Composites having both maximized adsorption capability and high photocatalytic activity are very promising for pollutant removal by combining adsorption and photocatalysis. In this work, we report a facile sonochemical synthesis of Cu₂O(nanoparticles)/Cu₂(OH)₃NO₃(sheets) composites with tunable composition using only copper powders and Cu(NO₃)₂ as precursors. The composites can be controlled from almost pure Cu₂O (98.1%) to pure Cu₂(OH)₃NO₃ (95.9%) through adjusting the initial ratio of Cu²⁺:Cu⁰and sonication time. Controlled experiments show that Cu₂O nanoparticles are formed first via the redox reaction between Cu²⁺ and Cu⁰, after that Cu₂O are converted to Cu₂(OH)₃NO₃. Cu₂(OH)₃NO₃synthesized using the sonochemical method exhibits outstanding adsorption capability toward organic dyes, subsequently Cu₂O can degrade them quickly via photocatalysis, so the Cu₂O/Cu₂(OH)₃NO₃ composites are very efficient to remove pollutant due to the synergetic effect of adsorption and photocatalysis. In particular, composite with 30.6% of Cu₂(OH)₃NO₃ and 69.4% of Cu₂O shows the highest removal capability and good stability.