Hydrothermal-assisted CuS hierarchical architectures were grown in the presence of anionic sulfur sources, and the investigation of their degradation efficiency for a pesticide 4-chlorophenol (4-CP) under visible light irradiation was carried out. The dissociation of S2- from the sulfur compound governs the nucleation of CuS followed by a specific pattern of growth to produce different morphologies. The self-assembled covellite spherical CuS flower architecture assembles in the presence of thiourea and exhibits the highest photodegradation activity. The open architecture of ∼2.3 μm spherical CuS flowers consisting of a ∼100 nm thick sheet encompasses a comparatively high surface area and particle growth along the (110) plane that facilitates more active sites for catalytic activity enhancement. The catalyst loading for 4-CP degradation has been optimized, and a detailed trapping mechanism has been explored. © 2017 American Chemical Society.