Green preparation of novel heptafluo-zirconate/hafnate nanocrystals at ambient temperature

Abstract

The fabrication of polynary fluoride nanocrystals (NCs) at ambient temperature is a well-known challenge, since heating is generally required to produce crystallized nanomaterials. Herein we report a convenient solution-phase strategy, namely, a complex chemical route, for producing pure and doped heptafluo-zirconate/hafnate NCs under ambient conditions. The production of nanocrystals is highly dependent on the chelating agent, the feed ratio of oleic acid to Zr⁴⁺, and the feed ratio of F⁻ to Zr⁴⁺. The functionalization of these NCs by means of doping strategy was also achieved at ambient temperature. Down-shifting and up-converting fluorescence was realized in these zirconium/hafnium-based matrices. The proposed method for preparing Zr⁴⁺/Hf⁴⁺-containing fluorides is simple, efficient, cheap and easy to mass produce, which might open up a new way for the synthesis of polynary fluorides.