As part of the grand sustainability challenges facing the global community both in the academia and in the industry, this project deals with achieving clean water and clean energy. Hierarchical structures of inorganic nano-materials (HSIN) were prepared and tested for performance in various applications, mainly as electrocatalysts and water purification filters. In the course of the project various fossil templates, as well as possible inorganic coating materials, were surveyed. To address the challenge of formation of nanostructured 3D structures we used chemical pathways to achieve nanoscale metal or metal-oxide coatings of natural scaffolds—namely, calcareous foraminiferal species. Foraminifera are highly diverse and abundant marine unicellular protists surrounded by complex porous hierarchical shells, which are identical. This allows using them as an alternative to current expensive methods such as lithography to achieve HSIN with macroscopic dimensions in the range of 0.1–200 mm.
Prototype HSIN filters for water purification were built based on the Sorites species, coated with an abundant, non-toxic iron hydroxide. These filters decrease inorganic contaminant metal cations such as lead, cadmium, and copper by more than 99.9%.
Prototype HSIN water oxidation electrocatalysts were assembled using Sorites coated with either metallic cobalt or nickel oxide, and their performance is among the highest reported using nickel- and cobalt-based materials.
