Guangdong Provincial Engineering Technology Research Center for Optical Agriculture, College of Materials and Energy , South China Agricultural University , Guangzhou 510642 , China.
ACS Appl Mater Interfaces. 2019 Feb 13;11(6):6634-6643. doi: 10.1021/acsami.8b20138. Epub 2019 Jan 30.
UV absorbers are very effective in the fields of antiyellowing, resistance of photocatalytic degradation, and sunscreen cosmetics. However, commercialized UV absorbers have the drawbacks of toxicity, low absorption efficiency, transparency, etc. Here, we report for the first time silicon quantum dots as full-band UV absorbers. The NH-refunctionalized silicon quantum dots with high-performance UV absorption were successfully synthesized under the synergistic effect of sodium citrate and ethanediamine, and the (NH, OH)-functionalized silicon quantum dots (SiQDs) with full-band UV absorption can be achieved by reregulating -NH and -OH groups on the surface. The as-prepared (NH, OH)-functionalized SiQDs exhibited good stability and underwent treatment of varying pH and temperature. Furthermore, experimental results demonstrated that compared to commercial water-soluble organic UV absorbers, the (NH, OH)-functionalized SiQDs showed better antiyellowing performance for polyurethane and resistance of photocatalytic degradation for rhodamine B, and presented huge application potential in sunscreen cosmetics. Finally, the UV absorption mechanism of SiQDs was explained to be mainly related to Γ → Γ direct band gap transition, which absorb UV light and release it as thermal radiation.
紫外吸收剂在防黄变、光催化降解抗性和防晒化妆品等领域非常有效。然而，商业化的紫外吸收剂存在毒性、吸收效率低、透明度等缺点。在这里，我们首次报道了硅量子点作为全波段紫外吸收剂。在柠檬酸钠和乙二胺的协同作用下，成功合成了具有高性能紫外吸收的 NH 官能化硅量子点，通过重新调节表面上的-NH 和-OH 基团，可以实现全波段紫外吸收的(NH, OH)-官能化硅量子点(SiQDs)。所制备的(NH, OH)-官能化 SiQDs 表现出良好的稳定性，并经受了不同 pH 值和温度的处理。此外，实验结果表明，与商业水溶性有机紫外吸收剂相比，(NH, OH)-官能化 SiQDs 对聚氨酯具有更好的防黄变性能和对罗丹明 B 的光催化降解抗性，在防晒化妆品中具有巨大的应用潜力。最后，解释了 SiQDs 的紫外吸收机制主要与 Γ → Γ 直接带隙跃迁有关，它吸收紫外光并将其作为热辐射释放。
