A photo-deposition method was developed to synthesise argentous oxide/calcium aluminate nanocomposites (Ag2O-CAONCS) with orthorhombic Ca5Al6O14 and cubic Ag2O phases. Micro-morphology, micro-structure, optical, and visible-light catalytic properties were investigated via different techniques. Ag2O enhances visible-light absorption performance and decreases the band gap of the Ag2O-CAONCS. About 20 mL crystal violet (CV) dye (10 mgL–1) is totally degraded using 20 mg Ag2O-CAONCS under sunlight irradiation for 20 min. The enhanced photocatalytic activity of the Ag2O-CAONCS towards CV under sunlight irradiation is ascribed to the reduction of the band gap, improvement in visible-light absorption and inhibitation role of carriers recombination by Ag2O. The high, stable visible-light catalytic activity makes Ag2O-CAONCS promising photocatalysts for removing organic pollutants.