Colloidal nanocrystals can offer exquisite control of physical and chemical properties for technological applications by tuning their sizes, shapes and crystal forms. Herein, a convenient phase-transfer route was presented to controllably prepare transparent dispersions of monodispersed ZrO₂ nanocrystals in an aqueous-organic two-phase medium. By adjusting the surfactants, solvents and basicity, the controllability of crystal forms from monoclinic to tetragonal phases, the particle length from 5 to 20 nm, and the different shapes including spindle, cobblestone, sphere, branch, rod and cube can be achieved. The as-prepared ZrO₂ nanocrystals can be readily dispersed in nonpolar solvents, thereby forming the ultra-highly concentrated (60 wt.%), highly stable (>18 months) and highly transparent nanodispersions. Density functional theory (DFT) calculations were further used to elucidate the root causes of underpinning growth mechanisms. This work not merely enriches the methodology of controllable fabrication of monodispersed sub-10 nm ZrO₂ nanocrystals, but also enables a platform to synthesize rare-earth-doped nanophosphors using ZrO₂ as the host matrix. The fluorescent ZrO₂:Yb³⁺/Er³⁺ nanocrystals, which can be easily monodispersed in organic solvents, were also prepared with visible luminescene properties under near-infrared irradiation.

胶体纳米晶体可以通过调节其尺寸，形状和晶形，为技术应用提供对物理和化学性质的精确控制。在本文中，提出了一种方便的相转移途径，以可控制地制备在水-有机两相介质中单分散的ZrO ₂纳米晶体的透明分散体。通过调节表面活性剂，溶剂和碱度，可以实现从单斜晶相到四方晶相的晶形可控性，5-20 nm的颗粒长度以及包括纺锤形，鹅卵石形，球形，分支形，棒形和立方体形的各种形状。准备好的ZrO ₂纳米晶体可以容易地分散在非极性溶剂中，从而形成超高浓缩（60 wt。％），高度稳定（> 18个月）和高度透明的纳米分散体。密度泛函理论（DFT）计算被进一步用于阐明支撑增长机制的根本原因。这项工作不仅丰富了可控制地制备10nm以下ZrO ₂单分散纳米晶体的方法，而且还使平台能够使用ZrO ₂作为基质来掺杂稀土掺杂的纳米磷光体。荧光ZrO ₂：Yb ³⁺ / Er ³⁺ 在近红外光照射下，还制备了具有可见光荧光性能的纳米晶体，该晶体很容易单分散在有机溶剂中。