Mesoporous Cu-Cu₂O@TiO₂ heterojunction photocatalysts derived from metal-organic frameworks

This study reveals a unique Cu-Cu₂O@TiO₂ heterojunction photocatalyst obtained with metal-organic framework as the precursor, which can be utilized in dye photodegradation under visible light irradiation. The composition, structure, morphology, porosity, optical properties and photocatalytic performance of the obtained catalysts were all investigated in detail. The Cu-Cu₂O@TiO₂ nanocomposite is composed of lamellar Cu-Cu₂O microspheres embedded by numerous TiO₂ nanoparticles. Methylene blue, methyl orange and 4-nitrophenol were used as model pollutants to evaluate the photocatalytic activity of the Cu-Cu₂O@TiO₂ nanocomposite for dye degradation under visible light irradiation. Nearly 95% decolourisation efficiency of Methylene blue was achieved by the Cu-Cu₂O@TiO₂ photocatalyst within 3 h, which is much higher than that of TiO₂ or Cu₂O catalysts. The excellent photocatalytic activity was primarily attributed to the unique MOF-based mesoporous structure, the enlarged photo-adsorption range and the efficient separation of the charge carriers in the Cu-Cu₂O@TiO₂ heterojunction.