Extreme biomimetics is a multidisciplinary field of modern materials science dealing with development of new generation of composite materials based on thermally and chemically stable three-dimensional (3D) biopolymers. In response to the growing interest in the development of morphologically defined 3D carbon-based materials at large scale, here we describe for the first time the carbonization of naturally prefabricated 3D spongin scaffolds from Hippospongia communis demosponge as a renewable biomaterial of marine origin. We developed up to 4x10 cm large microfibrous and mesoporous 3D turbostratic graphite at 1200°C in the argon atmosphere. The resulting graphite sponge resembles the shape and unique microarchitecture of the original spongin scaffold. Obtained material was analyzed in detail using NEXAFS, XPS, XRD, XAS and Raman spectroscopy. Intriguingly, using HRTEM we found that obtained turbostratic graphite is exceptional at resembling the nanostructural features typical for triple helix collagen. Due to well-known electroconductivity of graphite we carried out metallization of the scaffolds using Cu-based electroplating. This electrochemical approach leads to developing of the 3D Cu/Cu2O-carbon hybrid material with excellent catalytic performance regarding the reduction of p-nitrophenol in both freshwater as well as in marine environments.
Acknowledgements: This work was supported by Poznan University of Technology research grant no. 03/32/DSPB/0806 as well as by DFG Project HE 394/32.