In the organic systems, the interaction of organic molecules with molecular oxygen (O2)is essentially limited by the spin state of O2.  Thus the excitation of inert ground triplet O2to highly reactive singlet O2 is a key step of O2 activation in many organic reactions. Although it has been discovered that singlet O2 can be formed on noble metal nanoparticles, it remains elusive what factor induces the change of electron spin state on the surface of metal nanoparticles.  In this presentation, we first employ single-facet Pd nanocrystals as a model system to demonstrate that surface facet is a key parameter to determine the O2 activation process on metal nanocrystals.  With the capability of tuning O2 activation, we have been able to further implement the {100}-faceted nanocubes in the oxidation of organic molecules.  It is anticipated that this study will open a door to designing noble metal nanocatalysts for oxygen activation and organic oxidation.  Another perspective of this work would be the controllability in tailoring the cancer photodynamic therapy (PDT) materials based on the facet control of metal nanocrystals.

Facet control of Pd nanocrystals: A key parameter to the activation of molecular oxygen

245th National Meeting (2013)

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