Size-Dependent Thermodynamic Stability of Copper Sulfide Nanoparticles

Copper sulfide nanoparticles are extensively employed in the field of functional materials. However, synthesizing the desired nanoparticles in a controlled manner is challenging due to the variety of copper sulfide phases and their potential transformations. Here, we utilize a unified theoretical approach combining a high-throughput computational workflow, ab initio atomistic thermodynamics, and the Wulff theorem to study the thermodynamic stability of copper sulfide nanoparticles. Theoretical size-dependent phase diagrams are constructed for the first time, considering various sulfur chemical potentials. This study unveils the evolution of crystal morphology under varying external conditions and underlines the crucial role of surface energy in maintaining the stability of copper sulfide nanoparticles. Our findings offer a theoretical guide for experimental endeavors aimed at synthesizing the desired surface morphology and phases of copper sulfide nanomaterials.