Synthesis of Nonlayered 2D α-Fe2O3 Nanosheets by Ultralow Concentration Precursor with Se Catalysts Design

2D nonlayered materials have attracted more and more attention due to their novel properties and special surface structures. However, due to isotropic chemical bonds within the crystal, the synthesis of ultrathin 2D nonlayered materials is an urgent challenge. Herein, alpha-Fe2O3 2D nanosheets as thin as approximate to 8.2 nm on different substrates using self-designed ultralow concentration precursors combined with Gibbs free energy and Se catalysts design are successfully synthesized. The thickness-dependent growth mechanism is systematically studied, demonstrating the thermodynamic and kinetic controlling factors. The as-grown alpha-Fe2O3 nanosheets are demonstrated with single-crystal structures without any other elements doping. The alpha-Fe2O3 nanosheets photodetectors show the reasonable response performance with the positive photoconductive mechanism. This improved chemical vapor deposition method provides a promising idea for the synthesis of ultrathin 2D nonlayered materials.

Automated summary

This paper investigates the synthesis of ultrathin α-Fe2O3 2D nanosheets with a thickness of approximately 8.2 nm using self-designed ultralow concentration precursors and Se catalysts design, demonstrating the thermodynamic and kinetic controlling factors. The as-grown nanosheets exhibit single-crystal structures and show reasonable response performance as photodetectors.