Fig. 7. Main applications of high aspect ratio nanostructured HA. Energy applications for (A) catalytic fire-resistant paper (adapted with permission from ref. 83, copyright 2018 Royal Society of Chemistry); (B) high strength aerogel for energy driven water evaporation (adapted with permission from ref. 84, copyright 2018 Wiley), and (C) tree inspired aerogel for catalytic treatment of organic dyes (adapted with permission from ref. 56, copyright 2021 Wiley). Biomedical applications include (D) photoluminescent biomedical paper (adapted with permission from ref. 95, copyright 2017 American Chemical Society), and (E) antibacterial biomedical paper loaded with silver and antibiotics (adapted with permission from ref. 93, copyright 2017 American Chemical Society). Sustainability application of high aspect ratio illustrating (F) flexible aerogel for water–oil separation (adapted with permission from ref. 86, copyright 2018 American Chemical Society), (G) magnetic paper for on demand motion in oil filtration (adapted with permission from ref. 96, copyright 2018 American Chemical Society), (H) tuneable hydrophilic/hydrophobic synthetic fire resistant paper (adapted with permission from ref. 94, copyright 2016 American Chemical Society), and (I) large scale production of HA nanowires for flexible textiles (adapted with permission from ref. 50, copyright 2016 American Chemical Society).