Sub-1 nm MoS2 and WS2 with extremely enhanced performance

Abstract

Great efforts have been taken towards in-plane structural extension of two-dimensional materials. Compared with surface lattices, edge lattices represent non-equilibrium states and remain largely unexplored. Herein, we report the all-physical top-down production of sub-1 nm molybdenum disulfide (MoS2) and tungsten disulfide (WS2) with 100% broken lattice. Bulk MoS2 and WS2 are tailored into subnanometer species with satisfactory yields (7.2 and 4.8 wt%) by sequential combination of dual and triple synergy silica-assisted ball-milling. Such two-stage ball-milling push the top-down limit into single-lattice scale, which is far beyond the manufacturing capacity of any known top-down method. Exceptional solvent diversity and solvability of the sub-1 nm MoS2 and WS2 powder endow solution-processability towards hybrid thin film fabrication. The sub-1 nm intrinsic MoS2 and WS2 demonstrate comprehensively superior performances over those of their bulk, nanosheets, and quantum sheets. Both photoluminescence and nonlinear saturation absorption of sub-1 nm MoS2 and WS2 are extremely enhanced. The non-equilibrium states induced by the entirely exposed and broken, intrinsic lattices in sub-1 nm MoS2 and WS2 could be determinative to their extreme performances. Our work highlights the potential of broken lattice and opens up an avenue towards subnanometer materials.