One-pot solution synthesis of shape-controlled copper selenide nanostructures and their potential applications in photocatalysis and photothermal therapy.

Developing a facile and reliable method for the fabrication of transition metal chalcogenides is a vital and endless pursuit of scientific and technological disciplines. In this work, we develop a one-pot solution approach to obtain copper selenide nanostructures with different morphologies and crystal structures (Cu2Se nanoparticles, CuSe nanoplates and CuSe2 nanosheets). In comparison to previously reported methods, our method did not use expensive and very toxic raw materials. After detailed studies of reaction conditions, including temperature, reaction time, and feeding amount of surfactants and precursors, we found that the feeding ratio of precursors played a key role in the crystal structures and morphologies of the final products. Moreover, as a proof-of-concept study, the potential applications of the as-prepared copper selenide nanostructures in the photocatalytic discoloration of aqueous methylene blue (MB) under visible light irradiation and near-infrared (NIR) light induced photothermal therapy for cancer treatment were investigated. Encouraged by their strong photocatalytic activities and high photothermal conversion efficiencies (calculated to be 51.0%, 49.5% and 48.9% for Cu2Se nanoparticles, CuSe nanoplates and CuSe2 nanosheets, respectively), we believe that copper selenide nanostructures fabricated from the one-pot solution approach developed in this work would be promising candidates for a wide variety of emerging applications.