Scientists are developing ever-more effective methods to fabricate nanocatalysts with controlled size and morphology. However, many of these methods rely on the use of organic compounds during the synthesis, and it is known that the presence of these organics on the surface of the nanoparticles may block their active sites, drastically diminishing their activity in catalytic processes.

A new and simple chemical procedure for cleaning Pt nanoparticles without affecting their size, shape or structure is presented by P. Rodriguez and colleagues of Leiden University, The Netherlands. The team mixed a suspension of nanoparticles with H₂O₂/H₂SO₄ and found that H₂O₂ reacts on the surface of the nanoparticles, generating oxygen bubbles that physically remove the organic contaminant from the surface without affecting its properties.

According to the authors, conventional thermal and oxidative cleaning protocols typically lead to significant changes in the size and surface orientation of the nanoparticles. While other chemical approaches have been reported before, “those chemical cleaning procedures are specific for each of the organic components used in the nanoparticle synthesis”, Rodriguez says.

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• Removing Polyvinylpyrrolidone from Catalytic Pt Nanoparticles without Modification of Superficial Order,
  J. Monzó, M. T. M. Koper, P. Rodriguez,
  ChemPhysChem 2012, 13.
  DOI: 10.1002/cphc.201100894