In this work, a composite of CuO and CaO (CuO/CaO) is prepared and demonstrated to chemically reduce nitro groups in aromatic hydrocarbons to the corresponding amines at 353 K using hydrazine monohydrate in isopropyl alcohol. The CuO/CaO was synthesized in 1:1 molar ratio of Cu to Ca by a simple sol–gel method. The CuO/CaO possesses surface oxygen vacancies and basicity which enhances the reactivity and stability in comparison to bare CuO. The active sites are probed using FT-IR, H2-TPR, XPS and CO2-TPD. Reduction of nitroarenes to aminoarenes was completed in 10–20 min with 100% selectivity. CuO/CaO was reused three successive cycles without any further treatment making it a reusable solid reagent. © 2022, Indian National Science Academy.