Qiu Yi, Wen Zhuoqi, Mei Shiliang, Wei Jinxin, Chen Yuanyuan, Hu Zhe, Cui Zhongjie, Zhang Wanlu, Xie Fengxian, Guo Ruiqian
Institute for Electric Light Sources, School of Information Science and Technology, Fudan University, Shanghai 200433, China.
Institute of Future Lighting, Academy for Engineering and Technology, Fudan University, Shanghai 200433, China.
Nanomaterials (Basel). 2021 Dec 12;11(12):3371. doi: 10.3390/nano11123371.
Luminescent copper nanoclusters (Cu NCs) have shown great potential in light-emitting devices (LEDs), chemical sensing, catalysis and biological fields. However, their practical use has been restricted by poor stability, and study on the stability of Cu NCs solid powder along with the mechanism is absent. In this study, stablized Cu NCs powder was first obtained by cation crosslinking method. Compared with the powder synthesized by solvent precipitation method, the stability of Cu NCs powder crosslinked by ionic inducer Ce was enhanced around 100-fold. The storage time when the fluorescence intensity decreased to 85% (T) was improved from 2 h to 216 h, which is the longest so far. The results of characterizations indicated that the aggregation structure was formed by the binding of Ce with the capping ligands of Cu NCs, which helped in obtaining Ce-Cu NCs powder from aggregate precipitation in solution. Furthermore, this compact structure could avoid the destruction of ambient moisture resulting in long-lasting fluorescence and almost unchanged physical form. This demonstrated that phosphor, with excellent characteristics of unsophisticated synthesis, easy preservation and stable fluorescence, showed great potential in light sources, display technology and especially in latent fingerprints visualization on different substrates for forensic science.
发光铜纳米团簇（Cu NCs）在发光器件（LED）、化学传感、催化及生物领域展现出了巨大潜力。然而，其实际应用因稳定性差而受到限制，且目前尚无关于Cu NCs固体粉末稳定性及其机理的研究。在本研究中，首次通过阳离子交联法获得了稳定的Cu NCs粉末。与溶剂沉淀法合成的粉末相比，经离子诱导剂Ce交联的Cu NCs粉末稳定性提高了约100倍。荧光强度降至85%时的储存时间（T）从2小时延长至216小时，这是目前最长的。表征结果表明，Ce与Cu NCs的封端配体结合形成了聚集结构，有助于从溶液中的聚集沉淀获得Ce-Cu NCs粉末。此外，这种致密结构可避免环境水分的破坏，从而实现持久荧光且物理形态几乎不变。这表明，该荧光粉具有合成简单、易于保存和荧光稳定等优异特性，在光源、显示技术尤其是法医学中不同基质上的潜在指纹可视化方面具有巨大潜力。
