Depositing CdS nanoclusters on carbon-modified NaYF4:Yb,Tm upconversion nanocrystals for NIR-light enhanced photocatalysis
Depositing CdS nanoclusters on carbon-modified NaYF4:Yb,Tm upconversion nanocrystals for NIR-light enhanced photocatalysis
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在碳改性 NaYF4:Yb,Tm 上转换纳米晶体上沉积 CdS 纳米团簇用于近红外光增强光催化
DOI：
10.1039/c5nr06806a
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发表时间：
2016-01-01
期刊：
影响因子：
6.7
通讯作者：
Li, Zhengquan
中科院分区：
文献类型：
--
作者：
Tou, Meijie;Mei, Yuanyuan;Li, Zhengquan
在有机溶液中制备的高质量六方NaYF 4：Yb，Tm上转换纳米晶体（UCN）具有均匀的尺寸和强的UC发射，但它们具有疏水表面，这阻碍了它们与各种半导体纳米晶体（NC）结合形成混合NIR激活的光催化剂。在此，我们提出了一种简单的方法来修饰疏水性UCN与均匀的碳层，使它们具有亲水性和表面功能化。碳壳提供了一个很好的基板富集金属离子和原位生成的CdS纳米团簇的颗粒表面上，可以利用上转换的紫外和可见光发射。利用TEM、SEM、XRD、PL和UV-Vis等手段对所制备的NaYF 4：Yb，Tm@C@CdS纳米粒子进行了表征，并对其形成机理进行了探讨。产物在可见光下表现出良好的光催化活性，在可见-近红外光下表现出明显的增强性能，这是由于碳壳对UC排放物的有效利用和较强的吸附能力。并对复合光催化剂的作用机理进行了探讨。
High-quality hexagonal NaYF4:Yb,Tm upconversion nanocrystals (UCNs) prepared in organic solutions display uniform sizes and strong UC emissions, but they possess a hydrophobic surface which hinders combining them with various semiconductor nanocrystals (NCs) to form a hybrid NIR-activated photocatalyst. Herein we present a facile approach to modify hydrophobic UCNs with a uniform carbon layer and enable them with hydrophilicity and surface functionalization. The carbon shell provides a good substrate for enriching with metal ions and in situ generation of CdS nanoclusters on the particle surface which can utilize both the upconverted UV and visible emissions. The developed NaYF4:Yb,Tm@C@CdS nanoparticles are characterized with TEM, SEM, XRD, PL and UV-Vis spectra and their formation mechanism is elucidated. The products display good photocatalytic activity under visible light and obviously enhanced performance under Vis-NIR light, due to the efficient utilization of UC emissions and the strong adsorption capacity of the carbon shell. The working mechanism of the hybrid photocatalysts is also proposed.