As a new type of quantum dots (QDs), boron nitride QDs (BNQDs), show promising potentials in disease diagnosis, fluorescence imaging and bio-sensing due to its good biocompatibility, low cytotoxicity and excellent photoluminescence performance. However, there are still challenges in preparing BNQDs with uniform and small size. In this paper, the BNQDs with uniform and small size have been prepared through a hydrothermal process with the exfoliated hexagonal boron nitride nanosheets (h-BNNSs) as precursor. The as-prepared BNQDs were characterized by transmission electron microscope (TEM), high-resolution TEM, fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, UV-vis and photoluminescence spectra (PL) for morphology, surface functional groups, element composition and optical properties. The as-prepared BNQDs have uniform particle size distribution with an average lateral size of 1.65 nm, and a PL quantum yield of 2.49 %. In addition, the as-prepared BNQDs exhibit strong blue fluorescence under UV-vis (365 nm) irradiation and nanosecond luminescent decay. Furthermore, the effect of preparation parameters on the fluorescence performance of BNQDs was investigated which provides an optimal condition for the preparation of BNQDs with excellent fluorescence performance. Together with other advantages, such as excellent physical/chemical properties, good biocompatibility and low cytotoxicity, the as-prepared BNQDs have great potentials in medical diagnosis, biosensing, photoelectric devices and other fields in the future.

氮化硼量子点（BNQDs）作为一种新型的量子点（QDs），由于其良好的生物相容性，低细胞毒性和出色的光致发光性能，在疾病诊断，荧光成像和生物传感领域显示出广阔的前景。但是，在制备具有统一尺寸和小尺寸的BNQD时仍然存在挑战。在本文中，以脱落的六角形氮化硼纳米片（h -BNNSs）为前体，通过水热法制备了尺寸均匀且尺寸小的BNQD。通过透射电子显微镜（TEM），高分辨率TEM，傅立叶变换红外光谱，X射线光电子能谱，紫外可见光谱对制备的BNQD进行表征以及用于形态，表面官能团，元素组成和光学性质的光致发光光谱（PL）。所制备的BNQD具有均匀的粒径分布，平均横向尺寸为1.65nm，PL量子产率为2.49％。此外，所制备的BNQD在紫外可见光下显示出强蓝色荧光（365 nm）照射和纳秒级发光衰减。此外，研究了制备参数对BNQDs荧光性能的影响，为制备具有优异荧光性能的BNQDs提供了最佳条件。连同其他优点，例如出色的物理/化学性质，良好的生物相容性和低的细胞毒性，所制备的BNQD在未来的医学诊断，生物传感，光电设备和其他领域具有巨大的潜力。