Facile wet-chemical synthesis of antimonene nanosheets for visible-light-driven photoredox catalysis

Abstract

Two-dimensional (2D) pnictogens have attracted growing attention as an emerging class of semiconductor materials due to their remarkable optoelectronic properties. However, beyond phosphorene and bismuthene, their potential in photocatalysis has remained largely unexplored, mainly due to the limited availability of reliable and accessible synthesis routes for well-defined nanosheets. In this work, we demonstrate that two-dimensional antimony (antimonene, 2D Sb) can operate as an effective visible-light-driven photocatalyst for C–H arylation reactions for the first time. A bottom-up wet chemical synthesis strategy enables the scalable preparation of 3D layered Sb, which can be readily exfoliated into ultrathin 2D Sb nanosheets (∼110 nm lateral dimension, 1.96 nm thickness), exhibiting structure-dependent electronic behavior after exfoliation into the few-layer nanosheets. Structural and spectroscopic analyses confirm the formation of crystalline nanosheets with stable morphology and well-defined surface characteristics. Valence-band XPS and Mott–Schottky analysis reveal the semiconducting nature of the material with an estimated band gap ∼0.92 eV, which is in good agreement with the optical band gap of ∼ 0.94 eV obtained from a Tauc plot analysis. These band-structure features support photoinduced charge transfer under mild illumination. The yielded 2D Sb nanosheets exhibit strong catalytic activity for the C–H arylation of heteroarenes with diazonium salts, delivering product yields of up to 97% even under ambient indoor light irradiation. Mechanistic investigations suggest that the reaction proceeds through a photoredox pathway involving photoinduced single electron transfer and radical intermediates. Overall, this study highlights antimonene as a promising photocatalytic platform for sustainable organic transformations and expands the potential applications of two-dimensional pnictogen materials.