Acta Chimica Sinica ›› 2023, Vol. 81 ›› Issue (7): 763-770.DOI: 10.6023/A23040128 Previous Articles     Next Articles



郑文山a, 高冠斌a,b,*(), 邓浩a, 孙涛垒b,*()   

  1. a 武汉理工大学 材料复合新技术国家重点实验室 武汉 430070
    b 武汉理工大学 化学化工与生命科学学院 神经退行性疾病纳米医药湖北省重点实验室 武汉 430070
  • 投稿日期:2023-04-11 发布日期:2023-05-11
  • 基金资助:
    国家自然科学基金(52273110); 国家自然科学基金(21975191); 湖北省自然科学基金(2021CFB299)

Room Temperature Synthesis and Near-infrared Fluorescence Performance Optimization of Ag2Se@Ag2S Core-shell Quantum Dots

Wenshan Zhenga, Guanbin Gaoa,b(), Hao Denga, Taolei Sunb()   

  1. a State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070
    b Hubei Key Laboratory of Nano Medicine for Neurodegenerative Diseases, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070
  • Received:2023-04-11 Published:2023-05-11
  • Contact: *E-mail:;
  • Supported by:
    National Natural Science Foundation of China(52273110); National Natural Science Foundation of China(21975191); Natural Science Foundation of Hubei Province(2021CFB299)

Ag2Se quantum dots (QDs) is a narrow band-gap (ca. 0.15 eV) nanomaterial, which exhibits great potential in near-infrared (NIR) fluorescence emission. However, the bad photoluminescence (PL) performance caused by defects in QDs has limited its application greatly. It is an effective way to improve the photoluminescence performance of Ag2Se QDs by growing a wide band gap inorganic shell to eliminate surface defects. For Ag2Se QDs, Ag2S is an ideal shell due to its wider bandgap (ca. 1 eV) and similar lattice constants (0.488 nm for cubic Ag2S and 0.499 nm for cubic Ag2Se). However, the precise preparation of Ag2Se@Ag2S core-shell QDs at room temperature remains a challenge. In this study, oil-soluble and water-soluble Ag2Se@Ag2S core-shell QDs were synthesized by colloidal atomic layer deposition (c-ALD) and one-pot aqueous phase synthesis at room temperature, respectively. The NIR fluorescence properties of water-soluble Ag2Se@Ag2S core-shell QDs were optimized by regulating ligand chain length. In c-ALD, the oil-soluble Ag2Se@Ag2S core-shell QDs were prepared with 1-dodecanethiol (DDT) coated Ag2Se QDs as seeds, oleamine (OAM) coordinated Ag (OAM-Ag) and Na2S as shell precursors, the resultant product showed no fluorescence emission. After high temperature annealing, the fluorescence emission of this oil-soluble Ag2Se@Ag2S core-shell QDs could not be recovered. Subsequently, water-soluble Ag2Se@Ag2S core-shell QDs with enhanced NIR fluorescence emission at 1270 nm were prepared by using mercaptocarboxylic (HS-(CH2)x-COOH) coordinated Ag2Se QDs as seeds, (HS-(CH2)x-COOH) coordinated Ag and Na2S as shell precursors in one-pot water phase synthesis. By changing the chain length (x=2, 5, 10, 13) of HS-(CH2)x -COOH ligand, it is found that the water-soluble Ag2Se@Ag2S core-shell QDs which took medium chain length (x=10) 11-mercaptoundecanoic acid (MUA) as the ligand exhibited the strongest fluorescence emission. This work provides a reference for the preparation of Ag2Se@Ag2S core-shell QDs at room temperature.

Key words: Ag2Se@Ag2S, core-shell QDs, room temperature synthesis, near-infrared fluorescence, ligand optimization