Abstract
The desorption of conventional ligands from the surface of halide perovskite nanocrystals (NCs) often causes their structural instability and deterioration of the optoelectronic properties. To address this challenge, we present an approach of using a bidentate Lewis base ligand, namely, 1,4-bis-(diphenylphosphino)butane (DBPP), for the synthesis of CsPbBr3 NCs. The phosphine group of DBPP has a strong interaction with the PbBr2 precursor, forming a highly crystalline intermediate complex during the reaction. In the presence of oleic acid, the uncoordinated phosphine group of DBPP is converted into the phosphonium cation, which strongly binds to the surface bromide of the formed CsPbBr3 NCs through hydrogen bonding. Density functional theory calculations suggest that DBPP can strongly bind to the undercoordinated lead and surface bromide ions of CsPbBr3 NCs through its unprotonated and protonated phosphine groups, respectively. The robust binding of DBPP to the surface of perovskite NCs helps to preserve their structural integrity under various environmental stresses. Moreover, the electron density and energy levels are regulated in DBPP-capped CsPbBr3 NCs by the donation of electrons from the ligands to the NCs, resulting in their improved photocatalytic CO2 reduction performance. Our study highlights the potential of using bidentate ligands to stabilize the surface of perovskite NCs and modulate their optical and electronic properties. © 2024 American Chemical Society
| Original language | English |
|---|---|
| Pages (from-to) | 862-873 |
| Journal | Journal of the American Chemical Society |
| Volume | 147 |
| Issue number | 1 |
| Online published | 20 Dec 2024 |
| DOIs | |
| Publication status | Published - Jan 2025 |
Bibliographical note
Publisher Copyright:© 2024 American Chemical Society.
Funding
J.H.H. acknowledges financial support received from the City University of Hong Kong, designated by the funding number 9380107. P.B. and M.B.’s work was performed under the Liquid Sunlight Alliance, supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Fuels from Sunlight Hub under Award Number DE-SC0021266. This research used resources of the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 using NERSC award BES-ERCAP0024109. A.L.R. acknowledges financial support from the project MHP/068/21 from the Innovation and Technology Fund of Hong Kong SAR.
