Zinc oxide porous nano-cages fabricated by laser ablation of Zn in ammonium hydroxide.

Abstract

We report the successful synthesis of ZnO porous nano-cages with controllable hollow spaces by simply using laser ablation of Zn target in liquid medium containing deionized water and ammonia (V(water):V(ammonia) = 7:1~5:1). In addition to the porous surface, the created interior space of the ZnO nano-cage substantially increases with the ammonia concentration. The related growth mechanism has been illustrated based on the ultra-rapid alkaline etching process. Moreover, numerous Zn(NH3)(4)(2+) clusters generated by the selective etching route readily penetrate into the ZnO porous structures and can be embedded in these unique nano-cages. It is envisaged that these composite ions/ ZnO porous nano-cages have significant implications for gas sensing and catalytic applications. The synthetic scheme used here should also be applicable to other semiconductors.