Growth mechanism of 2D heterostructures of polypyrrole grown on TiO nanoribbons for high-performance supercapacitors.

The patterning of functional structures is crucial in the field of materials science. Despite the enticing nature of two-dimensional surfaces, the task of directly modeling them with regular structures remains a significant challenge. Here we present a novel method to pattern a two-dimensional polymer in a controlled way assisted by chemical polymerization, which is confirmed through discernible observation. The fabrication process involves polymerization to create 2D layers of polypyrrole (PPy) on extended 2D TiO nanoribbons, resulting in oriented arrays known as 2D PPy/TiO. These arrays exhibit enhanced electrochemical performance, making them ideal for supercapacitor applications. The skeleton structure of this material is distinctive, characterized by a homogeneous distribution of layers containing various elements. Additionally, it possesses a large contact surface, which effectively reduces the distance for ion transport and electron transfer. The 2D PPy/TiO electrode has a maximum specific capacitance of 280 F g at an applied current density of 0.5 A g. Moreover, it demonstrates excellent rate capability and cycling stability. Therefore, this approach will open an avenue for improving polymerization-based patterning toward recommended applications.