Insights into 3D-printed TiO₂-based architectures for photocatalytic and non-catalytic applications

3D printing has fundamentally transformed the design and engineering of photocatalytic materials, enabling the fabrication of geometrically complex, hierarchically structured TiO₂ to overcome the critical limitations of conventional approaches. This comprehensive review highlights advancements in the 3D printing of TiO₂, with a particular emphasis on fabrication methodologies, photocatalytic activity, performance optimization strategies, and other non-catalytic functional applications. The discussion encompasses the benefits of 3D-printed TiO₂ structures, including the fabrication of complex geometries and the optimization and enhancement of material performance, while also critically addressing the persistent challenges of scalability and operational stability. Recent advancements, including the incorporation of secondary dopants, the formation of synergistic composite materials, and surface modification strategies, are evaluated for their contributions to enhanced photocatalytic efficiency. Beyond photocatalysis, we also explore multi-functional applications in optical sensors, thermal-mechanical composites, and dental-orthopedic biomaterials, highlighting TiO₂'s versatility across diverse technological domains. The unique capabilities of additive manufacturing facilitate the rational design of TiO₂ with tailored geometries and compositional complexity, positioning it as a promising platform for both laboratory-scale mechanistic studies and practical real-world remediation applications.