Peng Yusi, Cai Ping, Yang Lili, Liu Yingying, Zhu Linfeng, Zhang Qiuqi, Liu Jianjun, Huang Zhengren, Yang Yong
State Key Laboratory of High-Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050, People's Republic of China.
Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Omega. 2020 Oct 9;5(41):26486-26496. doi: 10.1021/acsomega.0c03009. eCollection 2020 Oct 20.
Recent advances in MXenes with high carrier mobility show great application prospects in the surface-enhanced Raman scattering (SERS) field. However, challenges remain regarding the improvement of the SERS sensitivity. Herein, an effective strategy considering charge-transfer resonance for semiconductor-based substrates is presented to optimize the SERS sensitivity with the guidance of the density functional theory calculation. The theoretical calculation predicted that the excellent SERS enhancement for methylene blue (MeB) on TiC MXene can be excited by both 633 and 785 nm lasers, and the Raman enhanced effect is mainly originated from the charge-transfer resonance enhancement. In this work, the TiC MXenes exhibit an excellent SERS sensitivity with an enhancement factor of 2.9 × 10 and a low detection limit of 10 M for MeB molecules. Furthermore, the SERS enhancement of TiC and Au-TiC substrates exhibit higher selectivity on different molecules, which contributes to the detection of target molecules in complex solution environments. This work can provide some theoretical and experimental basis for the research on SERS activity of other MXene materials.
具有高载流子迁移率的MXenes材料的最新进展在表面增强拉曼散射（SERS）领域展现出巨大的应用前景。然而，在提高SERS灵敏度方面仍存在挑战。在此，提出了一种基于电荷转移共振的半导体基衬底有效策略，以在密度泛函理论计算的指导下优化SERS灵敏度。理论计算预测，633和785 nm激光均可激发TiC MXene上亚甲基蓝（MeB）出色的SERS增强效果，且拉曼增强效应主要源于电荷转移共振增强。在这项工作中，TiC MXenes对MeB分子表现出出色的SERS灵敏度，增强因子为2.9×10，检测限低至10 M。此外，TiC和Au-TiC衬底的SERS增强对不同分子表现出更高的选择性，这有助于在复杂溶液环境中检测目标分子。这项工作可为其他MXene材料的SERS活性研究提供一些理论和实验依据。
