“…Copper (I) oxide (Cu 2 O) is an attractive semiconductor for large‐scale applications such as wastewater treatment, and possesses a narrow bandgap (2.0–2.2 eV) enabling visible light utilisation. In addition, the position of the conduction band minimum (CBM) and valence band maximum (VBM) span the potentials for proton reduction and water oxidation required for overall water splitting . A wide range of Cu 2 O morphologies are amenable to synthesis, including cubes, rhombicuboctahedra, polyhedra, nanowires, nanocages, and hollow structures, and consequently their facet‐dependent photocatalytic properties have been investigated for the destruction of hazardous organic compounds .…”