Hierarchically Porous TiO2 Photocatalyst Prepared by Additive Manufacturing and Dealloying for Highly Efficient Photocatalytic Degradation of Tetracycline

Hierarchically porous photocatalysts exhibit superior light-harvesting capacity and enhanced photocatalytic activity. In this work, a facile method by combining additive manufacturing (AM) and dealloying was employed to prepare a hierarchically porous photocatalyst, namely, nanoporous-TiO2-encapsulating macroporous-double-gyroid-structure photocatalyst (TiO2@DGS). It was found that TiO2@DGS possessed deterministic macropores and interconnected nanopores, which offered efficient mass transfer channels and abundant active sites, respectively. Thus, TiO2@DGS showed excellent photocatalytic capability under ultraviolet–visible (UV–vis) light irradiation and achieved a tetracycline degradation efficiency of over 90% within 60 min (photocatalytic rate constant k = 4.0 × 10–2 min–1). Furthermore, TiO2@DGS exhibited excellent durability and reusability due to its stable three-dimensional structures. This work not only exemplifies the high performance of the prepared TiO2@DGS for environmental remediation but also provides an innovative approach to introduce tailored macrostructures into hierarchically porous photocatalysts through the incorporation of AM and dealloying.