3D Graphene Materials from the Reduction of CO₂

Abstract

Metrics & MoreArticle Recommendations CONSPECTUS:The content of carbon dioxide (CO 2 ) in the atmosphere has been continuously growing and threatens the global environment by contributing to the greenhouse effect. The conversion of CO 2 directly into value-added chemicals could not only reduce CO 2 emission but also make valuable use of the waste gas. However, achieving a highly efficient CO 2 conversion with high product selectivity and low energy cost remains a great challenge.Graphene, one of the most important engineering materials with a wide range of applications, is generally synthesized with valuable hydrocarbons as carbon sources. Producing versatile graphene materials directly from CO 2 is intriguing and of profound meaning. Furthermore, it is of critical importance to produce 3D-structured graphene materials, which can avoid the restacking of the graphene sheets and thus keep the graphene properties for practical applications. Alkali-metal-based exothermic reactions with inorganic carbon compounds, which have been discovered by our group since 2013, offer ideal solutions for efficient CO 2 utilization and cost-effective 3D graphene production. In the reactions, alkali metal salts formed simultaneously with the graphenization of CO 2 and served as in situ templates for creating the splendid microscale 3D structured graphene materials, which could hardly be achieved using other methods. Meanwhile, the etching effect of CO 2 molecules can realize controlled engineering of unique surface porous structures of the formed 3D graphene. Accordingly, diverse 3D graphene materials featuring fascinating properties that are desired for energy-related and environmental applications can be facilely obtained by tuning the conditions for the reactions of CO 2 with alkali metals. This Account provides an overview of the 3D graphene materials from the reduction of CO 2 via the state-of-the-art alkali-metalchemistry-based strategy. After an emphasis on the significance of the CO 2 -to-graphene conversion process, the alkali-metal-based chemistry for CO 2 conversion is introduced by delineating the thermodynamics of the reactions between CO 2 and alkali metals and the forming mechanism of the 3D-structured graphene materials as well as the carbon etching effect of CO 2 . Subsequently, as typical examples, 3D cauliflower-fungus-like graphene, 3D crape myrtle flower-like graphene and mesochannel carbon nanowalls, 3D honeycomb-like structured graphene, and 3D surface-microporous graphene are specifically discussed in terms of their synthesis processes, structural characteristics, and reaction-condition-dependent properties. Furthermore, the great promise of these CO 2derived graphene materials for application in solar cells, supercapacitors, batteries, and environmental remediation are demonstrated. Finally, the challenges remaining in this area and the directions for its future development are addressed.

Design, synthesis, and performance of adsorbents for heavy metal removal from wastewater: a review

“…Three-dimensional graphene (3DG) materials, which possess abundant meso- and macro-pores and a large accessible surface area, are promising adsorbents for the removal of heavy metal ions. 3DG materials can be fabricated via a direct chemical reaction between alkali metals (or their derivatives) and CO/CO 2 , 69–72 or integration with other materials as composite hydrogels/aerogels. 67 Yi and coworkers synthesized GO/alginate/polyvinyl alcohol (PVA) hydrogel microspheres (through crosslinking of the linear biopolymer sodium alginate with Ca 2+ ) for heavy metal removal.…”

“…201)), mesoporous carbon ( e.g. , CMK-1, 202 Seoul National University/SNU-2, 203 Fudan University/FDU-14, 204 3DG 69–72 ), mesoporous polymers ( e.g. , mesoporous CMPs 130 and mesoporous COFs 131 ), and mesoporous metal compounds ( e.g.…”

Plasma assisted CO2 splitting to carbon and oxygen: A concept review analysis

“…It is also known that graphene or graphene-like materials could be produced by CO2 decomposition. Sun and Hu [58] reviewed the topic recently. There are different methods to produce graphene-like materials from CO2: i) by electrolysis [59][60][61], ii) chemical vapor deposition -CVD [62] and iii) by alkali-metal chemistry [63][64][65][66][67], the latter being the method…”

“…Journal of CO2 Utilization Volume 54, December 2021, 101775 https://doi.org/10.1016/j.jcou.2021.101775 8 discussed in a more detail by Sun and Hu [58]. These and other studies on the production of graphene-like materials from CO2 decomposition demonstrate the possibility to obtain controlled 3D porous graphene materials with intriguing properties for use in solar cells and as energy materials, but the studies were finalized to obtain these materials, not to develop a catalytic CO2tC process.…”

High Fuel Yields, Solar‐to‐Fuel Efficiency, and Excellent Durability Achieved for Confined NiCo Alloy Nanoparticles Using MgO Overlayers for Photothermocatalytic CO2 Reduction

“…The depletion of fossil fuels and the increase in greenhouse gas, CO 2 , have seriously affected human survival and development. [ 1,2 ] Recycling CO 2 into fuels can simultaneously solve two major problems; global warming and the energy crisis. [ 3 ] However, CO 2 reduction requires a suitable catalyst and a large amount of energy input, owing to the high dissociation energies of COO bonds (750 kJ mol −1 ).…”