Construcción de Redes Orgánicas Metálicas de Enlace de Hidrógeno para la Reducción Fotocatalítica Directa de Uranio

Efficient uranium extraction from wastewater is essential for human security and environmental protection, and photocatalytic reduction is perceived as a green and sustainable strategy for effective uranium separation/removal. Herein, four metallic hydrogen-bonded organic frameworks (M-HOFs, M = Co, Ni, Cu, Zn) were constructed through precise metal coordination at the HOF centers. This innovative design enables sacrificial agent-free photocatalytic reduction of soluble U(VI) to insoluble U(IV), where Zn-HOF achieves a maximum removal capacity of 2344.95 mg g^-1 and a removal efficiency of 87% within 60 min. Mechanistic studies combining photoelectronic characterizations and density functional theory calculations reveal the metal-dependent charge separation dynamics and electron transfer efficiency, rationalizing the superior photocatalytic activity of Zn-HOF for uranium reduction. This work proposes a new strategy to modulate the photoactivity of HOFs by metal integration and provides an effective platform for radioactive contaminant remediation.