近日，西湖大学黄嘉兴团队实现了用未纯化的胶体片粗悬浮液直接制备致密单层涂料。2025年11月10日出版的《美国化学会志》发表了这项成果。

高纯度单层分散体一直是制备均匀二维（2D）材料单层薄膜的关键前提，但传统方法需要繁琐的工艺步骤，如反复剥离和彻底纯化。

研究组以氧化石墨烯（GO）为首个原型二维材料，提出一种“粘附-撕除”策略，可直接从含异质结构、多形貌聚集体及离子杂质的粗GO悬浮液中快速制备近乎完整的精确单层薄膜。在“粘附”步骤中，仅未纯化悬浮液中柔软柔顺的组分（如少层或单层薄片、松散聚集体）能贴合并牢固附着在基底上。随后的“撕除”步骤中，通过温和超声选择性去除多余层数、褶皱及重叠区域。实验表明，该工艺适用于宽泛的GO浓度、溶液pH值，且能耐受远超常规GO合成上限的盐浓度。

研究组已在SiO₂/Si、玻璃、氧化铟锡（ITO）/玻璃及曲面金属基底上成功制备单层薄膜。作为应用验证，该精确单层GO被证明是ITO上高效的空穴传输层，可提升有机光伏器件性能。该策略的普适性通过直接从粗悬浮液制备Ti₃C₂T_x MXene单层薄膜得到进一步验证。研究组通过利用二维材料固有的力学差异，建立了快速、可扩展的精确单层薄膜制备路径，突破传统纯化瓶颈，为多种胶体二维材料的功能器件开辟新途径。

附：英文原文

Title: Direct Fabrication of Dense Monolayer Coatings from Unpurified Crude Suspensions of Colloidal Sheets

Author: Kan Liu, Hun Park, Huitong Deng, Fan Guo, Dianyi Liu, Jiaxing Huang

Issue&Volume: November 10, 2025

Abstract: High-quality single-layer dispersions have long been a critical prerequisite for fabricating uniform monolayer coatings of two-dimensional (2D) materials, which unfortunately demand extensive processing steps such as iterative exfoliation and exhaustive purification. Here, using graphene oxide (GO) as the first prototypical 2D material, we demonstrate a “stick-and-tear” strategy to rapidly produce near-complete, precisely single-layer coatings on diverse substrates directly from crude GO suspensions, which contain heterogeneous structures and aggregates of various geometries and ionic impurities. In the “stick” step, only the soft, compliant components of the unpurified crude suspension (e.g., few- and single-layer sheets or loose aggregates) can conform to and strongly adhere to the substrate. During the subsequent “tear” step, excess layers, wrinkles, and overlapping regions are selectively removed by gentle sonication. It is demonstrated that the process works over a broad range of GO concentrations, solution pH values, and can tolerate salt concentrations well above the maximal levels of typical GO synthesis. Monolayer coatings on SiO2/Si, glass, indium–tin oxide (ITO)/glass, and curved metal surfaces have been demonstrated. As a proof-of-concept of potential uses, such precise monolayer coating of GO is demonstrated to be an effective hole-transport-layer on ITO for high-performance organic photovoltaic devices. The strategy’s material-agnostic nature is further validated by producing dense monolayer coatings of Ti3C2Tx MXene directly from its crude suspensions. By leveraging inherent mechanical contrasts in 2D materials, this work establishes a rapid, scalable pathway to precise monolayer coatings, circumventing conventional purification bottlenecks and opening avenues for functional devices with diverse colloidal 2D materials.

DOI: 10.1021/jacs.5c11088

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c11088