Biogenic Metal Oxides

Biogenic metal oxides (M_xO_y) feature structures as highly functional and unique as the organisms generating them. They have caught the attention of scientists for the development of novel materials by biomimicry. In order to understand how biogenic M_xO_y could inspire novel technologies, we have reviewed examples of all biogenic M_xO_y, as well as the current state of understanding of the interactions between the inorganic M_xO_y and the biological matter they originate from and are connected to. In this review, we first summarize the origins of the precursors that living nature converts into M_xO_y. From the point-of-view of our materials chemists, we present an overview of the biogenesis of silica, iron and manganese oxides, as the only reported biogenic M_xO_y to date. These M_xO_y are found across all five kingdoms (bacteria, protoctista, fungi, plants and animals). We discuss the key molecules involved in the biosynthesis of M_xO_y, the functionality of the M_xO_y structures, and the techniques by which the biogenic M_xO_y can be studied. We close by outlining the biomimetic approaches inspired by biogenic M_xO_y materials and their challenges, and we point at promising directions for future organic-inorganic materials and their synthesis.