The Green Synthesis of 2D Copper Nanosheets and Their Light Absorption

In this study, a new green synthesis method for two-dimensional (2D) copper nanosheets is developed using methylsulfonylmethane (DMSO₂). The chemical composition and light absorption of 2D copper nanosheets are also studied. A new green method is mainly to utilize DMSO₂, which is environmentally friendly enough to be considered a food-grade chemical, unlike the conventional method using toxic chemicals, such as ammonia and hydrazine (N₂H₄). With a reducing agent, the aggregation of uncertain copper products was produced in the absence of DMSO₂, while 2D copper nanosheets were formed in the presence of DMSO₂. The optimum concentration of DMSO₂ as a surfactant was determined to be 2 M, resulting in large surface areas with regular edges. FTIR spectrum confirmed C-H bonding from DMSO₂ used to synthesize 2D copper nanosheets. The light absorption peak was revealed at 800 nm in the UV-vis spectrum. This proposed new green method not only has a simpler process than the conventional methods, such as hydrothermal method and chemical bath deposition, but also substitutes toxic chemicals with DMSO₂. 2D copper nanosheets can be used for various applications, including conductive filler or ink in the flexible electronics and laser photonics fields.