Performance and mechanism of porous nanospherical Cu ₂ O/CuO@NPC heterojunctions for photocatalytic RhB degradation

Abstract This work designs a hierarchical porous nanospherical Cu ₂ O/CuO heterojunction catalyst in situ grown on the nanoporous copper (NPC) network via anodization, for efficient degradation of organic pollutants. The Cu ₂ O/CuO@NPC catalyst concurrently achieve a self-standing, hierarchical porous structure as well as the construction of Cu ₂ O/CuO heterojunction. Under visible light irradiation, the Cu ₂ O/CuO@NPC catalyst exhibits an excellent degradation performance towards Rhodamine B (RhB), achieving complete pollutant removal within 12 min. Notably, benefiting from the self-standing structure and stable nanosphere morphology, it still retains 94.5% of its degradation efficiency even after 14 consecutive cycles, which is much superior to most reported Cu ₂ O/CuO nanocatalysts. Most importantly, this work proposes the formation mechanism of the nanospheres and conducts an in-depth analysis of the photocatalytic degradation mechanism using electron paramagnetic resonance measurements and density functional theory calculations. This study provides both experimental and theoretical insights for designing efficient heterostructured photocatalysts, with promising application value in the field of environmental remediation.