Starbon® Materials for a Circular Economy

Starbons are a patented group of sustainably-produced bio-based mesoporous materials derived from polysaccharides, namely; starch (from potato peel waste), alginic acid (from brown algae) and pectin (from orange peel waste). Starbons exhibit exceptional surface areas and mesopore volumes as well as tuneable surface functionalities, making them ideal candidates for numerous applications, mainly heterogenous catalysis, chromatography and metal recovery.
This thesis reports studies on Starbon materials, as well as the first report on novel nitrogen-doped Starbon materials (N-Starbons). Both classes of materials were characterised by elemental analysis, nitrogen adsorption / desorption porosimetry, scanning electron microscopy and thermogravimetry. Being newly discovered materials, N-Starbons were further characterised by x-ray photoelectron spectroscopy, both solid-phase and gas-phase diffuse-reflectance infrared spectroscopy in Fourier Transform mode and attenuated total reflection Fourier Transform infrared spectroscopy.
Crucially, N-Starbons retained the typical high and stable surface areas (up to 563 m2 g-1) and pore volumes (up to 0.75 cm3 g-1) of Starbon materials. Apart from having remarkably high nitrogen content of up to 11.5%, N-Starbons were interestingly found to contain nitrile functionalities on their surface. Nitriles are highly valuable functionalities for porous materials due to their ease of reactivity and substitution, thus allowing for ease of further functionalisation. Furthermore, nitriles have a high dielectric constant and can therefore improve the electrical properties of a material.
Herein, a number of original applications for both Starbon and N-Starbon materials were demonstrated. Starbons proved to be successful in simple and 100% gold recovery from e-waste. Furthermore, in natural product purification, Starbon was found to be highly effective in isolating valuable compounds from a complex seaweed extract. In CO2 sequestration, N-Starbons showed improved adsorption capacities (2.4 mmol g-1) compared to Starbons, as well as significant and stable capacitance behaviour (> 100 F g-1).