Size and Shape\nModulation of Cu<sub>2</sub>S Nanoplates\nvia Chemical Reduction with NaOH and NH<sub>3</sub>·H<sub>2</sub>O

Copper(I) sulfide (Cu<sub>2</sub>S) has electrical, optical,\nand\nthermoelectric properties that make it a promising material for a\nvariety of applications, including energy conversion and antibacterial\ncoatings. Nevertheless, the current synthesis and morphological modulation\nof Cu<sub>2</sub>S typically focuses on thermolysis of the copper\nand sulfur precursors, is procedurally complex, and demands expensive\nequipment. In this article, a facile, high-yield, three-step, low-temperature\naqueous synthesis alternative for Cu<sub>2</sub>S nanoplates is introduced.\nBy variations of the reaction temperature, reducing agent concentration,\nand pH modifier (NaOH or NH<sub>3</sub>·H<sub>2</sub>O), the\nmorphological characteristics can be controlled. As confirmed with\nscanning and transmission electron microscopy, the lateral extent\nof the synthesized Cu<sub>2</sub>S nanoplates can be tuned from around\n30 nm to around 300 nm simply by varying the heating conditions from\n10–100 °C. A similar effect is more subtly observed by\nvarying the concentration of the reducing agent. In addition to size\nvariance, the morphological properties of the Cu<sub>2</sub>S nanoplates\ncan be changed by using different bases for the reaction. Characterization\nof the composition and crystalline structure of the materials has\nalso been performed using energy-dispersive spectroscopy and X-ray\ndiffraction, and optical properties are investigated by UV–visible\nand near-infrared spectroscopy (UV–vis–NIR). The synthesis\npathway described in this paper can be easily performed and feasibly\nscaled, which is advantageous as the retrieved material is suitable\nfor diverse applications, such as its use in battery electrodes, photonic\nand charged-particle sensors, and radiation shielding.