OICC Press Iranian Journal of Catalysis 2345-4865 10 2 2024 02 03 Eco-friendly preparation and characterization of CuMn2O4 nanoparticles with the green capping agent and their photocatalytic and photovoltaic applications EN Ali Sobhani-Nasab Young Researchers and Elite Club, Arak Branch, Islamic Azad University, Arak, Iran. Mohammad Eghbali-Arani Department of Physics, University of Kashan, Kashan, Iran. Seyed Mostafa Hosseinpour-Mashkani Young Researchers and Elite Club, Arak Branch, Islamic Azad University, Arak, Iran. Farhad Ahmadi Tehran, Iran. Mehdi Rahimi-Nasrabadi Department of Physics, Faculty of Science, University of Hormozgan, Bandar-Abbas, Iran. Journal Article 2024 02 03 In this study, copper manganese oxide (CuMn2O4) nanoparticles were successfully synthesized by a simple sol-gel technique in the presence of lactose as the green capping agent. The lactose concentration effect on the crystalline size and magnetic properties of final products were systematically investigated. The structural, morphological, magnetic, and optical properties of as-obtained products were examined by techniques such as the Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), scanning electron microscopy (FESEM), vibrating-sample magnetometer (VSM) and UV–Vis diffuse reflectance spectroscopy. SEM and VSM results show that lactose concentrations play an important role in the magnetic properties and morphology of CuMn2O4 nanoparticles. Degradation of type of dye (Rhodamine B = Rh B and Methyl orange = MO) under ultraviolet light was examined to assess the feasibility of using CuMn2O4 for photocatalytic activities. To demonstrate the possibility of developing an inexpensive solar cell, FTO/TiO2/CuMn2O4/Pt-FTO, the CuMn2O4 paste was put on the top of the TiO2 through the doctor blade technique.