Rapidly Roughening Polydopamine Nanocoating Through Polyphenol Chemistry

The dopamine (DA)‐mediated surface modification strategy is regarded as a facile yet versatile approach for developing multifunctional surfaces on diverse substrates. However, the rapid in situ fabrication of rough polydopamine nanocoatings (PD) remains a promising yet challenging task. Herein, a facile and rapid strategy for in situ rough PD fabrication through polyphenol chemistry is reported. Tannic acid (TA) is selected as a representative polyphenol molecule for the fabrication of polydopamine‐tannic acid nanocoating (PDT), resulting in a 2.40‐fold higher growth rate compared to the TA‐free process. In addition, the microscale roughness of PDT enhances the maximum methylene blue loading capacity by 1.30‐fold compared to PD. Furthermore, PDT exhibits multifunctionality such as hydrophilicity, antioxidant properties, and high‐capacity adsorption. Remarkably, PDT enables both direct surface modification and secondary surface functionalization of various substrates, demonstrating great potential in surface modification engineering. This strategy provides a simple yet universal approach for the rapid in situ fabrication of rough nanocoatings, opening new possibilities for developing advanced multifunctional nanomaterials.