ZrO2 bubbles from core-shell nanoparticles

Selective removal of metal cores from core-shell Ag@ZrO2 (ZrO2 coated Ag) and Au@ZrO2 (ZrO2 coated Au) nanoparticles result in stable and freely suspendable oxide nanobubbles of varying dimensions, both in thickness and in diameter. The metal core is removed by a newly found reaction in which halocarbons, generally chlorides, oxidise the metal core and leach out the metal ions. Reduction in the surface plasmon excitation intensity and decrease in the voltammetric current during metal core removal were used to study the process.