Hierarchical Cu₃BiS₃ Nanostructures with Thermally Controlled Morphology for Photoconductive, Photothermal, and Catalytic Applications

Studies and development of morphology-controlled synthesis of I–V–VI ternary semiconductor chalcogenide nanostructures with the use of earth-abundant, less toxic, and more environmentally friendly metals are in the forefront of current research due to their remarkable physical, chemical, and optoelectronic properties. Herein, we report the solvothermal synthesis of a ternary metal chalcogenide nanostructured material, wittichenite (Cu₃BiS₃) with 1D, 2D, and 1D–2D morphologies at three different temperatures, using the deep eutectic solvent (DES) of choline chloride/thiourea (ChCl/TU). The unique advantages of DES are that it acts as a safer solvent, an in situ source of sulfur, and a nonaqueous soft template for making the reaction system much simpler. The synthesis temperature plays a key role in the morphological evolution and anisotropic growth of copper-bismuth-sulfide nanostructures via oriented attachment, self-assembly, and Ostwald ripening mechanisms. The as-synthesized nanostructures of Cu₃BiS₃ exhibit multifunctional features, including photoconductivity, photothermal and catalytic activity for 4-nitrophenol reduction. This work provides a unique strategy for the design and synthesis of morphology-controlled metal chalcogenide nanostructures using DES as an “all-in-one” reactant, template, and green reaction medium.