The synthesis of copper oxide often uses metal salts such as copper nitrate (Cu(NO₃)₂) or copper chlorides precursors, combined with a strong base such as sodium hydroxide (NaOH), in a process called chemical precipitation .In this method, the metal precursor is dissolved in an aqueous solution, and the pH of the reaction medium is increased to between 8 and 12 by adding a strong base, creating an alkaline environment . Under these conditions, the copper ions (Cu²⁺)