Phosphate Adsorption on Cerium Oxide Surfaces

  • Khoa Ta (Speaker)
  • Samuel Moxon (Contributor to Paper or Presentation)
  • Phillips, R. (Contributor to Paper or Presentation)
  • Cooke, D. (Contributor to Paper or Presentation)
  • Molinari, M. (Contributor to Paper or Presentation)

Activity: Talk or presentation typesPoster presentation

Description

Cerium oxide nanoparticles (CeNPs) are promising candidates as nanozymes. CeNPs mimic enzymatic activities such as superoxide dismutase, catalase, phosphatase etc. However, the enzyme mimetic activities of CNPs are highly variable with many reactions able to occur simultaneously. It is therefore imperative that we investigate how to control such activities, especially for use in biomedicine. Surface composition and charge (e.g. CeIV/CeIII ratio) appear to be a key factor to control reactivity, in addition to shape and size. Whilst phosphates interact strongly with CeNPs, phosphate bearing molecules interact selectively. CeNPs may also be scavenged by phosphates and convert to cerium phosphate. The strength of interaction between phosphates and the {111}, {110}, and {100} surfaces of CeNPs is investigated using Density Functional Theory. It is found that the {100} surface forms strong bonds with phosphate species that can even displace surface atoms. The surface free energy is calculated as a function of phosphate concentration and temperature. This allow us to map the surface composition of CeNPs surfaces. Our results may indicate that CeNPs with an octahedral shape are better suited in protecting the nanoparticle shape, whereas CeNPs with a cuboidal shape are scavenged despite having higher catalytic activity.
Period7 Sep 2022
Event titleCCP5 Annual General Meeting 2022, 42th edition
Event typeConference
Conference number42
LocationHuddersfield, United Kingdom
Degree of RecognitionInternational