Aqueous CuS nanocrystals via a flow synthesis approach

Abstract Aqueous synthesis of covellite CuS nanoparticles holds significant importance in the field of nanomaterials and environmental sustainability. Using water as a solvent and reactant in the synthesis process aligns with green chemistry principles. It enhances nanoparticle production's scalability and safety. CuS nanoparticles have gained attention for their diverse applications in catalysis, energy storage, and environmental remediation. Aqueous synthesis reduces the environmental footprint associated with hazardous organic solvents, making it an eco‐friendly approach. We report on synthesis routes toward covellite CuS nanocrystals (NCs), emphasizing easy and fast synthesis techniques. Additionally, we develop a flow synthesis of small near infrared active CuS NCs in a custom‐made flow reactor. Combining the advantages of aqueous synthesis and flow chemistry yields a robust and sustainable method for producing covellite CuS NCs readily dispersible in water medium, paving the way for their widespread application in diverse fields.