Synergetic activity enhancement in 2D CuO-Fe ₂ O ₃ nanocomposites for the photodegradation of rhodamine B

Two dimensional (2D) nanocomposites of CuO nanoplates containing about 20 wt.% Fe ₂ O ₃ nanoplates have been obtained by a simple hydrothermal approach at 140 °C for 1 h. In this synthesis route, we have added pre-synthesized Fe ₂ O ₃ nanoplates to the bare CuO synthesis route. The CuO nanoplates are ∼30 nm thick and have average lengths of ∼1.1 ± 0.2 μm with average widths of ∼0.7 ± 0.1 μm. Pre-synthesized Fe ₂ O ₃ nanoplates were obtained by hydrothermal reaction at 200 °C for 12 h in the presence of CuO nanorods acting as templates, which have sizes around 160 nm with thicknesses of ∼15 nm. The CuO-Fe ₂ O ₃ nanocomposite has essentially kept the original morphologies of both constituents, distinguishing the present study from most of the literature, where the addition of a secondary compound modifies the morphology of the main compound, making the morphological effect somewhat indefinite. We have reported photocatalytic performance of this composite for the photodegradation of RhB under stimulated sunlight, which reveals a synergetic enhancement on the photocatalytic activity by performing better than the bare CuO and Fe ₂ O ₃ samples. Visible light-absorption of the CuO is also increased by the addition of Fe ₂ O ₃ samples, even though Fe ₂ O ₃ has much lower absorption properties than that of CuO. The synthesis route reported here can be applied to other CuO–Fe ₂ O ₃ composites with various morphologies.