Application of Biomass‐Derived Nitrogen‐Doped Carbon Aerogels in Electrocatalysis and Supercapacitors

Abstract

Biomass-derived carbon aerogels refer to carbon aerogels prepared using biomass as the precursor. They are environmentally friendly, cheap and have abundant precursors, which have aroused widespread interest and exhibit excellent performance in the fields of electrocatalysis (e. g. for the hydrogen evolution, oxygen evolution and oxygen reduction reactions) and energy storage (i. e. as electrode materials for supercapacitors). Furthermore, metal species can be incorporated into the porous carbon matrix without destroying the original 3D structure whilst improving its conductivity and electro-chemical performance. Above all, most biomass materials contain nitrogen functionalities, and can be doped in situ (selfdoping) with heteroatoms, such as N, without any additives, thereby creating additional defects and active centers with augmented electron density and electron-contributing attributes. Herein, the electrochemical applications of biomassderived carbon aerogels reported during the last decade, especially in the field of water electrolysis, metal-air batteries, fuel cells and supercapacitors, are summarized. Current research challenges and future directions are briefly highlighted.

Crosslinker-Free Hyaluronic Acid Aerogels

“…Bioaerogels have been prepared in various shapes, including monoliths, , millimeter-sized beads, , and microparticles. , Thanks to their mesoporosity and low density, bioaerogels generally have very low thermal conductivity and have been proposed as thermal insulation materials . Bioaerogels have also found application in food packaging, as a catalyst support and absorption/adsorption material . In the last decade, bioaerogels have attracted increasing interest as biomaterials, thanks to their unique properties. , For example, our group recently prepared pectin and pectin–cellulose aerogels for pH-controlled release of theophylline. − …”

Construction of N, O Codoped Petal-like Hierarchical Porous Carbon with an Ultrahigh Specific Surface from Waste Bamboo for High-Performance Supercapacitors

“…For the sustainability of human society and to overcome problems such as an energy crisis and environmental pollution caused by the utilization of fossil fuels, the development of new energy storage and utilization technologies is an essential route to solve these problems, which is considered as one of the feasible approaches for exploring green and sustainable energy alternatives. , Therefore, the development of new energy storage and conversion devices with high energy efficiency, excellent energy, power density, and green environmental protection has become an urgent requirement. , Nowadays, supercapacitors have become a worldwide research hotspot owing to their high charge/discharge efficiency, high power density, large specific capacitance ( C s ), and good cycle durability, which is practically attributable to the constant emergence of novel and various electrode materials. On the basis of the energy storage mechanism, supercapacitors can be divided into electric double-layer capacitors (EDLCs) and pseudocapacitors. , Although EDLCs have outstanding cycle stability, their energy storage capacity is inferior to that of pseudocapacitors. , While the pseudocapacitor can improve the capacity of charge storage and discharge by chemical reactions between electrodes and electrolytes, there is an irrecoverable loss of capacitor lifetime after a prolonged charging/discharging cycle …”

Chitin Derived Carbon Anchored Ultrafine Ru Nanoparticles for Efficient Hydrogen Evolution Reaction

“…The heteroatom-doped carbon support could deliver a regulatory effect on the electronic structure of Ru, while the porous morphology of support is beneficial for suppressing the ripening of nanoparticles. ,− Besides, three-dimensional supports offer more abundant accessible sites and facilitate the mass transfer process . Fortunately, the biomass derived carbon supports are abundant with N, and their morphologies are adjustable. ,− Besides, biomass acts as a sustainable source for the derived carbon supports, among which chitin plays an increasingly dominant role in materials and chemicals. Both the organonitrogen chemicals and inorganic nitrogen containing materials could be produced in large amounts via chitins. − …”