Fabrication of superhydrophilic Cu₂O and CuO membranes

The present work demonstrates a simple method on the direct preparation of Cu₂O and CuO membranes with super-hydrophilic property via calcination or reduction of the parent film of Cu(OH)₂. By controlling the reaction conditions, Cu(OH)₂ membranes with different surface patterns composed of nano-belts, whiskers, or stick-bundles were first prepared. Cu₂O and CuO membranes were obtained from Cu(OH)₂ membranes by subsequent reduction and dehydration, respectively. The patterns of the parent film of Cu(OH)₂ were kept in the as-prepared Cu₂O and CuO membranes. Interestingly, the Cu(OH)₂ crystals with various morphologies on the as-prepared film were all transformed to close-packed Cu₂O nanoparticles after the reduction. Wettability investigation reveals that both Cu₂O and CuO membranes have super-hydrophilic properties.