Controlled Growth of MoS2 Flakes from in-Plane to Edge-Enriched 3D Network and Their Surface-Energy Studies

Controlled and tunable growth of chemically active edge sites over inert in-plane MoS2 flakes is the key requirement to realize their vast number of applications in catalytic activities. Thermodynamically, growth of inert in-plane MoS2 is preferred due to fewer active sites on its surface over the edge sites. Here, we demonstrate controlled and tunable growth from in-plane MoS2 flakes to dense and electrically connected edge-enriched three-dimensional (3D) network of MoS2 flakes by varying the gas flow rate using tube-in-tube chemical vapor deposition technique. Field emission scanning electron microscope results demonstrated that the density of edge-enriched MoS2 flakes increase with increase in the gas flow rate. Raman and transmission electron microscopy analyses clearly revealed that the as-synthesized in-plane and edge-enriched MoS2 flakes are few layers in nature. Atomic force microscopy measurement revealed that the growth of the edge-enriched MoS2 takes place from the in-plane MoS2 flakes. On the ...