Nano‐Hollow Cubic NiCo‐Layered Double Oxide for Photocatalytic Uranium(VI) Reduction Under Ambient Atmosphere

ABSTRACT Photocatalytic reduction of U(VI) is a promising approach for the treatment of uranium‐containing solutions and resource recovery. However, due to the low charge transfer efficiency and the weak ability to activate dissolved oxygen, most photocatalysts are unable to reduce U(VI) under ambient air conditions, limiting the practical application of this approach. In this study, nano‐hollow cubic NiCo‐layered double oxide (NiCo‐LDO) was prepared using Ni 2+ ‐etched ZIF‐67 as a precursor and was employed for the photocatalytic reduction of U(VI). Within 180 min of illumination, the NiCo‐LDO achieved a U(VI) removal efficiency of 98.0% under ambient air conditions, which is 2.5 and 4.2 times higher than those of NiO and Co 3 O 4 , respectively. The efficiency of U(VI) removal remained above 98% after five cycles of reuse. Benefiting from uniformly dispersed heterojunctions and the oxygen vacancies, NiCo‐LDO exhibits efficient separation of photogenerated charge carriers. Furthermore, the increased d‐band center and hollow cubic structure effectively enhance its adsorption for U(VI) as well as the activation of dissolved oxygen. Together, these features promote electron transfer and oxygen activation, enabling the efficient U(VI) reduction under ambient air conditions. These findings offer implications for designing catalysts applicable to the photocatalytic reduction of U(VI) in practical scenarios.