3D Metal-Organic Framework-Based Photocatalysts for Environmental Remediation: Structural Features, Mechanistic Insights, and Emerging Strategies.

The intensifying challenges of global environmental pollution and energy scarcity have underscored the urgent demand for efficient, sustainable, and environmentally friendlyremediation technologies. Among the available approaches, photocatalysis, a solar-driven process, has emerged as a particularly promising strategy for applications such as water purification, air pollution control, and carbon dioxide reduction. Within this context, three-dimensional (3D) metal-organic frameworks (MOFs) have attracted significant research interest owing to their distinctive structural characteristics, tunable electronic properties, high porosity, and large surface area. This review provides a comprehensive examination of 3D MOF-based photocatalysts, with a focus on structural design principles, fundamental photocatalytic mechanisms, and their diverse environmental remediation. Particular emphasis is placed on advances in water treatment, air purification, carbon dioxide photoreduction, and antimicrobial activity, where recent strategies for boosting photocatalytic performance, such as bandgap engineering, functionalization of metal nodes and organic linkers, defect modulation, and the development of composite architectures, are systematically discussed. Finally, the persistent challenges and futureperspectives on the development of next-generation MOF-based photocatalysts are presented.