Construction of Au(Ag)/Cu2O-N integrated heterostructures for enhanced visible-light photocatalytic reduction of U(VI)

Cuprous oxide (Cu 2 O), a promising semiconductor material, has been less employed in the photocatalytic removal of uranium. In this work, silver and gold nanoparticles were introduced on the surface of Cu 2 O. HR-TEM, XRD and XPS were applied in characterized the physic-chemical properties of composite. In comparison to Cu 2 O, Au modified Cu 2 O (Au/Cu 2 O-N) demonstrated a significantly enhanced uranium removal rate, reaching 100% within 120   minutes. This represents a 2-fold increase in the uranium removal rate compared to pure Cu 2 O-N. The reason con be interpreted including the red-shift of the absorption band from 600nm-800nm, the formation of Schottky junction between Au and Cu 2 O, the electron traps constructed by Au itself. Consequently, the rate of photogenerated electron-hole complexation is significantly diminished. Free trapping and EPR prove that reactive radicals are O 2 - . This has led to the development of a novel approach, namely the synergistic strategy of noble metal loading and nitrogen-doped cuprous oxide, which has the potential to facilitate the visible light removal of U(VI) from toxic wastewater.