Beyond biotemplating: multiscale porous inorganic materials with high catalytic efficiency. Biotemplating makes it possible to prepare materials with complex structures by taking advantage of nature''s ability to generate unique morphologies. In this work, we designed and produced a multi-scale porosity (MSP) scaffold starting from sea urchin spines by adding an additional nano-porosity to its native micro-porosity. The final replica shows porosity in both length scales and is an effective high-performing photocatalytic material.