Defect‐Mediated Plasma S‐Scheme Heterostructure for Uranium Capture: The Synergistic Effect of Photogenerated Electrons and Hot Electrons

ABSTRACT It is crucial for strategic resource reuse and natural sustainability that environmentally transferable hexavalent uranium is converted into relatively insoluble tetravalent uranium from nuclear industrial wastewater via photocatalytic technologies. Unfortunately, the catalytic process of traditional photocatalysts is always seriously threatened by limited active sites and inefficient photogenerated electrons, resulting in unsatisfactory uranium reduction efficiency. Here, we have designed a defect‐mediated plasma S‐scheme C 3 N 5 /WO 3‐x heterostructure (PSCW), aiming to enhance uranium capture kinetics by utilizing the coupling of hot electrons and photogenerated electrons to regulate the electronic microenvironment. The results demonstrate that the uranium capture rate of PSCW exceeds 96% in 40 min and can survive under γ irradiation, the coexistence of multiple impurity cations, and typical organics. By means of theoretical calculations and in situ techniques, the origin of hot carriers and their coupling behavior with photogenerated electrons are elucidated, and the possible mechanism of photothermal catalytic uranium reduction is further revealed (i.e., uranyl is reduced to low‐crystallinity UO 2 via a two‐electron process driven by the high electron concentration of PSCW). This work can provide a valuable catalyst design for efficient uranium removal in wastewater, thereby promoting the application of plasma catalytic material systems in the field of environmental protection.