Mechanochemical conversion of elemental sulfur into functional sulfur nanomaterials for promising applications

Abstract

This review highlights the growing role of mechanochemistry in the synthesis and functionalization of sulfur-based nanomaterials. It begins with a conceptual and historical overview of mechanochemical processes, emphasizing how mechanical energy enables selective bond cleavage, defect formation, and structural transformations in solids. Particular focus is placed on the mechanochemical synthesis of sulfur nanomaterials, where mechanical activation overcomes the inherent chemical inertness of elemental sulfur, promoting the formation of nanodots and other nanostructures. Subsequent sections explore the structural, optical, and photophysical properties of these materials, including light absorption, photoluminescence (PL), optical stability, time-resolved photoluminescence (TRPL), and circularly polarized luminescence (CPL). These properties are strongly influenced by stress-induced defects and crystallinity, which are hallmark features of the mechanochemical approach. The review further surveys a range of application areas such as sensing, catalysis, and energy conversion, where sulfur nanomaterials exhibit promising performance owing to their unique physicochemical properties. In conclusion, we address current challenges, including defect control and the need for a deeper mechanistic understanding, and propose future directions for expanding the scope and enhancing the utility of mechanochemical methods in nanochemistry. Overall, this work underscores the potential of mechanochemistry not only as a green, solvent-free synthesis strategy but also as a powerful platform for uncovering novel functionalities in sulfur-based nanomaterials.