TiO_2/Ag@CDs的构筑及其SERS研究

Facile Systhesis of TiO_2/Ag@CDs for Surface-Enhanced Raman Scattering

碳点(CDs),尺寸在1~10nm,由于其独特的结构和光学性质,以及良好的生物相容性,在太阳能电池、有机污染物的降解和检测,光学染料、生物标记方面有着广泛的应用^([1])。TiO_2作为一种半导体材料,其粒子具有表面效应,量子尺寸效应,宏观量子隧道效应,催化等性质,可作为SERS基底。本文利用水热法成功制得粒径为2~6nm的发蓝光的CDs^([2]),然后在水浴下直接与TiO_2纤维和AgNO_3反应,形成在TiO_2表面包覆核壳结构的Ag@CDs纳米粒子复合物,TiO_2纤维长度和宽度不一,Ag@CDs平均尺寸在15nm左右,然后以TiO_2/Ag@CDs为SERS基底,PATP为探针分子,探究了其SERS性能,发现其检测的最低浓度可达到10^(-9) mol·L^(-1),具有良好的SERS增强能力。我们还分别研究了TiO_2/Ag@CDs的催化能力,用SERS监测了分子的变化过程,发现具有优良的催化性质,促进了CDs在SERS领域的应用。

Carbon dots（CDs）,whose size is smaller than 10 nm,owing to exceptional advantages such as high optical absorptivity,chemical stability,biocompatibility,and low toxicity,make them promising candidates for numerous exciting applications,such as bioimaging,medical diagnosis,catalysis,and photovoltaic devices.TiO2 as a semiconductor material,which has surface effect,quantum size effect,macroscopic quantum tunneling effect catalytic ability and other properties,and can be used as SERS substrate.The CDs was prepared via a hydrothermal process.The core-shell TiO2/Ag@CDs NPs was fabricated by heating the mixed solution of CDs,AgNO3 and TiO2 nanofiber.The TiO2 nanofiber has different size,the Ag@CDs NPs are 15 nm.The TiO2/Ag@CDs NPs as SERS substrate,the PATP as probe molecules,which show a detection concentration as low as 10-9 mol·L-1.We also investigated the TiO2/Ag@CDs catalytic ability,and we found that they have superior catalytic activity.This would make it possible to widen the application of CDs in SERS and catalytic reactions.