Hassan Md Samim, Basera Pooja, Khan Bilawal, Portniagin Arsenii S, Vighnesh Kunnathodi, Wu Ye, Rusanov Daniil A, Babak Maria, He Jr-Hau, Bajdich Michal, Rogach Andrey L
Department of Materials Science and Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong SAR, P. R. China.
Department of Chemical Engineering, Stanford University, Stanford, California 94305, United States.
J Am Chem Soc. 2025 Jan 8;147(1):862-873. doi: 10.1021/jacs.4c13724. Epub 2024 Dec 20.
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 CsPbBr NCs. The phosphine group of DBPP has a strong interaction with the PbBr 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 CsPbBr NCs through hydrogen bonding. Density functional theory calculations suggest that DBPP can strongly bind to the undercoordinated lead and surface bromide ions of CsPbBr 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 CsPbBr NCs by the donation of electrons from the ligands to the NCs, resulting in their improved photocatalytic CO 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.
传统配体从卤化物钙钛矿纳米晶体（NCs）表面解吸往往会导致其结构不稳定和光电性能恶化。为应对这一挑战，我们提出了一种使用双齿路易斯碱配体，即1,4-双（二苯基膦基）丁烷（DBPP）来合成CsPbBr NCs的方法。DBPP的膦基团与PbBr前驱体有很强的相互作用，在反应过程中形成高度结晶的中间络合物。在油酸存在下，DBPP未配位的膦基团转化为鏻阳离子，它通过氢键与形成的CsPbBr NCs的表面溴化物强烈结合。密度泛函理论计算表明，DBPP可以分别通过其未质子化和质子化的膦基团与CsPbBr NCs的低配位铅和表面溴离子强烈结合。DBPP与钙钛矿NCs表面的牢固结合有助于在各种环境应力下保持其结构完整性。此外，通过配体向NCs的电子捐赠，DBPP包覆的CsPbBr NCs中的电子密度和能级得到调节，从而提高了它们的光催化CO还原性能。我们的研究突出了使用双齿配体稳定钙钛矿NCs表面并调节其光学和电子性质的潜力。
