Nanoarchitectonics of centimeter-sized 3D multiphase carbon constructs created via carbonization of the sustainable biomaterial spongin at 2200 °C

The creation of carbon materials with controlled micro-architecture and 3D morphology from sustainable and biodegradable natural sources, especially at large scales, is a significant trend in modern materials science. Spongin, a renewable, fibrous biomaterial originating from industrially cultivated marine sponges, is already confirmed as a successful candidate for carbonization up to 1200 °C. This study shows for the first time that centimeter-sized 3D micro-fibrous spongin scaffolds can be carbonized at temperatures up to 2200 °C without loss of structural integrity or sponge-like form. Other biomaterials, even those initially having a 3D structural organization, crumble into powder when carbonized at such temperatures. The results of analytical studies obtained using XPS, Raman, NEXAFS, XRD, 13C solid state NMR spectroscopy and HRTEM clearly confirm the formation of turbostratic layered graphite with a surface containing diverse carbon nanophases including graphene, C60 nanocrystallites, and unique rhombohedral graphite with monoclinic C2/m space group symmetry. Examples of potential applications of the prepared graphite constructs are described, along with a discussion of the possibility of high-temperature production of exceptionally stable 3D carbon materials based on spongin. © 2026 The Authors