Composite photocatalyst containing Eosin Y and multiwalled carbon nanotubes loaded with CuO/NiO: Mixed metal oxide as an active center of H2 evolution from water

► CuO/NiO mixed metal oxide is an active center of H2 evolution from water. ► High photocatalytic activity may be from the synergistic effect between CuO and NiO. ► The interface between CuO particles and NiO particles plays an important role.