Highly porous, strong aerogels with anisotropic structural properties are of great interest for multifunctional materials for applications including insulators in buildings, filters for oil clean up, electrical storage devices etc. Contemporary aerogels are mostly extracted from fossil resources and synthesized from bottom-up techniques, often requiring additional strategies to obtain high anisotropy. In this work, a universal approach to prepare porous, strong, anisotropic aerogels is presented through exploiting the natural hierarchical and anisotropic structure of wood. The preparation comprises nanoscale removal of lignin, followed by dissolution-regeneration of nanofibers, leading to enhanced cell wall porosity with nanofibrillated networks occupying the pore space in the cellular wood structure. The aerogels retain structural anisotropy of natural wood, exhibit specific surface areas of 247 m2/g, and show high compression strength at 95% porosity. This is a record specific area value for wood aerogels/foams and even higher than most cellulose-based aerogels for its assigned strength. The aerogel can serve as a platform for multi-functional composites including scaffolds for catalysis, gas separation or liquid purification due to its porous matrix or as binder-free electrodes in electronics. To demonstrate the multifunctionality, the aerogels are successfully decorated with metal nanoparticles (Ag) and metal oxide nanoparticles (TiO2) by in-situ synthesis, coated by the conductive polymer (PEDOT:PSS) and carbonized to yield conductive aerogels. This approach is found to be a universal way to prepare highly porous anisotropic aerogels.

Adsorbents with small pores are especially relevant for capturing carbon dioxide at large emission sources.

Emerging organic contaminants (EOCs), such as pharmaceutical compounds, are of growing environmental concern, and there is a need to develop new materials and technologies for their efficient removal. Here we developed a highly porous and stable zirconium–ellagate framework, denoted SU-102, which was used to remove EOCs from water, including real municipal wastewater treatment plant effluent. SU-102 adsorbs cationic EOCs with particularly high efficiencies, and of the 17 pharmaceutical EOCs detected in wastewater treatment plant effluent, all 9 cationic species were removed with efficiencies of at least 79.0–99.6%, emphasizing the importance of framework charge on selectivity. As a second mechanism of EOC removal, SU-102 photodegraded the antibiotic sulphamethazine under visible light. SU-102 is synthesized from ellagic acid, an edible polyphenol building unit, highlighting the possibility of creating stable high-performance multi-functional materials from sustainably sourced plant-based components.

Solid oxides have been extensively investigated as possible high-temperature CO ₂ sorbents by a number of research groups. We summarised the different strategies to develop synthetic solid oxide sorbents.