.abstractUnderstanding the oxidation and reduction mechanisms of transition metals, such as nickel (Ni), is important for their use in industrial applications of catalysis. A powerful technique for investigating the redox reactive species is in situ environmental transmission electron microscopy (ETEM), where oxidation and reduction can be tracked in real time. One particular difficulty in understanding the underlying reactions is understanding the underlying morphology of the starting structure in a reaction, in particular the defects contained in the material, and the exposed surface facets. Here-in, we use a colloidal nanoparticle synthesis in a continuous flow reactor to form nanoplates of nickel coated with oleylamine as a capping agent. We utilise an in situ heating procedure at 300 °C in vacuum to remove the oleylamine ligands, and then oxidise the Ni nanoparticles at 25 °C with 2 Pa oxygen, and follow the nanoparticles initial oxidation. After that, the nanoparticles are oxidised at 200 and 300 °C, making the size of the oxide shell increase to ∼4 nm. The oxide shell could be reduced under 2 Pa hydrogen at 500 °C to its initial size of ∼1 nm. High temperature oxidation encouraged the nanoparticles to form pure NiO nanoparticles, which occurred via the Kirkendall effect leading to hollowing and void formation.en
dc.description.sponsorshipP.L.G. and E.D.B. thank the EPSRC (UK) for a critical mass Grant EP/J0118058/1, a postdoctoral research assistantship (PDRA) for A.P.L., and a PhD CASE studentship in association with Johnson Matthey plc, for D.C.L. We thank Ian Wright for expert technical assistance.en
dc.publisherWiley-Blackwellen
dc.relation.urlhttp://onlinelibrary.wiley.com/doi/10.1111/jmi.12621/abstracten
dc.titleIn situ oxidation and reduction of triangular nickel nanoplates via environmental transmission electron microscopyen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalJournal of Microscopyen
dc.contributor.institutionDepartment of Physics; University of York; York U.K.en
dc.contributor.institutionThe York Nanocentre; University of York; York U.K.en
dc.contributor.institutionDepartment of Electronics; University of York; York U.K.en
dc.contributor.institutionDepartment of Chemistry; University of York; York U.K.en
kaust.authorAlYami, Noktanen
kaust.authorBakr, Osman M.en
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