Diatomaceous Lessons in Nanotechnology and Advanced Materials

Abstract

Silicon, in its various forms, finds widespread use in electronic, optical, and structural materials. Research on uses of silicon and silica has been intense for decades, raising the question of how much diversity is left for innovation with this element. Shape variation is particularly well examined. Here, we review the principles revealed by diatom frustules, the porous silica shells of diatoms, microscopic, unicellular algae. The frustules have nanometer‐scale detail, and the almost 100 000 species with unique frustule morphologies suggest nuanced structural and optical functions well beyond the current ranges used in advanced materials. The unique frustule morphologies have arisen through tens of millions of years of evolutionary selection, and so are likely to reflect optimized design and function. Performing the structural and optical equivalent of data mining, and understanding and adopting these designs, affords a new paradigm in materials science, an alternative to combinatorial materials synthesis approaches in spurring the development of new material and more nuanced materials.

Possible mechanism of structural incorporation of Al into diatomite during the deposition process I. Via a condensation reaction of hydroxyl groups

“…Diatomite, also known as diatomaceous earth or kieselguhr, arises from the assemblage of the mineralized exoskeletons of diatoms, which have various macroporous structures with pore sizes extending from the nanometric to the micrometric domains [1,2]. Diatomite is primarily composed of amorphous hydrated silica (SiO 2 ÁnH 2 O), which is categorized as non-crystalline Opal-A, according to the mineralogical classification [3,4].…”

“…Diatomite is primarily composed of amorphous hydrated silica (SiO 2 ÁnH 2 O), which is categorized as non-crystalline Opal-A, according to the mineralogical classification [3,4]. Diatomite is easily obtained at very low cost and has many unique physical and chemical characteristics, enabling their wide uses in a variety of applications for high-performance technologies; thus and widely utilized [5][6][7][8]2,[9][10][11][12].…”

“…For example, the size of the nano-silica balls, which are the basic components of the diatom shell [28,29,2], most likely changes with the presence of Al in their framework because of the different sizes of Al and Si. In addition, the surface charge and solid acidity vary before and after Al incorporation into the structure [1,9].…”

Facile preparation of hierarchically porous carbon using diatomite as both template and catalyst and methylene blue adsorption of carbon products

“…It is the most abundant form of silica on earth and is easily obtained at very low cost [9]. Composed of biogenetic amorphous silica and classified as noncrystalline opal-A in mineralogy, diatom shell is characteristic of highly developed porosity and particularly macroporous structure [12][13][14] and thus has been used as the template for the preparation of macroporous materials [15,16]. The sizes of the macropores of diatomite range from nanometric to micrometric domains.…”

Bio-manufacturing technology based on diatom micro- and nanostructure

“…The potential of frustules has been extensively explored by academics and for commercial application. The resulting new theories and techniques have found wide application, leading to the formation of a new interdisciplinary area of research called diatom-based bio-nanotechnology (or diatom nanotechnology) [16][17][18][19][20][21]. The potential for diatoms in device applications, such as high-sensitivity gas sensors [22], drug delivery devices [23], biocarriers for biosensors [24][25][26][27], micro-filters [12,28], solar cells, battery electrodes and electroluminescent display devices [19] has been examined.…”