Carbon Aerogels for Environmental Clean‐Up

Abstract

Carbon aerogels are a fascinating three-dimensional (3D) monolithic porous material with remarkable physicochemical properties, including low density, large surface area, abundant pore structure, high electrical conductivity, chemical stability, environmental compatibility, adjustable surface chemistry, as well as controllable structural features. These properties endow carbon aerogels with excellent adsorption and catalytic performance. Therefore, they are widely applied in environmental chemistry for removing pollutants like oils, toxic organic solvents, dyes, heavy metal ions in aquatic environments, and vol- [a] Minireview Carbon aerogels show wonderful adsorption and catalytic performance because of the microscopic properties of carbon nanomaterials and the macroscopic structure of the gel. In addi-Guoqiang Gan received his master′s degree in 2016, and since then, he has studied environmental engineering at Dalian University of

Silica Aerogels/Xerogels Modified with Nitrogen-Containing Groups for Heavy Metal Adsorption

“…More recently, environmental applications of aerogels have gained traction, and come as natural fit for these high surface area, porous materials. Aerogels have been employed, for example, in carbon dioxide capture and removal of organic compounds and heavy metals [ 3 , 6 , 7 , 8 , 9 , 10 , 11 ]. Their persistence in the environment, accelerated release, associated with modern activities from human society, and high toxicity have made heavy metals priority pollutants, with some of them being restricted [ 7 , 12 , 13 ].…”

“…Different materials [ 14 ], including aerogels (silica-based, carbon, organic, other inorganic types and composites thereof) have been studied as heavy metal adsorbents by several authors [ 6 , 7 , 8 , 9 , 15 , 16 , 17 , 18 , 19 ]. These works are mostly based on featuring adequate surface groups for the adsorbent to interact with the cations in solution, namely amine groups (although thiol and carboxylic groups are also common).…”

Toward Next‐Generation Carbon‐Based Materials Derived from Waste and Biomass for High‐Performance Energy Applications

“…In general, as shown in Figure 8 , CAs are usually synthesized using an organic aerogel through three main steps: 1) gelation through sol–gel polymerization and aging, 2) drying, obtaining a gel‐like structure under freeze or supercritical conditions, and 3) carbonization/activation at inert atmosphere at relatively high temperatures. [ 83 ] Despite its outstanding properties, the utilization of CA in practical applications is challenging due to the following reasons. First, the precursor for the polymerization of organic aerogels is mainly based on expensive monomers such as resorcinol/formaldehyde, [ 84,85 ] melamine/formaldehyde, [ 86 ] and phenol/formaldehyde.…”

Designing Oxide Aerogels With Enhanced Sorptive and Degradative Activity for Acute Chemical Threats

“…However, even impregnated carbons do not fully neutralize toxic chemicals and may suffer from poor shelf-stability (DeCoste and . Other types of highly porous carbon, referred to as aerogels due to their mesoporosity and foam-like morphology, are derived from pyrolyzed polymer foams or freeze-dried foams containing graphene (Lee and Park, 2020) and function similarly to activated carbon, adsorbing intact CW agents (Han et al, 2017) and environmental pollutants (Gan et al, 2019).…”

“…Aerogels were first synthesized in 1931 (Kistler, 1931), but attracted more extensive research interest in later decades with developments in synthesis, notably the introduction of simplified sol-gel methods using alkoxide precursors in the 1960s and supercritical CO 2 drying of the wet gel in the 1980s (Pajonk, 1994). Aerogels have been constructed from oxides (Rolison et al, 2020), carbon (Gan et al, 2019), chalcogenides (Mohanan et al, 2005), metals (Wang et al, 2020), cellulose (Wang et al, 2017b), nitrides (Wang et al, 2019), and MXenes (Zhang et al, 2020) among other materials. Due to their low density, aerogels are commonly utilized as thermal insulators, and their combination of high-surface area and mesoporosity makes them appealing for use as adsorptive materials, heterogeneous catalysts, and for electrochemical charge storage (Pierre and Pajonk, 2002).…”