Novel Corn‐Cob‐Like Copper Oxide/Cuprous Oxide Heterostructure for Solar‐Driven Water Treatment

ABSTRACT In this work, a well‐structured corn‐cob‐like heterojunction composed of copper oxide (CuO) and cuprous oxide (Cu 2 O), crosslinked with polyvinyl alcohol (PVA) and maleic anhydride (MA), was successfully fabricated to achieve efficient interfacial solar‐driven water evaporation and photocatalysis. CuO and Cu 2 O were combined to form a heterojunction, which was then integrated into the corn‐cob‐like copper oxide structure. The hierarchical structure of the composite ensures uniform distribution of the materials, thereby facilitating rapid water transport, effective light absorption, and efficient utilization of solar energy. The CuO/Cu 2 O/polyurethane (PU) composite achieves a high water evaporation efficiency of 6.9 kg m −2 h −1 and a methylene blue (MB) photodegradation efficiencies ( C / C 0 ) of 72% under two‐sun irradiation.