Modeling the size- and shape-dependent cohesive energy of nanomaterials and its applications in heterogeneous systems

Studying the properties of nanomaterials can help us to understand the nature of the particular behavior of small-scale materials and forecast new advanced functionalized materials. The cohesive energy, as one of the most important fundamental properties, is strongly connected to the unique properties of nanostructures. In this work, we establish a theoretical model to investigate the effects of size and shape on the cohesive energies of free and embedded nanoparticles based on thermodynamic concepts. It is found that the cohesive energy of free nanoparticles usually decreases as its size decreases. However, there are two distinct variations of embedded nanoparticles in heterogeneous systems. One is that the cohesive energy decreases with the decreasing size, and the other is that the cohesive energy increases as size decreases. The present modeling results and predictions are very consistent with experiments and other existing theoretical models, implying that the model could be expected to be a general approach to understand the cohesive energy of nanomaterials. (papers)