Semiconductor nanostructures under irradiation catalyze the mineralization of organic dyes in solution. To improve the efficiency of this process, many novel nano-heterostructures have been fabricated using a variety of synthetic methods, however, many of these methods require management of difficult to control parameters, days of aging, and dangerous or expensive precursors to synthesize nanomaterials that may lack uniformity, recoverability, or efficiency. In this thesis, 1D CuO-TaO_x -NiO_y nano-heterostructures are fabricated using a combination of thermal oxidation and DC magnetron sputter deposition. CuO nanowires were synthesized by thermal oxidation, and TaO_x and NiO_y were deposited onto CuO nanowire template by sputter deposition of the metal followed by thermal annealing in air. A systematic study was done on the effect of sputter deposition parameters and annealing temperature for Ta. The completed heterostructure was evaluated by its performance in the degradation of various organic dyes. CuO-TaO_x -NiO_y nanowires with thin (10 nm thick) layers in methylene blue (concentration = 20 mg/L) with a catalyst dose of 1.0 g/L were found to be the most efficient catalyst. Rationally engineered semiconductor nano-heterostructures can be applied in environmental remediation and reduce the amount of pollution from industrial waste effluent.